In Situ Healing of Compromised Membranes via Polyethylenimine-Functionalized Silica Microparticles

Construction of self-repairing polyethersulfone membrane with high density hydrophilic microregions by two dimensional restricted channels for enhanced dyes/salts selective separation

Based on the dye/salts separation efficiency and membrane injury caused by serious pollution of dye/salts wastewater, this study constructed a 2D tight ultrafiltration membrane that could both solve the membrane injury problem and improve the dye/salts separation efficiency, the compatibility of good self-healing performance and penetration performance by 2D material magnesium-aluminum Layered double hydroxide (MgAl-LDH). The self-repairing of physical injury was achieved through the swelling effect of AMPS-PAN, this property was proved by permeate flux, the retention performance of salts in dye/salts solution, the comparison of scanning electron microscope (SEM), and the mechanical strength after physical injury. The healing of chemical injury occured through the reaction of CC and polyethersulfone chain breakage, which was confirmed by X-ray photoelectron spectroscopy (XPS), permeate flux, the retention performance of salts in dye/salts solution, and mechanical property. The high separation efficiency of dye/salts was achieved through 2D material MgAl-LDH, which was proved by separation selectivity ɑ. The compatibility of good self-healing performance and penetration performance was obtained by 2D material MgAl-LDH, which was proved by the penetration and self-healing performance. Morever, the membrane illustrated excellent both permeability and dye/sals separation efficiency, just like the permeate flux, the retention performance of sodium sulfate in methyl blue/sodium sulfate solution, the retention performance of Na2SO4 in methyl blue/Na2SO4 solution, the retention rate of methyl blue were 99.1 L/m2h, 12.5%, 7.9%, 97.7%, respectively. The results of pollution index and contact angle also proved that the membrane had anti-pollution performance.

High-quality syngas production: The green and efficient utilization of waste tire and waste heat from the steelmaking converter process

This study proposes a new technology in which waste tire powders are injected into a converter vaporization cooling flue for gas recovery via pyrolysis using high-temperature waste heat. The higher temperature pyrolysis behavior of waste tire powder under different heating rates was investigated using a TG-MS technique. A drop tube furnace was used to simulate the converter vaporization cooling flue to investigate the effect of high temperatures on waste tire powder pyrolysis. The results indicated that secondary pyrolysis occurred above 900 °C with low weight and weight loss rates, which were considerably lower than those observed in the thermal degradation stage. The main gaseous products formed were CO, CO₂, H₂, CH₄, and H₂O. The drop tube furnace experimental results indicated that high temperatures can facilitate the degradation of waste tire powder to generate more H₂ and CO and improve the low heating values. At 1200 °C, the H₂ and CO contents were approximately 19.60% and 4.90%, respectively. The low heating value was 29.64 MJ/Nm³. The char yield was in the range of 32.67%-37.33%; the fixed carbon content increased from 79.63% to 84.75%. The results provide preliminary verification of the feasibility of injecting waste tire powders into a converter vaporization cooling flue for gas recovery.

Efficient elimination of U(vi) by polyethyleneimine-decorated fly ash

The easily-synthesized FA@PEI showed an excellent performance in the elimination of U(vi) from wastewater, with the adsorption mechanism being explored.