Enhancing desalination and wastewater treatment by coupling microbial desalination cells with forward osmosis

Abstract Both microbial desalination cells (MDCs) and forwards osmosis (FO) are emerging technologies for energy-efficient water/wastewater treatment. However, incomplete treatment/desalination in both technologies creates challenges for further development and also synergy between the two. In this study, an integrated system was developed by coupling MDCs with a FO cell to enhance COD (chemical oxygen demand) removal in synthetic organic solution and desalination of saline water. The organic solution was treated in the MDC anode and its effluent was sent to the FO for water recovery. The diluted draw solution from the FO was desalinated in the MDC. Compared to a standalone MDC, the MDC–FO system reduced the wastewater volume by 64% and improved the conductivity reduction in saline water by two times. The coupled system also achieved higher COD removal than a standalone FO cell. The MDC–FO system was further investigated for the effects of COD, salt concentration and hydraulic retention time (HRT). It was observed that varying COD concentration had little impact on desalination. Lowering the initial NaCl concentration enhanced the COD removal to 93.0% and the conductivity reduction to 99.4%. In addition, the COD removal rate and the conductivity decrease rate were proportionally facilitated with a shortened HRT. These results have collectively demonstrated that the MDC–FO system has improved performance, compared with the standalone process. It holds great promise to either treat brackish water, or serve as pre-desalination of high-salinity water, with simultaneous wastewater treatment.

[1]  Bruce E Logan,et al.  The electric picnic: synergistic requirements for exoelectrogenic microbial communities. , 2011, Current opinion in biotechnology.

[2]  Zhiyong Ren,et al.  Sustainable desalination using a microbial capacitive desalination cell , 2012 .

[3]  Stefano Freguia,et al.  Microbial fuel cells: methodology and technology. , 2006, Environmental science & technology.

[4]  K. Xiao,et al.  A new method for water desalination using microbial desalination cells. , 2009, Environmental science & technology.

[5]  P. Liang,et al.  Microbial desalination cells packed with ion-exchange resin to enhance water desalination rate. , 2012, Bioresource technology.

[6]  Peng Liang,et al.  A ten liter stacked microbial desalination cell packed with mixed ion-exchange resins for secondary effluent desalination. , 2014, Environmental science & technology.

[7]  Chris Yuan,et al.  Facile Synthesis of MoS2@CNT as an Effective Catalyst for Hydrogen Production in Microbial Electrolysis Cells , 2014 .

[8]  K. Watkins.  Human Development Report 2006 - Beyond Scarcity: Power, Poverty and the Global Water Crisis , 2006 .

[9]  Renduo Zhang,et al.  Tetramethylammonium hydroxide production using the microbial electrolysis desalination and chemical-production cell , 2014 .

[10]  V. Gude,et al.  Sustainable photosynthetic biocathode in microbial desalination cells , 2015 .

[11]  Zhen He,et al.  Improving the flexibility of microbial desalination cells through spatially decoupling anode and cathode. , 2013, Bioresource technology.

[12]  Zhen He,et al.  An upflow microbial fuel cell with an interior cathode: assessment of the internal resistance by impedance spectroscopy. , 2006, Environmental science & technology.

[13]  Zhen He,et al.  Effects of inter-membrane distance and hydraulic retention time on the desalination performance of microbial desalination cells , 2014 .

[14]  Peng Liang,et al.  Capacitive deionization coupled with microbial fuel cells to desalinate low-concentration salt water. , 2012, Bioresource technology.

[15]  Raphael Semiat,et al.  Energy issues in desalination processes. , 2008, Environmental science & technology.

[16]  Jeonghwan Kim,et al.  Domestic wastewater treatment as a net energy producer--can this be achieved? , 2011, Environmental science & technology.

[17]  Zhen He,et al.  Integrated salinity reduction and water recovery in an osmotic microbial desalination cell , 2012 .

[18]  Zhen He,et al.  Electricity generation from artificial wastewater using an upflow microbial fuel cell. , 2005, Environmental science & technology.

[19]  Amy E. Childress,et al.  Forward osmosis: Principles, applications, and recent developments , 2006 .

[20]  Zhen He,et al.  Self-Supplied Ammonium Bicarbonate Draw Solute for Achieving Wastewater Treatment and Recovery in a Microbial Electrolysis Cell-Forward Osmosis-Coupled System , 2014 .

[21]  Bruce E Logan,et al.  Series assembly of microbial desalination cells containing stacked electrodialysis cells for partial or complete seawater desalination. , 2011, Environmental science & technology.

[22]  Nathan T. Hancock,et al.  Pilot demonstration of the NH3/CO2 forward osmosis desalination process on high salinity brines , 2013 .

[23]  Linda Zou,et al.  Recent developments in forward osmosis : opportunities and challenges. , 2012 .

[24]  B. Logan,et al.  Salt removal using multiple microbial desalination cells under continuous flow conditions , 2013 .

[25]  Irini Angelidaki,et al.  A new method for in situ nitrate removal from groundwater using submerged microbial desalination-denitrification cell (SMDDC). , 2013, Water research.

[26]  Bruce E. Logan,et al.  Microbial desalination cells for energy production and desalination , 2013 .

[27]  B. Helmreich,et al.  Determination of optimal conditions for 5-methyl-benzotriazole biodegradation with activated sludge communities by dilution of the inoculum. , 2014, The Science of the total environment.

[28]  Zhen He,et al.  Mathematical model of dynamic behavior of microbial desalination cells for simultaneous wastewater treatment and water desalination. , 2014, Environmental science & technology.

[29]  L. Rietveld,et al.  Forward osmosis for application in wastewater treatment: a review. , 2014, Water research.

[30]  Zhen He,et al.  Improving water desalination by hydraulically coupling an osmotic microbial fuel cell with a microbial desalination cell , 2013 .

[31]  Zhen He,et al.  Efficient salt removal in a continuously operated upflow microbial desalination cell with an air cathode. , 2011, Bioresource technology.

[32]  Darren Delai Sun,et al.  A low-energy forward osmosis process to produce drinking water , 2011 .

[33]  Haotian Sun,et al.  Stacked microbial desalination cells to enhance water desalination efficiency. , 2011, Environmental science & technology.

[34]  Luc Pinoy,et al.  A natural driven membrane process for brackish and wastewater treatment: photovoltaic powered ED and FO hybrid system. , 2013, Environmental science & technology.

[35]  Zhen He,et al.  Use of a liter-scale microbial desalination cell as a platform to study bioelectrochemical desalination with salt solution or artificial seawater. , 2011, Environmental science & technology.

[36]  Zhen He,et al.  When Bioelectrochemical Systems Meet Forward Osmosis: Accomplishing Wastewater Treatment and Reuse through Synergy , 2014 .

[37]  Zhen He,et al.  Long-term investigation of fouling of cation and anion exchange membranes in microbial desalination cells , 2013 .