Preparation of composite sludge carbon-based materials by LDHs conditioning and carbonization and its application in the simultaneous removal of dissolved organic matter and phosphate in sewage.

In this work, a novel carbon-based hydrotalcite-like compounds materials (LDO-SBCs) were prepared by coupling layered double hydroxides (LDHs) conditioning and pyrolytic carbonization, and characterized by X-ray diffraction (XRD), Thermogravimetric Analyzer (TGA), X-ray photoelectron spectroscopy (XPS) and Brunner-Emmet-Teller (BET) measurements. The synthesized LDO-SBCs composites were used in wastewater treatment for simultaneous removal of phosphate and dissolved organic matter (DOM). The adsorption of DOM and phosphate were well conformed to pseudo-second-order mode.

Performance and mechanisms of wastewater sludge conditioning with slag-based hydrotalcite-like minerals (Ca/Mg/Al-LDH).

Extracellular polymeric substances (EPS) in wastewater sludge form a network structure that is highly hydrophilic and compressible. Thus chemical conditioning is always required to improve sludge dewaterability by changing the gelatinous structure of sludge flocs. Layered double hydroxides (LDH) are generally characterized by large surface area and high anion exchange capacity, so we prepared three types of hydrotalcite-like compounds (Ca/Mg/Al-LDHs) from a typical solid waste, blast furnace slag, using NaOH precipitation (giving LDH), a hydrothermal method (LDH), and NaOH-NaCO precipitation (LDH).