总磷应急去除工艺研究

Research on Emergency Removal Technology of Total Phosphorus

目前污水处理除磷工艺主要以厌氧-缺氧-好氧(A^(2)/O)为主,然而A^(2)/O工艺仅能实现正磷酸盐的去除。当非正磷酸盐浓度过高时,采取应急措施去除污水中的非正磷酸盐以确保出水水质达标是非常必要的。基于此,开展了污水中总磷的应急去除的工艺研究。通过对传统芬顿氧化、臭氧-传统芬顿氧化、次氯酸钠(NaClO)氧化等方式对比,确定了NaClO氧化为最佳氧化方式,通过进一步的探索,得出了混凝法去除正磷酸盐的最佳条件:加入10 mL质量分数为5.5%的NaClO、氧化时间为30 min、氧化搅拌转速为60 r·min^(-1)、混凝剂体积为0.2 mL、混凝时间为20 min、搅拌速度为300 r·min^(-1)、慢速搅拌时间10 min、慢速搅拌速度60 r·min^(-1)、质量分数0.1%的聚丙烯酰胺体积为0.2 mL、助凝时间为30 min、助凝搅拌速度为60 r·min^(-1)。在上述条件下,非正磷酸盐的氧化去除率最高。该实验的开展可作为A^(2)/O工艺的重要辅助手段,当总磷浓度过高引起水质冲击时可确保出水水质达标。

At present,the phosphorus removal in sewage treatment process is mainly based on anaerobic-anoxic-aerobic(A^(2)/O)process.However,the A^(2)/O process cannot achieve the removal of non-orthophosphates.Thus,emergency measures to remove non-orthophosphates in sewage are very necessary.In this experiment,the research on the emergency removal of total phosphorus in sewage was carried out.Traditional Fenton oxidation,ozone-traditional Fenton oxidation,sodium hypochlorite(NaClO)oxidation were compared.The results indicated that sodium hypochlorite oxidation was a more practical method.By exploring a series of oxidation conditions,it was concluded that when 10 mL of NaClO with mass fraction of 5.5%was added,the oxidation time was 30 min,the oxidation stirring speed was 60 r·min^(-1),the dosage of coagulant was 0.2 mL,and the coagulation time was 20 min,the stirring speed was 300 r·min^(-1),the slow stirring time was 10 min,the slow stirring speed was 60 r·min^(-1),the dosage of polyacrylamide with mass fraction of 0.1%was 0.2 mL,the coagulation time was 30 min,and the coagulation stirring speed was 60 r·min^(-1),the oxidative removal rate of non-orthophosphate was the highest.The development of this experiment can be used as an important auxiliary method of the A^(2)/O process to ensure that the water quality of the effluent reaches the standard when the concentration of non-orthophosphate is high.