Photocatalytic Removal of Harmful Algae in Natural Waters by Ag/AgCl@ZIF-8 Coating under Sunlight

oleh: Gongduan Fan, Zhong Chen, Bo Wang, Shimin Wu, Jing Luo, Xiaomei Zheng, Jiajun Zhan, Yifan You, Zhi Zhang

Format: Article
Diterbitkan: MDPI AG 2019-08-01

Deskripsi

In order to control the cyanobacterial blooms in eutrophic water, an Ag/AgCl@ZIF-8 floating coating was prepared by a dip-coating method with a sponge, innovatively employed as a carrier for the removal of algae in natural water samples. The as-prepared photocatalyst was characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (SEM). The effects of this Ag/AgCl@ZIF-8 coating on algal removal and phytoplankton community structure in natural water samples with cyanobacterial blooms were investigated under sunlight. Results showed that Ag/AgCl@ZIF-8 distributed uniformly on the surface of the coating with good stability and algae removal efficiency in water bodies. After 6 h of exposure under sunlight, the chlorophyll <i>a</i> in the natural water samples was degraded by 99.9%, the densities of <i>Microcystis</i> <i>aeruginosa</i> were reduced by 92.6% and the densities and biomass of the other algae decreased by about 80%. Meanwhile, the content of colored dissolved organic matter (CDOM) in the samples was decreased, effectively controlling the cyanobacterial blooms. It was found that O<sub>2</sub><sup>&#8226;&#8722;</sup> played the main role in the photocatalytic inactivation. In conclusion, the Ag/AgCl@ZIF-8 coating has a promising application potential for the removal of harmful cyanobacteria, and provides a new idea for the control of cyanobacterial blooms in water bodies.