Selective flotation separation of ABS/PC from ESR plastic wastes mixtures assisted by ultrasonic catalyst/H2O2

The present study investigated the potential recycles of acrylonitile butadiene styrene terpolymers (ABS) from their blends with polymethylmehtacrylate (PMMA), polyCarbonate (PC) and high impact polyStyrene (HIPS) using flotation separation assisted by ultrasonic catalyst/H2O2. The effect of various factors such as H2O2 dose, duty cycle and contact time of the ultrasonication on the recovery rate and purity of ABS/PC were conducted. The results showed that H2O2 dose significantly influenced on the recovery rate of ABS/PC and the optimized H2O2 dose was found at 2%. The recovery rate and the purity of submerged ABS/PC reached 99.5 and 98.6%, respectively, at 300 s of contact time. The duty cycle and the contact time of the ultrasonification also exhibited highly effective for the recycle of ABS/PC from the plastic waste mixtures. The radical scavengers and the mechanism of flotation separation of ABS/PC by ultrasonic catalyst/H2O2 were proposed. Additionally, the economic potential and environmental impacts were discussed. These findings are crucial for flotation separation of ABS/PC from the plastic waste mixtures assisted by ultrasonic catalyst/H2O2 with high recovery rate and purity of ABS/PC in order to produce further value added products as well as reduce the environmental impact of plastic waste. - 2019 Elsevier Ltd.Scopu

Improvement of hydrogen production under solar light using cobalt (II) phosphide hydroxide co-doped g-C3N4 photocatalyst

Graphitic carbon nitride (g-C3N4) has been extensively studied as a model of photocatalyst material for water splitting. This study investigates potential of cobalt (II) phosphide hydroxide co-doped g-C3N4 (Co-P/C3N4) for solar water splitting to produce hydrogen gas as a clean energy source. Characterizations of the materials were done using X-ray diffraction, Scanning Electron Microscopy, X-ray Photoelectron Spectroscopy, and UV–visible spectroscopy (UV–Vis). Under solar light, the hydrogen production rates per hour using Co-P/C3N4 were 386.8 µmol/g which is 14-fold higher than that of g-C3N4 (28.1 µmol/g). The co-doping of cobalt (II) phosphide hydroxide onto g-C3N4 rapidly improved light harvesting capacity and photo-generated charge carrier separation, leading to increase photocatalytic H2 production. In addition, the reusability of Co-P/C3N4 was confirmed by performing the photocatalytic hydrogen production for five cycles. The material consistently produced H2 without any significant loss in hydrogen productivity. Based on these results, Co-P/C3N4 could be utilized as promising photocatalyst material for production of clean energy.This work was supported by Qatar University under Grant Number GCC-2017-007.Scopu