Real Textile and Domestic Wastewater Treatment by Novel Cross-linked Microbial Fuel Cell (CMFC) Reactor
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The microbial fuel cell (MFC) is an upsurging technology in the field of bio-energy generation along with wastewater treatment. The microbial fuel cell generates energy with the help of microbes that makes it green future source of energy. In MFC, anaerobic microbes degrade organic matter and produce hydrogen ions (H+) and electrons (e-) at the anode. H+ ion diffuses through the proton exchange membrane (PEM); and e- are transported through an electrode via an external circuit to the cathode. At a cathode, e- and H+ ions combine with oxygen to form water (H2O), this results in power generation . MFC has limited open circuit voltage (OCV) of 1.14 V because of the standard redox potential of NADH/ NAD+ and O2/H2O of -0.32 V and +0.82 V…show more content… Generally treatment processes are classified as physical, chemical or biological. Physical treatment process includes physical extraction of dyes by adsorption , membrane filtration  and ion-exchange. However, extracted dyes not be recovered, high cost and yet requirement of another process to degrade dyes makes these processes unsustainable. Chemical methods as Chemical Oxidation , Ozonization  and Electrochemical degradations are uneconomical and unfavorable for the environment. Biological methods are based on anaerobiotic or aerobiotic, microbial culture. But purely anaerobic digestion of azo-dye produces carcinogenic aromatic amine and aerobic deterioration alone is not able to degrade all dyes, also result in high amounts of sludge [12-14]. Sequential application of anaerobic followed by aerobic degradation has been providing a solution with the advantage of economic, reliable and ecological benefits [15,16].
Real textile wastewater (RTW) has low biological oxygen demand (BOD) to the chemical oxygen demand (COD) ratio, which implies chemical treatment is required. RTW also has greater color appearance; high total dissolved solid (TDS), suspended solids (SS), high temperature and variable pH (from 5 to 9) depending on dye. On the other hand, domestic wastewater has almost neutral pH, high BOD, normal temperature and high volume as well. Gingell and Walker  proposed two-step mechanism for degradation of azo-dyes Step 1 is the