原位生物修复Cr(Ⅵ)污染土壤的中试实验

Pilot experiment of in-situ bioremediation of Cr(Ⅵ)contaminated soil

针对重金属Cr(Ⅵ)污染土壤,采用原位生物修复技术,测量土壤粒径范围、渗透率、强制通风条件下液体在土壤中分布,并进行Cr(Ⅵ)污染物的微生物去除实验。结果表明,经过25 d微生物修复,各层土壤中的Cr(Ⅵ)均得到不同程度去除,Cr(Ⅵ)不会下渗到距土壤表层40 cm及以下。在含水量相同、通气量为0.3 m^3·h^-1条件下,比较不同碳源时的Cr(Ⅵ)去除率,有葡萄糖和蛋白胨存在时,Cr(Ⅵ)去除率最大,26 d监测到Cr(Ⅵ)去除率高达95%;而苯酚存在时,Cr(Ⅵ)去除率最低,26 d监测到Cr(Ⅵ)去除率仅52%。

In this study,in-situ bioremediation technology was used to measure the size range,permeability and other physical properties of soil and the effect of forced ventilation on the distribution of liquid saturation in soil contaminated by heavy metal Cr(Ⅵ).Microbial removal experiments were carried out using Cr(Ⅵ)as contaminant.The results showed that after 25 days of microbial remediation,the Cr(Ⅵ)in all layers of soil was removed,and the Cr(Ⅵ)did not infiltrate into the soil 40 cm down or more.When the water holding capacity was the same,the removal effect was the best when the aeration rate was 0.3 m^3·h^-1.The removal rates of Cr(Ⅵ)under different carbon sources were compared.The removal rates were the highest in the presence of glucose and peptone,which were up to 95%in 26 days,the lowest in the presence of phenol and 52%in 26 days.