预氧化-混合-澄清-超滤中试工艺优化运行研究

Study on operation optimization of pre-oxidation-mixing-clarification-UF pilot test process

以预氧化-混合-澄清-超滤中试工艺为对象,分别针对混合、澄清、预氧化单元的关键性运行参数进行优化研究。结果表明,一级/二级混合采用相同的搅拌速度98 r/min时,对浊度有较好的去除效果;采用2 mg/L PAC+4 mg/L FeCl_(3)对引江水浊度有良好的处理效果并兼顾经济性;澄清池的出水水质与进水负荷呈负相关关系,进水流量采用3.5 m~3/h能在保证处理效果的同时充分利用澄清池的处理能力;日常运行可考虑投加10 mg/L及以下浓度的粉末活性炭,提高对水中UV_(254)和TOC的去除效果,且不会明显增加超滤膜的跨膜压差;预氧化单元中投加臭氧可以显著提高对UV_(254)的去除效果,不会对超滤膜产生显著的不利影响。

Taking the pre-oxidation-mixing-clarification-ultrafiltration pilot test process as the case,the key operating parameters of the mixing,clarification and pre-oxidation units were optimized.The results showed that the turbidity could be removed better when the same mixing speed of 98 r/min was used in the first and second stage mixing.The combination dosage of 2 mg/L polyaluminum chloride(PAC)and 4 mg/L ferric chloride(FeCl_(3))had a good effect on turbidity removal in diverting water from the Yangtze River along with economic operation.The effluent quality of the clarification tank was negatively correlated with the inlet load,and the inlet flow of 3.5 m~3/h could ensure the treatment effect while making full use of the treatment capacity of the clarification tank.Dosing powdered carbon of 10 mg/L or less could improve the removal effect of UV_(254) and TOC,which did not significantly increase the transmembrane pressure.The addition of ozone in the preoxidation unit could significantly improve the removal effect of UV_(254) with no significant adverse effect on the UF membrane.