基于土壤中多环芳烃解吸特性的生物修复效果评价

Evaluation of effectiveness of bioremediation based on PAHs desorption characteristics in soil

采用XAD-2树脂辅助解吸方法测试了生物堆修复前后土壤中荧蒽、苯并(a)蒽、苯并(a)芘、苯并苝这4种PAHs的解吸特性,并根据解吸结果进行了生物修复效果评价.结果表明,土壤中这4种PAHs的累计解吸量随解吸时间延长而增加,但解吸速率逐渐降低,符合"两阶段"解吸模型,生物修复前土壤中不同种类PAHs"快解吸"量占PAHs总量的32%～70%,修复后土壤中不同种类PAHs"快解吸"量占PAHs总量的14%～39%.经过6个月的生物修复,基于生物可利用含量变化的荧蒽、苯并(a)蒽、苯并(a)芘、苯并苝修复效率依次为82.9%、79.7%、64.9%、54.3%,,明显高于基于PAHs总含量的生物修复效率61.0%、51.7%、37.2%、38.7%.

The desorption characteristics of four targeted PAHs （ fluoranthene, benz[ a] anthracene, benzo [ a] pyrene, benzo[ ghil perylene） in soil before and after biopile treatment was studied by using XAD-2 assisted desorption experiment and the bioremediation effectiveness was further evaluated based on the study of the desorption results. The findings revealed that the accumulative amount of desorbed PAHs in the experiment increased with time while the desorption rate decreased, which followed the ＂dual - phase＂ desorption model. The fast desorbable part of the four PAHs was 32% - 70% before bioremediation and dropped down to 14% -39% after 6 month bioremediation. The remediation effectiveness based on the bioavailable fluoranthene, benz[ a] anthracene, benzol a] pyrene, benzo[ ghi] perylene was 82.9% ,79.7% ,64.9% ,54.3% , respectively, which were higher than those calculated based on the total concentration of each contaminant, which was about 61.0% ,51.7% ,37.2% ,38.7% correspondingly.