| Sodium alkylbenzene sulfonate as an oil displacement agent used to enhance oil recovery when drilling and exploration,the production wastewater contains a large amount of sulfite,a small amount of sulfonate and petroleum substances,and the direct discharge into the environment will cause water pollution,ecological imbalance,the destruction of environmental media.Advanced oxidation technology has the advantages of strong oxidizing ability,no secondary pollution,no selectivity and so on.In view of the scientific research practice requires,the effects of various factors on COD degradation of sodium sulfonate wastewater were studied,perfect the related theory,completed the composite strength from small to pilot the practice application of oxidation technology:The laboratory experiment to study the degradation of petroleum sulfonate wastewater by ozone oxidation,the technique of photocatalysis combined with ozone and the integrated enhanced oxidation technologies.The COD degradation effects of three oxidation process(O3,O3/UV and O3/UV/TiO2)were compared.The results show that the order of COD degradation was O3/UV/TiO2>O3>O3/UV,and these three oxidation technique can achieve the degradation of more than 99%when the reaction is 2 hours,which can be discharged,then tends to be stable.The integrated enhanced oxidation technologies can greatly improve the oxidation rate of pollutants,the best technology is:5L wastewater,adding 250mL hydrogen peroxide,the air flow is set as 1m3/h,the oxygen flow is set as 10L/h,the current of ozonator set as 0.4A.This process can greatly improved the COD degradation rate,and processing time reduced to 40min.By analyzing and discussing the trend of wastewater degradation under different reaction systems,the mechanism is further explored to explain the reasons for the reaction phenomenon,It provides treatment method for the production of sodium sulfonate.Through the pilot study,the effects of aeration rate,ozone generation power,initial pH and H2O2 dosage on the COD degradation efficiency of wastewater were investigated.Treatment capacity of pilot experiment is 100L/h,COD degradation efficiency has increased significantly with the increase of aeration,but too much aeration will increase the cost of wastewater treatment,thus aeration is set as 10m3/h.However,not greater the power of ozone generation is better.This is because excessively high concentrations of ozone generate more hydroxyl radical,exacerbating the collision between free radicals,resulting in the reduction of oxidants in the system,and then reduce the oxidation efficiency.According to research,hydrogen peroxide dosage is set to 10L/h,air aeration is 10m3/h,ozone generation power of 200W,COD can be reduced to 60mg/L or less within four hours reaction,through the intermittent continuous running experiment of 4 hours hydraulic retention time,and then the results showed that the COD of waste water treated was less than 60mg/L and the removal rates of sulfonate and TOC reached 96.3%30.5%,water quality is stable,in line with emission standard of pollutants for petroleum refining industry(GB 31570-2015),The feasibility of compound strong oxidation technology for the degradation of sodium sulfonate wastewater is described,and provide technical means and reference value for this kind of wastewater in China. |
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