Preparation Of Nanometer Zero-valent Iron Supported By Kaolin And Removal Of Heavy Metal Ions

With the development of China's industry,environmental pollution has become an important factor threatening human society,among which the risk of heavy metal pollution is particularly prominent.Nanometer zero-valent iron has large specific surface area and strong reducibility,and has been widely studied and applied in the treatment of heavy metals in water and soil.However,nanometer zero-valent iron has high reactivity,easy agglomeration and oxidation,which is easily restricted in practical application.In order to improve the reaction performance of nanometer zero-valent iron,based on the liquid phase synthesis method of kaolin load reduction iron nanoparticles(K-n ZVI)and graphene/kaolin load nanometer iron oxide(GO-K-n ZVI),in different time,temperature,p H value,the concentration of heavy metal ions,and other environment study load type nanometer iron removal efficiency of heavy metal copper and lead ions.The experimental results are as follows:(1)under the same experiment conditions,adsorption dose of 1 g/L of kaolin nano zero-valent iron and kaolin clay to remove 1 g/L of 100mg/L of copper ions,the adsorption dose the same kaolin nano iron in copper ion removal effect is much better than that of kaolin,this isbecause the kaolin as the load increases nano electron transfer between iron and copper ion,improve the ability of iron reduction of copper ion.(2)40%K-n ZVI had the best removal effect on lead ions.After 24 hours of reaction,the removal rate was 93%,higher than that of30%K-n ZVI(78%).When the concentration of lead ions increased from50mg/L to 350mg/L,the removal rate of lead ions in the solution by 40%k-nzvi decreased from 100% to 33%.(3)In various experimental environments,6000 mesh K-n ZVI had the highest removal rate of lead ions in the solution,followed by 325 mesh K-n ZVI and 6000 mesh kaolin,while 325 mesh kaolin had the lowest removal rate of lead ions in the solution.The removal effect of K-n ZVI on lead ions in the solution is better than that of kaolin,and the greater mesh count of kaolin,the better the removal effect.(4)after 24 hours of reaction between two synthetic materials supported by kaolin,GO-K-n ZVI had the highest lead ion removal rate(99%),which was higher than that of K-n ZVI(91%).