| Excessive steroid estrogens in the environment can interfere with the normal endocrine system of human or animals and cause great harm.Steroid estrogens are mostly derived from excretion from large-scale livestock and poultry farms and incomplete removal of sewage treatment plants.At present,anaerobic digestion is often used to treat livestock and poultry excreta in large-scale farms,and the biogas slurry is used to soil irrigation.However,anaerobic treatment does not completely remove steroid estrogens from the excreta and will enter the environment with the biogas slurry.The composition of biogas slurry in large-scale livestock and poultry farms is diverse.It is difficult to detect estrogen in water and soil samples of biogas slurry irrigation area because of the complexity of sample matrix.At present,the commonly used estrogen detection methods generally need precision instruments and professional operators.Therefore,it is necessary to establish a reliable estrogen detection method and an estrogen content estimation model in biogas slurry.In this study,five estrogens(E1,17?-E2,17?-E2,E3 and E1-3S)in the biogas slurry irrigation area of large-scale dairy farm were studied for objects to detect the estrogens content in anaerobic tank effluent,aerobic tank effluent and soil.To study the relationship between estrogens content in anaerobic tank wastewater and soil and their physical and chemical properties,and to evaluate the potential ecological risk of estrogens in biogas slurry irrigation area.The main conclusions are as follows:(1)A two-step solid-phase extraction method was established for two kinds of complex liquid samples: anaerobic tank and aerobic tank effluent.The average recovery of estrogens was 92.87% and 91.94%,respectively.The anaerobic tank effluent was reclaimed for soil irrigation.A three-step shaken extraction-solid phase extraction method was established for soil samples.The average recovery of estrogens was 67.68% and 62.8%,respectively.The five target estrogensin samples were then determined by liquid chromatography tandem mass spectrometry(LC-MS/MS).The method has good selectivity and sensitivity for target estrogens,and the detection limit is 0.07~0.39 ng/L.(2)Estrogens in anaerobic tank and aerobic tank effluent was detected by the established method in a large-scale dairy farm.The results showed that the average concentration of five estrogens in anaerobic tank effluent was E1 > 17?-E2 > 17?-E2 > E1-3S > E3,and the average concentration of estrogens in aerobic tank effluent was 17?-E2 > 17?-E2 > E1 > E1-3S > E3,respectively.The experimnetal results of soil samples showed that estrogens were introduced into the soil environment by soil irrigation using anaerobic tank effluent.The average concentration of five estrogens in soil was 17?-E2 > E1 > 17?-E2 > E1-3S,respectively.At the same time,estrogens can also migrate to deep layer soil,causing potential groundwater pollution risk.(3)The SPSS software was used to analyze the correlation between estrogens content and physicochemical properties.The results showed that the estrogens content in anaerobic tank,aerobic tank effluent and soil was significantly correlated with the physical and chemical properties.The regression analysis results showed that the estrogens content in anaerobic tank effluent,aerobic tank effluent and soil had good fitting effect with physical and chemical properties.Estrogens content could be estimated according to the physical and chemical properties content in samples.(4)The ecological risk assessment of estrogens in anaerobic tank effluent,aerobic tank effluent and soil was carried out by risk quotient.The estradiol equivalent value in anaerobic tank effluent and aerobic tank effluent was high.The ecological risk to the environment is high,the estradiol equivalent value in soil is low,and the ecological risk to the environment is relatively low.In this study,estrogens content in anaerobic tank effluent,aerobic tank effluent and soil in large-scale dairy farm biogas slurry irrigation area was studied.The correlation analysis and linear regression fitting between estrogens content and physicochemical properties were carried out to establish estrogens emission estimation model in biogas slurry irrigation area.The ecological risk assessment was carried out,providing a basis for estimating estrogens content in the biogas slurry irrigation area of dairy farm. |
PDF Full Text Request