[Adsorption characteristics of typical PPCPs onto river sediments and its influencing factors].

A batch equilibrium method was used to investigate the adsorption characteristics of ciprofloxacin (CIP), tetracycline (TC), sulfamethoxazole (SMX) and triclosan (TCS) onto Huangpu River sediments. Effects of adsorption time, initial concentration, solution pH and temperature on the adsorption process were studied. The results showed that the adsorption process of these PPCPs onto sediments was a two-step process: a rapid adsorption followed by a slow balance. The equilibrium time was about 4 h. The pH value had a significant effect on the adsorption of CIP, TC and TCS, whereas the effect on SMX adsorption was negligible. The kinetic results indicated that the adsorption processes followed the pseudo-second-order model, with adsorption rate in the range of 4.89 x 10(-3)-1.96 x 10(-2) kg x (min x mg)(-1). Adsorption isotherms were well described by the Freundlich and linear equations. As temperature increased, the amount of SMX and TC adsorbed increased, whereas CIP and TCS decreased. CIP, TC and TCS had a strong tendency to adsorb onto sediments, while the adsorption of SMX was unfavorable. When the initial concentration of PPCPs was 10 mg x L(-1), the equilibrium adsorption capacities of CIP, TC, SMX and TCS reached 702.8, 733.1, 54.7 and 695.0 mg x kg(-1), respectively.

[Investigation of pollution characteristics of erythromycin resistance genes in a sewage treatment plant and the relevant selective factors].

Occurrence and distribution of twelve pharmaceutical and personal care products (PPCPs) were investigated in a sewage treatment plant in Shanghai using solid-phase extraction combined with high-performance liquid chromatography-tandem mass spectrometry (SPE-HPLC-MS/MS). Quantitative PCR (qPCR) was used to determine the distribution and removal of seven erythromycin resistance genes (ERY-ARGs). The results showed that five PPCPs including sulfamethoxazole, erythromycin, tetracycline, carbamazepine and triclosan were detected in the collected wastewater samples with concentrations in the ranges of 24.5- 38.7, 47.5-49.2, 43.1-85.4, 2.5-3.9 and 423.2-8 973.3 ng x L(-1), respectively. During the wastewater treatment process, a significant reduction of triclosan was observed, but the removal efficiencies for the other detected PPCPs were relatively low. Additionally, all target ERY-ARGs were detected in the wastewater samples ranging from 9.28 x 10(3) (ermA) to 1.83 x 10(8) (ereA) copies x L(-1) in raw influent. Though significant reductions (1.19 log-3.97 log) of ERY-ARGs were obtained, their concentrations found in the final effluent were still high. Moreover, the concentration of ERY-ARGs exhibited significant positive correlation with the concentration of erythromycin and triclosan (P < 0.05), respectively, elucidating that erythromycin played an important role in the occurrence and spread of ERY-ARGs, while triclosan may confer cross-selection for ERY-ARGs.