Accelerating Degradation And Stabilization Of Sludge In The Process Of Sludge Treatment Wetland By Bioelectrogenesis

Sludge as a by-product of wastewater treatment process is enormous. Treatment wetland sludge(STW) is a new type of sludge treatment technology, which has the obvious advantages of low energy consumption and easy to manage, but its ability to degrade organic matter is low, and its development is limited. Microbial fuel cells(MFC) can accelerate the anaerobic degradation of sludge and the synchronous recovery of electrical energy. In this paper, based on the characteristics of MFC and STW systems, MFC technology is introduced into the STW system, which theoretically can accelerate the degradation of the organic matter in the sludge wetland system and the recovery of the. In this paper, different sludge load MFC-STW system producing electric performance and sludge organic matter accelerated degradation efficiency of migration and transformation, and stable phase MFC-STW accumulation sludge stability of degree are studied.The research results show that the introduction of bioelectrogenesis technology can accelerate the dewatering performance of sludge and the degradation efficiency of organic compounds in STW system. MFC-STW system was successfully launched by the intermittent operation of 10 d. The sludge load gradually increased, the electricity generation performance of system increases, when sludge load is 0.343 kg TS/d·m2, MFC-STW system voltage,resistance,the power density are highest,respectively 0.794 V, 201.3 Ω, 0.268 w/m3. When the load is 0.343 kg TS/d·m2, the water content of the lower sludge in the MFC-STW system is the lowest, which is 84%, which is 13.58% lower than that of the original clay. The effect of MFC-STW system on the degradation of TCOD sludge in SLR0.343 was reached to the maximum value of 78% in the lower sludge. At this time, the highest concentration of SCOD was 2619 mg/L. In addition, MFC-STW can promote the hydrolysis of polysaccharide and protein in the system, the accumulation of sludge layer of soluble protein and soluble polysaccharide concentration increased. MFC-STW system sludge volume reduction is 96%.Bioelectricity production can accelerate the DOC degradation of sludge EBOM HPI and HPO-A fraction in STW system, MFC-STW on the lower sludge accumulate DOC removal rates are 33.02% and 37.46% respectively, improve 21.85% and 46.67% than in STW system respectively. Two systems of aromatic compounds and other aromatic organic humus substances mainly present hydrophilic and acidic organic substances.The degree of MFC-STW on the accumulation of sludge EBOM HPO-A of aromatic substances degradation is largest, can promote the accumulation of sludge EBOM group of acidic and neutral group protein hydrolysis.The hydrolysis effect of MFC-STW system on the neutral component of the sludge EBOM was greater than that of the acid component and the hydrolysis effect of the neutral component,had good removal effect of the original mud HPI component of fulvic acids, soluble microbial leaching and aromatic protein.After 60 days period of stability, MFC-STW system the upper and lower sludge moisture rate dropped to 32.25% and 30.08%, reduced 67.30% and 69.50% than original sludge, the dehydration efficiency improved 5.09% and 3.16% than STW system, showed the good effect of sludge dewatering sludge MFC-STW system.After the stabilization treatment, the lowest VS content of MFC-STW system is 34.37%, the highest removal rate is 38.54%; the TN content of the MFC-STW system on the accumulation of the upper and bottom sludge were reduced 9.39% and 13.12% than the original mud; the removal rate of TP were 42.42% and 52.94%, compared with STW system increased 26.47%, 47.31%.The whole operation process, the accumulation of heavy metals in the sludge of MFC-STW system waa without accumulation. The content of heavy metals in the final sludge products of MFC-STW system was in line with the sludge agricultural standard.