The Study Of Doped Coke And Iron Oxide Material For The Ecological Environmental Heavy Metal Polluted Water

The pollution of heavy metals has become one of the most considerable problems of water pollution, such as As Hg Pb and Cr elements, these elements are cause by water emissions including residential water emissions, in particular, the result of illegal discharges of a number of industrial enterprises regardless of national policy,such reports frequently reported on TV and newspaper,but such emissions has never been effectively curbed, which have caused serious pollution to the environment and ecosystem,and have caused direct impact on human and ecological health of animal and plant. Activated carbon and iron oxide adsorbent materials are classic materials, have the advantages of wide range of sources of raw materials, low cost, easy to use. Today, There are many reported applications of activated carbon and iron oxide materials to separation, adsorption of heavy metals. However, there are problems of directly using of these materials for heavy metals in polluted wastewater treatment,such as small adsorption capacity, fix difficult and hard to deal with fluidization process.Based on those problems,considering nanomaterials its superior physical and chemical properties have been applied to fields as catalysis, separation, optoelectronics and so on, This paper selected coke and iron oxide materials as the matrix for their good ability of adsorption of heavy metals in wastewater,. used the modified technology with La and Ce, we hope to get better performance separation and enrichment of heavy metals adsorption materials. The main contents and results are as follows:1. The results of rare earth doped coke adsorption of copper, lead, zinc, chromium, cadmium show:The Efficiency of Cerium modified coke increased by average of about30%comparing with the unmodified material.The adsorption of rare earth elements lanthanum-doped coke of trace metal ions Cu Pb Cr Cd show the lanthanum modified coke is better than the unmodified coke’s adsorption efficiency,which increased average about40%. Calculated in terms of100mg/L as the concentration of metal ions in waste water by the experimental results, to removal of these elments in one ton of water need lanthanum modified coke10kilogram,so which means that modified coke can be used to treat heavy metal contaminated water is feasible, and can used as a supplement and improvement to method of traditional methods. Experiments of coexistence of multi-element show that there is a certain degree of competitive adsorption relationship between each element. Sum up, the results of rare earth doped coke adsorption of copper, lead, zinc, chromium, cadmium show:rare earth elements lanthanum, cerium doped coke adsorption of trace amounts of copper, lead, zinc, chromium, cadmium has greatly inproved than the undoped coke, while to some elements,the adsorption improved significantly.2. Preparation of lanthanum, Cerium doped nano-iron oxide and the reaserch on adsorption of trace amounts of arsenic, mercury proved:analyse results of IR,SEM,XRD,BET and so on show that rare earth elements lanthanum,cerium are doped into iron oxide matrix successfully.Compare with undoped iron oxide,the modified nano iron oxide adsorption of mercury has been greatly improved. The adsorption of trace amounts of arsenic, mercury in simulated wastewater of nano iron oxide doped with rare earth elements lanthanum, cerium is accord with pseudo-second-order rate equation and the theoretical maximum amount of adsorption of arsenic of Cerium, lanthanum doped and undoped nano-iron oxide is28.33,28.49,22.22mg/g respectively, and the pseudo-second-order rate equation rates constant gained. Standard molar enthalpy change of reaction(ΔrHmθ) of unmodified nano iron oxide adsorption of arsenic, mercury is10.20,7.53kJ/mol respectively; Standard molar enthalpy change of reaction(ΔrHmθ) of cerium-modified nano iron oxide adsorption of arsenic, mercury is16.74,11.60kJ/mol; while Standard molar enthalpy change of reaction(ΔrHmθ) of lanthanum-modified nano iron oxide adsorption of arsenic, mercury is11.36,10.17kJ/mol respectively. Thus between20and50℃, the adsorption of arsenic, mercury of three nano-iron oxide is endothermic reaction.3. Preparation of lanthanum, Cerium doped nano-iron oxide and the reaserch on adsorption of trace amounts of lead, chromium showed that the capacity of La-doped iron oxide adsorption of lead ions enhanced significantly, better than the adsorption capacity of the modified coke. Rare earth modified iron oxide adsorption of chromium ions enhanced significantly, then Ce-doped iron oxide adsorption capacity for lead is the best, but less than the La-doped coke adsorption of chromiu. At temperature of25℃,the kinetics of the various iron oxide adsorption of lead ions in aqueous solution are found to follow the pseudo-second-order rate equations, and can reach equilibrium quickly. At temperature of25℃,the kinetics of the various iron oxide adsorption of chromium ions in aqueous solution are found to accord with follow the pseudo-second-order rate equations, and can reach equilibrium quickly.In summary, In this study, a new type of doped material has prepared with the advantages of cheap raw material, operation simple, low cost, easy preparation amplification, etc. Modified coke and iron oxide materials adsorption performance on several important heavy metal ion has improved significantly, and the adsorption process is fast. It provide a valuable reference for efficient adsorbent material preparation, and provide a choice of new materials and meaningful reference data for treatment on many important heavy metals incontaminated wastewater.