槐糖脂对含油盐碱土壤的处理及其植物生长评价

Treatment of sophorolipid to oil-bearing saline-alkali soil and evaluation of plant growth

以酸型槐糖脂为表面活性剂配制了一种微乳液用于对含油盐碱性土壤的无害化与资源化处理。固定柴油添加量,通过单因素实验筛选微乳液配方,并优化其清洗工艺参数。结果表明,最佳微乳液[酸型槐糖脂含量6%(以水的质量为基准,下同)、氯化钠含量1%、柴油含量13.36%]在液固比(质量比)2∶1、35℃、搅拌速率600r/min、清洗时间20min的条件下对原油脱除效果最高,脱除率可达95.95%。规模放大实验及重复使用实验表明,将含油土壤处理量放大至300倍,该乳液在上述条件下仍能保持原油脱除率在94%以上;微乳相在补加柴油的情况下,使用5次后仍能保持原油脱除率在87%以上。对土壤样品进行了对比分析发现,修复后土壤的pH由8.56下降到7.68,全盐含量由1.48%下降到0.29%,土壤由重度盐碱地降低为轻度盐碱地。种子萌发实验证明,修复后土壤毒性降低,适合部分植物生长。

A kind of microemulsion was prepared using acid-type sophorolipid as surfactant and then used to innocuous and resource treatment of oil-bearing saline-alkali soil. The formulation of microemulsion was screened by single factor experiments and the cleaning parameters were optimized. The results showed that the optimal microemulsion [acid-type sophorolipid content of 6%(based on the mass of water, the same below), NaCl content of 1% and diesel content of 13.36%] had the best removal effect of crude oil under the optimized cleaning conditions of liquid solid ratio(mass ratio) of 2∶1, temperature of 35 ℃, stirring rate of 600 r/min and cleaning time of 20 min. The removal rate of crude oil reached 95.95%. The scale and reuse experiments indicated that the microemulsion could still maintain the crude oil removal rate of more than 94% when the oil-containing soil was enlarged to 300-fold. The removal rate of crude oil could remain above 87% after the microemulsion being used for 5 times by adding diesel oil in each time. Comparative analysis of soil samples showed that after restoration, the pH of soil decreased from 8.56 to 7.68, the total salt content decreased from 1.48% to 0.29%, and the soil was reduced from severely saline to mildly saline.The experiment of seed germination revealed that the soil toxicity was reduced and suitable for the growth of some plants.