Dechlorination of fly ash through co-leaching with organic waste: effect of inoculum

Abstract

In order to improve the dechlorination amount of incineration fly ash and increase the mixture amount of fly ash into the kiln for cement kiln co-disposal, this study investigated the dechlorination effect of fly ash using co-leaching method with organic waste. Results revealed that the dechlorination effect of the experimental groups (co-leaching of organic waste and fly ash) was better than that of the control group (separate leaching of fly ash). The chlorine content in fly ash residue of the lactic acid bacteria group (organic waste + fly ash + 10% Enterococcus faecalis) was the lowest, at 0.39%. After dynamic leaching, the allowable incorporation rate of fly ash residue into the kiln was 10.30%, which was 9.6 percentage points higher than that achieved by static leaching (three-step water washing). In addition, to achieve the same dechlorination amount, the co-leaching of organic waste and fly ash could save at least 48.7% of water consumption compared to the separate leaching of fly ash. Therefore, the co-disposal of organic waste and incineration fly ash is an economical and efficient method for fly ash dechlorination.