Effect of acid on the strength of solidified sewage sludge

Abstract

The solidification technology can meet the requirements of landfill by enhancing the sewage sludge strength. The solidified sludge strength would be decreased by landfill leachate action because the acid could dissolve the hydrated materials. Chemical kinetics equation was obtained by reaction order α, β and rate constant k, which reflected the acid effect on hydrated materials by Ca2+ and were got based on the laboratory experiments. The research results showed that the strength loss could be neglected in engineering because pH value of leachate possessed less impaction on solidified sludge strength. Moreover, after adding clay minerals, the strength loss is smaller and the buffering capacity is stronger.