Application Of Combination Of Pfs-em Process Algae Eutrophication Source Water

This study integrates inorganic PFS and effective EM into a compound technology. It takes advantage of mutual effect to removal pollutant from algal eutrophic water. Through selecting the optimal operational conditions of PFS and investigating treatment effect of EM with different condition, then a relative perfect compound process confirmed, and operate it with a relative long period. Experimental results demonstrate as below:(1) PFS process stage: With these operational conditions: dosage of PFS 30mg/L, the mixing speed 105r/min at the first minute, then slow the speed with 50r/min for 15 minutes, and finally placed it for 20 minutes, the T-P and CODcr removal efficiency in effluent appear at 77.5% and 74.66 respectively.(2) EM process stage: When the eutrophic water is used as influent at temperature 25 癈, HRT/2, neutral pH value and EM casting proportion(VEM/Vsewage) 5/10000, EM has good effect on removing algae, and the Chl-a removal efficiency in effluent is up to 90%. This experiment also shows that if aeration time is too long, the T-P and Chl-a removal efficiency in effluent will decrease. At the same time, when dosage of EM is too much, for example more than 1/1000 of ratio of EM to waste water, then EM is useless to removal CODcr. The possible reason is EM itself has high CODcr.(3)Assembled process stage:The optimal conditions of assembled process: PFS 30mg/L, EM casting proportion(VEM/Vsewage) 5/10000, aeration time two HRT/2, water temperature 25 癈, neutral pH value, the Chl-a, T-P, CODcr, TN removal efficiency in effluent is 93%, 89%, 85%, 60% respectively. These removal rates are higher than PFS or EM process individual apparently. The effluent water meets or near to national III class surface water standard.The study attempts to integrate mature flocculation precipitation process with a prospect technology of EM into assembled process. Due to PFS and EM can dispose different pollutant, this assembled process takes advantage of mutual effect to treat eutorphic water, it can get sound results. The research methods and relative elementary results will promote the progress of the same research.