Degradation Of Typical Odor Compound 2-MIB In Drinking Water By Sulfate Radical:Performance And Mechanism

With the rapidly development of the agriculture and industry,water pollution phenomenon becomemore and more serious,italso lead to the eutrophication in water.The eutrophication in water not only cause rapid growth of algal and damage the ecological environment,but also release a large number of odor substance to cause large-area odor pollution.2-Methylisoborneol(2-MIB),as the mostly common odor substance,it can't be wiped out by conventional water treatment process.Persulfate oxidation technologyas an efficient new type of advanced oxidation technology,has received wide attention and under extensive researches.This study used automation headspace solid phase micro extraction- gas chromatography- mass spectrometrysynchronously to establish a method for determination of 2-MIB,it can be used to rapidly and efficiently detect the ultratrace 2-MIB in water.This article study the degradationmechanism and kinetics of 2-MIB to use heat activated persulfate.The effect of temperature,PSinitial concentration,2-MIB initialconcentration,pH and coexisting anions in water were also studiedin this experiment.The results indicated that 2-MIB could be rapidly and effectively degraded in heat activated persulfate system,and the degradation of 2-MIB exhibited a pseudo-first-order kinetics pattern at the tested conditions,it also meet to the Arrhenius equation theory well.Typically, high temperature, high PSinitial concentration and low initial2-MIB concentration would increase the decomposition rate of 2-MIB in heat activated persulfate system.The groundwater anionswould inhibit the 2-MIB removal with following order:CO32->HCO3->Cl-.This article also study the degradation mechanism and kinetics of 2-MIB to use ferrous ionactivated persulfate. The effect of ferrous ion concentration, PS concentration, molar ratio of Fe2+ to PS,thecitric acidconcentration and pH were studied in this experiment. The results showed thatferrous ion activated persulfate(PS) can play a very good effect of 2-MIB degradation at room temperature.There are two processes in the reaction: a quick stage in the first 5 minutes and a slow reaction stage after 5 minutes, and the slow reaction stage can conform pseudo-first-order kinetics pattern.Fe2 +: PS = 1: 1 is the most cost-effective way for the 2-MIB degradation in the Fe2 +/ PS system.The degradation rate from high to low is acidic, neutral and alkaline condition.The removal of 2-MIB can be raised by moderate addition of citric acid.This article also study thechanging rule of algal photosynthesis cytoactive,total 2-MIB and extracellular 2-MIB of preudanabaena sp. between different concentration Fe2 +/ PSto inactivatepreudanabaena sp..The results showed that, In the Fe2+/PS system the preudanabaena sp. die within 5min.Due to the rupture of algal cell,extracellular 2-MIB increased when Fe2+/PSconcentration were 0.5mM and 1mM,and then the extracellular 2-MIB will be gradually degraded.While higher concentration of Fe2+/PS(5mM) will not cause an increase in chlorophyll concentration and extracellular 2-MIB.When using different concentration Fe2+and PS to deal with the actual water samples, the best concentration is 0.5mM for degradation of 2-MIB and coagulation,the degradation rate of 2-MIB could reach 89.68% in 120 min,the turbidity decreased to 0.5NTU,and the TOC content is also decreased by 39%.