生物沥滤污泥土地利用适用性分析

研究了污泥生物沥滤对重金属(Cu、Pb和Zn)形态、营养物质和SO42-存在形式的影响,分析生物沥滤污泥土地利用的适用性。结果表明:生物沥滤后,污泥上清液中重金属通过固液分离而去除,污泥中Cu、Pb和Zn的去除率分别为84.1%、34.8%和80.0%,残存于污泥中的重金属含量大幅降低,且生物有效性低,提高了污泥土地利用的安全性。污泥经生物沥滤后氮、磷和钾的流失分别为38.2%、52.1%和42.8%,但仍能保持较好的肥效。采用X-射线衍射光谱分析发现,残留于污泥中的SO24-主要与Ca2 相结合,较为稳定,生物沥滤后的污泥施用于土地后对环境影响较小。

Feasibility of bioleached sewage sludge in land application

Based on the analysis of heavy metals, nutrients and sulfate in bioleached sewage sludge, the feasibility of this sludge in land application was approached in this paper. The results showed that after bioleaching, most of the heavy metals in the supernatant of the sludge were removed through solid-liquid separation, and the removal efficiency of Cu, Pb and Zn was 84.1%, 34.8% and 80.0%, respectively. The heavy metals remained in the sludge were mainly existed in stable forms, which made a higher security for land application. The bioleaching loss of the nitrogen, phosphorus and potassium in sludge was 38.2%, 52.1% and 42.8%, respectively, but the sludge still remained satisfactory fertilizer value. X-ray diffraction analysis indicated that the sulfate remained in the sludge after bioleaching was mostly combined with calcium, resulting in a negligible environmental impact.