Effect of the near-infrared activated photocatalyst Cu2(OH)PO4 nanoparticles on the growth of harmful algal blooms causing Microcystis aeruginosa.

The wide range existence of M. aeruginosa FACHB 905 strains in the aquatic environment becomes a great threat for the health of humans and animals; it also poses a great obstacle in the ecological ecosystem. Therefore, an effective, efficient, and environmentally friendly method of treatment is needed. In this work Cu2(OH)PO4 nanoparticles were successively synthesized from a mixture of Cu (NO3)2 and Na2HPO4 according to the results from Fourier-transform infrared (FT-IR), X-ray diffraction (XRD), ultraviolet/visible/near-infrared in diffuse reflectance spectroscopy (UV/Vis/NIR DRS), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) tests. Furthermore, Cu2(OH)PO4 was used to mitigate the growth of M. aeruginosa FACHB 905 strains on a lab-scale, and the investigation on the growth of the harmful algal bloom (HAB) causing M. aeruginosa FACHB 905 strains was worked on. The Cu2(OH)PO4 is effective in inhibiting the growth of the strain by more than 97% at a concentration of 0.032 mg mL-1. Furthermore, analysis of the chlorophyll a content and polysaccharide asserted that a remarkable decrease from 9.40 mg L-1 and 37.66 mg L-1 for the control to 0.07 mg L-1 and 10.21 mg L-1 for the treatment media with 0.032 mg mL-1 Cu2(OH)PO4 has been achieved. The results affirm the effectiveness of the Cu2(OH)PO4 as suitable candidates for preventing HABs caused by the M. aeruginosa FACHB 905 cyanobacterium and other similar strains.

Study on the degradation of accumulated bisphenol S and regeneration of magnetic sludge-derived biochar upon microwave irritation in the presence of hydrogen peroxide for application in integrated process.

Based on the multi-functional magnetic sludge-derived biochar (MSBC), an innovative integrated process-coupling accumulation by adsorbing, degradation by microwave (MW)-induced catalytic oxidation in the presence of H2O2 and the regeneration of adsorbent simultaneously, was proposed. In this study, bisphenol S (4,4'-sulfonyldiphenol) was chosen as the pollutant model, its behaviors and related mechanism of BPS and MSBC in MW + H2O2 system were investigated. The BPS effective degradation on MSBC was proved by decoupling the adsorption and degradation with solvent extraction. OH and h+ play vital roles based on the scavenger tests. The synergistic effects of hot-spot of microwave irradiation, activation of H2O2, and charge transfer-induced doping effects of MSBC were attributed to the reactions. This work proves the feasibility in economics and energy-save treatment approach for low concentration organic pollutants in water.