绿化废物低比例补充的市政污泥好氧堆肥可行性分析

为验证绿化废物低比例补充的市政污泥好氧堆肥工艺可行性，以回流污泥堆肥产品替代绿化废物为骨料，采用静态翻堆好氧堆肥工艺处理脱水市政污泥，分析一次发酵过程及产品的主要性质。结果表明:以回流污泥堆肥产品部分替代绿化废物时，堆体的高温期（≥55 ℃）均可持续超过3 d，产品含水率低于40%，挥发性固体含量（VS）超过45%，pH值稳定在6.0~7.0，种子发芽指数（GI）超过70%，满足园林绿化用途要求。其中，脱水市政污泥、绿化废物、回流污泥堆肥产品质量比为5:1.5:1的试验组一次发酵周期可控制为27 d，一次发酵产品总氮、总磷、总钾、腐植酸等营养物质的含量较高，肥效更优，适合于工程规模的园林绿化用途。在回流污泥堆肥产品完全替代绿化废物的试验组中，脱水市政污泥和回流污泥堆肥产品质量比为5:6和5:8的堆体可达到高温要求（≥55 ℃保持至少3 d），VS、pH、营养物质、蛔虫卵死亡率、粪大肠菌群数等指标均符合园林绿化用泥质和有机肥料的要求，且一次发酵周期可控制在16 d内。当回流污泥堆肥产品与脱水市政污泥质量比≤6/5时，GI超过90%，满足腐熟要求。污泥堆肥产品回流替代绿化废物作为市政污泥堆肥的骨料，可有效调节脱水市政污泥堆体性质，缩短堆肥周期，提高产品肥效。

FEASIBILITY INVESTIGATION ON AEROBIC COMPOSTING OF MUNICIPAL SLUDGE SUPPLEMENTED WITH LESS PROPORTION OF GREEN WASTE

In order to verify the feasibility of the aerobic composting process of municipal sludge supplemented with less proportion of green waste, the returned sludge composting product was used to replace the green waste as an aggregate, and the dewatered municipal sludge was treated by the static turn-over aerobic composting process. The indicators of the composting process and products were determined. When the green waste was partially replaced by the returned sludge composting product, the high temperature period of the heap (≥ 55℃) was not less than 3 days, the moisture content of the product was lower than 40%, the volatile solid content (VS) exceeded 45%, the pH value was stable at 6.0~7.0, and the seed germination index (GI) was higher than 70%, which could meet the requirements of landscaping application. Among them, the composting heap of the mass ratio at 5:1.5:1 of dewatered municipal sludge, green waste and returned sludge composting product, could be controlled within 27 d, and the contents of total nitrogen, total phosphorus, total potassium and humic acid in the primary fermentation products were higher, indicating a better fertilizer effect. This proportional composting material ratio was suitable for landscaping in engineering applications. In the test groups, in which the returned sludge composting product completely replaced the green waste, the composting heaps of the mass ratio at 5:6 and 5:8 of dewatered municipal sludge and returned sludge composting product could meet the high temperature requirements (not less than 55℃ and maintaining 3 d at least), the parameters such as VS, pH, nutrients, ascaris egg mortality and fecal coliform count met the sludge quality requirements applying of landscaping and as organic fertilizer, and the period of primary fermentation could be controlled within 16 d. When the mass ratio of the returned sludge composting product to the dewatered municipal sludge was no more than 6/5, the GI exceeded 90%, which met the requirements of maturity. Replacing green waste by returned sludge composting products as aggregate for municipal sludge composting can effectively adjust the properties of dewatered municipal sludge, shorten the composting cycle, and improve the product fertility.