Research On The Application Of Residue Soil Phosphorus Removal Composite In Urban Sewage Deep Treatment

Phosphorus is an important limiting factor affecting water productivity and causing water eutrophication.It is an important research direction in the field of water treatment to develop economical,efficient and widely applicable phosphorus removal materials.This paper takes this as the starting point,and on the basis of the research group's previous research,mixes the modified clay with two kinds of industrial waste residue(steel slag and fly ash)as adsorption substrate,with binder and the pore-foaming agent to make the Residue & Soil Phosphorus Removal Composite(RSPRC).Through the study on the properties of the residue composite phosphorus removal materials and the design of the concentric circular diversion wall adsorption reactor,the phosphorus concentration of sewage after deep treatment is stable to lower than 0.20 mg/L,meet the national Environmental Quality Standards for Surface Water(GB 3838-2002)of the total phosphorus concentrations of water requirement for ? class surface water.This project mainly includes the design of the concentric flow diversion wall adsorption reactor,the study of the phosphorus removal characteristics of self-made RSPRC particles,the static phosphorus removal effect of the reactor and the dynamic phosphorus removal effect of the reactor.Fixed-bed reactor is adopted in this study,which has the advantages of easy operation,continuous effect,stable effluent and huge water treatment amount.The basic structure of the reactor is a combination of concentric circles and guid walls,which allows sewage to pass through the reactor along the specified route,effectively extending its residence time in the reactor.The application of extraction grids makes the filling format of adsorbent more flexible and can achieve the multi-stage series adsorption effect in a single reactor.The self-made RSPRC particles have good phosphorus removal properties.With the study on the effect of static adsorption on phosphorus removal in adsorption reactor,it is found that when the adsorbent equally spaced evenly distributed between the adjacent diversion walls,the smaller the spacing,the larger the adsorption unit of adsorbent,and the lower phosphorus concentration in the effluent of reactor.When the hydraulic residence time is fixed,the higher the initial phosphorus concentration,the greater influence of adsorbent amount on the adsorption efficiency and effluent phosphorus concentration.When the initial phosphorus concentration is the same value,the phosphorus removal rate of unit mass adsorbent increases obviously with the increase of hydraulic residence time.When the hydraulic residence time is very long,the effect of fixed total amount on phosphorus removal in the adsorption reactor is small,which can be negligible.When the adsorption reactor was in the dynamic adsorption state,the effluent phosphorus concentration basically met the target concentration set by the subject.When the adsorbent was evenly distributed between the diversion walls at an interval of 10 cm,the effluent phosphorus concentration was 0.18 mg/L,and the phosphorus removal rate was up to 64%;When the hydraulic residence time is fixed for 3h,when the initial phosphorus concentration of sewage is 0.3mg /L,0.4mg /L and 0.5mg /L respectively,the corresponding phosphorus concentration of effluent is 0.192 mg /L,0.190 mg /L and 0.196 mg /L when the fixed total amount of adsorbent is 4kg,8kg and 12 kg respectively;When the fixed total amount of adsorbent is 8 kg and the hydraulic residence time is set as 3h,the effective service life of the adsorbent in the concentric circular-guide wall adsorption reactor is 112h;When the continuous adsorption reaction was greater than 112 h,the phosphorus removal effect of the reactor significantly decreased,and could not meet the effluent phosphorus concentration standard(< 0.20 mg /L).