Study On The Pretreatment Of Overhauling Wastewater Of Purification Of Natural Gas By Fenton Oxidation And Activated Carbon Adsorption

The wastewater from natural gas purification is comprised of normal purifying wastewater and overhauling wastewater, the concentration of organics in normal purifying wastewater is low and this wastewater is easy to dispose; while the concentration of organics in overhauling wastewater is high and complex, which is hard to deal with by biochemistry process, these years is diluted by fresh water and combustion furnace burning to deal with, but these two methods are inefficient and costs high, so need to develop a new wastewater treatment methods. Although we have studied the up-flow anaerobic sludge bed reactor (UASB) to deal with the high concentration wastewater from natural gas purification, but the start-up of pilot-scale UASB reactors 133d test results show that: when the influent is 6000mg/L, The COD removal from the water only about 40%, the result is not very good. Therefore, exploration and search for a pre-effective way to have some practical significance. In this paper, Fenton oxidation and activated carbon adsorption were used to treat overhauling wastewater from purification of natural gas, with a view of improving operating efficiency of UASB.The preliminary operating conditions were determined by Orthogonal experiments, and each effecting factor was analyzed according to preliminary operating conditions. In order to confirm the optimum response condition, the main factors influencing efficiency were investigated one by one, to test the impact to COD removal of wastewater, the experiment results indicated that the optimal Fenton oxidation operating conditions are determined as follows: the dosage of H₂O₂ is 0.3mol/L ,the proportion of H₂O₂ and Fe²⁺ is 20, the pH value is 3,the reaction temperature is 70℃and reaction time is 40min .Under these conditions, the COD removal rate reached 78.6 percent, BOD₅/COD value from 0.168 to 0.353-0.403, the bio- degradability can be greatly improved, if H₂O₂ been putted into by three times, for the time 10min, COD removal rate will rise by 78.6 percent to 82.3 percent, can be seen in batches using H₂O dosage will further enhance the effectiveness of the response. After Fenton oxidation treatment, then by activated carbon adsorption, in view of make further enhance to the wastewater COD removal rate. The subject of activated carbon adsorption is single-factor test method, test different adsorption PH value, dosage, as well as activated carbon adsorption waste time on COD removal, the results show that: Fenton oxidation treatment without adjusting pH value, the dosage of activated carbon is 20g/L ,at home temperature the adsorption time is 3h, COD removal rate reached 47.3%, BOD₅/COD value is 0.438-0.625, create the conditions for the anaerobic biological treatment follow-up .Research for this article, laid a theoretical foundation and provided a basis for the trial ,in Fenton oxidation and activated carbon adsorption as a pretreatments of UASB to treat overhauling wastewater of purification of natural gas .