Research On Preparation And Adsorption Of Lead,Copper By Manganese Dioxide/ Ferroferric Oxide Adsorbent

At present the pollution of heavy metals in water cause a serious threat to environmental and public health, and among these toxic heavy metals lead as well as copper are attracting wide attention of envitonmentalists. Lead release into the environment through existing widely in the industrial effluents such as those of battery manufacturing, ammunition, ceramic and other industries areas. Because of its stable property, it is non-biodegradable and accumulates readily in living systems which causes great negative effect on the toppist reaches of the food chain-humanbeing. Lead poisoning in human causes severe damage to the nervous system, reproductive system, kidney, liver and brain. Meanwhile Copper is another widely used heavy metal in many industries, such as electroplating, metal finishing, fertilizer and pigment industries. The rapid development of those industries also cause accumulation of copper in the environment. And if the level of copper is beyond the tolerance limit, it will cause serious environmental and public health problems.The wide attention to toxic heavy metals leads to the development of various treatment methods, among which adsorption is considered quite prospective in terms of its efficiency of heavy metal removal, economics and handling. A number of adsorbents such as activated carbon, iron oxides, molecular sieve have been exploredIn this study, Mn dioxide/ ferroferric oxide adsorbent were prepared to remove Pb²⁺, Cu²⁺ from solution. The result of surface area through the BET detection can explain why this adsorbents has a great characterization for adsorption. Combine the results of SEM images and XRD patterns, which reveals that the Mn dioxide is an amorphous phase and the ferroferric oxide is crystalline. The the influence of contact time, pH, ions concentration to the adsorption was analyzed. From the Langmuir isotherms(25℃) the maximum adsorption capacity(Q0) of the sorbents towards Pb²⁺, Cu²⁺ was determined(Q0=118.06mg/L and 43.84mg/L). The Pb²⁺, Cu²⁺ removal capacity of the sorbents increased with the increase of pH(1-6),temperature(30℃-50℃). Based on the adsorption equilibrium, contact time was determined and the kinetic adsorption can be described by the pseudo-first-order rate equation and the pseudo-second-order rate equation which reveals that the pseudo-second-order rate equation was much more fitted. Compared with different temperature the thermodynamics of Pb²⁺, Cu²⁺ was studied. Based on the thermodynamic parameters the results confirmed that the adsorption was endothermic reaction and the Pb²⁺, Cu²⁺ adsorption is mainly chemical effect. According to Point of zero charge value and FTIR analysis indicate that heavy metal removal by the adsorbent is an ion-exchange process.