Study On The Treatment Of Typical Pesticide Wastewater By Resin And Sodium Hypochlorite-struvite Precipitation Ion Exchange

Large amount of wastewater was produced from pesticide factory,the pollution concentration and component is complex and difficult to be degraded.Treatment technology of chemical and biological combination was used by most pesticide factory,but the treatment effect is not ideal.Aiming at the practical problem,Three chlorine and glyphosate was chosed for the processing object,using ion exchange resin method and sodium hypochlorite oxidation-struvite precipitation on the processing,to discuss relevant issues,to achieve the implementation of effective treatment and recycling of phosphorus resources.The productive process of thiophosphoryl chloride which was an important pesticide intermediate may produce high concentration and strong acid wastewater of Al³⁺and phosphate.This study focused on the above problems.001×7 strong acidic styrene cation exchange resin were used to investigate the dynamic adsorption exchange behavior of Al³⁺under various conditions involving pH levels,time intervals and resin dosage.Resin regeneration was mainly influence by HCl concentration and desorption time.SEM was used to observe morphology of virgin resin and the used one.Results showed that the resin had good adsorption performance for Al³⁺,the Al³⁺removal could be reached 98.77%.The Al deposition was observed on the surface of used resin by SEM.Regeneration rate reached 90.43%after 40.0 min of desorption with 17.50%HCl.Using cation exchange resin may be one of the effective means to achieve the separation of Al³⁺.It was found that the resin had good adsorption performance for Al³⁺,and the Thomas model could be used to simulate the adsorption process of Al³⁺effectively.And combined with the results of SEM/EDS characterization,it is speculated that the resin surface may be generated AlPO₄ and then lead to a certain degree of Al³⁺adsorption effect.The presence of phosphate promoted the exchange of Al³⁺.The HCl solution could be used as regenerator achieving a 98.3%of regeneration rate.It was feasible to separate and recover of Al³⁺and phosphate from strong acid wastewater by using cation exchange resin as scavenger.At last,this study focused on this problem and recycled phosphorus by using magnesium ammonium phosphate precipitation method after oxidation of glyphosate mother liquor wastewater with sodium hypochlorite.The effect of sodium hypochlorite dosage,pH and oxidation time on glyphosate-oxidation process was studied.The degradation pathways of glyphosate was analyzed by GC-MS and the orthogonal experiment method was used to optimize the precipitation process of magnesium ammonium phosphate.XRD analysis showed that the struvite purity was more than 80%.To the oxidized glyphosate solution,the results of orthogonal experiment showed that PO₄^3-P removal efficiency could be 99.34%.