Biotechnology - Pollution remediation

Title

Relationships between Soil Organic Matter, Nutrients, Bacterial Community Structure, And the Performance of Microbial Fuel Cells

Reference

Environmental Science & Technology 46 (3), 1914-1922. J.N., 2012.

Author(s)

Dunaj, S.J., Vallino, J.J., Hines, M.E., Gay, M., Kobyljanec, C., Rooney-Varga

Study type

Peer Review Journal    

Abstract

Microbial fuel cells (MFCs) offer the potential for generating electricity, mitigating greenhouse gas emissions, and bioremediating pollutants through utilization of a plentiful renewable resource: soil organic carbon. We analyzed bacterial community structure, MFC performance, and soil characteristics in different microhabitats within MFCs constructed from agricultural or forest soils in order to determine how soil type and bacterial dynamics influence MFC performance. Our results indicated that MFCs constructed from agricultural soil had power output about 17 times that of forest soil-based MFCs and respiration rates about 10 times higher than forest soil MFCs. Agricultural soil MFCs had lower C:N ratios, polyphenol content, and acetate concentrations than forest soil MFCs. Bacterial community profile data indicate that the bacterial communities at the anode of the high power MFCs were less diverse than in low power MFCs and were dominated by Deltaproteobacteria, Geobacter, and to a lesser extent, Clostridia, while low-power MFC anode communities were dominated by Clostridia. These results suggest that the presence of organic carbon substrate (acetate) was not the major limiting factor in selecting for highly electrogenic bacterial communities, while the quality of available organic matter may have played a significant role in supporting high performing bacterial communities.

Policy theme(s)

Biotechnology >> Pollution remediation
Climate change and energy >> Climate change mitigation >> Low carbon and renewable energy
Environmental technologies >> Climate change mitigation >> Low carbon technologies

Keywords

Entry Source:

Shortlisted for Science for Environment Policy News Alert

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http://pubs.acs.org/doi/abs/10.1021/es2032532
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Juliette_RooneyVarga@uml.edu

Title

Effect of oxic and anoxic conditions on nitrous oxide emissions from nitrification and denitrification processes

Reference

Biotechnology and bioengineering, DOI: 10.1002/bit.23147

Author(s)

Varit Rassamee, Chakkrid Sattayatewa, Krishna Pagilla, Kartik Chandran

Study type

Peer Review Journal

Abstract

A lab-scale sequencing batch reactor fed with real municipal wastewater was used to study nitrous oxide (N₂O) emissions from simulated wastewater treatment processes. The experiments were performed under four different controlled conditions as follows: (1) fully aerobic, (2) anoxic-aerobic with high dissolved oxygen (DO) concentration, (3) anoxic-aerobic with low DO concentration, and 4) intermittent aeration. The results indicated that N₂O production can occur from both incomplete nitrification and incomplete denitrification. N₂O production from denitrification was observed in both aerobic and anoxic phases. However, N₂O production from aerobic conditions occurred only when both low DO concentrations and high nitrite concentration existed simultaneously. The magnitude of N₂O produced via anoxic denitrification was lower than via oxic denitrification and required the presence of nitrite. Changes in DO, ammonium, and nitrite concentrations influenced the magnitude of N₂O production through denitrification. The results also suggested that N₂O can be produced from incomplete denitrification and then released to the atmosphere during aeration phase due to air stripping. Therefore, biological nitrogen removal systems should be optimized to promote complete nitrification and denitrification to minimize N₂O emissions.

Policy theme(s)

Biotechnology >> Pollution remediation
Environmental technologies >> Pollution control >> Water treatment
Water >> Water quality >> Water pollution and safety
Water >> Water quality >> Wastewater treatment

Keywords

nitrous oxide (N₂O), biological nitrogen removal (BNR), greenhouse gas (GHG), nitrification, denitrification

Entry Source:

Shortlisted for Science for Environment Policy News Alert

Referred to in EC doc:

N/A

View this study at:

http://onlinelibrary.wiley.com/doi/10.1002/bit.23147/abstract
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Contact the study author at:

pagilla@iit.edu

Title

Biofiltration of wastewater treatment plant effluent: Effective removal of pharmaceuticals and personal care products and reduction of toxicity

Reference

Water Research
Volume 45, Issue 9, April 2011, Pages 2751-2762

Author(s)

J. Reungoat , B.I. Escher, M. Macova and J. Keller

Study type

Peer Review Journal

Abstract

This study investigates biofiltration for the removal of dissolved organic carbon (DOC), pharmaceuticals and personal care products (PPCPs), and for the reduction of non-specific toxicity expressed as baseline toxicity equivalent concentration (baseline-TEQ). Two filtering media, sand and granular activated carbon, were tested. The influence of pre-ozonation and empty-bed contact time (EBCT, from 30 to 120 min) was determined. The experiments were performed at a pilot-scale with real WWTP effluent. A previous study showed that biological activity had developed on the filtering media and dissolved organic removal had reached a steady state before sampling commenced. The results show that biological activated carbon (BAC) has a good potential for the removal of DOC (35-60%), PPCPs (>90%) and baseline-TEQ (28-68%) even without pre-ozonation. On the contrary, the sand shows limited improvement of effluent quality. Varying the EBCT does not influence the performance of the BAC filters; however, dissolved oxygen concentration could be a limiting factor. The performances of the BAC filters were stable for over two years suggesting that the main mechanism of organic matter and PPCPs removal is biodegradation. It is concluded that BAC filtration without pre-ozonation could be implemented as a low cost advanced treatment option to improve WWTP effluent chemical quality.

Policy theme(s)

Biotechnology >> Pollution remediation
Environmental technologies >> Pollution control >> Water treatment
Water >> Water quality >> Water pollution and safety
Water >> Water quality >> Wastewater treatment

Keywords

Organic micropollutants, Biological activated carbon filtration, Sand filtration,  Baseline toxicity equivalent concentrations, Wastewater reclamation

Entry Source:

Shortlisted for Science for Environment Policy News Alert

Referred to in EC doc:

N/A

View this study at:

http://www.sciencedirect.com/science/article/pii/S0043135411000698
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j.reungoat@awmc.uq.edu.au

Title

Integration of a microbial fuel cell with activated sludge process for energy-saving wastewater treatment: Taking a sequencing batch reactor as an example

Reference

Biotechnology and Bioengineering
Volume 108, Issue 6, pages 1260-1267, June 2011

Author(s)

Xian-Wei Liu, Yong-Peng Wang, Yu-Xi Huang, Xue-Fei Sun, Guo-Ping Sheng, Raymond J. Zeng, Feng Li, Fang Dong, Shu-Guang Wang, Zhong-Hua Tong,
Han-Qing Yu

Study type

Peer Review Journal

Abstract

In the research and application of microbial fuel cell (MFC), how to incorporate MFCs into current wastewater infrastructure is an importance issue. Here, we report a novel strategy of integrating an MFC into a sequencing batch reactor (SBR) to test the energy production and the chemical oxygen demand (COD) removal. The membrane-less biocathode MFC is integrated with the SBR to recover energy from the aeration in the form of electricity and thus reduce the SBR operation costs. In a lab-scale integrated SBR-MFC system, the maximum power production of the MFC was 2.34 W/m3 for one typical cycle and the current density reached up to 14 A/m3. As a result, the MFC contributed to the 18.7% COD consumption of the integrated system and also recovered energy from the aeration tank with a volume fraction of only 12% of the SBR. Our strategy provides a feasible and effective energy-saving and -recovering solution to upgrade the existing activated sludge processes.

Policy theme(s)

Biotechnology >> Pollution remediation
Environmental technologies >> Climate change mitigation >> Low carbon and renewable energy
Environmental technologies >> Pollution control >> Water treatment
Water >> Water quality >> Wastewater treatment

Keywords

activated sludge, biocathode, energy recovery, microbial fuel cell (MFC), sequencing batch reactor (SBR), upgrade

Entry Source:

N/A

Referred to in EC doc:

Shortlisted for Science for Environment Policy News Alert

View this study at:

http://onlinelibrary.wiley.com/doi/10.1002/bit.23056/abstract
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Contact the study author at:

hqyu@ustc.edu.cn

Title

A Comparative Analysis of Odour Treatment Technologies in Wastewater Treatment Plants

Reference

Environ. Sci. Technol.
DOI: 10.1021/es103478j

Author(s)

Jose M. Estrada, N. J. R. Bart Kraakman, Raul Munoz, and Raquel Lebrero

Study type

Peer Review Journal

Abstract

Biofiltration, activated sludge diffusion, biotrickling filtration, chemical scrubbing, activated carbon adsorption, regenerative incineration, and a hybrid technology (biotrickling filtration coupled with carbon adsorption) are comparatively evaluated in terms of environmental performance, process economics, and social impact by using the IChemE Sustainability Metrics in the context of odor treatment from wastewater treatment plants (WWTP). This comparative analysis showed that physical/chemical technologies presented higher environmental impacts than their biological counterparts in terms of energy, material and reagents consumption, and hazardous-waste production. Among biological techniques, the main impact was caused by the high water consumption to maintain biological activity (although the use of secondary effluent water can reduce both this environmental impact and operating costs), biofiltration additionally exhibiting high land and material requirements. From a process economics viewpoint, technologies with the highest investments presented the lowest operating costs (biofiltration and biotrickling filtration), which suggested that the Net Present Value should be used as selection criterion. In addition, a significant effect of the economy of scale on the investment costs and odorant concentration on operating cost was observed. The social benefits derived from odor abatement were linked to nuisance reductions in the nearby population and improvements in occupational health within the WWTP, with the hybrid technology exhibiting the highest benefits. On the basis of their low environmental impact, high deodorization performance, and low Net Present Value, biotrickling filtration and AS diffusion emerged as the most promising technologies for odor treatment in WWTP.

Policy theme(s)

Biotechnology >> Pollution remediation
Environmental technologies >> Pollution control >> Water treatment
Water >> Water quality >> Wastewater treatment

Keywords

Wastewater, Odour

Entry Source:

Selected for Science for Environment Policy News Alert

Referred to in EC doc:

N/A

View this study at:

http://pubs.acs.org/doi/pdfplus/10.1021/es103478j
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Contact the study author at:

mutora@iq.uva.es