Removal Of Typical Odorants In Drinking Water By Advanced Oxidation Technology Of Ultraviolet Combined With Peroxodisulfate

In recent years,with the development of the society economy,people pay more and more attention to the quality of drinking water,and odorants that cause people feel unsatisfied are getting more and more concerant.The typical odorants in drinking water are 2-methylisoborneol?2-MIB?and geosmin?GSM?which cannot be effectively removed through the conventional water treatment processes,which affects the drinkability of water.So,it is urgent to find a effectively method to remove the typical odorants.The performance and reaction kinetics of removing odorants with ultraviole ultraviolet light combined with peroxodisulfate?UV/PS?and vacuum ultraviolet with peroxodisulfate?VUV/PS?on the removal efficiency of odorants and the reaction kinetics.At the same time,the power consumption indicators under different situations was compared.The main conclusions are as follows:?1?Both 2-MIB and GSM could hardly be removed by PS alone or UV alone,but they could be effectively removed by VUV/PS and UV/PS processes.Under PS concentration of 0.5mmol·L^-1,the removal rates of 2-MIB and GSM with VUV/PS process were increased by 76%and 74%than those with VUV alone.The performance of removing odorants with VUV/PS process was mainly influenced by the PS concentration and VUV light intensity.When the PS concentration increased from 0.25mmol·L^-1 to 2.00 mmol·L^-1 and VUV light intensity increased from 113.2?W·cm^-2 to618.5?W·cm^-2,the removal rate of 2-MIB was enhanced by 42%and 39%,and the removal rate of GSM was enhanced by 34%and 16%.The effect of pH on 2-MIB and GSM removal was not significant.The ion of HCO₃^-and humic acid will decrease the2-MIB and GSM removal rates,and the degree of reduction increases with the concentrations of HCO₃^-ion and humic acid.?2?Compared with the VUV/PS system,the removal rates of 2-MIB and GSM were lower with the UV/PS system under the same conditions,The preliminary analysis is due to the presence of a small amount of wavelength of 185 nm in the VUV/PS system.Which irradiate O₂ in water and transform it to O₃,The exist of O₃ further enhancing the degradation of 2-MIB and GSM.The effects of PS dosage,light intensity,HCO₃^-,humic acid,and system pH in the UV/PS process are similar to those of the VUV/PS process.Due to the existence of organic matter and a variety of inorganic ions in the municipal water,the degradation rates of odorants 2-MIB and GSM in the municipal water were significantly lower than those in the distilled water.?3?Using the index of power input per log reduction level(E_E0)to compare the power consumption of the VUV/PS and UV/PS processes,under the same conditions,VUV/PS combination not only has better degradation performance than UV/PS,but also consumes less energy than UV/PS.Meanwhile,the energy consumption for degrading 2-MIB is higher than that for degrading GSM under the same conditions.Increasing the light intensity and the dose of oxidant peroxydisulfate,the electric energy consumption will be reduced;the pH value in the system has little effect on the electric energy consumption,while the existing of alkalinity,humic acid in the system will increase the electric energy consumption.