剩余污泥高固态卧式厌氧消化的中试启动研究

Start Up Study of Pilot-Scale Horizontal Anaerobic Digestion from Excess Sludge by High-Solid

摘要:

针对含固率20%的剩余污泥，采用卧式反应器进行厌氧消化的中试启动研究.采取连续进料的方式，通过太阳能保温系统进行反应器的启动，经过3个月的运行，污泥产沼气率达到 274 mL/gVS，甲烷体积分数为58%，VS转化率达到46%，蛋白质和多糖降解率分别为36.7%和30.1%，消化过程中VFA质量分数最大值为 2 395 mg/kg，最大值出现在第42天。消化过程中氨氮质量分数一直缓慢增加，最大值约124.3 mg/kg。反应器沿程4个取样口污泥的VS，蛋白质和多糖降解率呈现出明显的差异性，反应器内污泥的降解率与其所处的沿程距离成正相关。经过73 d厌氧消化后，污泥的产甲烷潜力值达到273 mL/gVS，说明其已具备了良好的产甲烷潜力，反应器中的剩余污泥已转变为具有厌氧活性的污泥。

Abstract:

The pilot-scale horizontal reactor was investigated in this research for the anaerobic digestion of excess sludge. The reactor with the solar thermal insulation was operated under conditions of 20% solid content and continuous feeding mode. Results showed that the biogas yield reached 274 mL/g VS with methane content of 58% after 3 months' operation. The VS conversion rate was 46%, in which protein and polysaccharide were 36.7% and 30.1% respectively. Moreover, the maximum VFA content with the value of 2 395 mg/kg was appeared on the 42nd day during the whole process. The ammonia concentration increased slowly, then reached the maximum value of ~ 124.3 mg/kg during the digestion process. The degradation rate of VS, protein and polysaccharide in four sampling port of the reactor showed obvious difference, indicating that the sludge degradation rate in the reactor was positively collated with the distance along the reactor. After 73 days' anaerobic digestion, the methane producing potential of sludge could reach 273 mL/g VS, which showed that the system had a good potential for methane generation, and the residual municipal in the reactor had been successfully transformed into anaerobic activated sludge.