Preparation And Properties Of The Multi Functional Clay-based Water Purifying Agent

At present, water pollution is a serious problem for many developing countries. Waste water treatment technique is highly valued by Chinese government, which reinforce sustainable economic development policy. The study of wastewater is focus on to find an abundant, cheap and excellent water treatment agent. The palygorskite, has the advantages of abundant reserves, low prices and strong adsorption, attracted extensive attention. So, in this study, the palygorskite was modificated and applied to waste water.The thesis consist of four chapters as follows:Chapter 1:Reviews of treatment technique for waste water.The components of waste water including organic pollutants, toxic pollutants, radioactive contaminants, and oil contaminants. waste water can be divided into three types: industrial waste water, agricultural wastewater and urban wastewater. Among many waste water, the industrial waste water has wide range of pollution and great harm, which is difficult to prevention. the treatment methods of industrial waste water is chemical, physical, biological method, and so on. Palygorskite clay has a special structure, and the study of waste water treatment has made some achievements. Chapter 2: The structure and properties of palygorskite.The palygorskite structure and properties were characterized by TG, SEM, TEM, IR, Zeta size and potential, nitrogen adsorption and desorption. And the adsorption of lead ions and adsorption behavior of palygorskite are also studied. Palygorskite has many porous, the pore volume, specific surface area and Zeta potential are 0.243 cm3/g ,143 m2/g and 23 mV, respectively. The calcination and acid treatment can increase the surface area and adsorption of palygorskite. The optimum conditions is calcination temperature selection 400℃and acid concentration 2 mol/L. The adsorption isotherm of Palygorskite on lead ion is in accordance with the Langmuir isotherm and the Freundlich isotherm, but, the Langmuir isotherm is better. The maximum adsorption of lead ions on acidified palygorskite reach to 166.7mg/g. Chapter 3:The preparation and properties of palygorskite adsorbent.Palygorskite adsorbent was prepared by surface graft polymerization and characterized by the thermogravimetry, electron microscopy and elemental analysis. Hydrolysis polymerization rate of silane coupling depends on the reaction temperature and pH vaue. The best preparation conditions is: temperature of 80℃, and pH = 3. Palygorskite sorbents, has a strong adsorptive power and deodorizing ability, also has some of oil absorption capacity for industrial waste water and fuchsin solution. Chapter 4: The preparation and properties of palygorskite, acrylic acid and maleic anhydride copolymer adsorbent.The palygorskite copolymer adsorbent was prepared and characterized with IR, and SEM. We studied adsorption behavior of our adsorbent on aniline. The results show that our adsorbent has a good adsorption of aniline, consistent with physical adsorption, with Freundlich adsorption isotherm and two dynamic processes.In short, the modified palygorskite has a strong adsorption capacity for heavy metals, oils, organic matter when used for waste water. Modified palygorskite has the advantages of environmentally friendly and low-priced, for that reason, it has wide range of uses in waste water treatment.