市政污泥水热法脱水试验研究

市政污泥具有水分含量高、脱水困难的特点,水热法工艺可改善其脱水性能,降低污泥含水率,有利于实现污泥的无害化、稳定化及资源化利用。考察了反应温度、 pH值、泥浆浓度、保温时间、泥浆过滤温度等工艺条件对污泥脱水效果的影响。结果显示,在反应温度为180℃、 pH值为6.85、生污泥与水的质量比约为2∶1、保温时间为30 min、水热泥浆冷却到80℃时抽滤脱水,污泥含水率由处理前的75.81%下降到48.69%,脱水率达到77.44%。该工艺具有流程短、能耗低、生态环保的特点,脱水污泥符合燃料化、土地化利用的要求。

Experiment study on municipal sludge dewatering by hydrothermal method

As municipal sludge has characteristics of high moisture content and difficult to be dewatered,hydrothermal process can be used to improve its dewatering performance,reduce sludge moisture content,which is conducive to the realization of harmless,stable and resource utilization of sludge.The effect of reaction temperature,pH value,slurry concentration,holding time,slurry filtration temperature,and some other factors on sludge dewatering were investigated.The results showed that,under the condition that the reaction temperature was 180℃,the pH value was 6.85,the mass ratio of raw sludge to water was 2:1,the holding time was 30 min,and the hydrothermal slurry was cooled to 80℃,the moisture content of the sludge decreased from 75.81%to 48.69%,and the dehydration rate reached 77.44%.The said process has characteristics of short process,low energy consumption and environmental protection,the dewatered sludge meets the requirements of fuel and land utilization.