污泥生物处理技术在长江大保护中的应用前景

污泥是污水处理的副产物，是污水处理过程的延续和必然要求.截至2017年，长江经济带11省市污泥产量接近2 000×104 t/a，大量污泥没有得到妥善处置，严重制约着“长江水质根本好转”目标的实现.厌氧消化与好氧发酵是两种主流的污泥生物处理技术，都已有广泛的应用案例，但是也存在运营不畅的现象.为识别长江大保护中污泥生物处理项目的问题并提出解决方案，分析了长江经济带的污泥产率及性质，梳理了污泥生物处理技术的发展及适用性.结果表明:长江经济带各省市污泥产量约占全国污泥产量的40%，污泥产率普遍低于全国平均水平，长江经济带各省市污泥有机质含量低于55%，pH为中性、总养分含量超过5.0%、重金属含量存在超过GB 4284—2018《农用污泥污染物控制标准》标准限值的风险；高级厌氧消化、协同厌氧消化和高含固厌氧消化等技术的发展破解了由于长江经济带污泥有机质含量普遍较低而导致的污泥厌氧消化稳定性低的问题，降低了污泥厌氧消化工程的成本；污泥好氧发酵过程重金属钝化技术的发展在一定程度上破解了由于长江经济带污泥重金属含量过高而导致的污泥发酵产物出路不畅的问题.研究显示，污泥生物处理技术仍具有一定的局限性，但通过合适的规划，污泥生物处理技术可与其他污泥处理处置技术高效耦合，具有广泛应用于长江大保护污泥处理处置项目的潜力. 

Application Prospect of Biological Treatment Technology of Sewage Sludge in Yangtze River Protection

Sewage sludge is a by-product of sewage treatment and the continuation of sewage treatment process. The Yangtze River Economic Belt (YREB) sewage sludge production is close to 2000×104 t/a by 2017, and large amounts of sewage sludge are not properly disposed, which seriously restricts the realization of 'fundamental improvement of Yangtze River water quality'. Anaerobic digestion and composting are two mainstreams sewage sludge biological treatment technologies, but some biological treatment projects were in poor operation. To identify and solve the problems in the sewage sludge biological treatment projects of the Yangtze River Protection (YRP), the yield and properties of YREB sewage sludge were analyzed and the development and applicability of sewage sludge biological treatment technologies were reviewed. The results showed YREB sewage sludge accounted for 40% of the national sewage sludge production, and YREB sewage sludge yield was generally lower than the national average level. For YREB sewage sludge, organic matter content was lower than 55%, pH was neutral, total nutrient content was more than 5.0%, and heavy metal content might exceed the limit values of Control Standards of Pollutants in Sludge for Agricultural Use(GB 4284-2018). The development of advanced anaerobic digestion, collaborative anaerobic digestion and high solid anaerobic digestion technologies solved the problem of low stability of anaerobic digestion caused by the low organic matter content of YREB sewage sludge and reduced the anaerobic digestion project cost. The development of composting passivation technology solved market problems of sewage sludge compost caused by high heavy metal content in YREB sewage sludge. The research showed though sewage sludge biological treatment technologies has some limitations, they can be effectively combined with other sewage sludge treatment technologies through appropriate planning and can be widely used in YRP sewage sludge treatment and disposal projects.