摘要
针对冬季低温条件下城区河道水质难以保持的特点,研究采用强化混凝沉淀+活性炭过滤两段式组合处理工艺对河道水质净化处理的效果。现场工程试验结合取水泵站设施和局部河段来完成水质净化工艺处理过程,考察冬季河道低温水工况下的净化处理效果。现场工程试验结果表明,在冬季河道水体水温约5. 5℃~8. 5℃时,絮凝剂(PAC)投加量4 mg/L、助凝剂(PAM)投加量0. 03 mg/L对水质的净化处理效果最佳。此时河道水体浊度去除率96%、透明度1. 2 m、CODMn去除率34. 9%、TP去除率约90. 2%,滤后水中残余铝和丙烯酰胺单体均满足国标限值要求,其中残余铝浓度有所增加但低于国标标准限值,丙烯酰胺单体低于检测值。采用Delta-tox生物毒性测试系统结果表明,当PAC投加量超过5 mg/L时,滤后水对水体中微生物生命活动表现出一定的抑制作用。比较分析处理前后底泥颗粒粒径分布情况,净化处理后底泥颗粒粒径有所增大,有助于悬浮物和胶体物质的吸附和沉降。
In view of the difficulty in maintaining water quality in urban rivers under low temperature conditions in winter, the effect of enhanced coagulation sedimentation + activated carbon filtration two-stage combined treatment on river water purification treatment was studied. The on-site engineering test combines the water pumping station facilities and local river sections to complete the water purification process, and investigates the purification treatment effect of the winter river channel under low temperature water conditions. The result shows the optimum doses of PAC and PAM are 4 mg/L and 0. 03 mg/L respectively when the water temperature is between 5. 5℃ to 8. 5℃ and the remove rate of turbidity, CODMn, TP is 96%,34. 9% and 90. 2% respectively. The residual aluminum concentration is far below the national limit and the amount of acrylamide monomer in the effluent is below the detection limit. The result of Delta-tox biological toxicity system shows the effluent after activated carbon filtration causes the inhibition of micrograms when the dose of PAC is over 5 mg/L. According to analysis of the particle size distribution, the particle size of sediment is become larger,which can improve the ability of flocculation and settlement.
引文
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