两种表面活性剂对塿土吸附苯酚的影响

Effect of different surfactants on phenol adsorption on lou soil

表面活性剂对旱地土壤吸附有机污染物可以产生重要影响。用吸附平衡法,研究在阳离子表面活性剂十六烷基三甲基溴化铵(CTMAB)和阴离子表面活性剂十二烷基磺酸钠(SDS)共存条件下,苯酚在土中的吸附特征。结果表明:20℃和40℃下,在CTMAB共存条件下,土样对苯酚的吸附能力有明显提高,且随CTMAB浓度增加而增大,表现为0.01 mol/L CTMAB>0.005 mol/L CTMAB>0.002 5 mol/L CTMAB>CK。温度升高,随着CTMAB浓度增加,土对苯酚的吸附由增温正效应向增温负效应转变;在SDS共存条件下,在苯酚平衡浓度较低时,两个温度下不同SDS共存浓度对土吸附苯酚的影响差异不大,且低于CK。随苯酚平衡浓度增大,各浓度SDS处理土对苯酚的吸附开始时均显著增大并超过CK,最终吸附量趋于接近。随SDS浓度的增加,土对苯酚的吸附也由增温正效应向增温负效应转变。

The coexistence of surfactant can affect the adsorption of organic pollutants on the dry-land soil significantly. In this paper, We study the effects of different surfactants, cetyltrimethylammonium bromide （CTMAB） and sodium dodecylsulphonate （SDS）,on the adsorption characteristics of phenol on Lou soil. The results show that with the： increase of concentration of the CTMAB, the phenol adsorption ability of the soil at both 20℃ and 40℃ is enhanced, the effects of CTMAB concentration on phenol adsorption is ordered by 0.01 mol/LCTMAB〉0. 005 mol/L CTMAB〉0. 002 5 mol/L CTMAB〉 CK. The phenol adsorption changes from positive temperature effect to negative temperature effect with increase of CTMAB concentration when the temperature rises. In contrast, when the equilibrium concentration of phenol is less than 0.09 mmol/L, all the phenol adsorptions on soil coexisted with different SDS concentration are close to each other and are lower than that on CK at both temperatures. Furthermore, with increase of equilibrium concentration of phenol, the phenol adsorption on soil with SDS coexistence increases significantly and exceeds that on CK. The phenol adsorption changes also from positive temperature effect to negative temperature effect with increase of SDS concentration when the temperature rises.