污泥浓缩消化一体化中试反应器的启动研究

Study on Start-up of Pilot-scale Integrated Sludge Thickening and Digestion Reactor

对污泥浓缩消化一体化(ISTD)中试反应器处理城市污泥的启动进行研究。试验进泥为二沉剩余污泥,含水率为98.1%～99.3%、pH值为6.75～7.2、挥发性脂肪酸(VFA)为30～144 mgHAc/L、碱度为172～277 mg/L(以CaCO3计,下同)、VS/TS值为0.355～0.434。启动试验采用逐步培养法、以投配率为10%的方式进行,污泥经加热后进入反应器。在中温条件下,经过约55 d的运行,ISTD反应器内各项指标趋于稳定,内反应室的VFA平均值为250 mgHAc/L,启动期间未出现酸化现象。稳定后,产气量为280～300 L/d、排泥含水率为92.0%～93.5%、VS/TS值为0.320～0.340、碱度为1 200～1 300 mg/L。

A study on the start-up of a pilot-scale integrated sludge thickening and digestion （ISTD） reactor was carried out. The experimental sludge was the excess sludge from secondary sedimentation tank, characterized by water content 98. 1% to 99.3%, pH 6.75 to 7.2, volatile fatty acid （VFA） 30 to 144 mgHAc/L, alkalinity 172 to 277 mg/L （calculated as CaCO3 ）, and VS/TS 0. 355 to 0.434. The pilot-scale ISTD reactor was started up using step-by-step culture with 10% dosage. After being heated, sludge was fed into the reactor. The various indexes of the ISTD were stable after operation for 55 days under mesophilic condition. VFA concentration in the inner reactor was 250 mgHAc/L. A- cidification was not observed during start-up period. During the steady operation phase, key parameter values of discharged sludge were water content 92.0% to 93.5% , VS/TS 0. 320 to 0. 340, alkalinity 1 200 to 1 300 mg/L and gas yield was 280 to 300 L/d.