Study On Adsorption/photocatalysis Of Dye Wastewater By LZH And Its Composites

Water pollution which caused by the discharge of a large amount of organic dye wastewater has become one of the severe environmental problems facing the world.The organic dye usually has a benzene ring structure,certain toxicity,and is poor in biodegradability.It is difficult to be degraded by the natural world after being discharged into a water body.If it is enriched in the human body,it will cause great harm to the human body.However,it is difficult to achieve good processing results in general functional materials.Therefore,it is important to develop a new environment-friendly adsorbent material and high-efficiency photocatalytic functional materials.In this paper,layered hydroxide salt LZH,layered double hydroxide Zn-Co-LDH,Ag-LZH and Zn-MOF-LZH functional materials were prepared by hydrothermal method,and the materials were characterized by a series of characterization methods.The optimum process conditions for the preparation of LZH were determined and the mechanism of material control growth was discussed.The factors such as pH value,solution concentration,reaction time and dosage of adsorbent were studied systematically for the adsorption of LZH and Zn-Co-LDH.The influence of the properties of the base orange and the adsorption mechanism were studied.The effects of Ag-LZH and Zn-MOF-LZH functional materials on the photocatalytic performance of methyl orange under different conditions were studied,and the photodegradation mechanism was discussed.The results show that the optimum conditions for LZH are 0.01 mmol of zinc nitrate,12 mL of deionized water,1 mL of triethanolamine,120 °C,and 2 h.The optimum pH for LZH adsorption of methyl orange is 6 On the left and right,the adsorption process matches the pseudo second-order kinetic model.The theoretical maximum adsorption amount calculated by the Langmuir model is 529.3 mg/g;the most suitable pH range for Zn-Co-LDH adsorption of methyl orange is 4-8.Under the optimal conditions,the adsorption amount of Zn-Co-LDH-2 to methyl orange was as high as 1261.2 mg/g;adding 1 g/L of 3%-Ag-LZH photocatalyst to 10 mg/L methyl orange solution could be 60 min.The methyl orange is almost completely degraded,and the highest degradation efficiency is as high as 99.77%,and the material can achieve high photocatalytic effect after repeated use.The Zn-MOF-LZH material prepared by hydrothermal method has a catalyst addition amount of 10 mg in a 10 mg/L methyl orange solution at a pH of 10,and its degradation efficiency to methyl orange is almost 100%.