Nitrogen doped bimetallic sludge biochar composite for synergistic persulfate activation: Reactivity, stability and mechanisms.

As a recycling use of waste activated sludge (WAS), we used high-temperature pyrolysis of WAS to support bimetallic Fe-Mn with nitrogen (N) co-doping (FeMn@N-S), a customized composite catalyst that activates peroxysulphate (PS) for the breakdown of tetracycline (TC). First, the performance of TC degradation was evaluated and optimized under different N doping, pH, catalyst dosages, PS dosages, and contaminant concentrations. Activating PS with FeMn@N-S caused the degradation of 91% of the TC in 120 min.

Complete defluorination of perfluorooctanoic acid (PFOA) by ultrasonic pyrolysis towards zero fluoro-pollution.

Advanced oxidation/reduction of PFAS is challenged and concerned by the formation of toxic, short-chain intermediates during water treatments. In this study, we investigated the complete defluorination of PFOA by ultrasound/persulfate (US/PS) with harmless end-products of CO, HO, and F ions. We observed 100% defluorination after 4 h of US treatment alone with a power input of 900 W.

Cationic polyacrylamide (CPAM) enhanced pressurized vertical electro-osmotic dewatering of activated sludge.

Pressurized vertical electro-osmotic dewatering (PVEOD) has been regarded as a feasible method to achieve sludge deep-dewatering, but the dewatering efficiency is still challenged by high electric resistance. This study employed cationic polyacrylamide (CPAM) as a skeleton builder to enhance electro-osmotic flow in PVEOD. The sludge dewatering efficiency and synergistic effect of CPAM and PVEOD were elucidated.

Treatment of overhaul wastewater containing N-methyldiethanolamine (MDEA) through modified Fe-C microelectrolysis-configured ozonation: Investigation on process optimization and degradation mechanisms.

In this study, the microelectrolysis system was applied to generate strong reductants, such as free hydrogen [H] and O, and thus removing N-Methyldiethanolamine (MDEA) in overhaul wastewater. Effects of initial influent pH, mass ratio of filings to wastewater, air aeration rate, and reaction temperature on the removal of MDEA were investigated intensively. Experimental results indicate that optimum removal rate of MDEA can be obtained at pH = 2, inlet air rate = 1 L min, mass ratio of filings to wastewater = 1:1 and temperature = 25 °C.