采用异位阴燃修复技术处理含油固废中试实验

Pilot studies on treatment of oily solid waste with ex situ smoldering remediation technology

工程化异位阴燃修复技术在含油固废处置领域具有较大潜力。采用此技术对2个场地的石油烃重度污染土壤及油田含油污泥进行了异位阴燃修复中试,研究了不同空气通量、掺混介质、掺混比例等对阴燃启动、燃烧锋面推进、含油固废中石油烃去除率的影响,以及阴燃技术适用的污染物类型和添加辅助燃料植物油维持自持阴燃反应的可行性。结果表明,工程化异位阴燃技术适用于含水率较低的低挥发性含油固废的自持修复,对于自身不能自持阴燃的,通过添加辅助燃料可实现其阴燃自持。当石油烃污染土壤和含油污泥的石油烃质量分数分别为2759~4146 mg·kg^(-1)和3360~30600 mg·kg^(-1)时,在0.18 cm·s^(-1)的初始达西空气通量下均成功启动阴燃,平均燃烧锋面自持蔓延速率分别达1.04、0.60 m·d^(-1),阴燃反应过程最高温度达990℃,石油烃去除率达99.5%以上;1∶2的油泥与修复土体积比更利于工程化应用。本研究结果可为工程化异位阴燃修复技术在含油固废修复的应用提供参考。

Engineered ex situ smoldering remediation technology has great potential in the field of oily solid waste treatment.Two pilot studies were conducted to treat a site heavily contaminated by petroleum hydrocarbons and oil sludge at an oil field,respectively,using this technology in this research.Impact of different air fluxes,blending medium,mixing ratios on smoldering ignition and smoldering front propagation petroleum hydrocarbon degradation rate of the oily solid waste,applicable types of contaminants,and feasibility of adding auxiliary fuel-vegetable oil to sustain smoldering reaction were explored.Results demonstrated tha engineered smoldering technology was applicable to self-sustaining remediation of low water content and low volatile oily solid waste,and vegetable oil could be added into solid waste unable to self-sustain smoldering to realize self-sustaining smoldering.Smoldering was initiated successfully for both oily solid waste with oi content from 2759 to 4146 mg·kg^(-1) and oil sludge with oil content from 3360 to 30600 mg·kg^(-1) with initia Darcy air flux of 0.18 cm·s^(-1),smoldering combustion front propagation average velocities,1.04 m·d^(-1) and0.60 m·d^(-1),were achieved respectively,peak combustion temperature reached 990℃,and petroleum hydrocarbon removal rates exceeded 99.5%.Volume ratio of 1∶2(sludge:remediated soil)was more suitable for engineering application.The pilot studies provide a reference for the application of ex situ smoldering technology in treatment of oily solid waste.