表面活性剂Tween80及DOM对土壤中菲、芘解吸的影响

Effect of Nonionic Surfactant Tween80 and DOM on the Behaviors of Desorption of Phenanthrene and Pyrene in Soil-Water Systems

采用室内序批试验研究了水溶性有机物(DOM)及表面活性剂Tween80对污染土壤中菲、芘解吸行为的影响.结果表明,DOM能够增加土壤中菲、芘的解吸率,且猪粪堆肥的DOM作用效果较好;随着体系中Tween80浓度的增加,土壤中菲、芘的解吸率也明显地增加,当Tween80浓度为150 mg.L-1时,菲、芘的解吸率分别是对照的1.7倍(菲)和6.2倍(芘);DOM与Tween80联合作用时受Tween80浓度的影响,低浓度时联合作用效果不明显,当Tween80为150 mg.L-1时,菲、芘的解吸率显著增加且大于两者单独作用的结果之和.试验结果还表明,同等条件下高相对分子质量DOM组分(>25000)对土壤中菲、芘的解吸作用大于低相对分子质量DOM组分(<1000).

Batch experiments were conducted to study the effects of dissolved organic matter （DOM） and nonionic surfactant （Tween80） on the desorption of phenanthrene and pyrene in soil-water systems. The results showed that DOM derived from pig manure and pig manure compost increased the desorption of phenanthrene and pyrene in soil-water systems, and the effect of pig manure compost DOM was better than that of pig manure DOM; with the increase of Tween80, the desorption rate of phenanthrene and pyrene also increased compared with the control, especially at high concentration of Tween80 （150 mg· L^-1）. And at this concentration, the desorption rates were increased by 1.7 times for phenanthrene and 6.2 times for pyrene than that of the control. The combined effects of Tween80 and DOM on the desorption of phenanthrene and pyrene were influenced by the concentration of Tween80. When Tween80 at low concentration, the combined effects were not significant. Howerver, with 150 mg· L^-1 Tween80 in soil-water systems, the desorption rates of phenanthrene and P3 rene were drastically higher than the sum of DOM and Tween80. The results also indicated that DOMs with high molecular-size fraction （ 〉 25 000 could attain a higher desorption of both phenanthrene and pyrene in soil-water systems than their low molecular-size counterpart （ 〈 1000） under the same experiments conditions.