SEPR技术对土壤中芘的强化去除机制研究

Study on enhanced removal mechanism of pyrene from soil by SEPR technology

为探讨表面活性剂强化植物修复(SEPR)技术对土壤中芘的强化去除机制,选用延安市常见的紫花苜蓿为材料,以Tween 80为表面活性剂代表,通过室内栽培试验,系统分析研究SEPR技术对土壤中芘的强化去除效果和强化去除途径。结果表明:1)紫花苜蓿在一定芘初始质量比的土壤中能够正常生长,对污染土壤有一定的治理作用,而表面活性剂Tween 80能够促进植物的生长;2)表面活性剂Tween 80能够提高土壤中芘的去除率,其强化去除率为8.96%~14.02%;3)SEPR技术能够减少植物体内芘的富集量,对植物具有减毒效应;4)表面活性剂Tween 80可通过增强土壤中不同去除要素的去除效果以达到对芘的强化去除,其中最为明显为植物-微生物交互作用,且在中等污染程度去除效果最好。因此,SEPR技术对土壤中芘的强化去除可行、安全。

To explore the enhanced removal mechanism of pyrene in soil by surfactant-enhanced phytoremediation techniques(SEPR),a 70-day pot experiment was carried out in the greenhouse.Alfalfa was selected as the representative of herbs,which was a common species in Yan’an.Tween 80 was used as a surfactant for the experiment.The entire experiment set up the A and B groups.The A Group was an experiment on removing the pyrene from the soil by biological factors.The B Group was an experiment on SEPR technology strengthening the removal of pyrene in the soil.After the 70-day pot experiment,the content of pyrene in the soil,plant roots,stems,and leaves in the A and B groups was determined respectively.Through comparative analysis,the effect and the approaches of SEPR technology on strengthening the removal of pyrene in soil were systematically studied.Finally,the strengthening removal mechanism of pyrene in soil was discussed.The results show that:1)Alfalfa has strong adaptability to pyrene stress.Alfalfa can grow normally in lightly polluted and moderately contaminated soil.The growth of alfalfa is slightly limited in heavily contaminated soil.Tween 80 can promote plant growth;2)Surfactant Tween 80 can strengthen the removal of pyrene in the soil.The enhanced removal concentration of pyrene increases with the initial concentration of pyrene in the soil The enhanced removal rates reached the maximum in moderately contaminated soil;3)The enrichment of pyrene in the alfalfa underground tissue is significantly higher than that of the above-ground part(p<0.05).The enrichment of pyrene in alfalfa tissue shows a significantly linearly positive correlation with the initial concentration of pyrene in the soil.SEPR technology can reduce pyrene enrichment in plants and has a detoxification effect on plants;4)Surfactant Tween 80 enhances the removal of pyrene by enhancing the removal effect of different removal elements in the soil.The effect on plant-microbial interaction is the most significant,which is the best at moderate pollution level.It is clear to see that the enhanced removal of pyrene in soil by SEPR technology is feasible and safe.