Rapid evaluation of leaching potential of heavy metals from municipal solid waste incineration fly ash

Municipal solid waste incineration fly ash is directly landfilled after solidification in the industry. The rapid evaluation of contaminant leaching is required before the landfill of fly ash. In order to reduce the time to evaluate the effect of solidification, a set of rapid evaluation method was developed through the determination of characteristic index, heavy metal leaching analysis, principal component analysis, and mathematical model construction. It was found that f-CaO, acid neutralizing capacity, pH and soluble calcium were negatively correlated with heavy metal leaching. The soluble chlorine was positively correlated with heavy metal leaching. The effect of each feature indicators on heavy metal leaching was evaluated using principal component analysis and mathematical analysis software R.3.4.4. Furthermore, R.3.4.4 was used to detect the optimal model and the excess probability formula by stepwise linear regression and logistic regression analysis method. By introducing the measured value of feature indicator into the excess probability formula, the rate of excess-standard of heavy metals leaching can be preliminarily determined. Based on the above ideas, a rapid detection and evaluation system could be developed according to the local leaching standards and the components of fly ash selected locally.