| A wide variety of particles exist in natural water environment. Source of drinking water contain large amounts of small particles, especially the particles whose diameter is less than 1 ?m. Although they are small, their specific surface areas are great. And they are often able to interact with the pollutants as carriers, and cannot very well be removed by conventional drinking water treatment processes. Then they will enter the human's body along with drinking water, which will pose a serious threat to human health. In order to verify the powerful adsorption capacity of small particles, the cut-off point for classifying particles of drinking water was 1 ?m after analyzing of drinking water treatment process characteristics of particulates removal. The particles were divided into large particle whose size was larger than 1?m and small particles whose size was between 0.05-1?m. So, characteristics of antibiotic compounds adsorbed particles in drinking water were carried out.The abuse of antibiotics is very serious. Aquatic environments have detected antibiotic residues around the world. When antibiotics go into the water, it will be adsorbed by particles, which may be in the drinking water with particles. This will seriously affect the safety of drinking water and human health. By reviewing of literature, four categories of antibiotics were chosen for the study. Microwave extraction methods(MAE) for pretreatment and high performance liquid chromatography and mass spectrometry(HPLC-MS) for determination were established of these antibiotics by optimizing the pretreatment process and instrument measurement conditions.The continuous adsorption experiments have reached balance in 360 min. When the system was in equilibrium, 32%-44% of the antibiotic was distributed in solid phase. In addition to penicillin G, the adsorption of 0.05-1 ?m particles accounted for the total adsorption amount of 56%-70% phase. Although the concentration of small particulate matter is very low in natural waters, its adsorption capacity is very strong. A considerable part of the residual antibiotic is adsorbed on the particles. These particles are difficult to effectively remove through drinking water treatment, which also produced a certain security risk to the safety of drinking water.pH value has significant influence on particle adsorption capacity to antibiotics. Large particle's adsorption capacity greatly influenced by pH, and the peak value appears in acidic or alkaline condition. The adsorption capacity of small particles was rule changes with different pH value, and the peak value appears in neutral condition. However, the maximum adsorption capacity of the solid phase occurred at pH=7. In most cases, the adsorption capacity of 0.05-1?m diameter's particle is greater than the particle of d> 1?m.Adsorption sites on the size of the particles did not reach saturation when the adsorption equilibrium. The two adsorption amount increased to some extent when the two kinds of antibiotics exist at the same time. In general, the percentage increase of the adsorption amount is less than the percentage increase of total antibiotic. The competitive adsorption ability of these antibiotics was as follows: the competition ability of roxithromycin(ROX) and penicillin G(PG) was stronger than trimethoprim(TMP). The competition ability of nalidixic acid(NAL) was the weakest. The experimental results have important implications for water quality improvement and increasing drinking water treatment processes. |
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