生物黑炭-水泥固化稳定化石油污染土壤

Stabilization/solidification of petroleum contaminated soil using biochar-cement

石油在开采、储运、加工和使用过程中出现的漏油以及突发性泄漏事故对土壤造成了严重的污染。笔者考察生物黑炭(BC)和水泥联合固化稳定化修复石油污染土壤的可行性,发现黑炭制备的热解温度是影响生物黑炭吸附性能的直接因素。与400℃热解的生物黑炭(BC400)相比,600℃热解的生物黑炭(BC600)具有更加类似活性表(AC)的性能。AC、BC对石油污染土壤均有较好的稳定化效果,石油烃的浸出浓度随着稳定化剂添加量的增加而降低。水泥添加量是影响石油污染土壤固化稳定化效果的重要因素。当水泥添加量为50%,以2%的AC或BC600作为稳定化剂,均能有效固化稳定化石油污染土壤,处理后的固化产物满足可接受浸出浓度限值的要求,无侧限抗压强度达到卫生填埋和建筑回填土强度标准。生物黑炭可以替代活性炭用于石油污染土壤的固化稳定化。

Many soils are heavily polluted by petroleum leakage during mining,storage,transportation,manufacturing,usage,and by accidental leaks. Petroleum-contaminated soil was treated by stabilization / solidification（ S / S） with biochar-cement. The pyrolysis temperature was the main factor that influenced the adsorption properties of biochar（ BC）. Compared with biochar produced at 400 ℃（ BC400）,the physico-chemical properties of biochar produced at 600 ℃（ BC600） were similar to those of activated carbon（ AC）. Both AC and BC were effective in stabilizing petroleum-contaminated soil. The leaching concentrations of petroleum hydrocarbons were reduced with increasing AC or BC amounts. The cement amount was an important factor affecting the concentrations of petroleum hydrocarbons leached from the S / S products. When 50% cement and 2% AC / BC600 were employed,the leaching concentrations of petroleum hydrocarbons from the S / S products were below the acceptable level. Moreover,the unconfined compressive strength of the S / S products fulfilled the standard for sanitary landfill and constructional backfill. Biochar can substitute for activated carbon as a stabilizing agent when treating petroleum-contaminated soil by stabilization / solidification.