| In today’s highly developed society,the demand for water resources is increasing,but the total amount of water is limited.The advanced treatment and recycling of sewage is currently an effective means to alleviate the shortage of water resources.At present,most of my country’s urban sewage treatment plants adopt the activated sludge method,and the quality of the secondary effluent is basically stable,which can meet my country’s urban sewage discharge standards.However,after treatment,the effluent still contains difficult-to-degrade organic matter,microorganisms,phosphorus and nitrogen and other pollutants,which still have certain hazards to surface water bodies,and it is difficult to directly reuse them.The purpose of the advanced treatment of the secondary effluent of the city is to further deepen the treatment of pollutants in the effluent of the conventional process.Magnetic flocculation is an enhanced coagulation method.Compared with the current conventional coagulation technology,it has better sedimentation efficiency,small footprint,flexible and convenient,can quickly separate solid-liquid by magnetic adsorption,and has strong impact load resistance.And the added magnetic seeds can be regenerated by washing with water,with good recovery rate and regeneration rate,and can be used to replace the coagulant in the advanced treatment of sewage.However,this technology cannot effectively remove the soluble pollutants in the water,so it is often necessary to couple with other processes to jointly carry out advanced treatment of sewage.(1)This article explores the effect of strengthening the treatment of magnetic flocculation effluent by potassium ferrate pre-oxidation.By changing the dosage of potassium ferrate and the pre-oxidation time,the TOC,TP,relative molecular weight,three-dimensional fluorescence and trace pollutants of the effluent are used as reference indicators to explore the best dosage and pre-oxidation time of potassium ferrate.Experiments show that potassium ferrate can play a certain role in oxidation.When the dosage of potassium ferrate is 20mg/L and the pre-oxidation time is 10 min,the TOC removal rate is basically stable at 16.21%-18.37%.After treatment,the total phosphorus was reduced from 0.59mg/L of raw water to 0.173mg/L,and the removal rate was 70.3%.At this time,the removal rates of trace pollutants NPX,ATL and GFZ in the water body are 40.4%,37.9% and 30.5%,respectively,which are significantly improved compared to the removal effect of magnetic flocculation alone.And through the analysis of the intensity change of the three-dimensional fluorescence region,it is shown that with the addition of potassium ferrate,the main reactions are the microbial metabolites,humic acid and fulvic acid in the effluent.(2)This article explores the effect of magnetic and MIL-53(Fe)on carbon nanotubes as the base material to adsorb the effluent after magnetic flocculation.By fitting adsorption kinetics and adsorption isotherms,using UV254 as a reference standard,we explored the adsorption behavior characteristics of two different loaded MWCNTs.The experimental results show that the quasi-second-order kinetic model and the Freundlich model can better fit the adsorption behavior of the two loaded MWCNTs,indicating that the adsorption of the two materials to the organic matter in the water is chemical adsorption and multi-layer adsorption.And explore and compare the adsorption effects of two different loaded MWCNTs on COD,TP,three-dimensional fluorescence and trace pollutants.Experimental results show that loading MIL-53(Fe)is more conducive to the removal of COD and TP than loading magnetism.And through the analysis of the three-dimensional fluorescence,it is found that MIL-53(Fe)and magnetic load have the same good adsorption effect on fulvic acid substances,but for humic acid humus,microbial metabolites and tryptophan protein The removal of MIL-53(Fe)shows better results,and the removal rate reaches 73.84%,40.11% and 42.17% respectively at the dosage of 250mg/L。... |
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