Adsorption and photodegradation of micropollutant in wastewater by photocatalyst TiO2/rice husk biochar.

With the acceleration of global industrialization, organic pollutants have become a threat to ecological safety and human health. This work prepared TiO2/rice husk biochar (TiO2/BC) for removal of bisphenol A (BA) micropollutant in wastewater. Experiment results revealed a low BA removal efficiency by TiO2/BC was observed at 34.5% under the dark environment. However, the removal rate of BA by UV light-assisted TiO2/BC significantly increased to 97.6% in 1 h. The results also demonstrated that the removal performance of BA using TiO2/BC was 2.1times higher than that of commercial TiO2 (46.4%). Besides, the removal efficiency of BA by reused TiO2/BC after eight cycles slightly decreased by 12.8%, demonstrating the excellent properties of the prepared composite. TiO2/BC also exhibited high removal efficiency of BA (over 89%) from the synthetic wastewater sample, indicating the potential utilization of composite for removing BA in wastewater. This work provides a new way to turn biomass waste into useful material and effective method to remove micropollutant BA.

Enhanced recovery of phosphate as a value-added product from wastewater by using lanthanum modified carbon-fiber.

The aim of this study is to present the potential of activated carbon fiber (CF) impregnated with lanthanum (La) as a novel adsorbent (La-CF) of phosphate-phosphorus (P) and to assess the value-added due to P-recovery from wastewater using La-CF. The CF were loaded with La and the loaded CF was then calcined at 500 °C. The La-CF adsorbent was used in a series of batch experiments to characterize the adsorption of P at pH of 6-10 and P concentrations of 1-200 mg/L. Physical-chemical properties such as surface morphology, surface charge, surface area, and surface chemistry were determined for the La-CF. The La-CF exhibited adsorption capacity of 196.5 mg/g, fast sorption kinetics and high selectivity for P removal from aqueous solution. La-CF removed 97.3% of P from wastewater and achieved P-level to below 2 mg/L. It was repetitively reused over 10 times in successive cycles to remove P from wastewater. The value-added by recovery of P from wastewater was calculated at around 0.12 US$/L, demonstrating economic benefits of La-CF. In conclusion, the successful removal, recycling, and recovery value-added of P using La-CF adsorbent displayed good potential for developing the technology for treatment of wastewaters to recover valuable compounds such as phosphorus.