北京地区土壤对柴油的吸附及影响因素研究

Sorption of Diesel Oil and Its Influence Factor on Beijing Soils

通过静态吸附实验,研究了北京地区土壤对柴油的吸附行为,考察了溶液pH和添加乙醇对柴油吸附的影响.结果表明,6种不同土样对柴油的吸附等温线均较好地符合Langmuir吸附方程,其吸附系数(K)分别为0.193,0.218,0.203,0.199,0.211和0.182 L/mg,6种土样吸附能力依次为轻壤土>轻粘土>中壤土>砂壤土>重壤土>紧砂土,这主要是由于6种土样的pH,有机质含量和机械组成不同所致;溶液pH的升高,不利于柴油在土壤中的吸附,pH从4升高到10,柴油在1-6号土样中的吸附量分别从1 012,1 800,1 377,1 272,1 601和862μg/g降低到114,236,163,150,201和85μg/g;向柴油中添加乙醇会减小柴油的吸附量,并且吸附量随添加乙醇量的增大而降低,这有利于柴油的向下运移.

Static experiments for sorption behaviour of diesel oil on Beijing soils were carried out to investigate the influence of pH and ethanol on sorption. The results indicated that the adsorption isotherms of diesel oil on six soils were well described by the Langmuir type, and the adsorption coefficient was 0.193, 0.218, 0.203, 0. 199, 0.211 and 0. 182 L/mg, respectively. It suggests that the adsorption capacity of diesel oil on the six soils from high to low is： Light loam, Light clay, Medium loam, Sand loam, Dense loam and Dense sand, because of different pH, organic matter content and mechanical Composition. The increase of pH was not favourable to adsorption of diesel oil. Increasing the pH from 4 to 10 led to the decrease of the adsorbed quantity on the six soils from 1 012, 1 800, 1 377, 1 272, 1 601 and 862 μg/g to 114, 236, 163, 150, 201 and 85 μg/g, respectively. The addition of ethanol to diesel oil was found to decrease adsorption. The adsorbed quantity decreased with the increasing concentration of ethanol, which enhanced the movement of diesel oil.