Search

A laboratory investigation of solidilication ol copper contaminated soil by Ily ash based geopolymer with bottom ash(BA-FAG) was carried out The ellects of curing time, binder content and initial copper content on the solidilication ol copper contaminated soil were studied by Unconlined Compressive Strength (UCS), toxic leaching test, X-Ray Dillraction(XRD), scanning Electron Microscopy(SEM) and X-ray Photoelectron Spectroscopy (XPS). The results showed that the UCS value of BA-FAG solidified soil can be increased together with the decrease of leaching concentration ol copper ion by increasing binder content and curing time. The initial concentration of copper ion in contaminated soil negatively correlated with the strength ol solidified soil, and positively correlated with leaching concentration. The copper contaminated soil with initial concentration of no more than 6 000 mg/kg and 10 000 mg/kg can be solidified by 2()% and 30 % binder contents, respectively. Meanwhile, the UCS values of solidified soil at 28 days of curing are no less than 0. 3 58 MPa and 0. 4 57 MPa, respectively, and the leaching concentration is lower than 100 mg/L at the conditions of both acidic and neutral leaching. The copper in the contaminated soil mainly exists in the form of Cu2+ and Cu(OH) 2 precipitation during the physical encapsulation by BA-FAG. [ABSTRACT FROM AUTHOR]