2450MHz电磁波污泥脱水过程中的温度效应

采用2450MHz电磁波进行污泥脱水，研究电磁波加载过程中污泥温度变化对于剩余污泥性质和溶出效应的影响.研究发现，经电磁波加载后，污泥的容积指数（SVI）随着温度的升高而降低，在温度为80℃时由原泥的130.73mL/g降至最低值95.25mL/g，污泥沉降性能得到改善；经电磁波加载后，污泥离心含水率也随着温度的升高持续降低，最低降到80℃时的93.52%；污泥的毛细吸水时间（CST）在60℃时由原泥的29.4s降至最低值23.2s，污泥比阻（SRF）始终高于初始值，说明电磁波的加载一定程度上可以改善剩余污泥的离心脱水和板框压滤脱水效果，但不利于剩余污泥的真空抽滤.在电磁波加载过程中，检测污泥胞外聚合物（EPS）及上清液中可溶性化学需氧量（SCOD）的含量，发现污泥温度升高有利于污泥胞内物质的溶出.在80℃时，污泥上清液中SCOD含量由初始的124.1mg/L增大到883.4mg/L；同时也发现，温度高于60℃后，污泥中微生物细胞破壁更明显，污泥EPS含量随之发生变化，对污泥脱水性能的影响更加显著.

Temperature effect of 2450MHz electromagnetic wave during sludge dewatering

In this paper, the influence of temperature on residual sludge properties and solubility was studied during the process of sludge dewatering with 2450MHz electromagnetic wave. Results showed that sludge volume index (SVI) decreased from 130.73mL/g to 95.25mL/g at 80℃, which improved the sludge settlement performance. At the same time, the centrifugal water content of the sludge achieved the lowest of 93.52% at 80℃ and the capillary suction time (CST) of the sludge decreased to 23.2s at 60℃. The value of the specific resistance to filtration (SRF), however, was always higher than the initial value of the raw sludge. Therefore, electromagnetic wave treatment of sludge could improve the dewaterability of centrifugal and plate frame filter press of residual sludge, while deteriorated the dewaterability of vacuum filtration. According to the analysis of the extracellular polymeric substances (EPS) and the soluble chemical oxygen demand (SCOD) in the supernatant, higher temperature was beneficial for the solubilization of sludge. The SCOD raised from the initial value of 124.1mg/L to 883.4mg/L at 80℃. The disruption of microbial cell in sludge was more obvious, when the sludge temperature was higher than 60℃. The EPS in the sludge was closely related to the change of dewaterability of the sludge.