Research On Trihalomethanes Produce’s Influencing Of Chlorination Disinfection By-product In Drinking Water

Because of the advantage of highefficiency, low cost and easy to use,the chlorinehas beenwidely usedaround the world.It will be used for long tine.However,someresearches show,the reactionofchlorinewithorganic compounds in waterwillproduce a lotofharmfuldisinfection byproducts which have goodcorrelation withanimal cancers,malformations andgeneticdiseases and cause a serious threatto humanhealth while effectively killinga large number ofbacteria,virus harmfulmicroorganisms In theprocess of s chlorination. This study selects the THMs whichhas the maximum amount among DBPs and isveryrepresentativeas the studysubjects,has researches of itsresultingimpactfactors and establishes theformationkinetics equation of THMs in order to providescientificdatabasisfortheactualtreatment.Firstly,this study uses GC-MS method to detecttheTHMs andestablishes thedetection method which has the advantage of speediness andhighefficiency,highspectral resolution and low minimum detectableconcentration.Pre-treatment usingthepurge and trapmethodandjointing autosamplergreatly reduces theworkloadofthedetected and greatly improves thedegree ofconfidenceoftheanalysis results.Secondly,This test examinestheinfluenceofthereaction conditions on theorganicconcentration, chlorination amount, pH, temperature, contact time during theformation of THMs. On this basis it also has a research ofiron, copper,calcium,magnesium, aluminum, carbonate,bromide and ammoniumion.The result shows, theabovefactors canproduceacertainimpactontheformationofTHMs,the specificconclusionsareasfollows：（1） When chlorine concentration is1mg/L-20mg/L,concentration of organic matter is1mg/L-8mg/L,Chlorination time is1h-48h, temperature is5℃-40℃,the factorscan promote thegenerationofTHMs, and the THMstotalcontentincreases, thetotalcancer riskisalso growing.（2） Br^-can significantly change the generating distribution of THMs, the increase iftheconcentrationofBr^-promoting the formationofbromide ion-containingTHMs,CHBr₃increases gradually,CHBrCl₂andCHBr₂Clfirst increasesbut reduceslater,the CHCl₃generation reducesgradually, and total cancer riskis also increasing.（3） NH₄⁺in water sample can effectively reducetheamountofTHMs especially theamountofCHCl₃,when the concentration of NH₄⁺reaches to1.0mg/L,thegeneration amount of CHCl₃is almost zero, andtotal cancer riskisalsoreduced（4） The CHCl₃generationvolumegraduallyreduces with theincrease of theconcentration of Fe³⁺andCu²⁺within acertain range of concentrations, it explainsthat Fe³⁺and Cu²⁺has inhibitory effectonthegenerationofCHCl₃and Al³⁺also hasinhibitory effectonthegenerationofTHMs. Ca²⁺and Mg²⁺hasless impact on tthegenerationofTHMs. When Ca²⁺orMg²⁺exists, boththetotal amount of THMsandthe totalcancer riskhave a decreasingtrendinthethree environments. Finally, accordingtothedata obtainedthetrihalomethaneformationdynamicsequations, and thesignificant is good. Itcanpredictitsformationoftrihalomethanes.