Light-Oxygen Coupling Criving Mechanism And Effect Of Hydrotalcite/Cu₂O On Removing Algae By Photocatalytic

Algae blooms caused by eutrophication pollution has become a serious environmental problem. Cyanobacteria blooms reduce water clarity and produce microcystins which threats drinking water safety, fisheries and aquaculture. Full use of natural conditions to gover environmental pollutants is a trend in recent years. Harmful algal bloom outbreaks in seasons with sufficient sunshine and warm temperature. Photosynthesis of large amount of algae will bring high dissolved oxygen concentration in water. Therefore, light and supersaturated dissolved oxygen is the key environmental factors in algae blooms. It will provide new ideas for using nature law to remove algal bloom by efficient use of these factors to be the driving factors in purifying water pollution.In this paper, based on p-type semiconductor Cu₂O, we prepared Fe-HDL/Cu₂O composite. Cu₂O can be excited by visible light to produce H₂O₂, which will replace the addition of H₂O₂ in classical Fenton system. H₂O₂ produced by Cu₂O will form Fenton system with magnetite, together with which hydrotalcite will capture Microcystis aeruginosa to achieve a light- oxygen coupling system in algae removing. In this way, we can take full advantage of the light and dissolved oxygen in algal bloom to remove algae. The main contents are as follows: 1. Fe-HDL/Cu₂O composite materials is prepared by co-precipitation method. XRD, FT-IR, SEM, XPS and Uv-vis DRS were used to characterize and analyze the Cu₂O, magnetite, hydrotalcite. The morphology and structural features before and after composition of them were studied. On this basis, we analyzed the composite mechanism of magnetite, hydrotalcite and Cu₂O. In addition, by Uv-vis DRS Characterization, we studied the optical absorption properties of Cu₂O and Fe-HDL/Cu₂O composites. 2. According to the determination of H₂O₂ concentration in multiple systems, we studied the performance of Cu₂O produce H₂O₂ and magnetite decomposing H₂O₂, establishing the light Fenton system driving by factors appearing when algal bloom breaks out. 3. According to the determination of concentrations of Chlorophyll-a, we studied the photocatalytic properties of Fe-HDL/Cu₂O composites. And by changing the light, oxygen conditions, we studied the effects of light and oxygen concentration on algicidal properties of Fe-HDL/Cu₂O immobilization Fenton system. 4. According to the determination of the process parameters on killing algae, as well as nd the measure of physiological indicators and observation of the morphology, we studied the mechanism of light-oxygen coupling driving Fe-HDL/Cu₂O immobilization Fenton system killing Microcystis aeruginosa and apoptosis.