Antibiotics in wastewater from multiple sources and surface water of the Yangtze River in Chongqing in China.

Abstract

Antibiotic contamination attracts growing concerns because of their deleterious effects on the ecosystem and human health. In this study, 43 antibiotics in wastewater from a variety of sources and water of the Yangtze River in Chongqing City in western China were measured. Thirty compounds were detected, and their concentrations were highest in leachates from the municipal solid waste treatment facilities (landfills and incineration plants) with total concentrations of 3584-57,106ng/L. The total concentrations in influents of municipal and industrial wastewater treatment plants (WWTPs) were comparable (401-7994ng/L versus 640-8945ng/L). The concentrations in raw sewage from swine farms (with a total of 10,219-39,195ng/L) and poultry farms (1419-36,027ng/L) were noticeably higher than those from other farms (54.0-5516ng/L). Fluoroquinolones were the dominant antibiotics contributing over 50% in all the sources, and sulfonamides and imidazole fungicides contributed 3.2-34%, whereas tetracyclines and macrolides had minor contributions. The overall antibiotic removal rates were highest in solid waste treatment facilities (88% on average), comparable between municipal and industrial WWTPs (61%), and lowest in animal farms (39%). The mass loads to the investigated municipal WWTPs via influent wastewater ranged from 7.80 to 1531kg/year (53.2-2482μg/day per capital). The influent mass loads to the industrial WWTPs and farms were 3.7-50kg/year and 0.9-5437g/year, respectively. We estimated that the mass inventories of antibiotics from these sources to the environment via effluent discharges were approximately 2044kg for municipal WWTPs, 61kg for industrial WWTPs, and 34kg for animal farms in the whole city. Antibiotic concentrations in the Yangtze River water were substantially low (< 492ng/L, with a mean of 57.8ng/L) suggesting dissipation during the movement.