Research On Removal Of Organic Chloride And Heavy Lead From Aqueous Solution By Nanoscale Zero Valent Iron

With the rapid development of social production,contamination of groundwater resources by a variety of factors municipal waste,industrial waste,agricultural production,mining and smelting.Our country was a severe drought and water shortage,groundwater accounts for around 31% of the total water resources in China,how do groundwater resources pollution remediation work has been widespread concern in society.Since the late 1990 s,nanoscale zero valent iron due to its reduction of underground pollutants such as PCBs,chlorinated solvents and heavy metals were being investigated for potential groundwater remediation.Nanoscale zero valent iron due to its high activity was displayed in the environment of great promise,and a large number of laboratory and field studies to evaluate its effectiveness.However,nanoscale zero valent iron were exposed in the air prone to spontaneous combustion,even if slowly in contact with air was also prone to oxidation,the surface oxide or hydroxide generated reduced reactivity,these problems were affecting the nanoscale zero valent iron in practice application.To solve the above problems,the present study in an environmentally friendly kaolin?Kaolin?,bentonite?Bentonite?,zeolite?Zeolite?,sodium carboxymethyl cellulose?CMC?,Agar?Agar?and starch?Starch?was prepared as a package agent Coated nanoscale zero valent iron materials and Berberis thunbergii leaves extract green synthetic nano zero valent iron,and by X-ray powder diffraction?XRD?,scanning electron microscopy?SEM?,transmission electron microscopy?TEM?,Fourier transform infrared spectrometer?FTIR?,etc.to the obtained samples were characterized;investigated its chloroform?trichloromethane,TCM?,carbon tetrachloride?Carbon tetrachloride,CTC?,and Pb2 +-TCM mixed wastewater removal capacity reduction.The main conclusions of the paper are:1.Kaolin,Bentonite and Zeolite as Environmentally friendly surface modification of materials,preparation of mineral inclusions nanoscale zero valent iron.Mineral Coated nanoscale zero valent iron removing chloroform?TCM?batch experimental results show that: the main factors affecting TCM removal of mineral inclusions nano zero valent iron dosage,initial concentration and pH value of TCM.Lower initial concentration,the amount of large mineral inclusions nano zero valent iron facilitate removal of TCM.In the simulation TCM concentration of 10mg/L,the dosage of Kaolin-nZVI,Bentonite-n ZVI and Zeolite-nZVI was 1.5g/L,pH 5,reaction 2h,TCM dechlorination rates were 73.1 %,70.9% and 74.4%,the dechlorination better.2.Budget environmental Agar,CMC and Starch was a surface modifier,preparation Coated nanoscale zero valent iron.Coated nanoscale zero valent iron removing chloroform?TCM?column experimental results showed that: the main factors affect the TCM removal has Agar-nZVI,CMC-nZVI,dosage of Starch-n ZVI,TCM and initial concentration of the water flow.In the case of sufficient dosage,TCM wastewater removal efficiency without effect concentration.TCM simulated wastewater concentration of 0.1mg/L,Agar-nZVI,CMC-nZVI,Starch-nZVI,n ZVI dosage of 0.04g/L,flow rate of 5m L/min,near the outlet of the sampling port removal reaction 1h preferably,the removal rates were 99.21%,98.13% and 97.6%.Coated nanoscale zero valent iron degradation TCM system in line with the quasi first-order kinetics,reaction rate increases with the increase of initial concentration TCM greatly reduced margin,with dosage package nano zero valent iron increases increased to a lesser extent.3.The main factors CMC wrapped nanoscale zero valent iron degradation chloroform?TCM?and lead the orthogonal experiment were: CMC package nano zero valent iron dosage,the initial concentration of TCM and lead,reaction time and initial pH value.The results show that: the higher the dosage of CMC package nanoscale zero valent iron and lower initial concentration of lead in favor of TCM and degradation reduction effect;in TCM concentration of 0.4mg/L,concentration of Pb²⁺ 40mg/L,pH 5.0,CMC-nZVI dosage was 1 mg/L,reaction 3h,the removal rate was higher,removal rates of TCM and Pb²⁺ were 96.5% and 92.0%,the total removal rate was 94.3%.4.Berberis thunbergii leaves extract of green synthesis have,TCM initial concentration,pH and initial pH.The results showed that purple leaf barberry leaves extract was prepared nanoscale zero valent iron has better dispersion,the average particle diameter of about 20-50 nm.Green Synthesis of nanoscale zero valent iron in water CTC has better removal.Effect of green synthesis of nanoscale zero valent iron removal factors affecting CTC CTC has an initial concentration,pH,and the dosage of green synthetic nanoscale zero valent iron.When CTC initial concentration of 4mg / L,pH 6.0,green synthesis of nanoscale zero valent iron dosage of 0.14 g / L,reaction 90 min,the removal efficiency was better,CTC removal rate was 99.8%.