Study On The Treatment Of Thallium Pollution Based On The Composite Adsorption Technology Of Fly Ash/Chitosan

Along with the development of our country economy and industrial,environmental pollution has become an important issue,the impact of water pollution on society is becoming more and more important.Due to the large destruction,long-term harm,the heavy metal pollution problem is also highly social attention from all walks of life.In the treatment of heavy metals,the method of adsorption is widely applied in wastewater treatment because of its low cost and simple operation.Taking the Hongnong Jian River in Lingbao City as an example.This paper investigated the main source of industrial pollution caused by heavy metal pollution TI in Hongnongjian River,sampling and testing the water quality of industrial enterprises'outlet water,sewage treatment plant's import and export water and the main monitoring water,so as to analysis and understand the status of thallium pollution in Hongnongjian River of Lingbao City.Aiming at its pollution status,the adsorption of TI in water was studied by using fly ash/chitosan?FACS?composite as adsorbent.In the experiment,FACS composite adsorbents were synthesized with fly ash and chitosan.Then the adsorbents were characterized by SEM,FTIR and XRD.The adsorption properties of FACS composite adsorbents on TI in water showed that:?1?The efflux in industrial wastewater of Gold smelting Co.Ltd,Kaiyuan mining Co.Ltd and Xinling lead industry Co.Ltd containing TI,the efflux of water quality monitoring results showed that the heavy metal content of TI exceeded the standard of surface water quality 0.0001mg/L,so as the sewage treatment plant import and export water quality.The heavy metal content of TI in the key monitoring section,Potou bridge section,the distance to the 500 meters and 3000 meters before entering the Yellow River,the reserve water,are different degrees of exceeding the standard in addition to the reserve water.?2?FACS composite adsorbents were synthesized from fly ash and chitosan.The results of SEM characterization showed that the surface of FACS particles had a large number of microporous structures,and the porosity was larger.After the adsorption reaction,the microporous structure would be filled and the porosity decreased.The characterization results of FTIR and XRD indicated that FACS contains a large number of O-H,C-H and Si-O covalent bonds.The adsorption materials mainly contain silicate compounds,which are related to the main chemical composition of fly ash.After adsorption of TI?I?wastewater with different systems,the main chemical bonds and chemical groups of the adsorbents will not change.?3?When the value of pH is low,with the increase of pH value,the adsorption effect of FACS composite adsorption material becomes worse.As close to neutral,the adsorption effect with the increase of pH value has gradually improved,the optimum adsorption at the condition that the value of pH was 8,the reaction time is 60min,the adsorption dose was 2g,with the maximum adsorption capacity the rotating speed is 225r/min;when Fe³⁺coexists with TI⁺alone,it has no effect on the adsorption of TI⁺,when Mn²⁺coexist with TI⁺alone,it was not good for the adsorption of TI⁺,however,as Fe³⁺,Mn²⁺coexist with TI⁺together,it was helpful to the adsorption of TI⁺with FACS.?4?The adsorption kinetics results showed that the pseudo-two level kinetic model was more suitable to the adsorption process fitting.The chemical reaction was the rate controlling step of adsorption;The adsorption isotherm fitting results showed that the fitting results of Langmuir isothermal and actual reaction equilibrium adsorption quantity had certain deviation,Freundlich isotherm was more suitable for fitting the isothermal adsorption process.It was indicated that the adsorption of FACS composite on TI belongs to the adsorption of multimolecular layer on the heterogeneous reaction surface?5?The adsorption and regeneration results showed that after adsorption,desorption,and adsorption process,FACS composites still have high adsorption capacity for TI.The material can be reused and it belongs to environment-friendly materials,which has good environmental and economic benefits.