| Anthropogenic activities such as metal mining,smelting,refining and a large number of tailings,have polluted the soils and aqueous systems with potentially toxic metals(PTMs)in many places throughout the world.The research was undertaken to assess the pollution risk of PTMs from Pb/Zn mine tailing of Feng County,and use two kinds of remedial agents,viz.calcium oxide(Ca O)and bamboo biochar(BC)to immobilize PTMs come from Pb/Zn tailings located in Fengxian River Basin.The main findings were given below:1.The content of Cu,Zn,Pb and Cd in the Pb/Zn tailings were 131?3332?4474 and 140 mg/kg.These Pb/Zn tailings seriously polluted the environment.The concentration of Zn was 683 mg/kg in Hispid Arthraxon L shoot.The concentration of Pb and Zn were 757 and 702 mg/kg in Stellaria chinensis L shoot.2.The Zn had moderate ecological risks to the environment.The heavy metals Cd and Pb had a strong ecological risk to the environment.The comprehensive potential ecological risk grade of Pb/Zn tailings was extremely high.3.The p H in the leachates was 7.88~8.89.But p H in the leachates column B was 12.80~13.03.4.The results of Pb/Zn tailings leaching experiments highlighted that the dissolution of river water for PTMs was better than that of acid rain and deionized water by using Ca O as stabilizing agent.The results of Pb/Zn tailings leaching experiments showed that the dissolution of river and acid rain metal was better than deionized water by using bamboo biochar as stabilization agent.5.Calcium oxide had a good stabilization effect on heavy metal Cd and Zn.But calcium oxide had low impact on Pb and Cu.6.Bamboo biochar had a good stabilization effect on heavy metal Cd,Pb and Zn.Bamboo charcoal had a significant stabilization effect on free Pb and Zn. |
PDF Full Text Request