Co-occurrence and risk emission potential of antibiotics, antibiotic resistance genes, and heavy metals in concentrated leachate in China

Membrane-driven process was widely applied for advanced treatment of leachate to achieve the final limitation, but around 10-million-ton concentrated leachate (CL) generated annually has become a hot potato. CL properties and their potential risks were overlooked, and here, we filled in these blanks based on samples from seven provinces from traditional and emerging pollutants perspective. Cd, Pb and Cr were the main contributors for hazardous waste identification with the concentration of 0.07–5.10 mg/L. ΣSulfonamides, Σfluoroquinolones and Σtetracyclines were 408–1,590 ng/L, 2,499–8,306 ng/L and 1,294–1,432 ng/L, respectively. Fluoroquinolones presented critical eco-risks with acute and chronic risk quotients of 85.2–123.1 and 60.3–492.2. Significant correlations between antibiotics, antibiotics resistant genes, and heavy metals were also gained. Annual generation of antibiotics and heavy metal were estimated to be 61.4 kg and 693 tons in 1,955 existing landfills and 214 incineration plants in China. CL seems to be a hazardous waste-like compound based on the toxic substance contents listed in GB 5085.6–2007 and the eco-risks of emerging antibiotics. Regulation permit writers should consider not only water quality, but also the best available technology economically achievable and potential secondary pollutants.