表面活性剂强化好氧生物修复PAHs污染土壤效果研究

通过实验测试不同浓度梯度表面活性剂对PAHs的增溶效果,筛选出一种能够提升PAHs脱附于液相的表面活性剂,利用其与好氧生物促进剂的协同作用,强化土壤中PAHs的脱附及生物降解过程,并应用于中低浓度PAHs污染土壤的中试实验。通过对比营养物质投加量、氧气供给方式、含水率控制、人工翻抛频次等条件确定最佳的现场实施方式,其中氧气供给方式采用缓释氧药剂和人工翻抛2种曝气方式。结果显示:缓释氧+生物促进剂,辅以定期补水的养护操作,是最为有效的处理方式,总PAHs降解率可达91.24%,苯并(a)芘降解率可达89.86%,此技术路线不需要人工曝气,可大幅节省实施成本。该成果为国内中低浓度PAHs污染土壤提供了一种更加经济高效的解决方案。

PERFORMANCE OF SURFACTANTS ENHANCED AEROBIC BIOREMEDIATION OF PAHs CONTAMINATED SOIL

The solubilisation effect of several surfactants with different concentration gradients on polycyclic aromatic hydrocarbons (PAHs) was tested by experiments. The optimal surfactant which could increase the solubility of PAHs in liquid phase efficiently was screened out. And the synergistic effect of the surfactant and aerobic bio-nutrients was used to enhance the desorption and biodegradation of PAHs. Pilot-scale experiments on PAHs contaminated soils with medium and low concentration were conducted. The experiments were carried out by comparing the nutrient dosage, oxygen supply mode, water content control and manual stirring frequency. Two aeration modes, slow-release oxygen reagent and artificial land cultivation, were applied to realize oxygen supply. The results showed that slow-release oxygen+aerobic bio-nutrients, supplemented by the maintenance operation of regular water supply, was the most effective treatment method. The total PAHs degradation rate was up to 91.24%, and benzo (a) pyrene degradation rate was up to 89.86%. At the same time, this technical route didn’t need artificial aeration, which could greatly cut the implementation cost. Through this study, an economical and efficient solution was provided for the soil contaminated by low and medium concentration of PAHs.