Abstract:

With the upgrading of wastewater discharge standard in environmentally sensitive area，ultra-advanced phosphorus removal is required in municipal wastewater treatment plant. The phosphorus（including total phosphorus，suspended phosphorus，dissolved orthophosphate and other dissolved phosphorus） distribution along the whole treatment process were monitored and analyzed in a municipal wastewater treatment plant of water environmental sensitive area. The data indicated that the suspended phosphorus and dissolved phosphorus were the main components in total phosphorus in each treatment unit and account for over 86%. Meanwhile，the average total phosphorus concentration of the secondary sedimentation tank effluent was 0.192 mg/L. The feasibility and boundary conditions of ultra-advanced chemical phosphorus removal（total phosphorus concentration<0.05 mg/L） from secondary effluent were investigated. The results showed that the optimum dosage of polyaluminum chloride（PAC） was 60 mg/L and all forms of phosphorus were removed to various extent. When the optimum dosage was used and the pH was between 6.75 and 8，the total phosphorus concentration of the effluent was below 0.05 mg/L and the best coagulation effect could be achieved at a pH of 7.25.

Key words: municipal wastewater, phosphorus composition, advanced phosphorus removal

摘要：

随着环境敏感水体区域污水排放标准的不断提高，该区域内的污水处理厂需要进行超深度除磷。针对环境敏感地区某污水处理厂的现有处理工艺，对全流程的磷素（总磷、悬浮态磷、溶解性正磷酸盐、其他溶解性磷）进行监测分析，结果表明沿程总磷都是以悬浮态磷和溶解性正磷酸盐为主，在各处理单元中悬浮态磷和溶解性正磷酸盐质量分数都在86%以上，二沉池出水平均总磷为0.192 mg/L。以该污水处理厂的二级处理出水为研究对象，考察超深度化学除磷（出水总磷<0.05 mg/L）的可行性和边界条件，结果表明聚合氯化铝（PAC）的最佳投加量为60 mg/L，此时各形态的磷都得到不同程度的去除，使用最佳投加量并且pH在6.75~8之间时，出水总磷低于0.05 mg/L，pH为7.25时混凝效果最佳。

关键词: 城市污水, 磷组分, 深度除磷

CLC Number: 

• X703