Characterization of solidification for disposal of hazardous waste landfill leachate.

Hazardous waste landfill leachate (HWLL) with high concentrations of salt and pollutants has created a bottleneck at hazardous waste landfills. This study applied a cement-based curing method to the disposal of HWLL. The highest contaminant fixing rate was achieved by adjusting the composition and proportion of the curing base, the content of additives, and the liquid-solid (L/S) ratio of the leachate to the curing base. The fixing rates for chemical oxygen demand and salt content in HWLL reached the highest values of 95.1% and 86.1%, respectively, when the Portland cement to metakaolin ratio was 3:2; the L/S was 1; and diatomite and activated carbon were added at 0.5% and 0.25%, respectively. The addition of glass fiber to the curing base improved the crack resistance of the solidified product. A simulated landfill experiment further indicated that after 116 days of leaching, the leachate effluent pollutant concentrations of the landfill column were lower than the effluent standard. Solidification is a feasible method for HWLL disposal.