Study On Catalytic Oxidation For Purification Of Surface Water Provided Lifting Water And Aeration

Catalytic Wet Air Oxidation (CWAO) is an effective treatment method to destroy high-concentration organic pollutants in wastewater. However, CWAO process under room temperature and atmospheric pressure to remove natural organic pollutant in surface water has been rarely reported. According to the current situation, CWAO process was tried to study to be attached to Water-lifting and Aeration for pretreating surface water polluted by bits of natural organic compounds under room temperature and atmospheric pressure.The situation of this research as follows:(1) Through comparing the different activity and stability of homemade catalysts in this experiment,Fe2O3/sphericalγ-Al2O3 was proved to be the best catalyst.(2) Effect of Fe2O3 involved in adsorption ofγ-Al2O3 on CODMn, TOC, UV254 and UV410 distribution and changes of TOC and UV254 in various molecular weight region was investigated. And the results revealed that the catalytic oxidation reaction existed in the removal process of nature organic pollutant in surface water under room temperature and atmospheric pressure.(3) Through investigating the activity of reused catalysts, it was found that the organic removal capacity of catalyst had begun to be stable after the catalyst was used for one time.(4) Through investigating the dissolution of active metal, it was found that the deactivation was caused by the degradation products of nature organic pollutant remained on the surface of catalyst and covered the active sites. (5) The Fe2O3/γ-Al2O3 whose effect of removal on natural organic pollutant had been stable were selected as the catalyst used in this part of CWAO process. Through investigating the activity of catalyst with dosing quantity of 0.1 g/L,0.5g/L and lg/L,it was showed that Fe2O3/γ-Al2O3 should been put into water with the dosing quantity of a little more than lmg/L,so that CODMn would been roughly reduced from 5mg/L to 4mg/L in ten days.(6) It was assumed that the optimal dosing quantity of catalyst was 1.5 g/L,and the catalytic activity was investigated. The results showed that, for surface water at the third grade with 40-day hydraulic retention time, the effects of removal on natural organic indexes were notable,and stable for long term. After the experiment of CWAO process had progressed for a month, the removing rate of CODMn, TOC, UV254 and UV410 could respectively reach 50.9%,38.5%,57.5% and 62.5%.This research showed that it was feasible that the combined technique of Water-lifting with Aeration and CWAO was used to pretreat surface water polluted by bits of natural organic compounds under room temperature and atmospheric pressure.