烟气干化污泥及其对霾的源头控制作用

Sludge drying using flue gas and its role in haze source control

如何彻底处理城市污水处理厂污泥？如何有效控制有霾天气？这是当今中国所面临的两大亟待解决的环境难题．本文在分析污泥化学组成的基础上，通过模拟实验与结合工程实践，深入研究了烟气干化污泥的工作原理和关键技术及其对霾的源头控制作用．研究结果表明，利用烟气余热干化污泥克服了污泥热干化的“能耗瓶颈”，干化造粒一体化装置与分段式工艺满足了烟气．污泥热交换反应所需要的足够空间和充分时间，湿污泥与热烟气直接接触不仅使污泥干化的效率最大化，而且可以吸附烟气中60％的PM2．5和43％的PM10以及20％-25％的S02，这为创建利用烟气余热的污泥低温干化新方法提供了科学依据，也为开辟一条以废治废、节能减排的“泥与霾”共治的新途径提供了技术支撑．

China is faced with two severe environmental issues, how to dispose massive sludge in city and how to reduce the possibility of haze condition. This study analyzed the chemical composition of sludge, discussed the key method of sludge drying and its role in source controlling of haze based on simulation experiments and monitoring data from engineering practices. The results showed that using flue gas to dry the sludge overcame the ＂bottleneck of energy consumption＂ in sludge drying. The multiple-stage process and invented drying ＆ granulation equipment provided sufficient space and time for thermal exchange between flue gas and sludge. The direct contact of wet sludge with flue gas promoted drying efficiency. Furthermore, the sludge adsorbed 60% PM2.5 and 20%-25% SO2 in flue gas during sludge drying. Our research served as the scientific base supporting the low-temperature sludge drying technology, and it is an exploration on co-management of sludge ＆ haze in an energy saving way.