摘要
研究了微米Fe_3O_4磁粉调理污泥的投加量的优化以及微米磁粉调理-压力电场污泥脱水工艺(MPEOD)的操作参数(电场作用时间、机械压力、电压)对脱水效果和能耗的影响,分析了磁化调理后污泥上清液、污泥絮体理化性质及接触能变化特征。结果表明,微米Fe_3O_4磁粉最佳调理投加量为0.15g·g~(-1);结合能耗与脱水效果,电场作用时间、电压和机械压力分别确定为2h、30V~50V和400~600k Pa。当MPEOD工艺的机械压力、电场作用时间和电压分别为400kPa、2h和50V时,污泥含水率由初始的99.18%降低至44.46%,水分脱除率和污泥减量化分别可达99.34%和98.30%,相应的能耗仅为0.0133k W·h·kg~(-1)。微米磁粉调理污泥时,絮凝作用机制的影响很小,污泥脱水性能得到提高的主要原因是微米磁粉大大降低了污泥颗粒间的路易斯酸碱作用,致使污泥絮体聚集,絮体间孔径增大,利于脱水。较之经典的DLVO理论,扩展后的EDLVO理论能准确描述污泥颗粒的凝聚及分散行为。
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