Enhanced Removal Of Sulfadimidine And Cr(?)with Ball Milled Natural Pyrite

With the rapid development of economy,the environmental pollution comes along and is getting worse day by day.Water pollution is becoming more and more serious.Organic pollution such as pesticides and antibiotics,as well as heavy metal pollution are extremely urgent to resolve.People are constantly looking for green,economic and environmental friendly water environment treatment methods and technologies.Although traditional water pollution treatment methods can help improve the water environment to a certain extent,there are also problems such as low treatment efficiency,high energy consumption and high cost.Recent years,the application of natural minerals in Fenton oxidation technology and as reducing agent or adsorbent to treat heavy metal has attracted more and more attention.However,most of minerals have disadvantages of poor treatment effect and slow rate.This paper is devoted to the natural minerals treated by ball milling and its application in Fenton oxidation technology and the removal of heavy metal chromium in the environment as a reducing agent and adsorbent.First,natural pyrite(mainly containing FeS2)was treated by mechanical ball milling.Ball milled pyrite is applied to Fenton degrading sulfamethazine.After 30 minutes,ball milled pyrite could completely remove Sulfamethazine in solution,while only 20%Sulfamethazine could be removed from pyrite.In order to figure the reason and mechanism,we designed experiments and discussed the reason why the properties of ball milled natural pyrite improved.We know the decrease of particle size,the increase of specific surface area,the increase of surface ferrous and sulfur vacancy that improve the degradation of sulfamethazine.The results show that the sulfur vacancies can decompose hydrogen peroxide and water to hydroxyl radicals.The hydroxyl radicals are not affected by pH,can still be produced under strong alkaline conditions.The capture experiments and electron spin resonance techniques show that the main active oxygen species in the system are hydroxyl radicals.Finally,we propose the mechanism that ball milled natural pyrite decompose hydrogen peroxide to degrade sulfamethazine.Then,it was found that the reduction performance of ball milled natural pyrite(mainly containing FeS2)was significantly improved,99%hexavalent chromium in water could be removed after 6 minutes.Through design experiments and characterization,it is concluded that the main reasons for the remarkable improvement of the removal efficiency of hexavalent chromium from ball milled natural pyrite are the increase of the specific surface area,the enhancement of iron dissolution ability,the enhancement of hydrophilicity and the acceleration of surface electron transport rate.In order to prove that ball milled pyrite has good application value in industrial chromium removal,we compared the removal of chromium(VI)from water and soil by ball milled pyrite and industrial ferrous sulfate.The results show that ball milled pyrite show stronger total chromium fixation ability at the removal of chromium(VI)from water and soil,which confirms the possibility of ball milled pyrite in industrial chromium removal.This paper explains the reasons why ball milled natural pyrite can improve Fenton removal organic pollutants and why ball milled natural pyrite can significantly removal chromium(VI),which provides theoretical support for the application of natural mineral materials in environmental remediation.