Study On Preparation Of Modified Red Mud Photocatalytic Material And Its Performance Of Antibiotic Degradation

In the production of the metallurgical industry,bauxite will produce a polluting industrial solid waste residue-red mud?Red Mud,RM?after refining.Because red mud contains a lot of strong alkaline substances,it will cause serious pollution to soil,water and air.At the same time,the antibiotics remaining in the water body pose a serious threat to the ecological environment and human health.In this paper,red mud is used as a photocatalyst and modified to enhance its photocatalytic activity,and degradation of antibiotics in water through photocatalytic technology.This paper has introduced photocatalysts prepared by modifying red mud by calcining,loading graphene oxide?GO?,and carbon nitride?g-C3N4?.Further study the photocatalytic activity and photocatalytic reaction mechanism of these materials to degrade antibiotics in water.The specific work includes the following parts:?1?The red mud is calcined at different temperatures in the air to prepare a modified photocatalyst,and the photocatalytic degradation of tetracycline?TC?in the water body under visible light.The results show that the calcined red mud's photocatalytic degradation activity on TC is significantly better than that of the original red mud.Among them,RM-350?the sintering temperature is 350°C?showed the best photocatalytic performance(100 m L,10mg·L^-1;TC degradation rate was 88.4%within 80 min).Further explore the reasons for the photocatalytic activity improvement of red mud after calcination.Finally,the possible photocatalytic degradation mechanism of calcined red mud was discussed and proposed.?2?A new type of composite photocatalyst?RM-GO?was prepared using graphene oxide?GO?modified red mud.Through a series of characterizations,it was confirmed that GO can effectively improve the shortcomings of red mud,such as weak light absorption capacity,rapid recombination of photogenerated charges and easy reunion,and showed excellent photocatalytic activity and good stability under visible light.Among them,RM-7GO?the mass ratio of RM and GO is 100:7?showed the best photocatalytic performance?within 80min,the degradation rate of TC was 79.8%?.In addition,the synthesized composite materials were used to degrade oxytetracycline?OTC?and chlortetracycline?CTC?to confirm its good universality for antibiotic degradation.Finally,according to the capture experiment,the possible photocatalytic degradation mechanism of RM-GO composites was proposed.?3?Red mud/g-C3N4?RM-CN?composite material was prepared by one-step calcination method using red mud and melamine as raw materials.Through a series of characterization,it was confirmed that recombination can effectively promote the absorption of visible light and the separation of photogenerated electron-hole pairs.Under the synergistic effect of adsorption and photocatalytic degradation,RM-CN can effectively remove antibiotics?TC,OTC and CTC?and dyes?methylene blue,referred to as MB;malachite green,referred to as MG?in water.Compared with pure CN,the maximum adsorption capacity and photocatalytic activity of RM-CN are significantly improved.Among them,0.8%RM-CN?red mud mass ratio is 0.8%?showed the best degradation effect on antibiotic and dye pollutants.The degradation rates of TC,OTC and CTC were 79.0%,60.0%and 83.8%,and the degradation rates of MB and MG were 96.9%and 97.2%,respectively.The possible photocatalytic degradation mechanism of RM-CN composites is further proposed.