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  • 1.
    Anbalagan, Anbarasan
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Lindberg, Carl-Fredrik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Influence of light intensity and phosphorous on microalgae activated sludge in phosphate precipitated conditionManuskript (preprint) (Övrigt vetenskapligt)
  • 2.
    Anbalagan, Anbarasan
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Lindberg, Carl Fredrik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. ABB AB, Corporate Research, Västerås, Sweden.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Influence of hydraulic retention time on indigenous microalgae and activated sludge process2016Ingår i: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 91, s. 277-284Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Integration of the microalgae and activated sludge (MAAS) process in municipal wastewater treatment and biogas production from recovered MAAS was investigated by studying the hydraulic retention time (HRT) of semi-continuous photo-bioreactors. An average total nitrogen (TN) removal efficiency (RE) of maximum 81.5 ± 5.1 and 64.6 ± 16.2% was achieved at 6 and 4 days HRT. RE of total phosphorous (TP) increased slightly at 6 days (80 ± 12%) HRT and stabilized at 4 days (56 ± 5%) and 2 days (55.5 ± 5.5%) HRT due to the fluctuations in COD and N/P mass ratio of the periodic wastewater. COD and organic carbon were removed efficiently and a rapidly settleable MAAS with a sludge volume index (SVI_10) of less than 117 mL g-1 was observed at all HRTs. The anaerobic digestion of the untreated MAAS showed a higher biogas yield of 349 ± 10 mL g VS-1 with 2 days HRT due to a low solids retention time (SRT). Thermal pretreatment of the MAAS (120 °C, 120 min) did not show any improvement with biogas production at 6 days (269 ± 3 (untreated) and 266 ± 16 (treated) mL gVS-1), 4 days (258 ± 11(untreated) and 263 ± 10 (treated) mL gVS-1) and 2 days (308 ± 19 mL (treated) gVS-1) HRT. Hence, the biogas potential tests showed that the untreated MAAS was a feasible substrate for biogas production. Results from this proof of concept support the application of MAAS in wastewater treatment for Swedish conditions to reduce aeration, precipitation chemicals and CO2 emissions. 

  • 3.
    Anbalagan, Anbarasan
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Lindberg, Carl-Fredrik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. ABB AB.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Continuous microalgae-activated sludge flocs for remediation of municipal wastewater under low temperature2017Ingår i: / [ed] Peter Van der Steen, 2017, s. 1-8Konferensbidrag (Refereegranskat)
    Abstract [en]

    The operational performance of indigenous microalgae-activated sludge was evaluated regarding the nutrient removal efficiency using raw wastewater collected from Västerås wastewater treatment plant, Sweden at limited artificial surface lighting (290 μmol m-1 sec-1) and Nordic wastewater conditions (13°C). Additionally, the oxygen production and consumption, biomass concentration and its settling was evaluated during the symbiotic algal-bacterial interaction. The results confirmed oxygenic organic compound removal (COD removal of 65-94%) at higher (31-45 d) and lower (13-18 d) sludge retention time (SRT). Also, a complete removal of ammonium throughout the process and partial nitrite-nitrate removal at all SRTs (total nitrogen removal of 41- 62%) were observed. Likewise, a partial phosphorus (P)removal was observed in the effluent which provides an opportunity to capture free P fromthe effluent for recovery as fertiliser. Further, the microalgal growth was slower due to lightor inorganic carbon limitation or ammonium repression caused by higher internal recirculationas observed from ammonium and nitrite-nitrate levels in the PBR. Most importantly, effectivePBR biomass concentration based nutrient removal and relative sludge recirculation have tobe considered in the PBR design to avoid light limitation and activate symbiosis.

  • 4.
    Anbalagan, Anbarasan
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Lindberg, Carl-Fredrik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. ABB AB, Corporate Research, Västerås, Sweden.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Influence of iron precipitated condition and light intensity on microalgae activated sludge based wastewater remediation2017Ingår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, s. 1523-1530Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The indigenous microalgae-activated sludge (MAAS) process during remediation of municipal wastewater was investigated by studying the influence of iron flocculation step and light intensity. In addition, availability of total phosphorous (P) and photosynthetic activity was examined in fed-batch and batch mode under northern climatic conditions and limited lighting. This was followed by a semi-continuous operation with 4 d of hydraulic retention time and mean cell residence time of 6.75 d in a photo-bioreactor (PBR) with varying P availability. The fed-batch condition showed that P concentrations of 3–4 mg L−1 were effective for photosynthetic chl. a development in iron flocculated conditions. In the PBR, the oxygen evolution rate increased with increase in the concentration of MAAS (from 258 to 573 mg TSS L−1) at higher surface photosynthetic active radiation (250 and 500 μmol m−2 s−1). Additionally, the rate approached a saturation phase at low MAAS (110 mg L−1) with higher light intensities. Semi-continuous operation with luxury P uptake and effective P condition showed stable average total nitrogen removal of 88 and 92% respectively, with residual concentrations of 3.77 and 2.21 mg L−1. The corresponding average P removal was 68 and 59% with residual concentrations of 2.32 and 1.75 mg L−1. The semi-continuous operation produced a rapidly settleable MAAS under iron flocculated condition with a settling velocity of 92–106 m h−1 and sludge volume index of 31–43 ml g−1 in the studied cases.

  • 5.
    Anbalagan, Anbarasan
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Influence of light emitting diodes on indigenous microalgae cultivation in municipal wastewater2015Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, s. 786-792Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, the effect of light emitting diodes (LEDs) on microalgae cultivation in municipal wastewater was examined in comparison to the fluorescent light. Two kinds of wastewater were evaluated: first one with low concentration of total phosphorous (TP) and second one with high TP concentration. The nutrient removal and biomass production using LEDs is efficient at photo-synthetically active radiation (PAR) intensity of 107-112 mu mol m(-2) s(-1) which is slightly higher than fluorescent light. Furthermore, this study demonstrates the applicability and distribution of light in wastewater where the environment is not defined. More importantly, winter and rainy periods contribute to dark condition and dilution of wastewater, intense LED light offers a feasible option for the functioning of closed micro algae based activated sludge (MAAS) process for recovery and reuse of nutrients. 

  • 6.
    Anbalagan, Anbarasan
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. University of Valladolid, Dr. Mergelina s/n, Valladolid, Spain.
    Toledo-Cervantes, A.
    University of Valladolid, Dr. Mergelina s/n, Valladolid, Spain.
    Posadas, E.
    University of Valladolid, Dr. Mergelina s/n, Valladolid, Spain.
    Rojo, E. M.
    University of Valladolid, Dr. Mergelina s/n, Valladolid, Spain.
    Lebrero, R.
    University of Valladolid, Dr. Mergelina s/n, Valladolid, Spain.
    González-Sánchez, A.
    University of Valladolid, Dr. Mergelina s/n, Valladolid, Spain.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Muñoz, R.
    University of Valladolid, Dr. Mergelina s/n, Valladolid, Spain.
    Continuous photosynthetic abatement of CO2 and volatile organic compounds from exhaust gas coupled to wastewater treatment: Evaluation of tubular algal-bacterial photobioreactor2017Ingår i: Journal of CO2 Utilization, ISSN 2212-9820, E-ISSN 2212-9839, Vol. 21, s. 353-359Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The continuous abatement of CO2 and toluene from the exhaust gas by an indigenous microalgal-bacterial consortium was investigated in a pilot tubular photobioreactor interconnected to an absorption column using diluted centrate in seawater as a free nutrient source. The removal efficiency of CO2 and toluene was maximised in the vertical absorption column by identifying an optimum liquid to gas (L/G) ratio of 15. The photobioreactor supported steady-state nitrogen and phosphorus removals of 91 ± 2% and 95 ± 4% using 15% diluted centrate at 14 and 7 d of hydraulic retention time (HRT), respectively. A decrease in the removal efficiencies of nitrogen (36 ± 5%) and phosphorus (58 ± 10%) was recorded when using 30% diluted centrate at 7 d of HRT. The volumetric biomass productivities obtained at an HRT of 7 d accounted for 42 ± 11 and 80 ± 3 mg TSS L-1 d-1 using 15 and 30% centrate, respectively. Stable CO2 (76 ± 7%) and toluene removals (89 ± 5%) were achieved at an L/G ratio of 15 regardless of the HRT or centrate dilution. Hence, this study demonstrated the potential of algal-bacterial systems for the continuous removal of CO2 and volatile organic compounds from exhaust gas coupled with the simultaneous treatment of centrate. 

  • 7.
    Ashihmina, Olga
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Hajem, Nedaa
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    REMEDIATION OF TNT USING PINE BARK IN A BATCH STUDY: COMETABOLIC REDUCTION AND SORPTION2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    Water contaminated with 2,4,6-trinitrotoluene (TNT) is regulated as a hazardous material. The objective of this study was to evaluate two bioremediation methods, namely, sorption and anoxic degradation for the removal of TNT from contaminated water in 7-day long batch experiment. TNT was co-metabolized with glucose under oxygen-limiting conditions using a mixed inoculum culture from a wastewater treatment plant, enriched with glucose and TNT. By the third day of the experiment most of TNT was adsorbed onto the pine bark and 96-98% of TNT was degraded. The results also indicated that the concentration of glucose is an important factor for the effective degradation of TNT, which is consistent with earlier research; the content of 0.15% w/v resulted in a more rapid TNT removal in comparison with 0.50% w/v. Two metabolites; 2-amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT) were detected. The para nitro group of TNT was preferentially reduced compared to the ortho nitro group. On the seventh day of incubation the concentration of 4-ADNT had decreased by 10% and 2-ADNT was no longer detectable. 

  • 8.
    Chukwuma Leonard, Leonard
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Wallin, Fredrik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Karlsson, Björn
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Chowdhury, S.P.
    University of Cape Town.
    Chowdhury, Sunetra
    University of Cape Town.
    Using Renewable Energy Paradigm as a Tool for Sustainable Village Concept (SVC) in Africa2012Konferensbidrag (Refereegranskat)
  • 9.
    Chusova, Olga
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Nolvak, H.
    Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, Tartu 51014, Estonia.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Truu, J.
    University of Tartu, Estonia.
    Odlare, Monica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Oopkaup, K.
    University of Tartu, Estonia.
    Truu, M.
    University of Tartu, Estonia.
    Effect of pine bark on the biotransformation of trinitrotoluene and on the bacterial community structure in a batch experiment2014Ingår i: Environmental technology, ISSN 0959-3330, E-ISSN 1479-487X, Vol. 35, nr 19, s. 2456-2465Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pine bark, a low-cost industrial residue, has been suggested as a promising substitute for granular activated carbon in the on-site treatment of water contaminated with 2,4,6-trinitrotoluene (TNT). However, the complex organic structure and indigenous microbial community of pine bark have thus far not been thoroughly described in the context of TNT-contaminated water treatment. This two-week batch study examined the removal efficiency of TNT from water by (1) adsorption on pine bark and (2) simultaneous adsorption on pine bark and biotransformation by specialized TNT-biotransforming microbial inocula. The bacterial community composition of experimental batches, inocula and pine bark, was profiled by Illumina sequencing of the V6 region ofthe 16S rRNA gene. The results revealed that the inocula and experimental batches were dominated by phylotypes belonging to the Enterobacteriaceae family and that the tested inocula had good potential for TNT biotransformation. The type of applied inocula had the most profound effect on the TNT-transforming bacterial community structure in the experimental batches. The indigenous microbial community of pine bark harboured phylotypes that also have a potential to degrade TNT. Altogether, the combination of a specialized inoculum and pine bark proved to be the most efficient treatment option for TNT-contaminated water.

  • 10.
    Chusova, Olga
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Nõlvak, H.
    University of Tartu, Tartu, Estonia.
    Odlare, Monica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Truu, J.
    University of Tartu, Tartu, Estonia.
    Truu, M.
    University of Tartu, Tartu, Estonia.
    Oopkaup, K.
    University of Tartu, Tartu, Estonia.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Biotransformation of pink water TNT on the surface of a low-cost adsorbent pine bark2015Ingår i: Biodegradation, ISSN 0923-9820, E-ISSN 1572-9729, Vol. 26, nr 5, s. 375-386Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This two-week anaerobic batch study evaluated 2,4,6-trinitrotoluene (TNT) removal efficiency from industrial pink water by (1) adsorption on low-cost adsorbent pine bark, and (2) adsorption coupled with TNT biotransformation by specialised microbial communities. Samples of the supernatant and acetonitrile extracts of pine bark were analysed by HPLC, while the composition of the bacterial community of the experimental batches, inocula and pine bark were profiled by high-throughput sequencing the V6 region of the bacterial 16S rRNA gene. Integrated adsorption and biotransformation proved to be the most efficient method for TNT removal from pink water. The type of applied inoculum had a profound effect on TNT removal efficiencies and microbial community structures, which were dominated by phylotypes belonging to the Enterobacteriaceae family. The analysis of acetonitrile extracts of pine bark supported the hypothesis that the microbial community indigenous to pine bark has the ability to degrade TNT.

  • 11.
    Jonfelt, Clara
    et al.
    Uppsala University, Sweden.
    Zambrano, Jesús
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Lindblom, Erik
    Stockholm Vatten, Sweden.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Key parameters for modelling Anammox process with N2O emissions2017Ingår i: French Federation of Biotechnology - Bioreactors Symposium 2017: Innovative approaches in bioreactors design and operation, France, 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, a sensitivity analysis and a calibration were applied to a recent published model used to replicate N2O emissions in an Anammox process of a moving-bed biofilm reactor (MBBR). The model used in this study was designed to replicate a one-stage nitrification-Anammox system in a MBBR at Hammarby-Sjöstad pilot plant (Stockholm, Sweden), whichtreats of anaerobic digestion liquor. The aeration was intermittently (45/15 minutes - on/off). During the aeration, a 1.5 mg/L DO set-point was set. Three main measurements wereobtained: NH4 in water, N2O in both water and gas phase.The sensitivity analysis was done via the one-at-a-time method, where one parameter at a timeis changed (in our case, 10%) from its nominal value and the model output is quantified. Next,the most sensitive parameters were used in the model calibration. Results indicate that the biofilm porosity (η [-]), biofilm density (ρ [gTS/m3]), maximum biofilmthickness (Lmax [mm]) and boundary layer thickness of the biofilm (L0 [μm]) were the mostsensitive parameters of the model. These parameters performed the model calibration.

  • 12.
    Kanders, Linda
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Purac AB, Box 1146, Lund, SE-221 05, Sweden.
    Beier, M.
    Institute for Sanitary Engineering and Waste Management (ISAH), Leibniz Universitaet Hannover, Germany.
    Nogueira, R.
    Institute for Sanitary Engineering and Waste Management (ISAH), Leibniz Universitaet Hannover, Welfengarten 1, Hannover, 30167, Germany.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Sinks and sources of anammox bacteria in a wastewater treatment plant - screening with qPCR2018Ingår i: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 78, nr 2, s. 441-451Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The deammonification process, which includes nitritation and anammox bacteria, is an energyefficient nitrogen removal process. Starting up an anammox process in a wastewater treatment plant (WWTP) is still widely believed to require external seeding of anammox bacteria. To demonstrate the principle of a non-seeded anammox start-up, anammox bacteria in potential sources must be quantified. In this study, seven digesters, their substrates and reject water were sampled and quantitative polymerase chain reaction (qPCR) was used to quantify both total and viable anammox bacteria. The results show that mesophilic digesters fed with nitrifying sludge (with high sludge ages) can be classified as a reliable source of anammox bacteria. Sludge hygienization and dewatering of digestate reduce the amount of anammox bacteria by one to two orders of magnitude and can be considered as a sink. The sampled reject waters contained on average >4.0 × 104 copies mL1 and the majority of these cells (>87%) were viable cells. Furthermore, plants with side-stream anammox treatment appear to have higher overall quantities of anammox bacteria than those without such treatment. The present study contributes to the development of sustainable strategies for both startup of anammox reactors and the possibility of improving microbial management in WWTPs.

  • 13.
    Kanders, Linda
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Industriell ekonomi och organisation. Purac AB, Lund, Sweden.
    Ling, Daniel
    Purac AB, Lund, Sweden..
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Rapid start-up of one-stage deammonification MBBR without addition of external inoculum2016Ingår i: WATER SCIENCE AND TECHNOLOGY, ISSN 0273-1223, Vol. 74, nr 11, s. 2541-2550Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In recent years, the anammox process has emerged as a useful method for robust and efficient nitrogen removal in wastewater treatment plants (WWTPs). This paper evaluates a one-stage deammonification (nitritation and anammox) start-up using carrier material without using anammox inoculum. A continuous laboratory-scale process was followed by full-scale operation with reject water from the digesters at Bekkelaget WWTP in Oslo, Norway. A third laboratory reactor was run in operational mode to verify the suitability of reject water from thermophilic digestion for the deammonification process. The two start-ups presented were run with indigenous bacterial populations, intermittent aeration and dilution, to favour growth of the anammox bacterial branches. Evaluation was done by chemical and fluorescence in situ hybridization analyses. The results demonstrate that anammox culture can be set up in a one-stage process only using indigenous anammox bacteria and that a full-scale start-up process can be completed in less than 120 days.

  • 14.
    Krustok, Ivo
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Diaz, J G
    Faculty of Science, Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, Madrid, Spain.
    Odlare, Monica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Algae biomass cultivation in nitrogen rich biogas digestate.2015Ingår i: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 72, nr 10, s. 1723-1729Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Because microalgae are known for quick biomass growth and nutrient uptake, there has been much interest in their use in research on wastewater treatment methods. While many studies have concentrated on the algal treatment of wastewaters with low to medium ammonium concentrations, there are several liquid waste streams with high ammonium concentrations that microalgae could potentially treat. The aim of this paper was to test ammonium tolerance of the indigenous algae community of Lake Malaren and to use this mixed consortia of algae to remove nutrients from biogas digestate. Algae from Lake Malaren were cultivated in Jaworski's Medium containing a range of ammonium concentrations and the resulting algal growth was determined. The algae were able to grow at NH4-N concentrations of up to 200 mg L(-1) after which there was significant inhibition. To test the effectiveness of the lake water algae on the treatment of biogas digestate, different pre-cultivation set-ups and biogas digestate concentrations were tested. It was determined that mixing pre-cultivated suspension algae with 25% of biogas digestate by volume, resulting in an ammonium concentration of around 300 mg L(-1), produced the highest algal growth. The algae were effective in removing 72.8 ± 2.2% of NH4-N and 41.4 ± 41.4% of PO4-P.

  • 15.
    Krustok, Ivo
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Odlare, Monica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Cultivation of microalgae for potential heavy metal reduction in a wastewater treatmet plant2012Ingår i: / [ed] Jinyue Yan, 2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    Sorption capacity of microalgae in 10 different mixtures of wastewater and lake water was evaluated for their ability to reduce heavy metal concentrations in wastewater. Cu, Zn and Ba concentrations were mostly reduced whereas Al and As concentrations actually increased in some samples. Co and Ni concentrations were more reduced in samples with pure wastewater compared to samples with wastewater/lake water mixtures. Hence, a mixture of wastewater and lake water seemed to decrease the metal reduction process in the water. Finally, for Fe and Mn concentrations, there was no significant difference between samples with pure wastewater and wastewater/lake water mixture. In positive cases reduction of heavy metal concentrations in the samples with 50-70% of wastewater worked best.

  • 16.
    Krustok, Ivo
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Liu, Xiaoling
    Tsinghua University, China.
    Li, S
    Tsinghua University, China.
    CULTIVATION OF INDIGENOUS ALGAE FOR INCREASED BIOGAS PRODUCTION2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    There is an increased demand for biogas in the society and one way to meet this is to use cultivated microalgae as fermentation substrate. In the present study, a co-digestion experiment was established where municipal food waste was fermented with harvested microalgae cultivated in lake water. The experiment was carried out as a laboratory batch experiment with fermentation bottles, where 0, 12, 25 and 37% of the food waste was replaced with harvested microalgae, respectively. The results showed that the biogas production was generally improved after addition of microalgae. During the first 25 days of fermentation, replacement of 12% food waste with microalgae gave the highest biogas production rate. However, higher proportions of microalgae (25% and 37%) slightly decreased the gas production rate compared to 12% and compared to using food waste alone. 

  • 17.
    Krustok, Ivo
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Odlare, Monica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    M.A., Shabiimam
    Indian Institute of Technology, Bombay, India..
    Truu, Jaak
    University of Tartu, Estonia.
    Ligi, Teele
    University of Tartu, Estonia.
    Truu, Marika
    University of Tartu, Estonia.
    Characterization of algal and microbial community dynamics in a wastewater photo-bioreactor using indigenous algae from lake mälaren2014Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Microalgae grown in photo-bioreactors can be a valuable source for biomass especially when combined with the treatment of wastewater. While most published research has been studying pure cultures, consortia of algae and bacteria from the wastewater have more complex dynamics affecting both the biomass production and pollutant removal. In this paper we investigate dynamics of algal and bacterial communities in mixed culture photo-bioreactors using chlorophyll and real-time PCR analysis. Wastewater photo-bioreactors were inoculated with water from a nearby lake to add native algae species. The results indicated a decline in bacterial 16S rDNA copy numbers before algae started to multiply. The photo-bioreactors inoculated with lake algae produced more biomass and grew faster than the algae originating only from wastewater. The reactors were effective in removing ammonia from the wastewater which seemed work to mostly through nitrification thus causing an increase in nitrate concentration. There was also an increase in Cr, Co and Ni ion concentrations during the experiment suggesting they may have moved from organic complexes to the water phase as free ions.

  • 18.
    Krustok, Ivo
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Odlare, Monica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    M.A., Shabiimam
    Indian Institute of Technology, Bombay, India..
    Truu, Jaak
    University of Tartu, Estonia.
    Truu, Marika
    University of Tartu, Estonia.
    Ligi, Teele
    University of Tartu, Estonia.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Characterization of algal and microbial community growth in a wastewater treating batch photo-bioreactor inoculated with lake water2015Ingår i: Algal Research, ISSN 2211-9264, Vol. 11, nr Sept, s. 421-427Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Microalgae grown in photo-bioreactors can be a valuable source of biomass, especially when combined with wastewater treatment. While most published research has studied pure cultures, the consortia of algae and bacteria from wastewater have more complex community dynamics which affect both the biomass production and pollutant removal. In this paper we investigate the dynamics of algal and bacterial growth in wastewater treating batch photo-bioreactors. The photo-bioreactors were inoculated with water from a nearby lake. Lake water was obtained in August, November and December in order to add native algal species and study the effects of the season. The photo-bioreactors inoculated with lake water obtained in August and November produced more biomass and grew faster than those that only contained the algae from wastewater. The results indicated a rapid decline in bacterial abundance before algae began to multiply in reactors supplemented with lake water in November and December. The reactors were also successful in removing nitrogen and phosphorous from wastewater.

  • 19.
    Krustok, Ivo
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Odlare, Monica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Truu, Jaak
    University of Tartu, Estonia.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Inhibition of nitrification in municipal wastewater treating photobioreactors: effect on algal growth and nutrient uptake2016Ingår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 202, s. 238-243Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effect of inhibiting nitrification on algal growth and nutrient uptake was studied in photobioreactors treating municipal wastewater. As previous studies have indicated that algae prefer certain nitrogen species to others, and because nitrifying bacteria are inhibited by microalgae, it is important to shed more light on these interactions. In this study allylthiourea (ATU) was used to inhibit nitrification in wastewater-treating photobioreactors. The nitrification-inhibited reactors were compared to control reactors with no ATU added.

    Microalgae had higher growth in the inhibited reactors, resulting in a higher chlorophyll a concentration. The species mix also differed, with Chlorella and Scenedesmus being the dominant genera in the control reactors and Cryptomonas and Chlorella dominating in the inhibited reactors. The nitrogen speciation in the reactors after 8 days incubation was also different in the two setups, with N existing mostly as NH4-N in the inhibited reactors and as NO3-N in the control reactors.

  • 20.
    Krustok, Ivo
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Odlare, Monica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Truu, Marika
    University of Tartu, Estonia.
    Truu, Jaak
    University of Tartu, Estonia.
    Ligi, Teele
    University of Tartu, Estonia.
    Tiirik, Kertu
    University of Tartu, Estonia.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Effect of lake water on algal biomass and microbial community structure in municipal wastewater based lab-scale photobioreactors2015Ingår i: Applied Microbiology and Biotechnology, ISSN 0175-7598, E-ISSN 1432-0614, Vol. 99, nr 21, s. 6537-6549Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Photobioreactors are a novel environmental technology that can produce biofuels with the simultaneous removal of nutrients and pollutants from wastewaters. The aim of this study was to evaluate the effect of the lake water addition to the production of algal biomass, and phylogenetic and functional structure of the algal and bacterial communities in the lab-scale bioreactors treating municipal wastewater.

    The lake water addition has significant benefit to the overall algal biomass growth and nutrient reduction in the reactors with wastewater and lake water (ratio 70/30 v/v). The metagenome based survey showed that the most abundant algal phylum in these reactors was Chlorophyta with Scenedesmus being the most prominent genus. The most abundant bacterial phyla were Proteobacteria and Bacteroidetes with most dominant families being Sphingobacteriaceae, Cytophagaceae, Flavobacteriaceae, Comamonadaceae, Planctomycetaceae, Nocardiaceae and Nostocaceae. These photobioreactors were also effective in reducing the overall amount of pathogens in wastewater compared to reactors with wastewater/tap water mixture. Functional analysis of the photobioreactor metagenomes revealed an increase in relative abundance genes related to photosynthesis, synthesis of vitamins important for auxotrophic algae, and decrease in virulence and nitrogen metabolism subsystems in lake water reactors.

  • 21.
    Krustok, Ivo
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Oopkaup, Kristjan
    University of Tartu, Estonia.
    Truu, Jaak
    University of Tartu, Estonia.
    Odlare, Monica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Comparative analysis of the metagenomes extracted from wastewater treating photobioreactorsManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    The metagenomes of lab-scale municipal wastewater treating batch photobioreactors were studied with a focus on nitrogen metabolism, pathogen abundance and antibiotic resistance genes. Previous studies based on the dataset showed that in general, as algae growth in the reactors increased, nitrogen metabolism and virulence genes decreased. With this study, a more detailed view of these gene groups is presented.

  • 22.
    Kumm, Mia
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Innovative Measures for Environmental Technologies at Tunnel Fires2008Ingår i: Research of Technogenic Envionment Protection: RTU-49th International Scientific Conference. October 9-10, 2008, Riga / [ed] Silvija Minkevica, 2008, s. 152-159Konferensbidrag (Refereegranskat)
    Abstract [en]

    Many tunnels are built below the ground water level. In case of a fire or oil spill there is a risk of environmental contamination of ground water supplies or sensitive recipients. Successful treatment of extinguishing water or spills needs rapid attention in such cases. This paper discusses the environmental consequences of a tunnel fire or an oil spill inside the tunnel. It is suggested from the present study of existing technologies, that the work of development within this field be divided into three different areas where two are pro-active while the last requires the development of new technologies for on-site collection and treatment of water. In sensitive areas, this treatment could be combined with in-situ surveys and treatments both prior to and after an incident.

     

    The two pro-active steps are characterization and categorization of tunnels along with the development of a digital system where site specific properties can be modeled. Additionally, at the fire scene, new mobile technologies are needed for effective treatment.Finally the paper discusses the environmental challenges the fire officer has to with deal during an incident and the need for further education of first responders on how to deal with these issues both in terms of short term and long term incident management priorities.

  • 23.
    Loutfi, Amy
    et al.
    Örebro Universitet.
    Coradeschi, Silvia
    Örebro Universitet.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Allard, Bert
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Using e-noses for environmental monitoring: ICCE 2009, Abstracts, 12th EuCheMS International Conference on Chemistry and the Environment 14-17 June 2009Stockholm University, Stockholm, Sweden2009Konferensbidrag (Refereegranskat)
  • 24.
    Mara, Grube
    et al.
    Latvia University, Latvia.
    Olga, Chusova
    Marita, Gavare
    Latvia University, Latvia.
    Karlis, Shvirksts
    Latvia University, Latvia.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Odlare, Monica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Application of FT-IR Spectroscopy for Investigation of Pink Water Remediation by Pine Bark2015Ingår i: Open Biotechnology Journal, ISSN 1874-0707, Vol. 9Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study demonstrates the application of FT-IR spectroscopy for investigating the remediation of pink water with the low cost adsorbent pine bark. The removal of 2,4,6-trinitrotoluene (TNT) from pink water by adsorption to pine bark was accompanied by a reduction in intensities of peaks at 1544 and 1347 cm-1 in the spectra of acetonitrile extracts of the pine bark. Hierarchial cluster analysis differentiated samples with high (30-180 mg/L) and low (0-4 mg/L) TNT concentrations, demonstrating the potential of this approach as a quick screening method for the control of the removal of TNT from pink water. The amount of lignin in pine bark was inversely proportional to the size of the pine bark particles, while the concentration of phenolic hydroxyl groups increases with increasing size of pine bark particles. FT-IR spectra showed that as well as TNT, pine bark can also adsorb nitramine explosives such as RDX and HMX.

  • 25.
    Muter, Olga
    et al.
    University of Latvia.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Rodriguez, Adrian
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Demilitarization industry sludge: assessment of toxicity and biodegradation potential2009Konferensbidrag (Refereegranskat)
  • 26.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Energy and Natural Resources: Introductory Article2013Ingår i: Reference Module in Earth Systems and Environmental Sciences / [ed] Scott Elias, Elsevier, 2013Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Renewable energy is distinguished from fossil energy, or non-renewables, by the time it takes to form. Renewable energy uses energy from the sun, winds, waves and other direct energies or forces. Also bio-fuels are considered as renewable, even though there is no balance between the production and e.g. incineration of the material. Compared to fossil fuels, formed from the degradation of prehistoric organic material, biomass formed in modern times at least releases no ancient carbon (as CO2) to the atmosphere. The renewable energy sector is rapidly becoming more feasible due to the increased threat to our planet of global warming caused by burning of fossil fuels.

  • 27.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Industrial by-products in treatment of metals from polluted water2008Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Water treatment can be carried out effectively by passive, low cost methods, as an addition or alternative to existing advanced technology. Energy and resource use can be optimized (i.e. minimized) by reusing by-products from local or regional manufacturing of timber and steel. The ability of pine bark and blast furnace slag to treat metal contaminated water, primarily landfill leachate, has been evaluated. Several issues of concern were addressed in laboratory experiments and pilot scale measurements at a landfill site, including metal adsorption capability, saturation, variables influencing the adsorption process and potential leaching of organic toxicants from pine bark. The data was analyzed using kinetic modeling, regression and multivariate data analysis, i.e. PCA. These experiments showed that pine bark and blast furnace slag have great potential to retain metals from solution. Pine bark could also be used to treat solutions with high concentrations (>200 mg/l) and containing several heavy metals simultaneously (Cu, Pb, Zn, Cr and Ni). A constructed pilot plant showed poor retention of metals, which was somewhat improved by increased contact time, a variable which was found to be important in one of the laboratory experiments. Studies of organic content in landfill leachate, primarily dissolved organic carbon (DOC), showed that this could limit adsorption to pine bark. Another important finding, which is in contrast to the suggestions of other researchers, was that leaching of phenols from pine bark constituted only a small fraction of the DOC and was not toxic to the test-organism Daphnia Magna at neutral pH. In order to understand more about the relationships between the different variables, a multivariate approach (PCA) was applied to data on the treatment of landfill leachate with pine bark. This study showed that the metal concentration of the leachate was the variable most strongly related to metal adsorption. The concentration of DOC had only a minor effect according to PCA. Overall, pine bark and blast furnace slag can be used as adsorbents, but with caution and preferably in effluents of moderate metal concentration and low DOC.

  • 28. Nehrenheim, Emma
    Introduction to Renewable Energy2013Ingår i: Reference Module in Earth Systems and Environmental Sciences, Elsevier, 2013Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    Renewable energy is distinguished from fossil energy, or non-renewables, by the time it takes to form. Renewable energy uses energy from the sun, winds, waves and other direct energies or forces. Also bio-fuels are considered as renewable, even though there is no balance between the production and e.g. incineration of the material. Compared to fossil fuels, formed from the degradation of prehistoric organic material, biomass formed in modern times at least releases no ancient carbon (as CO2) to the atmosphere. The renewable energy sector is rapidly becoming more feasible due to the increased threat to our planet of global warming caused by burning of fossil fuels.

  • 29.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Metal Reduction from Landfill Leachate by using Blast Furnace Slag and Pine Bark – Discussion about the Parameters significant for Metal Removal2005Konferensbidrag (Refereegranskat)
  • 30.
    Nehrenheim, Emma
    Mälardalens högskola, Institutionen för samhällsteknik.
    Metal retention from leachate using Industrial Waste Products2007Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Landfill leachate arises when water percolates through a landfill. The degree and type of pollution is dependent on the content of the landfill but also on a range of other factors, including the age of the landfill and the landfilling technique. In recent years, concerns about potentially hazardous compounds in landfill leachate have stimulated research into on-site treatment. Examples of new techniques for treatment are the sequent batch reactor technique (SBR), wetland systems and different forms of filter solutions.

    Lilla Nyby landfill is the municipal landfill in Eskilstuna, Sweden. Leachate streams have been found on site that are weaker than the main stream. One of these has been investigated in the present study. It contains heavy metals, especially zinc, copper and nickel, in concentrations which require treatment. Low strength landfill leachate streams require special treatment. There are various reasons for this, but examples can be geological reasons or dilution problems in the treatment facility for the main leachate.

    The technique chosen for the leachate stream, reactive filters, is rather new and few pilot scale experiments have been conducted. Therefore many questions still remain concerning the applicability of the method on site, and there was a need for more experimental data. Previous research has shown that many industrial by-products may be suitable to capture metals from leachate. Among the materials previously recommended, blast furnace slag and pine bark had advantages which were well suited for the present application. They were also available in large quantities near the site. A column experiment was set up at the landfill and three filter materials were chosen; pine bark and two types of blast furnace slag. In addition, one of the columns was filled with sand as a reference. As a complement to the column study, laboratory experiments were conducted at Mälardalen University. The aim of the laboratory experiments was to investigate factors that might limit metal retention by the filter materials. Different concentrations and contact times were tested as well as the presence of other substances (i.e. metals and organic carbon).

    The results from the first laboratory experiments (initial metal concentration, competing metal ions and contact time) and the on-site column study were contradictory. Metal uptake in the laboratory was very efficient, as has also been found by other researchers. On-site, many factors influenced sorption and uptake was very unstable, especially for the slags. It was found that pine bark is more effective and stable than the slags with respect to metal retention, especially at low concentrations. The contact time between the substrate and metals is important for effective retention. The final experiment, showed that dissolved organic carbon (DOC) can greatly inhibit metal retention. To further develop reactive filter technology, a method to reduce the DOC content may be necessary.

    In contrast to what has been previously assumed, leaching of COD from the pine bark column at Lilla Nyby landfill was negligible. Finally, some suggestions for future work on reactive filter technology are made. For instance, it could be interesting to develop an alternative technique for filtration. Packed columns have been addressed with a series of problems, related to hydraulic parameters. By using fluidised reactors, a comparison with batch experiments becomes possible.

  • 31.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Waste Management: Introduction2013Ingår i: Reference Module in Earth Systems and Environmental Sciences, Elsevier, 2013Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    Waste management is a multidisciplinary subject. All human activities produce waste, hazardous or nonhazardous. In the waste hierarchy set by the European Union Waste Framework Directive (2008), the following order is prioritized for any waste unit: reduce-reuse-recycle-recover-landfill. This means that waste should primarily be minimized and products should be reused as they are or their materials should be recycled. If this is not possible, waste should be recovered for energy, a good alternative to using fossil fuels or harvesting biological materials. The least favorable option for waste is to dump it in a landfill. Landfilling requires large land areas and the sites pollute the environment by leaching of polluted water and gas.

  • 32.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Institutionen för samhällsteknik. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Gustafsson, Jon-Petter
    KTH.
    Kinetic sorption modelling of Cu, Ni, Zn, Pb and Cr ions to pine bark and blast furnace slag by using batch experiments2008Ingår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 99, nr 6, s. 1571-1577Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Storm water and landfill leachate can both contain significant amounts of toxic metals such as Zn, Cu, Pb, Cr and Ni. Pine bark and blast furnace slag are both residual waste products that have shown a large potential for metal removal from contaminated water. There are however many variables that must be optimized in order to achieve efficient metal retention. One of these variables is the time of which the solution is in contact with each unit of filter material. Metal sorption was studied in two laboratory experiments to improve the knowledge of the effects of contact time. The results showed that pine bark was generally more efficient than blast furnace slag when the metal concentrations were relatively small, whereas blast furnace slag sorbed most metals to a larger extent at increased metal loads. In addition, sorption to blast furnace slag was found to be faster than metal binding to pine bark. A pseudo-second-order kinetic model was able to describe the data well within 1000 s of reaction time. 

  • 33.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Johansson Westholm, Lena
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Waara, Sylvia
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Treatment of landfill leachate using filter substrates2005Ingår i: Proceedings Sardinia 2005, Tenth International Waste Management and Landfill Symposium, 2005Konferensbidrag (Refereegranskat)
  • 34.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Klintenberg, Patrik
    Desert Research Foundation of Namibia.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    RECIRCULATION OF BIOGAS RESIDUE TO AGRICULTURAL LAND IN NAMIBIA– RISKS AND POTENTIALS IN FULL UTILIZATION OF ORGANIC WASTE2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    The current situation of waste disposal in Namibia is under developed. The country has a large meat and dairy industry as well as some breweries and wineries and today, none of the organic wastes are reused, recycled or utilized for energy utilization. Little has been done in order to collect and utilize the resources in the organic waste from these industries but there is currently some early stage projects in planning related to biogas production from organic wastes. This study aims at evaluating the potential for some three planned biogas projects in Namibia at early stage, especially regarding the management of the biogas residue. In this processes, a first screening of the potential biogas substrate in the southern part of Namibia (south of Windhoek) was conducted. Moreover, the paper aims to point out the potentials in using organic waste for biogas production and thereafter recycling the nutrient rich residue to the farmland of Namibia. The risks in such utilization will be touched upon, such as the toxic effects of the alkali rich liquid phase or the NO2-emissions. Of which the first can be considered a risk but also a potential if the alkali residue partly can replace the use of pesticide. We conclude that the availability of substrates, i.e. organic wastes, is sufficient for supplying one or several biogas plants to the area. According to our conclusions, fertilization with biogas residue should be promoted in Namibia as an alternative to the current fertilization. 

  • 35.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Muter, Olga
    Latvia University.
    Odlare, Monica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Rodriguez, Adrian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Institute for Catalan Water Research.
    Cepurnieks, Guntis
    National Diagnostic Centre, Latvia.
    Bartkevics, Vadims
    National Diagnostic Centre, Latvia.
    Toxicity assessment and biodegradation potential of water-soluble sludge containing 2,4,6-trinitrotoluen2013Ingår i: Water Science & Technology, ISSN 0273-1223, Vol. 68, nr 8, s. 1707-1714Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    he water-soluble phase of trinitrotoluene-containing sludge (SLP) was characterized with regard to trinitrotoluene (TNT) concentration, ecotoxicity, and a model biodegradation experiment as evaluation criteria for further development of appropriate treatment technologies. SLP contained 67.8 mg TNT/l. The results of germination and root-elongation tests indicated that SLP had a species-specific phytotoxic effect. The results of a 21 day degradation experiment demonstrated TNT conversion to 4-amino-2,6-DNT and 2-amino-4,6-DNT, with a simultaneous reduction in the total concentration of nitroaromatics. Addition of inoculum stimulated the TNT degradation process. The presence of the sludge solid phase inhibited microbial activity. Measurement of microbial enzyme activity was used to assess changes in the microbial community during the biodegradation process.

  • 36.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Biological degradation of explosives in columns - new research ideas2006Ingår i: The Swedish Section for Detonics and Combustion, Fourth International Disposal Conference November 13-14, 2006, Katrineholm, Sweden, Linköping: Linköping University Electronic Press, Linköpings universitet , 2006, s. 9-11Konferensbidrag (Refereegranskat)
  • 37.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Treatment of explosives contaminated water by using pine bark in a batch process: potentials and kinetics2010Konferensbidrag (Refereegranskat)
    Abstract [en]

     Waste water from ammunition disposal can be of high volumes and heavily contaminated with toxic substances such as explosives and heavy metals. In the present paper, a contaminated waste water from a Swedish disposal industry was treated with the organic byproduct pine bark (Pinus Silvestris) as an adsorbent for capture of primarily the very common explosives substance TNT (2,4,6-trinitrotoluen). Traditionally, TNT is primarily a military explosive, and the source can be leaching from production, disposal or stockpiles of ammunition. TNT is toxic, both acute and chronically, and resistant to natural microbiological degradation why it can cause severe effects to an eco-system.

  • 38.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Treatment of TNT contaminated sludge by using a pilot scale bioreactor: a low cost method for on-site waste management2010Ingår i: Second International Conference of Hazardous and Industrial Waste Management, Chania, Crete, Greece, October 5-8, 2010, 2010Konferensbidrag (Refereegranskat)
  • 39.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Allard, Bert
    Örebro Universitet.
    Retention of 2,4,6-trinitrotoluen (TNT) and heavy metals from industrial waste water by using the low cost adsorbent pine bark in a batch experiment2009Konferensbidrag (Refereegranskat)
  • 40.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Allard, Bert
    Örebro Univ.
    Retention of 2,4,6-trinitrotoluene and heavy metals from industrial waste water by using the low cost adsorbent pine bark in a batch experiment2011Ingår i: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 64, nr 10, s. 2052-2058Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pine bark is a low cost sorbent originating from the forest industry. In recent years, it has been found to show promise as an adsorbent for metals and organic substances in contaminated water, especially landfill leachates and storm water. This study aims to investigate if pine bark can replace commercial adsorbents such as active carbon. An industrial effluent, collected from a treatment plant of a demilitarization factory, was diluted to form concentration ranges of contaminants and shaken with pine bark for 24 hours. Metals (e.g. Pb, Zn, Cd, As and Ni) and explosives, e. g., 2,4,6-trinitrotoluene (TNT), were analysed before and after treatment. The aim of the experiment was twofold; firstly, it was to investigate whether metals are efficiently removed in the presence of explosives and secondly, if adsorption of explosive substances to pine bark was possible. Langmuir and Freundlich isotherms were used to describe the adsorption process where this was possible. It was found that metal uptake was possible in the presence of TNT and other explosive contaminants. The uptake of TNT was satisfactory with up to 80% of the TNT adsorbed by pine bark.

  • 41.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Allard, Bert
    Örebro Universitet.
    Rodriguez, Adrian
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Treatment of metal contaminated water by using pine bark – a multivariate approach2009Konferensbidrag (Refereegranskat)
  • 42.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Eriksson, Pekka
    Allard, Bert
    Örebro Universitet.
    Simultaneous treatment of TNT and heavy metals in waste water from demilitarization industry by using pine bark (Pinus Silvestris)2008Konferensbidrag (Refereegranskat)
  • 43.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Fredrik, Vallin
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Eva, Thorin
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Algal blooms - an environmental problem or a potential energy resource? the potentials for algae cultivation in lake Mälaren, an eutrophicated lake in Sweden2010Konferensbidrag (Refereegranskat)
  • 44.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Ribé, Veronica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Carlsson, Peter
    Structor Miljöteknik.
    Eneroth, Peder
    Flexiclean.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Treatment of heavily contaminated storm water from an industrial site area by filtration through an adsorbent barrier with pine bark (Pinus Silvestris), polonite and active carbon in a comparison study2011Ingår i: Water and Industry, IWA Specialist conference, 1-5 May 2011, 2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    This study aims to evaluate a simple and robust filtration method for separation of of heavy metals from storm water. The storm water, collected at a metals manufacturing site, is heavily contaminated with heavy metals, A first analysis of a water sample collected from the site in mid Sweden showed exceptionally high concentrations of especially Zn, which was present in concentrations exceeding 200 mgL-1. The basic idea is to filter the water as it flows out of the industry area through a passive barrier in the storm water well pipeline. The advantages with using pine bark are many,  it is, for instance, a waste material that can be recycled into a new life cycle step and it has been shown to be a promising materia in previous studies l for capturing  heavy metal contaminants . Pine bark was in this study compared to two other materials; polonite and the conventional adsorbent active carbon. The forestry by-product pine bark (Pinus silvestris) consists of approximately 85-90 % dried and granulated pine bark and 10-15 % wood fibres. Polonite is a manufactured product originating from the cretaceous rock opoka. A laboratory  experiment was  set up, where  the storm water from the industrial site was filtered through all three filter materials in a pilot-scale model of the proposed installation. The filter cartridge model could be filled with approximately 2.2 L filter material. 3 L of the storm water was poured through the material through natural percolation, approximately 0.35 Lmin-1. Treated and untreated storm water was analyzed for heavy metals, suspended solids, electric conductivity and pH. Active carbon showed the highest level of adsorption, with nearly 100 % of all metals adsorbing to the filter. However, significant concentrations of As was desorbed from the material into the filtered water. Pine bark retained 90 % of the metals, even the Zn which was present in high concentrations. Polonite could only adsorb 70 % of the heavy metals and released Cr from the material.

  • 45.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Rodriguez, Adrian
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Johansson Westholm, Lena
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Wastewater phosphorous removal by blast furnace slag: Laboratory and field investigations in Sweden2009Konferensbidrag (Refereegranskat)
  • 46.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Institutionen för samhällsteknik.
    Waara, Sylvia
    Gustafsson, Jon-Petter
    Johansson Westholm, Lena
    The influence of dissolved organic carbon (DOC) on the metal sorption process to pine barkManuskript (Övrigt vetenskapligt)
  • 47.
    Nehrenheim, Emma
    et al.
    Mälardalens högskola, Institutionen för samhällsteknik.
    Waara, Sylvia
    Johansson Westholm, Lena
    Mälardalens högskola, Institutionen för samhällsteknik.
    Metal retention on pine bark and blast furnace slag - on-site experiment for treatment of low strenght landfill leachate2008Ingår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 99, nr 5, s. 998-1005Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Treatment of landfill leachate using blast furnace slag and pine bark as reactive sorbents was studied in an in situ column experiment at the Lilla Nyby landfill site in Eskilstuna, Sweden. The columns were filled with approximately 10 1 of each sorbent and leachate was supplied at three different flow rates during a period of 4 months. Samples of inflow and outflow were collected three times a week and were analyzed for physical and chemical parameters, including concentrations of some metals, and toxicity. It was found that pine bark removed metals more efficiently than did the blast furnace slags; that Zn was most efficiently retained in the filters and that both retention time and initial concentration played an important role in the sorption process. It was also observed that the pine bark column did not release COD. No toxicity of the untreated or the treated leachate was found with the test organisms and test responses used.  

  • 48.
    Nõlvak, H.
    et al.
    Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of Tartu, 46 Vanemuise St., Tartu, Estonia.
    Truu, M.
    Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of Tartu, 46 Vanemuise St., Tartu, Estonia.
    Oopkaup, K.
    Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of Tartu, 46 Vanemuise St., Tartu, Estonia.
    Kanger, K.
    Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of Tartu, 46 Vanemuise St., Tartu, Estonia.
    Krustok, I.
    Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of Tartu, 46 Vanemuise St., Tartu, Estonia.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Truu, J.
    Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of Tartu, 46 Vanemuise St., Tartu, Estonia.
    Reduction of antibiotic resistome and integron-integrase genes in laboratory-scale photobioreactors treating municipal wastewater2018Ingår i: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 142, s. 363-372Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Wastewater treatment systems receiving municipal wastewater are major dissemination nodes of antibiotic resistance genes (ARGs) between anthropogenic and natural environments. This study examined the fate of antibiotic resistome and class 1–3 integron-integrase genes in photobioreactors that were treating municipal wastewater diluted (70/30) with lake or tap water for the algal biomass production. A combined approach of metagenomic and quantitative (qPCR) analysis was undertaken. Municipal wastewater treatment in the photobioreactors led to reduced antibiotic resistome proportion, number of ARG subtypes, and abundances of individual ARGs in the bacterial community. The ARGs and intI1 gene abundances and relative abundances in the discharges of the photobioreactors were either comparable or lower than the respective values in the effluents of conventional wastewater treatment plants. The reduction of the resistome proved to be strongly related to the changes in the bacterial community composition during the wastewater treatment process as it was responding to rising pH levels caused by intense algal growth. Several bacterial genera (e.g., Azoarcus, Dechloromonas, and Sulfuritalea) were recognized as potential hosts of multiple antibiotic resistance types. Although the lake water contributed a diverse and abundant resistome and intI genes profile to the treatment system, it proved to be considerably more beneficial for wastewater dilution than the tap water. The diversity (number of detected resistance types and subtypes) and proportion of the antibiotic resistome, the amount of plasmid borne integron-integrase gene reads, and the abundances and relative abundances of the majority of quantified ARGs (aadA, sul1, tetQ, tetW, qnrS, ermB, blaOXA2-type) and intI1 gene as well as the amount of multi-resistance determinants were significantly lower in the discharges of photobioreactors where lake water was used to dilute wastewater.

  • 49.
    Odlare, Monica
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Abubaker, Jamal
    SLU.
    Lindmark, Johan
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Pell, Mikael
    SLU.
    Thorin, Eva
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Emissions of N2O and CH4 from agricultural soils amended with two types of biogas residues2012Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 44, s. 112-116Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Biogas residues contain valuable plant nutrients, important to the crops and also to soil microorganisms. However, application of these materials to the soils may contribute to the emission of greenhouse gases (GHG) causing global warming and climate change. In the present study, incubation experiment was carried out, where the emission rates of N2O and CH4 were measured after amending two soils with two types of biogas residues: (1) a regular residue from a large scale biogas plant (BR) and (2) a residue from an ultrafiltration membrane unit connected to a pilot-scale biogas plant (BRMF). The emissions of N2O and CH4 were measured at two occasions: at 24 h and at 7 days after residue amendment, respectively. Amendment with filtered biogas residues (BRMF) led to an increase in N2O emissions with about 6-23 times in organic and clay soil, respectively, in comparison to unfiltered biogas residues (BR). Methane emission was detected in small amounts when filtered biogas residue was added to the soil. Amendment of unfiltered biogas to the organic soil resulted in net consumption. In conclusion, fertilization with BRMF can be combined with risk of an increase N2O emission, especially when applied to organic soils. However, in order to transfer these results to real life agriculture, large scale field studies need to be carried out

  • 50.
    Odlare, Monica
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Arthurson, Veronica
    SLU.
    Pell, Mikael
    SLU.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Abubaker, Jamal
    SLU.
    Svensson, Kalle
    Hushållningssällskapet.
    Land application of organic waste: Effects on the soil ecosystem2011Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 88, nr 6, s. 2210-2218Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Growing populations and the increasing use of existing resources has led to growth in organic waste emissions. Therefore, a sustainable approach to managing this waste has become a major concern in densely populated areas. Biological treatment is an efficient method for reducing the amount of organic waste, and for producing energy. A large number of biogas plants and compost facilities that use organic waste as a substrate for electricity and fuel production are being built around the world. The biological treatment process in these plants produces large amounts of organic waste, and there is therefore a growing need to find a sustainable use for this material. Organic waste, such as biogas residues and compost can be a valuable fertilizer for agricultural soils. They can serve as a source of plant nutrients and can also improve soil structure and water holding capacity. However, as organic residues are known to contain both heavy metals and organic contaminants there is a need for long term field experiments to ensure that soil and plant quality is maintained. In order to investigate the potential risks and benefits of using organic waste in agriculture, an 8 year field experiment was established in central Sweden. Under realistic conditions, compost and biogas residues from source-separated household waste were compared with traditional mineral fertilizer. We examined crop yield and soil chemical and microbiological properties. The main conclusion from the field experiment was that biogas residues resulted in crop yields almost as high as the mineral fertilizer NPS. In addition, several important soil microbiological properties, such as substrate induced respiration, potential ammonium oxidation and nitrogen mineralization were improved after application of both biogas residues and compost. Moreover, no negative effects could be detected from using either of the organic wastes. In particular the genetic structure of the soil bacterial community appeared to resist changes caused by addition of organic waste.

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