Study on Biochemical Methane Potential and Engineering Application of Sludge Dehydrated Water through Hydrothermal Drying Treatment

The Hohhot sewage sludge dehydrated water (SDW)throughhydrothermal drying treatmentwas studied in this paper, which was evaluated by Biochemical Methane Potential (BMP) test as well as the guidance foranbiochemical methane potentialproject. The results showed that under 35 degree, after continuous 21 days fermentation, the sludge dehydrated water performed the maximum cumulative gas production (9450mL) with the concentration of 20gCOD/L. With the increase of concentration of sludge dehydrated water, both unit biogas production and methane conversion raterose at first and then fell, and it achieved 499.8mL/Gcodwhich was the maximum of 10gCOD/L slurry. According to the optimal results of commercial project in Hohhot, the efficiency of 20gCOD/L sample, 83.42 tons of sludge dehydrated water if all the loading of COD was degraded were calculated to produce 342m^3 methane, corresponding to the heat from 239.5kg standard coal, which could be used forrecycling.