Experimental Study On Oxidative Degradation Of GSM And 2-MIB By UV/H₂O₂

In recent years,the seasonal blooms of algae were more and more seriously with intensified eutrophication.The process of algae grows,breeds,metabolises produces taste and odor pollution that not only affected the sensory quality of drinking water,but also caused harm to human health.Besides,it can trigger water supply crisis that pose a threat to national public security system seriously.Taking the risk of odor caused by algae into consideration,GSM and 2-MIB have been identified as the most severe occurring chemicals in odor contamination.The current water treatment processes have a few shortcomings such as treatment systems occupied large area,the potential threats of bromate disinfection by-products and the low removal efficiencies for GSM and 2-MIB in current water treatment processes.So it is necessary to find an efficient and environmentally friendly water treatment technology.In this case,the advanced oxidation technology of UV/H₂O₂ was applied widely in water treatment systems which could make up the shortages and remove GSM and 2-MIB effectively.In this paper,UV/H₂O₂ were utilized in small and pilot study to examine its practical feasibility of application and provide new idea and technique for the removal of odor pollution.Kinetic studies of GSM and 2-MIB in UV/H₂O₂ treatment process have already been carried out but only for the first order reaction kinetics.Therefore,in this study,natural water model systems were established by pure water with HA added to explore the competitive dynamic researches of HA and GSM,2-MIB in UV/H₂O₂ system.The results showed that UV254 could represent the concentration of HA ideally and HA were in line with first-order kinetics mode.When the reference organics was NB,NB and HA fit the competitive kinetics model in the UV/H₂O₂ and the kineticsparameters of HA was 3.5×108M-1s-1.When the reference organics was HA,HA and GSM,2-MIB also fit competitive kinetics model in the UV/H₂O₂ process.The kinetics parameters of GSM was 7.1 × 107M-1s-1.And the kinetics parameters of2-MIB was 6.7 × 107M-1s-1.When experiment condition was different,kinetics parameters can be a little different.But these were diversed in the same order of magnitude.So they tended to model of competitive dynamics.Based on these results,this research laied a theoretical basis for further study on competitive kinetics model of natural water.According to the pilot study,the removal efficiencies of GSM and 2-MIB were stable in UV/H₂O₂ system under the long-term stable operation.GSM and 2-MIB were totally degraded when the background concentration was 150ng/L.At the same time,the conventional indicators,such as pH,UV254,turbidity and so on,which indicated the water quality becoming better.Although the formation tread of THMS was slightly increased,it is consistent with the drinking water health standards?GB5749-2006?.According to the analysis of EEM,part of NOM can be degraded on the basis of removal of GSM and 2-MIB.However,there are still some disadvantages for the technology that residual H₂O₂ may consume chlorine in wastewater treatment plants.Some studies have reported that the activated carbon can absorb excess H₂O₂,Therefore activated carbon was combined with UV/H₂O₂ system to build the combination process?UV/H₂O₂-activated carbon process?.In the further study,the process can not only remove odor effectively,but it could also solve the problem of excess H₂O₂.Therefore,UV/H₂O₂-activated carbon promoted the quality of water and provide strong technical support for practical application.