Degradation Of Organic Pollutants In Wastewater By Advanced Catalyti Oxidation

With the rapid development of industry,water pollution is becoming more and more serious.The severe environmental situation has put forward higher requirements on several aspects such as energy conservation,emission reduction,consumption reduction and water pollution control.Promoting green development and building new industries has become the primary task at present.As an important component of water pollution,organic wastewater comes from a wide range of sources,including coal chemical industry and pesticide industry.In this paper,photocatalytic coupled hydrogen peroxide?H₂O₂?degradation technology is used to study the degradation of simulated wastewater of phenol,2,4-dichlorophenol and quinoline,as well as the actual wastewater from an agricultural and pharmaceutical plant.In experiments,the TiO₂@diatomite photocatalyst was prepared with diatomite as carrier,using sol-gel method,and catalyst performance was found to come the best when catalyst using acetic as inhibitors,icalcined for 2.5 h under 500?C.Scanning Electron Microscopy?SEM?,Energy Dispersive X-ray spectroscopy?EDS?,Fourier Transform Infra-Red spectroscopy?FT-IR?and X-ray Powder Diffraction?XRD?methods were used to analyze the catalyst.The photocatalyst was modified by metal ion doping and semiconductor composite,and it was found that ions,Cu²⁺,Ag⁺and Co²⁺,co-doping could achieve the best optimization effect.Comparing the five kinds of wastewater degradation process including:H₂O₂?H₂O₂?,H₂O₂ and light?H₂O₂+UV?,photocatalytic?photocatalyst+UV?,adding H₂O₂ for photocatalytic?H₂O₂+UV+light catalyst?and controling the temperature of the reaction system,adding H₂O₂ and photocatalytic?H₂O₂+photocatalyst+UV+temperature?,it was found that H₂O₂+photocatalyst+UV+temperature process achieved the best results.In the experiment,the photocatalytic coupling H₂O₂ method was used to explore the optimal degradation process for simulated wastewater of 2,4-dichlorophenol and quinoline in terms of initial concentration,temperature,H₂O₂ dosage,solution pH and catalyst dosage.The COD degradation rate of 2,4-dichlorophenol comes 94.1%,when the H₂O₂ dosage,temperature,initial concentration,initial pH and catalyst dosage are 10.0 mL,40?C,200 mg/L,5-6 and 6.0 g,respectively.The COD degradation rate of quinoline comes 96.3%,when the H₂O₂ dosage,temperature,initial concentration,initial pH and catalyst dosage are 10.0 mL,50?C,200 mg/L,8-9and 4.0 g,respectively.Adopting the method of photocatalytic coupling of H₂O₂,the COD concentration of actual production wastewater of high concentration and colority form a pesticide plant decreases from initial 25306.9 mg/L and 32670.0 mg/L to 2282.7 mg/L and 4410.4 mg/L,and the degradation rates achieve 90.9%and 86.5%,respectively.The experimental results prove that the process is effective for organic production wastewater of high concentration and colority form pesticide plant.