Microbial Electrolysis Coupled Sludge Anaerobic Digestion Methanogenic Process For Waste Activated Sludge Treatment

The test subjects to benefit the remaining sludge recycling methods, andmethanogenic sludge anaerobic digestion performance improved as the main object ofstudy. Presented at the anaerobic digestion process, speed up the introduction ofmicrobial electrolysis cell activated sludge methanogenic anaerobic digestion process,anaerobic digestion of sludge to improve the rate of methane production ideas.Establishment of sludge anaerobic digestion and microbial electrolysis system couplingof methane production, build AD-MEC coupling process in the form of methaneproduction, and reactor startup and operation carried out a preliminary study.Anaerobic sludge digestion process can produce large amounts of volatile fatty acids,acid sludge fermentation reactor after the alkali treatment use secondary clarifier sludge,acid production achieved a stable performance, volatile acid concentration from811mgCOD/L reached2811mgCOD/L, and the content of acetic acid which graduallyincreased.Sodium acetate as substrate for the AD-MEC coupled methanogenic reactorstartup, separate AD and control groups compared methanogenic reactor. After startingthe stable coupling of methane-producing reactor utilization rate of sodium acetate as asubstrate for methane production reached0.031m3CH4/m3d, and join in the controlgroup rate0.016m3CH4/m3/d, microbial electrolysis cell auxiliary systems of puremethane-producing reactions AD methane ’s performance significantly improved byabout90%. Sodium acetate as substrate coupling reactor to achieve good resultsstarting in about fourteen cycles coupled methanogenic reactor performance, substrateutilization for both stabilized.After the successful launch of the reactor to the anaerobic sludge fermentationbroth as complex carbon sources, study AD-MEC coupled methanogenic reactormethane production performance. After the stable coupling of methane production rateof the reactor reached0.17m3CH4/m3d, the control group AD methanogenic reactormethane production rate of about0.064m3CH4/m3d, microbial electrolysis cell auxiliarysystems added to the pure AD methanogenic reactor methanogenic significantlyimproved performance, increased by about3times. The remaining sludge can beproduced in addition to the direct use of acetic acid methanogens there are a lot ofmulti-volatile organic carbon fatty acids, these multi-volatile organic carbon fatty acidsthat can not be directly used methanogens, need to hydrolysis fermentation anaerobicdigestion process generates acid, methane-producing bacteria can be utilized, thusanaerobic digestion process is more complicated, not timely reasons for the use of acidsmethane production rate is also low. Microbial electrolysis cell can utilize complexorganic substrates, under the action of external electronic circuits quickly passed. Therefore, the introduction of microbial electrochemical systems to anaerobic digestionprocess, the use of residual sludge microbial electrolysis cell complex organics, somicrobial electrolysis system assisted anaerobic digestion can accelerate theperformance of its production of methane.According to AD-MEC reaction of methane-producing electronic balancecalculation, the amount of methane produced per day coupled reactor is substantiallyequal to the amount of methanogenic reactor control group and electron transfer theoryto calculate the methane production. This further validates the supporting role ofmicrobial electrolysis cell for the production of methane anaerobic digestion system.