No abstract

An efficient pretreatment and analytical method was developed to investigate the occurrence and fate of four free estrogens (estrone (E1), 17β-estradiol (17β-E2), estriol (E3), and 17α-ethinylestradiol (EE2)), four conjugated estrogens (estrone-3-sulfate sodium salt (E1-3S), 17β-estradiol-3-sulfate sodium salt (E2-3S), estrone-3-glucuronide sodium salt (E1-3G), and 17β-estradiol-3-glucuronide sodium salt (E2-3G)), and bisphenol A (BPA) in three livestock farms raising beef cattle, cows, sheep, swine, and chickens in Qi County, which is located in North China. The results demonstrated that one cow and one beef cattle excreted 956.25-1,270.41 and 244.38-319.99 μg/day of total (free and conjugated) estrogen, respectively, primarily through feces (greater than 91%), while swine excreted 260.09-289.99 μg/day of estrogens, primarily through urine (98-99%). The total estrogen excreted in sheep and broiler chicken feces was calculated to be 21.64-28.67 and 4.62-5.40 μg/day, respectively. It was determined that conjugated estrogens contributed to 21.1-21.9% of the total estrogen excreted in cow feces and more than 98% of the total estrogen excreted in swine urine. After composting, the concentration of total estrogen decreased by 18.7-59.6%; however, increased levels of BPA were measured. In treated compost samples, estrogens were detected at concentrations up to 74.0 ng/g, which indicates a potential risk of estrogens entering the surrounding environment.

The relationships between land use types, water and sediment parameters, and macrobenthos community structures in the upper and middle reaches of the Fenhe River and urbanization intensity were studied. Samples were collected from 23 sampling sites. Spearman rank correlation analyses were performed to assess the relationships between the percentages of impervious area or the proportions of four land uses and the water and sediment physicochemical properties, heavy metal and polycyclic aromatic hydrocarbon concentrations in water and sediment, and biological indicators of the macrobenthos communities. Some water parameters (temperature, oxidation-reduction potential, electrical conductivity, total N concentration, total P concentration, ammonia-N concentration, and nitrate-N concentration), some sediment parameters (total N concentration, total P concentration, organic matter content, percentage of particles with diameters <2 mm, and polycyclic aromatic hydrocarbon, Cd, Cr, Cu, Ni Pb, and Zn concentrations), and some macrobenthos parameters (Berger–Parker index and percentages of collectors, tolerant taxa, and Oligochaeta) significantly positively correlated with the percentage of impervious area. Some water parameters (pH and dissolved oxygen concentration), some sediment parameters (percentage of particles with diameters >2 mm), and some macrobenthos parameters (total biomass, total number of taxa, Shannon’s index, N diversity index, and percentages of Ephemeroptera, Plecoptera, Trichoptera, filterers, scrapers, and sensitive taxa) significantly negatively correlated with the percentage of impervious area. The results indicate that intensification of urbanization has strongly affected the water, sediment, and macrobenthos in the Fenhe River watershed.

Identification of nitrate sources is important for the management of rivers. In this study, stable isotopes (δ15N and δ18O) and a Bayesian model (stable isotope analysis in R, SIAR) were applied to identify nitrate sources and estimate the proportional contributions of multiple nitrate sources in the upstream of Fenhe River Reservoir that serves as a source of drinking water in Shanxi Province of North China. The results showed that the 86.4% of total nitrogen (TN) concentrations in the water samples exceeded the guided values of the Chinese Surface Water Environmental Quality Standard (GB 3838-2002). The influent of tributary and discharges of sewage caused the severe nitrogen pollution. SIAR was used to estimate the proportional contribution of three nitrate sources (sewage, inorganic fertilizer, and soil nitrogen). It was revealed that domestic sewage was the dominant nitrate source, and the contributions were 33%–41%. The contributions of inorganic fertilizer and soil to nitrogen load were 30%–31% and 31%–37%, respectively. Therefore, the pollution sources of nitrogen can be determined more accurately if the rules of sewage discharges are considered.