非离子表面活性剂淋洗萘污染土壤的修复研究

采用土柱实验研究了非离子表面活性剂对焦化厂萘污染砂土的淋洗效果,同时研究了超声预处理对非离子表面活性剂土壤淋洗的增强效果及粉土和粘土对非离子表面活性剂土壤淋洗的不利影响.研究表明,1)1g·L-1的TritonX-100、AEO-9和Tween80对同一萘浓度(192.4mg·kg-1)的土壤洗脱效率分别为73.0%、81.5%和59.0%,2g·L-1的表面活性剂的洗脱效率要高于1g·L-1的洗脱率,分别为96.5%、95.1%和88.2%.2)对土壤进行短时超声处理(80Hz)促进了洗脱率的提高,超声10min的淋洗效果要高于超声5min的淋洗效果;土壤分别经5min和10min超声处理后,2g·L-1浓度的TritonX-100对萘的洗脱率从94%分别提高到98.8%和99.6%,洗脱时间从255min分别减少到172min和160min.3)砂土中含有粉土和粘土对洗脱效果有不利影响,且粘土的影响要更严重,当萘污染的砂土混入5%的粘土时,2g·L-1浓度的TritonX-100对萘的洗脱率从94.7%下降至73.8%,洗脱时间从255min增加至605min,而混入20%的粉土洗脱率仅下降到88.4%,洗脱时间增加至512min.

Flushing Remediation for Naphthalene-Contaminated Soil at the Coking Works Site with Non-ionic Surfactants

The soil column experiments were used to study the flushing efficiency of naphthalene-contaminated sandy soil with three types of non-ionic surfactants(Triton X-100,AEO-9 and Tween80).In addition,the effects of ultrasonic wave pre-treatment and soil texture on the flushing efficiency of naphthalene-contaminated soil with Triton X-100 were investigated.The results indicated that 1)1g·L-1 of Triton X-100,AEO-9 and Tween80 solutions removed 73.0%,81.5% and 59.0% of naphthalene from the sandy soil containing initial 192.4mg·kg-1 of naphthalene,respectively.At the same initial content of naphthalene,96.5%,95.1% and 88.2% of naphthalene were removed from the sandy soil by 2g·L-1 of TritonX-100,AEO-9 and Tween80 solutions,respectively,indicating that increase in the concentration of non-ionic surfactants from 1 to 2g·L-1 improved the flushing efficiency of the naphthalene-contaminated soil.In addition,5 and 10min of ultrasonic wave pretreatments increased flushing removal efficiency of naphthalene with 2g·L-1 Triton X-100 solution from 94.0% to 98.8% and 99.6%,respectively.At the same time,they decreased flushing time from 255min to 172min and 160min,respectively.However,addition of silt and clay into the naphthalene-contaminated sandy soil decreased flushing efficiency of naphthalene and increased flushing time.In details,increase of clay content by 5% in the naphthalene-contaminated sandy soil decreased the removal efficiency of naphthalene from 94.7% to 73.8% and increased flushing time from 255min to 605min for 2g·L-1 Triton X-100 solution.On the other hand,increase of silt content by 20% in the naphthalene-contaminated sandy soil decreased the removal efficiency of naphthalene from 94.7% to 88.4% and increased flushing time from 255min to 512min for 2g·L-1 Triton X-100 solution.Our study got some important initial parameters for flushing remediation of naphthalene-contaminated soil with non-ionic surfactants and hence is important for the remediation of organics-contaminated soils at Coking Work Sites.