Effects Of Pre-chemical Oxidation Of Phenolic Compounds In The Process Of Disinfection By-products Generated

With the development of economy and the improvement of people’s living standard, the water quality cause more and more attention of people, among which, the control of drinking water chlorination by-products is still a hot spot in the field of water treatment. Disinfection by-products refers to a kind of material generated by the the reactions of disinfectants and some water components in the process of drinking water disinfection process, such as THMs, HAAs and so on, which kinds of material is usually very teratogenic carcinogenicity. There are many kinds of methods to removal disinfection by-products, in which chemical oxidation is one of the most commonly used in water treatment method. Chlorophenol compounds(Chlorophenols, CPs) is a common compound. In addition, chlorophenol‘s substituent types, quantity and location are easy to control. It‘s a good model compounds. So, the study of chlorophenol cancellation law of disinfection by-products generated, will be conducive to understand the generating mechani sm of chlorination by-products. On the basis of using KMn O4, K2 Fe O4 pre-oxidation method, study the control of the chlorination by-products, which has important significance for the further study on the control of drinking water disinfection by-products.In this paper, to the traditional process of chlorine disinfection, we choose seven kinds of targets, including phenol, 2-CP, 3-CP, 4-CP, 2,4-DCP, 2,6-DCP and 2,4,6-TCP. Then we take analysis of two volatile disinfection by-products and two non-volatile disinfection by-products by GC-ECD. Through different oxidant species and dosage of contrast, this paper discusses different substituent position, quantity, and oxidation methods on the effects of four kinds of chlorination by-products.Through the chlorinated dynamics research on the different chlorophenol, TCM increased first then remain stable, CH has been increased; When the number of substituent is 1, put the substituent in phenol?s between place has a larger effect on the target properties; When the number of substituent is 2, 2,4-DCP and 2, 6-DCP‘s TCM and CH roughly the same over time. Through the study of chlorophenol chlorinated in different p H conditions, When the number of substituent is 1, for the production of TCM, 2-CP and 3-CP are greatly influenced by p H, 4-CP basically isn‘ t affected by p H; To CH,3-CP is greatly influenced by p H; To DCAA, under the condition of weak acid DCAA generation decreases with p H increases. When p H is neutral, DCAA generated flatten out. When the p H is alkaline, DCAA firstly increases then reduce; To TCAA, 3-CP is affected by p H greatly. When the number of substituent is 2, the affect of p H on 2,4-DCP and 2,6-DCP‘s chlorination by-products is roughly the same.Though study the effect of KMNO4 pre-oxidation on chlorophenol chlorination by-products, we found that four kinds of chloride products all have better inhibition, and with the increase of high manganese volumes, the inhibition will be more stronger. Experimental also contrast Mn O2‘s effect on chloride product. The results showed that to TCM and CH, Mn O2 has inhibitory effect, but will promote to CH of 3-CP; To DCAA and TCAA, Mn O2 particles have a certain role in promoting, and the promoting effect on TCAA is more apparent.Through the study of K2 Fe O4 pre-oxidation on chlorophenol chlorination by-products, the effect is not obvious on TCM and CH. To the generation of DCAA, it has certain inhibitory effect, and with the increase of oxidizer dosage, the inhibition is more stronger. To TCAA, first adding oxidant in small concentration, compared with no additive, the existence of K2 Fe O4 promoted the generation of TCAA, and the promoting effect weakened with the increase of concentration of K2 Fe O4. Through the contrast of KMn O4 and KFe2O4 pre-oxidation, under the condition of low antioxidant additive quantity, for TCM and CH almost the same. But especially for the TCM of 3-CP, KMn O4 is obviously better than K2 Fe O4; To DCAA and TCAA, the effect of KMn O4 is better than K2 Fe O4, but especially for 2-CP and 4-CP, the effect of K2 Fe O4 is better. As the amount of antioxidant additive increase, KMn O4‘s advantage is more and more obvious.