生物修复在土壤重金属污染中的探索

EXPLORATION OF BIOREMEDIATION TECHNOLOGY IN SOIL HEAVY METAL POLLUTION

为阐明四川省宜宾市翠屏区岷江二桥旁建筑工地到某酒厂厂区土壤重金属污染现状,通过蛇形布点、随机采样法进行采样,将风干、过筛的土壤样品经浸提法测定pH后进行微波消解,通过原子荧光法测定土壤中砷、汞含量,电感耦合等离子发射光谱法测定铜、铬、锌、铅、镍含量,王水提取-电感耦合等离子体质谱法测定镉含量。根据该地区各重金属含量选用地累积指数法进行污染等级分析,结果表明:该研究区域存在重金属Cu、Pb、Cd、Hg和Zn污染,其中,土壤Cd污染最严重。对此,根据该区域土壤重金属污染程度结合相关的生物修复技术,如植物、动物及微生物修复提出相应的改善与修复措施。岷江二桥下农用地1号可采用大豆甜高粱套种,田埂边种植黄花达到对铜、铅、镉、汞和锌重金属的去除;某酒厂厂区2号可适当种植观赏性蒲公英针对土壤中镉的去除,种植麻风树作为行道树增加对汞的富集,种植狼尾草去除铜,适当引入蚯蚓从而提高土壤的肥力,以及增加植物对土壤中锌和铅的吸收;居民居住小区3号适当增加乔木类麻风树,草本类种植莎草和蒲公英作为观赏性植物增加汞和镉的去除;岷江二桥旁建筑工地4号种植狼尾草增加对铜的去除,可适当增加麻风树的种植,莎草和蒲公英的套种增加汞和镉的去除。

To illustrate the construction site in Yibin city,Sichuan province to a winery of soil heavy metal pollution,through snake cloth,random sampling,drying,sieve soil samples after the dip test pH microwave digestion,by atomic fluorescence determination of arsenic,mercury,inductive coupling plasma emission spectrum of copper,chromium,zinc,lead,nickel,water extraction-inductance coupled plasma mass spectrum to determine the content of cadmium.According to the pollution grade analysis of heavy metal content,the results showed that Cu,Pb,Cd,Hg and Zn pollution,among which soil Cd pollution was the most serious.In this regard,according to the degree of heavy metal pollution in the soil in this region combined with related bioremediation technologies,such as plant,animal and microbial remediation,the corresponding improvement and remediation measures are proposed.Agricultural land No.1 can be used soybean sweet sorghum interplanting,Planting yellow flowers on theridge of the field to achieve the removal of copper,lead,cadmium,mercury and zinc heavy metals;A winery factory No.2 can be appropriately planted ornamental dandelion for the removal of cadmium in the soil,Planting lepers as a street tree increases the enrichment for mercury,Planting Wolftail weed to remove copper,Appropriate introduction of earthworms to improve soil fertility,And increasing the absorption of zinc and lead in the soil by plants;Residential community No.3 appropriately increase jatropha arborescens,Herbaceous planting sedges and dandelion as ornamental plants increase the removal of mercury and cadmium;No.4 construction site beside the No.2 Minjiang Bridge to increase the removal of copper,jatropha planting can be increased appropriately,Intercropping of sedges and dandelion increases the removal of mercury and cadmium.