Assessing the estrogenic potency in a Portuguese wastewater treatment plant using an integrated approach

The estrogenic potency of a wastewater treatment plant （WWTP） was evaluated using chemical and biological analyses, which showed that after the station treatment processes some of the selected endocrine disruptor compounds （EDCs） were still present in the treated effluent （e.g., bisphenol A, alkylphenols, estrone）. Thus, the most common endocrine EDCs were identified and quantified and the overall estrogenicity of the treated effluent assessed by integrating the results. Male goldfish （Carassius auratus） were used as biological indicators in a 28-day experiment. Vitellogenin （Vtg）, gonadosomatic and hepatosomatic indices, steroids （17β-estradiol and 11-ketotestosterone） and histopathology were biomarkers used in fish to evaluate WWTP treated effluent estrogenicity, in combination with instrumental analyses. The results showed a significant increase （P 〈 0.01） in plasma and liver Vtg, which were significantly correlated （r = 0.66; P 〈 0.01）. The gonadosmatic index was significantly （P 〈 0.01） reduced in exposed fish. The steroid analyses revealed significant elevations in 17β-estradiol and depressed 11-ketotestosterone concentrations. The histological examinations show changes in exposed fish gonads, such as regressed testes and in some cases （43% to 75%） the development of ovo-testis in fish exposed to 50% and 100% treated effluent.

Evaluation of the effectiveness of horizontal subsurface flow constructed wetlands for different media

Two media bed （gravel and Filtralite NR） were tested in a mesocosm to evaluate the removal of organic matter （as chemical oxygen demand （COD））, ammonia （NH4-N）, nitrite, nitrate and solid matter （as total suspended solids （TSS）） for a synthetic wastewater （acetate-based） and a domestic wastewater. The use of Filtralite allowed average removal rates （6--16.8 g COD/（m^2·day）, 0.8-1.1 g NH4-N/（m^2·day） and 3.1 g TSS/（m^2·day）） and removal efficiencies （65%-93%, 57%-85% and 78% for COD, NH4-N and TSS, respectively）, higher than that observed in the experiments with gravel. The applied loads of COD, ammonia, nitrate and TSS seem to influence the respective removal rates but only for the treatment of domestic wastewater with nigher correlation coefficients for Filtralite. Regardless the type of media bed and the type of wastewater, nitrate was completely removed for nitrogen loading rates up to 1.3 g NO3-N/（m^2·day）. There was no evidence of the influence of nitrate loads on the removal of organic matter.

Efficacy assessment of peracetic acid in the removal of synthetic 17α-ethinyl estradiol contraceptive hormone in wastewater

Increasing concerns have been raised on endocrine disrupting chemicals like the sex hormone 17 a-ethinylestradiol(EE2),the more since traditional wastewater(WW) treatments appear to be ineffective for their removal.The efficacy of the relatively novel disinfectant peracetic acid(PAA) in EE2 removal was evaluated,as well as its potential effects on WW quality parameters.The treatments tested for EE2 removal were also evaluated in terms of toxicity,through the determination of biochemical responses(antioxidant enzymes,lipid peroxidation and vitellogenin induction) using zebrafish(Danio rerio) as a biological model.PAA contact times less than 20 min appeared insufficient regardless of the PAA dose tested,but a 100% EE2 removal was attained at a PAA concentration of 15 mg/L with a contact time of20 min.Total suspended solids,chemical oxygen demand and pH in PAA treatments remained well within levels set in European legislation for WW discharge.EE2 induced signific ant increased vitellogenin(VTG) levels in both female and male fish,indic ating increased estrogenic activity,especially in males suggesting an endocrine disruption effect.With the addition of PAA(15 mg/L),however,VTG levels in both sexes returned to control values.Although this PAA treatment showed increased levels of the antioxidant enzyme catalase,the lipid peroxidation levels were similar or even lower than in controls.Overall the results suggest that the use of PAA appears a promising way forward as a less toxic alternative to chlorine disinfection with high efficiency in the removal of EDC like EE2.