Electro-dewatering treatment of sludge: Assessment of the influence on relevant indicators for disposal in agriculture.

Waste activated sludge requires effective dewatering, high biological stability and retention of nutrients prior to disposal for agricultural application. The study was conducted to evaluate the impact of pressure-driven electro-dewatering (EDW) on improving sludge characteristics related to disposal in agriculture, including biological stability, pathogen availability, heavy metals concentrations and nutrients content. Thickened conditioned and mechanically dewatered sludge samples were collected from two wastewater treatment plants (WWTPs), characterized by different stabilization processes, and treated by a lab-scale device at 5, 15 and 25 V.

Performance of electro-osmotic dewatering on different types of sewage sludge.

The feasibility of pressure-driven electro-dewatering (EDW) on sludge samples taken after different biological processes, stabilisation methods or mechanical dewatering techniques was assessed. First, the influence of potential values on EDW of anaerobically and aerobically stabilised, mechanically dewatered, sludge samples was investigated. Preliminary tests carried out by applying a constant potential (10, 15 and 20V) in a lab-scale device confirmed the possibility to reach a dry solid (DS) content of up to 42.

Modeling the adsorption behavior of linear end-functionalized poly(ethylene glycol) on an ionic substrate by a coarse-grained Monte Carlo approach.

The rheology of cement pastes can be controlled by polymeric dispersants such as branched polyelectrolytes that adsorb on the surfaces of silicate particles. In the present work, we analyze the adsorption behavior of ad hoc-prepared end-carboxylated poly(ethylene glycol), or PEG, on CaCO(3) particles as a model of cement in an early hydration stage. The experimental adsorption isotherms form the base of a theoretical study aimed at unraveling polymer conformational aspects of adsorption.