Experimental Study On Repairing Eutrophic Water By Combined Of Phoslock And Immobilized Aerobic Denitrifying Bacteria

With the rapid development of industrial and agricultural production and the improvement of people's living standards,a large number of N and P nutrients are enriched in water bodies,and the phenomenon of eutrophication of water bodies is becoming more and more serious.Therefore,it is urgent to develop efficient and economical water body repair technology.In this paper,Phoslock and the domesticated heterotrophic nitrification-aerobic denitrifying bacteria AL-2 were used as raw materials,immobilizing the strain AL-2 by biofilm method,combined with Phoslock and biofilm immobilized aerobic denitrifying bacteria to construct a membrane immobilization reaction system.The phosphorus-controlling efficiency of the Phoslock and the nitrogen-removing performance of the strain AL-2 were mainly investigated,and the treatment effect and feasibility of the in-situ remediation technology were discussed by using the river channel simulation type batch reactor.This paper aims to provide a theoretical basis for the application of this in-situ repair technology in water restoration engineering.The main research contents and conclusions of this paper are as follows:1.Using Phoslock?Phoslock,Lanthanum Modified Bentonite?as raw material to study the enhanced phosphorus-controlling ability of Phoslock.The research found that under the optimal dosage ratio of 80:1?phoslock content:phosphorus content?,its stable phosphorus control efficiency is above 95%.The Phoslock is stable and efficient,and it is effective for simulation.The average removal rate of PO₄^3-in vegetative water was 93.6%,and it could inhibit the release of phosphorus from sediment.2.Screening of domesticated aerobic denitrifying bacteria AL-2 is Pseudomonas sp.Heterotrophic nitrification-aerobic denitrification performance can simultaneously remove ammonia nitrogen and nitrate nitrogen in water.Under the condition of mixed nitrogen source,the removal rates of NH₄⁺,NO₃^--and TN were 98.04%,99.06%and 58.89%,respectively,without NO₂^-accumulation.The optimum C/N=10 for this strain was the optimum temperature.30°C.3.The strain AL-2 was fixed by a biofilm method to form a membrane immobilization reaction device to treat simulated waste water.In the three-round continuous reaction experiment of the membrane immobilization reaction device,the average removal rates of COD_Cr,NO₃^--,NH₄⁺,and TN were 76%,100%,70%,and 73%,respectively.The denitrification performance and recycle ability of the reaction apparatus are high.4.The Phoslock is combined with the membrane immobilization reaction device to repair the simulated eutrophic water body.The in-situ treatment method was used to repair the simulated eutrophic water,and the treatment effect was good.After continuous reaction,the removal rates of NH₄⁺,TN,TP and COD_Crr were 93.7%,90.73%,89.6%and81.59%,respectively.Reach the surface water V water quality,NH₄⁺,TP meet the IV standard,and can effectively and stably inhibit the release of phosphorus in the sediment.