A Study On Treatment Of Surfactant Wastewater Based On STEP Chemical Process

Alkylbenzene sulfonate is an important kind of surfactant and brings convenience to the production and life of human beings.However,it also poses a threat to the environment,.The traditional treatment methods of SDBS wastewater have been thoroughly studied,but there are still many problems and defects,making it difficult to achieve satisfactory result.So the degradation of SDBS is still an important subject.In 2009,Licht and Wang proposed the theoretical model of STEP（solar thermal electrochemical process）,coupling solar,thermal,electrical and electrochemical process up to achieve efficient oxidation of organic wastewater treatment.The process takes high temperature chemical process as the core and uses the synergistic effect of solar,electrical and thermal effects of solar energy to decompose stable molecules that have high reaction energy into energetic molecules.STEP process has broad application prospects for the high efficiency,energy saving and environmental protection.In this paper,we applied STEP process to SDBS wastewater treatment firstly.In the experiment,solar-thermal conversion supplied the high temperature environment and solar-electric conversion provided the energy for the degrading system.Pollutant removal rate and reaction energy consumption were taken as indexes to analyze the effects of temperature,applied voltage,electrolyte concentration,initial concentration of pollutant,concentration of electrolyte and p H.The products were investigated by gas chromatograph（GC）and infrared spectrometer（FTIR）to study the degradation process of SDBS by STEP technology.Experimental results show that,STEP technology can effectively remove SDBS by coupling technology of solar-electrical-thermal effects,reducing the energy consumption of reaction at the same time.Besides,The pollutant removal effect enhances with the increasing of the applied voltage,current density,electrolyte concentration,the concentration of SDBS,and is better under acidic condition.Outdoor STEP experiment proves further evidence that STEP process is conducive to the degradation of SDBS.At 30min,the removal rate reaches about 40%.Kinetic analysis shows that the treatment process of SDBS by STEP technology is a first-order reaction.At the temperature of 30^oC,50^oC,70^oC and 90^oC,the reaction rates are0.00572s^-1,0.00724s^-1,0.00996s^-1and 0.01199s^-1.Current efficiency increases with the increase of temperature,which can reach more than 53%at 90 ^oC.Infrared spectrum and gas chromatography results show that the main reaction products of the treatment process of SDBS by STEP technology are sulfate,water and CO₂...