城市污泥堆肥过程中堆体表面沉降及减容率的研究

Study on pile surface settlements and volume reduction ratios during sewage sludge composting

通过测定堆肥过程中堆体表面沉降量的动态变化,结合堆肥温度、含水量和挥发性固体(VS)含量的变化,对堆体表面沉降和减容率及其影响因素进行研究。研究结果表明,城市污泥∶树皮(1∶1)处理的升温速率、最高温度和高温维持时间、含水量和VS含量去除率等均高于城市污泥∶秸秆(1∶1)处理,其灭菌、生物干燥和有机质降解效果较好。堆体表面沉降可分为物理压实沉降和有机质降解沉降,城市污泥∶树皮(1∶1)的物理压缩沉降量低于城市污泥∶秸秆(1∶1),主要是因为秸秆作为调理剂的支撑作用比树皮差;前者的有机质降解沉降量大于后者,这与堆肥温度、含水量和VS含量的去除率等因素有关。

Through determination of the composting surface settlement dynamic variations, combined with the composting temperature, moisture and volatile solids （VS） content changes, the pile surface settlements and reduction ratios and its influence factor were studied. The results show that sewage sludge： bark（l： 1） treatment had a better effect for sterilization, biological drying and organic matter degradation than sewage sludge： corn- stalks （1：1 ） treatment in the aspect of temperature rising rate, maximum temperature, high temperature lasting time, water content and VS content removal rate. Pile surface settlements should be divided into physical com- paction settlement and organic matter degradation settlement. Moreover, sewage sludge： bark （ 1：1 ） treatment had a lower physical compaction settlement than sewage sludge： cornstalks （1：1 ） treatment, which was caused by the worse supporting effects provide by the cornstalks as an amendments. As a result, the former treatment had a lower organic matter degradation settlement than the latter ones, which was correlated with the factors of composting temperature, water content and VS content removal rate.