Occurrence of estrogenic endocrine disrupting chemicals concern in sewage plant effluent

The purpose of this study was to give a worldwide overview of the concentrations of typical estrogenic endocrine disrupting chemicals （EDCs） in the effluent of sewage plants and then compare the concentra- tion distribution of the estrogenic EDCs in ten countries based on the survey data of the estrogenic EDCs research. The concentrations of three main categories （totally eight kinds） of estrogenic EDCs including steroidal estrogens （estrone （El）, estradiol （E2）, estriol （E3） and 17a- ethynylestradiol （EE2））, phenolic compounds （nonylphe- nol （NP） and bisphenol A （BPA）） and phthalate esters （dibutyl phthalate （DBP） and dibutyl phthalate （2- ethylhexyl） phthalate （DEHP）） in the effluents of sewage plants reported in major international journals over the past decade were collected. The statistics showed that the concentration distributions of eight kinds of EDCs were in the range of ng·L^-1 to μg·L^-1. The concentrations of steroidal estrogens mainly ranged within 50.00 ng. L-1, and the median concentrations of El, E2, E3 and EE2 were 11.00, 3.68, 4.90 and 1.00 ng·L^-1, respectively. Phenolic compounds and phthalate esters were found at pg. L-1 level （some individual values were at the high level of 40.00 μg·L^-1）. The median concentrations of BPA, NP, DBP and DEHP were 0.06, 0.55, 0.07 and 0.88 μg·L^-1, respectively. The concentrations of phenolic compounds and phthalate esters in the effluents were higher than that of steroids estrogens. The analysis of the concentration in various ten countries showed that steroids estrogens, phenolic compounds and phthalate esters in sewage plant effluents were detected with high concentration in Canada, Spain and China, respectively.

Change in genotoxicity of wastewater during chlorine dioxide and chlorine disinfections and the influence of ammonia nitrogen

The effects of chlorine dioxide and chlorine disinfections on the genotoxicity of different biologically treated sewage wastewater samples were studied by umu-test.The experiment results showed that when chlorine dioxide dosage was increased from 0 to 30 mg/L,the genotoxicity of wastewater first decreased rapidly and then tended to be stable,while when the chlorine dosage was increased from 0 to 30 mg/L,the genotoxicity of wastewater changed diver sely for different samples.It was then found that ammonia nitro-gen did not affect the change of genotoxicity during chlorine dioxide disinfection of wastewater,while it greatly affected the change of genotoxicity during chlorine disin fection of wastewater.When the concentration of ammonia nitrogen was low(<10-20 mg/L),the genotoxicity of wastewater decreased after chlorine disinfection,and when the con-centration of ammonia nitrogen was high(>10-20 mg/L),the genotoxicity of wastewater increased after chlorine disinfection.