Abstract:
This study demonstrated the efficiency of the soil trench system for removal of EDCs, COD
Cr, phosphorous and nitrogen contaminants in rural sewage and the effectiveness in controlling the non-point source agricultural pollution. Attenuation of endocrine disrupting compounds (EDCs) including three natural (Estrone (E1), estradiol (E2) and estriol (E3)) and two artificially synthesized (17α-ethinylestradiol (EE2) and biphenyl-A (BPA)) chemicals were evaluated in soil trench systems along with a rural domestic sewage in the basin area of Erhai Lake. The results showed that concentrations of natural estrogens were higher than those of synthetic EE2and BPA for the sixteen sampling sites. The sum of E1and E2accounted for 87.1%-99.2% of the total amount of natural estrogen. The removal rates of the soil trench system for Natural estrogen, EE2and BPA were 1.42-168.21,0.64and 3.48mg/(m
2·a), while the amount of natural estrogens remaining in the soil accounted for approximately 4.3%, 6.3% and 3.8% of the initial influent amounts of E1, E2and E3, respectively. In general, soil trench system can effectively remove natural estrogens (70.3%), EE2(63.6%) and BPA (77.8%). Meanwhile, removals of COD
Cr (69.8%), TP (88.7%), TN (57.2%) and NH
3-N (88.7%) were also observed during system operation.