Highly Removal Of Phosphorus In Effluent Of Wastewater Treatment Plant With Micro-electrolysis

Nowadays,nearly 3/4 of the lakes in China are close to the degree of eutrophication,and the problem of eutrophication in water is increasingly prominent.The concentration of the effluent of TP from waste water treatment plant is far higher than the discharge standard of surface lake water,which will still cause eutrophication of water.For this reason,highly removal of phosphorus must be carried out.At present,the effluent of TP in deep phosphorus removal technology in China is still difficult to meet the discharge standard of surface water lake.Microelectrolysis can theoretically remove both TP and COD,and some studies have been conducted to make TP less than or equal to 0.2 mg/L.Therefore,this project uses micro-electrolysis to further remove the phosphorusl of waste water treatment plant,and at the same time to explore the removal effect of other pollutants.On this basis,the stability of long-term continuous operation system was explored.The influence of various factors on the removal of phosphorus in the micro-electrolysis was determined through experiments.The results showed that under aeration,when the contact time of empty bed?EBCT?was 4 minutes,TP decreased from 0.44 mg/L to 0.03 mg/L.And when the initial concentration of TP was less than 0.4 mg/L,the TP concentration of effluent was lower than the detection limit?0.01 mg/L?.The removal of phosphorus by iron carbon micro-electrolysis is mainly the flocculation precipitation,co-precipitation and adsorption of iron phosphate salt,basic iron phosphate and Fe?OH?₃.By comparing the removal effects of coagulation precipitation method,sand filtration method and sulfur particle filter column on iron ions,it was found that coagulation precipitation method and sand filtration method have certain treatment effects on iron ions.Under the optimal conditions,the average iron ion concentration of effluent water is 1.19 mg/L and 1.27 mg/L respectively,but there are no removal effects on TP,TN and COD.Sulfur particle filter column has a good removal effect on iron ions.When EBCT is 6 minutes,iron ions in effluent are lower than the detection limit?0.05 mg/L?and the concentration of TP is also lower than the detection limit.TN has a certain removal effect.The concentration of TN decreases by 3³.5 mg/L,and COD is basically not removed.On the basis of the intermittent trial experiment,the long-term continuous operation experiment was carried out.The results showed that in the first 60 days,the mean TP and COD in the water were 0.40 mg/L and 40.8 mg/L,and the mean effluent were 0.02 mg/L and 27.7 mg/L respectively.In the last 30 days,the mean effluent was 0.05 mg/L and 32.4 mg/L respectively.After regeneration,the activity of the regenerated fillers recovered,and the removal rate of TP and COD was similar to that of the new fillers.The concentration of iron ions in water and TP in sulfur particle filter column was lower than the detection limit.After the device was in stable operation for 2 weeks,TN removed 3⁴ mg/L.