Characteristics of leachate from refuse transfer stations in rural China

The properties of leachate from refuse transfer stations (RTSs) in rural China was indefinite. In this study, a total of 14 leachate samples from RTSs in nine provinces of China were characterized for their pH, electric conductivity, chromaticity, concentration of organic substances, nitrogen distribution, volatile organic compounds (VOCs), organic phosphorous pesticide, and heavy metals. The structural composition of chromophoric dissolved organic matter (CDOM) was also determined. To evaluate the leachate pollution potential in this study, a leachate pollution index (LPI) was derived and used. Chromium (Cr) was the most polluting heavy metal present in rural leachate. Ethanol and ethyl acetate were the most frequently detected VOCs at high concentrations. Three-dimensional fluorescence excitation-emission matrix spectra was used to characterize the CDOM. Three components, tryptophan (C 1 ), tyrosine-like (C 2 ), and humic and fulvic acid-like (C 3 ) substances were identified from all 14 samples. Tryptophan was the major component of CDOM and present in 45.7% of the samples by calculating the fluorescence intensity percentage, on average. Pearson correlations revealed that the fluorescence intensity of C 1 and C 3 was strongly related to soluble chemical oxygen demand and dissolved oxygen carbon, while C 2 had significant positive correlations with ammonia nitrogen and total phosphorus of the solid waste. This study provided detailed data and findings that could serve as a preliminary basis for broadening options for the treatment and management of leachate from rural RTSs in China.