生物沥浸法对常规脱水污泥再深度脱水的效果

Advanced Dewatering of Conventional Dewatered Sludge by Bioleaching Technology

为了考察生物沥浸法对常规脱水污泥（指在浓缩污泥中加PAM等高分子絮凝剂并经带式或离心脱水后获得的含水率在80％左右的脱水污泥）进一步深度脱水的效果，将常规脱水污泥用中水稀释成含水率为97％左右的液态污泥后，采用批式运行模式进行生产性生物沥浸法调理（每批次处理污泥为60m3），然后在不加任何化学絮凝剂的情况下直接用隔膜厢式压滤机进行压滤脱水。结果表明，以浓缩池含水率为97％的浓缩污泥作为对照，在上批次沥浸污泥（接种物）与待处理的液态污泥体积比为1：1时，生物沥浸过程可在24h内完成，污泥比阻由沥浸初期的3．56×10^12m／kg降低至0．43×10^12m／kg。生物沥浸后的污泥通过150m。的隔膜厢式压滤机，在1．2～1．5MPa压力下压滤1．5h，泥饼含水率可稳定地降低到60％以下，外观呈土黄色块状，无臭味。经检测，泥饼有机质和高位热值在生物沥浸处理前后没有降低，且压滤液清澈，无色无味，COD为120—170mg／L，总氮为40～60mg／L，总磷在0．5mg/L以下。可见，常规脱水污泥经稀释后进行生物沥浸法深度脱水处理是完全可行的。

The conventional dewatered sludge with 80% moisture content was obtained by adding polymer flocculants such as PAM in concentrated sludge and dewatering with belt press filter or centri- fuge. To investigate the advanced dewatering effect of bioleaching process on the conventional dewatered sludge, the conventional dewatered sludge was diluted into liquid sludge with 97% moisture content by recycled water, and then conditioned by productive bioleaehing process with sequencing batch. The liq- uid sludge of each batch was 60 m3. The bioleached sludge was dewatered by diaphragm chamber filter press without any chemical flocculant. The results showed that using the concentrated sludge with 97% moisture content in the concentrated tank as a control, the bioleaching process could be completed within 24 h with the 1 ： 1 mixing ratio of bioleached sludge to of the sludge was reduced from the original 3.56 × 10^12 raw sludge, and the specific resistance to filtration m/kg to 0.43 × 10^12 m/kg. After bioleaching, the moisture content of the cake could be stably reduced to below 60% by 150 m2 diaphragm chamber filterpress at 1.2 to 1.5 MPa pressure for 1.5 h, and the sludge cake was yellow block without offensive odor. After testing, it was found that the organic matter and high calorific value of the cake in bioleaching treat- ment did not decrease, and the pressure filtrate was clear, colorless and tasteless. The concentrations of COD, TN and TP were 120 to 170 mg/L, 40 to 60 mg/L and below 0. 5 mg/L, respectively. Thus it can be seen that advanced dewatering treatment of conventional dewatered sludge after dilution by bioleaching is feasible.