Analysis Of Distribution Characteristics In The Solid-liquid Of Antibiotics In Drinking Water Sources

In recent years, with the development of the chemical industry, various chemicalsare gradually entering people’s lives. As a class of drugs very successful to theprotection of human health, antibiotics take more and more proportion in the use ofdrugs. Although antibiotics could be partly degraded in natural state, the residualconcentration of antibiotics in natural water bodies may remain in the range ofharmful to human body because antibiotics have been introduced into the naturalwater constantly. With the antibiotics into the water, they will be adsorbed by particles,then may end up in drinking water, finally they will seriously affect the quality andsafety of drinking water and human life and health.Depending on the literature，this paper selects six categories of antibiotics whichare often detected as research objects. By optimizing the pre-treatment process andinstrument measurement conditions, determination techniques of17antibiotics wereestablished by applying liquid chromatography and mass spectrometry. Determinationof methods to various antibiotics minimum detection limits are of1.26-9.16ng/L, therecovery rate is between72.59%-110.54%, the linear range from5to1000μg/L, andthe correlation coefficient R2of standard curves of antibiotics are between0.9930and0.9998. By the determination of water samples of water plants in the four processingstages using LC-MS, the results show that concentration of antibiotics in raw water ishighest, and the vast majority of antibiotic concentrations are in30-150ng/L inaddition to several antibiotic concentrations lower than the detection limits.The element analysis to particles in feed water treatment，which are a kind ofclay minerals and mainly composed C, O, Si, Al and other elements in the form ofoxide，are conducted using field emission scanning electron microscopy (FESEM).Through an analysis of the particle size of particulate matter in water by usingnano-particle size analyzer, particulates of1μm or less in water samples of fourstages are dominant in number, size and strength, and has the biggest impact on onthe entire system.Antibiotics, from entering into natural water bodies to reaching a relative stablestates, shows an distinct adsorption advantage in two periods. Within0-30min theadsorption rate is fast and the adsorption capacity is at4.20%-26.58%of the total antibiotics; the adsorption rate is higher in270-300min than in0-30min and theabsorbed amount is50.70%-87.72%. Smaller particles are dominant in the aspects ofnumber and volume in natural water and the adsorption capacity is much larger thanthe large size particles. In the water treatment process， we can use adsorption timeand adsorption properties of small particles for process improvement.