Advanced Oxidation Processes For Advanced Treatment Of Coking Wastewater

Advanced oxidation processes(AOPs) are paid grater attention by environmental scholar. AOPs have high efficiency, have no pollution affter treatment, so they are prospective technology for treating toxic and low biodegradativ contaminations in water. In this study, the second effluent of coking wastewater as the object mainly discussed how to treat, and was treated by using Fenton reagent oxidation and Titanium dioxide(TiO₂) photocatalysis oxidation, the process and mechanism of reaction was searched also.The results of Fenton reagent(Fe²⁺+H₂O₂) showed that the optimal conditions are as following: H₂O₂7.6ml, pH value4, reaction time 85min, 0.065 mmol/L Fe²⁺, the removal efficiency of CODcr is 65%; at the same time, we study the UV-Fenton which also attain the high CODcr and colour removal efficiency at low volume of H₂O₂.When using the TiO₂ photocatalysis oxidation to treat coking wastewater, the removal efficiency of CODcr is 65% at the following conditions: photocatalyst is industrical TiO₂, concentration of TiO₂ is 0.8g/L, the flux of air is 0.25m³/h, the irradiation time is 1.5h, pH value is about 10 and the volume ratio of H₂O₂ and wastewater is 0.012; The nano-TiO₂ is smaller than 100nm by using reverse microemulsion, the removal efficiency of CODcr can reach 78.3% when nano-TiO₂ coated on grass, nano-TiO₂ films calcined at 600°C, two dipping times and the volume ratio of H₂O₂ and wastewater is 0.015, and the concentration of CODcr of effluent is 89.1mg/L which reach the First wastewater let standard.The nano-TiO₂ film can combine the grass closely, and it's photocatalysis have not fail in after using some times.Finally,all this results prove the feasibility of using AOPs to advanced treatment of coking wastewater, and would be offer scientific methods and theory to further study on the advanced treatment of coking wastewaterand and other organic wastewater which is poisonous, noxious,high concentration and hard to degradation.