The Removal Of Taste And Odor Substances In Water By Attapulgite Adsorption And Enhanced Coagulation

Along with the enlargement of citizen population and development of industry, all kinds of pollutants and chemicals was abandoned recklessly into rivers and lakes, lead most of produced water have eutrophication problems, dring water was polluted. Also lead blooming algae breed largely and ralease some secondary metabolin with smelling disgusting,cause taste and odor problem in water. Traditional drinking water treatment can not quite effctively solve the taste and odor prolem of drinking water. So it is very important to explore new advanced drinking water treatment for resolving taste and ordo problem.Attapulgite is the natural mineral material, its origin is very widespread, for its low costs and great performance in the adsorption of many pollutants, attapulgite abound in Soochow of our country. Attapulgite is widely used in water treatment industry. This thesis is based on the analysis of surface physical and chemical properties of attapulgite, to study the adsorption efficiency for the typical taste and odor substances of 2-MIB and GSM in purify water.Firstly, make 2-MIB and GSM as a representative of the typical taste and odor substances in water, the effect of pH,temperature, hunting speed and competition adsorption on 2-MIB and GSM adsorption onto attapulgite was studied, eventually to identify the optimum conditions of 2-MIB and GSM adsorption on attapulgite in water.Sencondly, make GSM as a representative of the typical taste and odor substances in water, the adsorption kinetics and isotherms of GSM was conducted in water with attapulgite, and using three common adsorption isotherm model to fit the adsorption thermodynamics experiment data, and using pseudo-first-order,pseudo-second-order,pseudo-third- order kinetics model to fit the experiment data, to selecte the optimum mathematical models for the experiment data.Finally, on the basis of adsorption experiment, to research the removal efficiency of attapulgite enhanced coagulation experiment about 2-MIB and GSM in raw water. At the same time, the removal efficiency of 2-MIB and GSM in raw water with potassium permanganate and attapulgite coupled process was studied. Results showed that the adsorption isotherm can be fitted well with Freundlich model, the correlation coefficient of fitting curve is above 0.95.The adsorption of GSM on attapulgite was an exothermic process, low temperature is benefit for the poditive reaction proceed.Attapulgite can adsorption the taste and odor substances 2-MIB and GSM in purify water fastly, the adsorption capacities were more than 60% and 80% of that of equilibrium at the time of 15 min and 30 min respectively, after about 2 hours, the adsorption process tends to reaching equilibrium. The adsorption exeperiment data showed that it is good correlation with pseudo-second-order kinetics equation, which had a satisfied description of the process of GSM adsorption on attapulgite within 2 hours, the correlation coefficient of fitting curve is above than 0.99. In the attapulgite enhanced coagulation process, the adsorption property of attapulgite made the main contribution for the remove of 2-MIB and GSM in raw water.The combination process of potassium permanganate oxidantion and attapulgite adsorption can improve the removal rate, the removal rate of 2-MIB and GSM is higher as the longer time of potassium permanganate oxidantion jioning before coagu-flocculation.