Investigation And Adsorption As Well As Oxidation Disposals For Organic Sustances In Surface Water In Beijing-hebei Region

The issue of drinking safety is related to human health.The disinfection process is essential in the process of drinking water treatment.It can efficiently eliminate microbial infections and diseases,however,the disinfectants will act with the existent organic substances to form disinfection by-products.Among the hazardous disinfection by-products,humic acid and fulvic acid can be always detected.Therefore,in this paper,we first conducted water quality investigations on the source water,process water and pipe network water for five water plants（i.e.,water plants 1-5）to reveal the changes in content,type and molecular weight distribution of the organic sustances with the variation of season.Then,the effects of type and dosage for employed disinfectants on the formations of disinfection by-products were analyzed.Before the treatment of disinfection,different disinfectants with various doses were added into water samples to explore the generation of disinfection by-products.Based on this,the experiments for the removals of humic acid and fulvic acid by activated carbon adsorption and sodium hypochlorite oxdation as well as the coupling process were performed.The main content and core results of this paper are described as follows:（1）The comparison of water quality of source water for five water plants:Compared with surface water,the source water derived from groundwater has lower UV₂₅₄ and DOC values and this water quality is excellent.From the seasonal perspective,the water quality of the source water for each water plant in summer,autumn and winter is superb than that in spring;for the by-products,the tryptophan-like substances are the major component,while the soluble microbials are the least.（2）The comparison of the water quality of the process water and pipeline water for five water plants:the water quality of water plant 1 in autumn outerperforms that of summer and winter,and the water quality of water plants 2,3 and 4 in summer is advantageous to that of autumn and winter.The water quality of Plant 5 in winter is better than that in summer and autumn.In terms of molecular weight distribution,there is no difference between the process water and pipe network water of each water plant and its source water.（3）Under the same dosage condition,the amounts of disinfection by-products produced by chloramine disinfection are scare.According to the World Health Organization drinking water quality standards,if chlorine is used as the disinfectant,the dosage should be less than 0.10 m M,otherwise the content of dichloroacetonitrile can exceed the acceptable concentration.（4）Herein,the activated carbon adsorption is validated for the removals of humic acid and other disinfection by-products.The adsorption effect of coconut shell activated carbon on humic acid and fulvic acid is superior to other commercial activated carbons,and the removal rate can reach 60%and above.During the adsorption process,the molecular weight of organic substance in the solution increases because of the acculation of them.While,the disinfection of sodium hypochlorite reduces the molecular weight of organic substance,this can be due to the oxidation effect of this disinfectant.