Study On Determination And Controling Antibiotics In Water Supply System In Tianjin

With the rapid economic development and the continuous improvement ofpeople’s living standards, contradiction between water supply and demandincreasingly acute, not only in the lack of water, but also in the increasing frequencyof pollution incidents recently. As an important antibiotic production and usagenation, antibiotic contamination in the water environment in China is inevitably veryserious， while China has just started researches on antibiotics.Method to detect trace30kinds of antibiotics in drinking water is established inthis research projects firstly. The method has high sensitivity, and applicability, canqualitative and quantitative detect antibiotic drug residues in drinking water samples.Tetracycline，chlortetracycline and Doxycycline items are approved by CNAS, thereports can be used as official documents, which are accepted worldwidely. Thisstudy carry out sampling at32sampling points of the Tianjin water supply systemfor30antibiotics. The pollution situation begin to be known. The fish cages in thePanjiakou Reservoir is the main sources of the reservoir. The maximum totalconcentration of antibiotics were118.30ng/L and98.42ng/L, the minimum totalconcentration of antibiotics were7.70ng/L and16.83ng/L. And pollution spread todownstream quickly. In the samples of Xinkaihe water plant and one of itsconveyance contain antibiotic residues. The conventional process cannot remove theantibiotics, and in the distribution process natural degradation is very small.After comparison and selection of various types of water treatment technology,activated carbon adsorption technology has a good removal to antibiotics which isabove93%. Activated carbon can be used in the Tianjin water plant in processmodification quickly. In the first10minutes of powdered activated carbon’sadsorption process of antibiotics is for the fast adsorption process, and adsorptionreached saturation in120min. The adsorption kinetics of the process is related toantibiotic type and structure. Same type antibiotics have similar molecular structure,and similar kinetics equation. Granular activated carbon removal is influenced by the filtration rate, pollutant concentration.12m/h is the best flow rate. The elution ofantibiotics in the particulate carbon bed is related to their molecular structure. Theelution effect is influenced by the van der Waals forces, hydrogen bonding andsubstituent group. The greater molecular weight and the more hydrogen bonds is,the better eluting is. But antibiotics with the molecular structure of the F-,Cl-substituent groups is almost impossible to be eluted. For antibiotics which can beeluted, the concentration of antibiotics, particulate carbon bed adsorption capacity,backwash elution ability and penetration equations should be considered to design areasonable process parameters. For antibiotics which cannot be eluted, only usepowdered activated carbon to adsorb.