Study On The Treatment Of Dyeing Wastewater By The Two-doping Immobilized TiO₂ Activator

Photo catalytic Oxidation technique is a new advanced oxidation of treating waste water with a high efficiency of treatment. It use the UV illuminate on the semiconductor activators which have the band structure, such as TiO₂, ZnO, CdS, WO₃, which can produce the strongly oxidation·OH,·OH can degraded any organic pollution to CO₂, H₂O or mineral salts etal. In the so many semiconductor activators, TiO₂ is a photo-catalysis material with innocuity, high catalytic activity, strong oxidizing power, stable chemical reactivity and low-cost, make it become the most common and potential one.With C2H5OH as solvent and Ti(OBu)₄ as precursor, using activated carbon particles as the carrier and Cerium sulfate, Chlorinated La, Thiourea or Ammonia as doping agent. We use the Sol-Gel technique to make the immobilized modified TiO₂ photo-catalyst. In the he Photo catalytic& Oxidation reactor which was made and designed by myself, using the methyl orange dyeing wastewater to test the photo-catalytic activity, and study on the photo catalytic degradation of dyeing wastewater.Experiments are conducted to the TiO₂ photo-catalyst preparation conditions such as coating cycle times, calcinations temperature, the doped quantity of rare earth elements and nonmetal elements to the Immobilized modification TiO₂ activator photo catalytic activity. The experimental results indicated that the deposition 3 times, calcinations temperature is 450℃, calcinations 2h, in this condition the Immobilized TiO₂ activator have the better photo catalytic activity. But also inspects the dyeing wastewater pH, reaction time, dosing quantity of catalyst etc single factor in load type modified TiO₂ photocatalytic degradation of dyeing wastewater, the influence of different load type are decided the best light catalysts modified TiO₂ reaction conditions.Determining the dyeing wastewater initial concentration is 40mg/L, solution pH, aeration amount is 0.6m3/L, Ultraviolet irradiation response 210min. When the dosage of Immobilized Ce⁴⁺-S-TiO₂ photo-catalyst is 8g/L, the optimum doping of Ce⁴⁺is 2.5%, the optimum doping of S is 1.6%, the removal rates of chromaticity is respectively 82.1%. When the dosage of Immobilized Ce⁴⁺-N-TiO₂ catalyst is 4g/L, the optimum doping of Ce⁴⁺is 2.0%, the optimum doping of N is 1.3%, the removal rates of chromaticity is respectively 86.6%. When the dosage of Immobilized La³⁺-N-TiO₂ photo-catalyst is 2.6g/L, the optimum doping of La³⁺ is 1.1%, the optimum doping of N is 0.8 %, the removal rates of chromaticity is respectively 90.9%. When the dosage of Immobilized La³⁺-S-TiO₂ photo-catalyst is 1.5g/L, the optimum doping of La³⁺ is 0.5%, the optimum doping of S is 1.2 %, the removal rates of chromaticity is respectively 96.2%.Meanwhile, we also inspect the effect of different modification catalyst treating dyeing wastewater illuminated by sunshine. The test results show that,the removal of dyeing wastewater order from low to high is Immobilized Ce⁴⁺-S-TiO₂ photo-catalyst4+-N-TiO₂ photo-catalyst3+-N-TiO₂ catalyst3+-S-TiO₂ photo-catalyst. the Immobilized La³⁺-S-TiO₂ photo-catalyst have the best effective on the dying wastewater, the removal rates of chromaticity over 80%.The Immobilized modified TiO₂ photo-catalyst can effectively degrade the dyeing wastewater, easy to operate, without secondary pollution, has good feasibility. The modified TiO₂ photo-catalyst which has the better photo catalytic activity, and in the sunshine conditions can also have high removal. Therefore, preparation of high-performance, low-cost load-TiO₂ photo-catalyst, in search of better technology is bound to be modified TiO₂ research hot spots in order to make it better applied to the actual hard-biodegradable waste water treatment.