Study On The Non-living Biomass For Adsorption Of Cu²⁺ From Aqueous Solutions

At present, China is confronted with the problem of water shortage as well as the problem of water pollution. Heavy metal is a kind of harmful substance leading to water pollution. Therefore, the treatment for wastewater containing heavy metals is becoming the focus of attention in society. The biosorption method has attracted much attention because of its high adsorption capacity, no secondary pollution, and good adsorption performance. Agricultural and forestry waste enjoys a broad space for development and has huge market potential, for it derives from a wealth of sources, it is cheap and it is easy to get. Many domestic and international studies show that a lot of agricultural and forestry waste, such as barley shin, rice hull, peanut shell, bagasse, Betelnut slag, loofah, sawdust, cotton, bark etc. can be directly utilized as adsorbent to control wastewater containing heavy metals. As for developing countries like China, it is great importance to do research on new low-cost absorbent.Based on researches both at home and abroad, this thesis selects walnut shells, rice husk, corn cobs, and tea seed shells as the raw material to make walnut shell adsorbent, rice husk adsorbent, acid-modified corn cob adsorbent, alkali-modified corn cob adsorbent and carbide-modified tea seed shells adsorbent. To each adsorbents, the characterization were performance analysis, the effcet of single factor were researched, and the adsorption process kinetics and thermodynamic models were fitted.The performance characterization study shows that, each adsorbent has pores or fibrous structures such beneficial adsorption, and also have all kinds of chemical groups.The experimental results show that the four above mentioned adsorbents are of high adsorption capacities for low concentration Cu2+and the adsorption effect of carbide-modified tea seed shells adsorbent is the best which reaches95.7%Adsorption equilibrium generally able in a short time (120min) to reach. The pH has a significant influence on the adsorption process. Weak acid environment will benefit adsorption, generally preferably4to6. The temperature and the amount of adsorbent have little impact on the adsorption process. Under the condition of normal temperature(25℃), little dose of adsorbent(lg) is enough for the adsorption process.Get the adsorption fitted with the kinetics and thermodynamics model, the results show that these five adsorbent results were associated with quasi-two kinetic model and Langmuir isotherm models have a higher degree of fit, the R2more than0.9. It is shows that the adsorption process for the adsorption isotherm, and the adsorption rate is controlled by chemical adsorption mechanism.In this study, green materials, clean production as guidance for the development of low-cost, high-efficiency, environmentally friendly wastewater treatment methods were explored, with a wastewater treatment practical value.