Investigating the Dewatering Efficiency of Sewage Sludge with Optimized Ratios of Electrolytic Manganese Residue Components.

As an industrial waste residue, Electrolytic Manganese Residue (EMR) can greatly promote sludge dewatering and further particle-size optimization can significantly strengthen sludge dewaterability. In this study, the effects of ammonium sulfate, calcium sulphate dihydrate, and manganese carbonate in EMR on sludge dewatering performance were investigated using the response surface optimization method. It was found that the optimized ratio of three components in EMR was 1.

Zero-carbon inertization processes of hazardous mine tailings: Mineral physicochemical properties, transformation mechanism, and long-term stability.

Hazardous mine tailings (HMTs) dam failures can cause devastation to the ecology environment, people's lives and property, which require expensive and complicated remediation engineering systematacially. A cheap and sustainable inertization disposal is proposed for de-risking HMTs without any carbon emissions, stabilizing hazardous heavy metal cations within safety minerals and also sequestering CO in the process, simultaneously. Herein, lead-zinc tailings as target HMTs were inertized by using waste rice husk ashes (RHAs) and carbide slag (CS) with a certain ratio, and lead-zinc tailings hardened pastes (LZTHPs) were investigated based on the experimental performance, analytical characteristics, and simulation diffusion methods, to deeply unveil the minerals transformation mechanisms and long-term stability from the cation perspectives.

Comprehensive effects of grain-size modification of electrolytic manganese residue on deep dehydration performance and microstructure of sludge.

As the by-product accompanied by sewage treatment, sludge has complex composition and high moisture content, therefore, its reutilization and disposal are still a challenge. In this paper, five kinds of quartz sand conditioners with different particle sizes (denoted as QS1, QS2, QS3, QS4 and QS5, respectively) were used to explore the effect of particle size distribution of conditioners on sludge dewatering performance. The moisture content, capillary suction time (CST), time to filter (TTF), specific resistance of filtration (SRF), particle size distribution curve, pore distribution law, scanning electron microscopy, isothermal adsorption-desorption curve and extracellular polymeric substances distribution were employed to characterize the modified sludge and explore the improvement mechanism.

Enhanced Selenate Removal in Aqueous Phase by Copper-Coated Activated Carbon.

In this study, we prepared a novel sorbent derived from precipitating copper ion onto the surfaces of activated carbon (Cu-AC). The sorbents were comprehensively characterized by Brunauer-Emmett-Teller (BET), zeta potential analysis, SEM, XRD, and FTIR. Batch experiments were conducted to evaluate selenate removal by Cu-AC under different conditions.

Properties of Phosphorus-Slag-Based Cementitious Pastes for Stabilizing Lead.

The properties and curing mechanism of leaded samples solidified with phosphorous-slag-based cementitious pastes are studied. The compressive strength, pH of percolate, and lead-ion concentrations of leaded samples stabilized with the phosphorous-slag-based cementitious pastes and cement were analyzed. Results confirmed that the phosphorous-slag-based cementitious paste performed much better than cement in terms of solidifying lead.