摘要
城市污水处理厂的污泥上清液中TP含量高,回流到进水端会增加进水的TP负荷。经过对化学除磷技术的研究,发现在特定条件下,将含有Ca2+、Mg2+等金属离子的海水加入污泥上清液可实现化学除磷的目的。采用正交试验得到了该技术的最佳操作条件:水温为20℃,pH值为10.5,海水与污泥上清液的混合比例为1∶5,搅拌时间为10 m in,静沉时间为20 m in。在静态试验中,对污泥上清液中PO43--P的平均去除率可达96%,动态处理的平均去除率为92%。该技术不仅除磷效果好,而且处理成本也较投加铝盐、氢氧化钙的大为降低,同时生成的沉淀物为MAP、HAP,可以作为肥料施用。可见,该技术能够有效去除污泥上清液中的磷,适用于沿海地区城市污水处理厂的升级改造。
There is high concentration of TP in the sludge supernatant of WWTPs. If the supernatant is returned to the influent, the influent TP load is increased. Through research of chemical phosphorus removal technology, it is found that under the special conditions, adding seawater containing Ca^2＋ and Mg^2＋ ions into the supernatant can achieve chemical phosphate removal. Through orthogonal experiment, the optimal operation conditions are obtained as follows ： water temperature of 20℃, pH value of 10.5, seawater/supernatant ratio of 1 ： 5, agitation time of 10 min and sedimentation time of 20 min. In the static experiment, the average phosphate removal rate is 96%. In the dynamic experiment, the average phosphate removal rate is 92%. This technology has better phosphorus removal efficiency, and its cost is lower than that using aluminum salt and calcium hydroxide. The formed precipitates are MAP and HAP which can be used as fertilizers. It is concluded that this technology can effectively remove phosphorus from sludge supernatant, and is suitable for upgrading and reconstruction of WWTPs in coastal areas.
出处
《中国给水排水》
CAS
CSCD
北大核心
2008年第19期25-27,共3页
China Water & Wastewater
基金
建设部2007年科学技术项目(2007-K7-4)
关键词
污泥上清液
磷酸盐
混凝
海水
正交试验
sludge supematant
phosphate
coagulation
seawater
orthogonal experiment
