Application Of Ecological Floating Bed Technology In Tailing Water Treatment From Wastewater Treatment Plant In Chemical Industry Park

After a series of physicochemical and biochemical treatment,the chemical wastewater is discharged into the receiving water body.At this time,the concentration of pollutants in the tail water reaches the national standard for chemical wastewater discharge,but these pollutants will still have a certain impact on the ecological environment of the water body.The residual organic matter and nitrogen phosphates in the chemical tail water will make the receiving water body eutrophic.In this paper,based on the traditional ecological floating bed,according to the requirements of advanced treatment of chemical tail water,a new type of combined ecological floating bed was designed and constructed,and a sample device was made for pilot study,in order to provide a reference for the advanced treatment of chemical tail water by ecological floating bed technology.The main conclusions are as follows:（1）The ecological floating bed with the synergetic purification mechanism of the four effect of substrate adsorption,plant absorption,biofilm metabolism,and aeration oxidation was constructed from four aspects of filler enhancement,plant optimization,microorganism enhancement and aeration enhancement.Additionally,the staggered partition was added in the floating bed frame to improve the treatment effect of the ecological floating bed for tail water.（2）The composite ceramsite with bentonite and activated carbon was prepared to be used as the floating bed filler.It was found that the best performance of the composite ceramsite was obtained when the mass ratio of bentonite to activated carbon was 7:3,the amount of pore forming agent and binder were 15%and 10%of the total mass of carbon soil respectively.Moreover,the cylindrical particles with a cross-section diameter of 8 mm and a length of 8 mm were prepared and calcined at 550℃for 1h.The compressive strength and porosity of the composite ceramsite were 73.2 N and 59.18%respectively,and the specific surface area could reach 68.3 m²/g.（3）In order to improve the treatment efficiency of chemical tail water by the ecological floating bed,activated sludge from wastewater treatment plant of Chemical Industrial Park was selected.The biofilm was formed after cultivation and acclimation.The composite ceramsite filler was used as biofilm carrier,and the biofilm amount could reach 0.0364 g/g.By comparing the decontamination effect of two pre selected plants,it was found that iris sibirica had better decontamination effect.（4）The results showed that the removal rates of COD_Cr,NH₃-N,TN and TP could reach 31%,36.5%,43%and 27%under the condition of a hydraulic retention time of 15 minutes,respectively.After a long period of operation,the plants of the floating bed grew well,the composite ceramsite did not collapse and wear.In addition,it presented that the biofilm on ceramsite surface grew well.