Insights into the dewatering of excavated landfill sludge conditioned by polyferric silicate sulfate.

Large quantities of landfill sludge (LS) with higher water content (WC) were stored underground, and excavation and re-dewatering of LS is a sustainable and economic strategy to save landfill space and reduce the leaching of contaminants. In this study, polyferric silicate sulfate (PFSS) was first applied in the conditioning of excavated LS, and the effects of the Si/Fe mass ratio and PFSS dosage on physicochemical properties, dewaterability and rheological properties were investigated. At the best Si/Fe of 0.

Applying organic polymer flocculants in conditioning and advanced dewatering of landfill sludge as a substitution of ferric trichloride and lime: Mechanism, optimization and pilot-scale study.

In this study, poly dimethyl diallyl ammonium chloride (PDADMAC) and polyacrylamide (PAM) were applied to substitute ferric trichloride (FeCl) and lime conditioning for advanced dewatering of landfill sludge (LS). Four response surface methodology (RSM) models were constructed for FeCl-lime, FeCl-PAM, PDADMAC-lime and PDADMAC-PAM, and identical dosages, namely 29.86, 57.

A full-scale survey of sludge landfill: sludge properties, leachate characteristics and microbial community structure.

In this study, a full-scale survey was conducted of a sludge landfill that had been sealed for 10 years to investigate sludge properties, leachate characteristics and microbial community structure. Vertical distribution of sludge and leachate pollutants in the landfill site showed that the sludge and soluble pollutants in the leachate were both distributed almost evenly even after long-term anaerobic digestion, and higher concentrations of soluble pollutants and richness of microbial community were observed at the middle layer. Compared to dewatered excess sludge generated from the activated sludge process before landfill, landfill sludge had a much lower organic content (28.

Insights into conditioning of landfill sludge by FeCl and lime.

In this study, landfill sludge (LS) was excavated from a 10 year old full-scale sludge landfill and used to investigate effects of dosage on sludge dewaterability, rheological properties and extracellular polymeric substances (EPS) variations by FeCl-lime conditioning. LS had lower content of organic matters (0.28) and smaller particle size than excess sludge (ES), and greatly lower viscosity and high flowability.