Studying On Removal Of Selenium From Water By Activated Carbon Process

The project is subsidized by Natural Science Fund of Yunnan province (No. 2001E0020M). this dissertation investigated the adsorbability of activated carbon for selenium in order to study the possibility of using carbon absorbent for waste water treatment.The adsorption of selenium by activated carbon from aqueous solution was investigated. Activated carbon is a highly porous material. It is the most widely used absorbent, due to its large surface area, chemical stability, resistances to acid and alkali, high temperature and high press. Physical adsorption is the primary adsorption mechanism. Chemical adsorption also often happens, but it is not primary.The main content of study includes:Firstly, a systematic study was carried out to investigate influence of diferent conditions on the adsorption., such as pH value, temperature, dosage of activated carbon and turbidity. It determined the optimal adsorption conditions. The result of research shew that the optimal absorbent process based on the following condition:selenium removal by powered activated carbon was optimized at absorbent 4. 2g/l, PH of between 5.0 and 8.0, contact time 2 hour and solution temperature 23℃. Under these conditions, the removal efficiency can reach 98% more. the conditon of particle activated carbon is like the former, but the removal efficiency is no more than 93%. What's more, but selenium removal was less dependent on turbidity for activated carbon in water ; Secondly, The adsorption isotherm tests was made for selenium removal, and the adsorption model for resin absorbing selenium was presented; Thirdly, the preliminary research about mechanism of selenium removal was made in the end of this paper.The result of research shew that The advanced attributes of the activated carbon process are its simplicity,effeciency and practicality. Above-mentioned results shew that selenium removal with the method of ion exchange is fessible. In order to remove selenium to reach the quality standard of drinking water of national stipulation, water was handled with the absorption of activated carbon and a kind of effective method was provided for solving the problem of over standard of selenium in water of the partial area of our country.