Research On The Adsorption Of Atrazine In Water By Modified Sawdust

The Atrazine was analyzed by high performance liquid chromatography (HPLC) method with ethyl acetate as extractant. Three granular activated carbon (coconut shell, granular and Shell) and modified sawdust were selected as adsorbents to adsorb Atrazine in water. The main contents included two sections.The first section was that in GB/T 5750.9-2006 monitoring methods, dichloromethane as extractant was moderately toxic pollutant. Therefore several low-toxicity organic solvents instead of dichloromethane were selected as extractants for atrazine enrichment in the water samples. The atrazine was measured under the new chromatographic conditions. The best extractant was confirmed by comparing extraction efficiency. The new analysis methods for atrazine in the water samples were established. The accuracy and precision of the testing results all achieved the analytical requirements of national standards.The second section was the preparation for adsorbent. Alkalization treatment on wood, Load cationic surfactant cetyltrimethylammonium bromide (CTAB), then obtained the modified sawdust. Influence factors of adsorption such as adsorption time, temperature, pH and adsorbent dosage were investigated. Adsorption isotherms were plotted.The experiments were conducted with four kinds of adsorbents for adsorption at room temperature. The absorption time was all within 12h, the balance time in the modified sawdust was the fastest and it achieved adsorption equilibrium for about 1h. With the increase of the temperature for Atrazine adsorptions, the adsorption removal efficiency decreased. The modified sawdust was most affected by temperature. As the temperature increased to 50℃, the removal efficiency dropped to 65% or less. The adsorption of granular activated carbon and modified sawdust had small changes within pH 5-9, generally in downward trend and the most decline rate was about 10%.Adsorption isotherm of Freundlich and Langmuir can be better used to describe the adsorption of atrazine in the three kinds of granular activated carbon and modified sawdust. Compared the performance of four adsorption materials, the adsorbances of three kinds of granular activated carbon were all about 5mg/g, which were better than the modified sawdust. Adsorption rules of coal granular activated carbon and the modified sawdust met the Langmuir equation well, which belonged to monolayer adsorption.At pH 7 and room temperature, the removal efficiency of modified sawdust in the low concentration of atrazine was over 90%, which was much better than nature wood.