Estrogenic compounds in drinking water: A systematic review and risk analysis.

Estrogenic compounds are the endocrine disruptors that receive major attention because of their ability to imitate the natural female hormone, 17ß-estradiol and cause adverse effects on the reproductive system of animals. The presence of estrogenic compounds in drinking water is a warning to assess the risks to which human beings are exposed. The present work has the objectives of carrying out a systematic review of studies that investigated estrogenic compounds in drinking water around the world and estimate the human health and estrogenic activity risks, based on the concentrations of each compound reported. The systematic review returned 505 scientific papers from the Web of Science®, SCOPUS® and PubMED® databases and after careful analysis, 45 papers were accepted. Sixteen estrogenic compounds were identified in drinking water, from the classes of hormones, pharmaceutical drugs and personal care products, plasticizers, corrosion inhibitors, pesticides and surfactants. Di-(2-ethylhexyl) phthalate (DEHP) was the compound found at the highest concentration, reaching a value of 1.43 mg/L. Non-carcinogenic human health risk was classified as high for 17α-ethynilestradiol and DEHP, medium for dibutyl phthalate, and low for bisphenol A. The estrogenic activity risks were negligible for all the compounds, except DEHP, with a low risk. None of the estrogenic compounds presented an unacceptable carcinogenic risk, due to estrogenic activity. However, the risk assessment did not evaluate the interactions between compounds, that occurs in drinking water and can increase the risks and adverse effects to human health. Nonetheless, this study demonstrates the need for improvement of drinking water treatment plants, with more efficient technologies for micropollutant removal.

Ecological risk assessment of pharmaceuticals and endocrine disrupting compounds in Brazilian surface waters.

Pharmaceuticals and endocrine disrupting compounds are organic micropollutants that can cause adverse effects at low concentrations. Their occurrence in surface waters has been reported in several countries, including Brazil, at concentrations on the order of ngL-1, while the concentrations at which toxic effects are observed are often in the range of mg.L-1 to µg.L -1, however few studies have been undertaken to characterize risks they represent in Brazilian surface waters. Thus, the objective of this study was to evaluate the ecological risk to Brazilian surface waters caused by the presence of pharmaceuticals and natural and environmental estrogens. Twenty-nine pharmaceuticals, hormones and environmental estrogens were included in the risk assessment while twelve were discarded due to insufficient data availability. The endocrine disrupting compounds were the most frequently detected (39.8% of the reported concentrations), followed by non-steroidal anti-inflammatory drugs (16.3%), antibiotics (6.6%), antiseptics (5.1%), analgesics (5.1%), antihypertensives (4.6%), and to a lesser extent, lipid controllers, anticonvulsants, antidepressants, antihistamines, antivirals and corticosteroids. Bisphenol-A was the most frequently detected compound, followed by diclofenac, 17-ß-estradiol, 17-α-ethynilestradiol, naproxen, triclosan and 4-n-nonylphenol. Acute ecological risk was predicted in two thirds and chronic risk in one third of the water bodies surveyed. The presence of diclofenac or triclosan was determinant for acute risk while estrogenic hormones proved to be decisive for chronic risk. In addition to natural and synthetic endocrine disruptors, the pharmacological groups estimated to have the highest average associated risks were non-steroidal anti-inflammatory drugs, followed by anticonvulsants. No discharge limits exist for most of the compounds found to contribute to ecological risks, indicating the need for regulatory action by the proper Brazilian authorities.

Improving biological removal of pharmaceutical active compounds and estrogenic activity in a mesophilic anaerobic osmotic membrane bioreactor treating municipal sewage.

The contamination of water sources by pharmaceutically active compounds (PhACs) and their effect on aquatic communities and human health have become an environmental concern worldwide. Membrane bioreactors (MBRs) are an alternative to improve biological removal of recalcitrant organic compounds from municipal sewage. Their efficiency can be increased by using high retention membranes such as forward osmosis (FO) and membrane distillation (MD). Thus, this research aimed to evaluate the performance of an anaerobic osmotic MBR coupled with MD (OMBR-MD) in the treatment of municipal sewage containing PhACs and estrogenic activity. A submerged hybrid FO-MD module was integrated into the bioreactor. PhACs removal was higher than 96% due to biological degradation, biosorption and membrane retention. Biological removal of the PhACs was affected by the salinity build-up in the bioreactor, with reduction in biodegradation after 32 d. However, salinity increment had little or no effect on biosorption removal. The anaerobic OMBR-MD removed >99.9% of estrogenic activity, resulting in a distillate with 0.14 ng L-1 E2-eq, after 22 d, and 0.04 ng L-1 E2-eq, after 32 d. OMBR-MD treatment promoted reduction in environmental and human health risks from high to low, except for ketoprofen, which led to medium acute environmental and human health risks. Carcinogenic risks were reduced from unacceptable to negligible, regarding estrogenic activity. Thus, the hybrid anaerobic OMBR-MD demonstrated strong performance in reducing risks, even when human health is considered.

Evaluation of toxicity and estrogenicity in UASB - Treated municipal sewage.

This study was undertaken to assess the capacity of the upflow anaerobic sludge blanket (UASB) reactor, one of the most commonly used systems in Brazilian sewage treatment plants, to remove municipal sewage toxicity using different Danio rerio life stages (embryo, embryo-larval, larval, adult), and estrogenicity using in vitro (yeast Saccharomyces cerevisiae) and in vivo (vitellogenin induction in D. rerio) assays. Sensitivity of chronic fish assays were compared to the chronic Ceriodaphnia dubia assay. UASB-treated sewage met Brazilian legal limits for BOD and COD removals, but did not remove toxicity, and treated sewage remained extremely toxic to D. rerio larvae and C. dubia, and highly toxic to D. rerio embryos. The 4-day embryo assay had the same sensitivity as the adult acute toxicity assay, and could safely replace it, avoiding the need to sacrifice adult fish. No significant differences were identified in vitellogenin induction among organisms exposed to sewage or control. However, the in vitro test showed that anaerobic treatment increased sample estrogenicity from 27 to 40 ng equivalents of 17-ß estradiol per liter, a result corroborated by the greater induction of vitellogenin in male fish exposed to 5% (2.73 µg/g) and 20% (2.12 µg/g) treated sewage compared to the same concentrations of raw sewage (0.174 µg/g at 5% and 0.188 µg/g at 20%). Thus, UASB reactor should be followed by post-treatment to reduce risks of sewage discharge to receiving waters.

ADMI color and toxicity reductions in raw textile mill effluent and dye mixtures by TiO2/UV is limited by presence of vat dyes.

Full-scale application of heterogeneous photocatalysis for industrial wastewater treatment remains a challenge because of the complex nature of these matrices and the potential to form toxic by-products during treatment. A recent unsuccessful attempt to find adequate conditions for TiO2/UV treatment of a cotton dyeing textile mill led to this study on the treatability of mixtures of the dyes used in the greatest amounts at the mill and therefore most likely to be present in mill effluent. Four reactive and three vat dyes were mixed in different combinations and treated (10 mg/L of each dye, 0.5 mg/L TiO2, pH 4) to evaluate the influence of the different dyes on ADMI color, chemical oxygen demand (COD), and acute toxicity. While ADMI color removal was similar in all dye mixtures, COD removal was higher when vat dyes were absent. When treated individually, vat dyes exhibited greater recalcitrance, with no ADMI color removal and COD removals of less than 30%. Toxicity to Daphnia similis was decreased or eliminated from dye mixtures that exhibited the highest COD removals and corresponded to those in which reactive dyes were partially degraded. For raw textile mill effluent, photocatalysis reduced but did not eliminate treated effluent toxicity (EC50 = 26.8%).

Heterogeneous photocatalysis using TiO2 modified with hydrotalcite and iron oxide under UV-visible irradiation for color and toxicity reduction in secondary textile mill effluent.

The objective of this study was to evaluate ADMI color removal from a biologically treated textile mill effluent by heterogeneous photocatalysis with UV-visible irradiation (UV-vis) using a novel catalyst composed of TiO2 supported on hydrotalcite and doped with iron oxide (HT/Fe/TiO2). Simulated biological treatment of solutions of the dyes (50 mg/L) used in the greatest amounts at the mill where the textile effluent was collected resulted in no color removal in reactive dye solutions and about 50% color removal in vat dye solutions, after 96 h, indicating that the secondary effluent still contained a large proportion of anionic reactive dyes. Photocatalytic treatments were carried out with TiO2 and HT/Fe/TiO2 of Fe:Ti molar ratios of 0.25, 0.5, 0.75 and 1, with varying catalyst doses (0-3 mg/L), initial pH values (4-10) and UV-vis times (0-6 h). The highest ADMI color removal with unmodified TiO2 was found at a dose of 2 g/L and pH 4, an impractical pH value for industrial application. The most efficient composite was HT/Fe/TiO2 1 at pH 10, also at a dose of 2 g/L, which provided more complete ADMI color removal, from 303 to 9 ADMI color units (96%), than unmodified TiO2, from 303 to 37 ADMI color units (88%), under the same conditions. Hydroxyl radicals were responsible for the color reduction, since when 2-propanol, an OH scavenger, was added color removal was very low. For this reason, the HT/Fe/TiO2 1 composite performed better at pH 10, because the higher concentration of hydroxide ions present at higher pH favored hydroxyl radical formation. COD reductions were relatively low and similar, approximately 20% for both catalysts after 6 h under UV-vis, because of the low initial COD (78 mg/L). Secondary effluent toxicity to Daphnia similis (EC50 = 70.7%) was reduced by photocatalysis with TiO2 (EC50 = 95.0%) and the HT/Fe/TiO2 1 composite (EC50 = 78.6%). HT/Fe/TiO2 1 was reused five times and still lowered secondary effluent ADMI color below local discharge limits. Benefits of the HT/Fe/TiO2 1 catalyst compared to TiO2 include its lower bandgap energy (2.34 eV vs 3.25 eV), higher ADMI color removal and its magnetic nature that facilitated its recovery and would reduce treatment costs.

Hydrotalcite-TiO2 magnetic iron oxide intercalated with the anionic surfactant dodecylsulfate in the photocatalytic degradation of methylene blue dye.

The new magnetic photocatalysts HT/TiO2/Fe and HT-DS/TiO2/Fe, modified with the anionic surfactant sodium dodecylsulfate (DS) were successfully synthesized in this work. Titanium dioxide (anatase) followed by iron oxide were deposited on the hydrotalcite support. Several catalyst samples were prepared with different amounts of titanium and iron. The photocatalysts were characterized by infrared and Raman spectroscopy, X-ray diffraction, scanning electron microscopy. Photocatalytic performance was analyzed by UV-visible radiation (filter cutoff, λ > 300 nm) of an aqueous solution (24 mg/L) of methylene blue (MB). The most efficient catalyst was obtained at an iron oxide:TiO2 molar ratio of 2:3. This catalyst showed high photocatalytic activity, removing 96% of the color and 61% of total organic carbon from the MB solution after 120 min. It was easily removed from solution after use because of its magnetic properties. The reuse of the HT-DS/TiO2/Fe23 catalyst was viable and the catalyst was structurally stable for at least four consecutive photocatalytic cycles.

Toxicity identification evaluation of cosmetics industry wastewater.

The cosmetics industry has shown steady growth in many developing countries over the past several years, yet little research exists on toxicity of wastewaters it generates. This study describes a toxicity identification evaluation conducted on wastewater from a small Brazilian hair care products manufacturing plant. Physicochemical and ecotoxicological analyses of three wastewater treatment plant inlet and outlet samples collected over a six month period revealed inefficient operation of the treatment system and thus treated wastewater organic matter, suspended solids and surfactants contents consistently exceeded discharge limits. Treated wastewater also presented high acute toxicity to Daphnia similis and chronic toxicity to Ceriodaphnia dubia and Pseudokirchneriella subcapitata. This toxicity was associated with suspended solids, volatile or sublatable and non-polar to moderately polar organic compounds that could be recovered in filtration and aeration residues. Seven surfactants used in the largest quantities in the production process were highly toxic to P. subcapitata and D. similis. These results indicated that surfactants, important production raw materials, are a probable source of toxicity, although other possible sources, such as fragrances, should not be discarded. Improved treatment plant operational control may reduce toxicity and lower impact of wastewater discharge to receiving waters.

Biological activity of bleached kraft pulp mill effluents before and after activated sludge and ozone treatments.

Eucalyptus bleached kraft pulp production, an important sector of the Brazilian national economy, is responsible for generating large volume, high pollutant load effluents, containing a considerable fraction of recalcitrant organic matter. The objectives of this study were to quantify the biological activity of the effluent from a eucalyptus bleached kraft pulp mill, characterize the nature of compounds responsible for biological activity and assess the effect of ozone treatment on its removal. Primary and secondary effluents were collected bimonthly over the course of one year at a Brazilian bleached eucalypt kraft pulp mill and their pollutant loads (biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), adsorbable organic halogen (AOX), lignin, extractives) and biological activity (acute and chronic toxicity and estrogenic activity) quantified. The effluent studied did not present acute toxicity to Daphnia, but presented the chronic toxicity effects of algal growth inhibition and reduced survival and reproduction in Ceriodaphnia, as well as estrogenic activity. Chronic toxicity and estrogenic activity were reduced but not eliminated during activated sludge biological treatment. The toxicity identification evaluation revealed that lipophilic organic compounds (such as residual lignin, extractives and their byproducts) were responsible for the toxicity and estrogenic activity. Ozone treatment (50 mg/L O(3)) of the secondary effluent eliminated the chronic toxicity and significantly reduced estrogen activity.

Eradication of Plant Pathogens in Forest Nursery Irrigation Water.

Interest in rational use and reuse of water has increased in recent years, especially in forest nurseries. However, before water can be reused in nurseries, it must be properly treated to eradicate plant pathogens to reduce risks of pathogen dispersal and losses to disease. In the present study, the efficacy of irrigation water treatment by ultrafiltration and conventional physical-chemical treatment was studied to eliminate Botrytis cinerea, Cylindrocladium candelabrum, Ralstonia solanacearum, and Xanthomonas axonopodis, the pathogens most commonly found in Brazilian forest nurseries. Ultrafiltration eradicated over 99% of R. solanacearum, X. axonopodis, and B. cinerea and 100% of C. candelabrum. The few remaining cells or conidia of R. solanacearum and B. cinerea did not induce disease in irrigated rooted cuttings. Flocculation and fast sand filtration used in physical-chemical treatment completely eliminated C. candelabrum but the other pathogens were only removed after chlorination of the filtered water. Both forms of treatment are viable, practical, and safe methods for plant pathogen removal from irrigation water.

Rhizobacterial promotion of eucalypt rooting and growth

A total of 107 rhizobacterial isolates, obtained from the rhizosphere of eucalypt clones were tested as rooting inducers of cuttings and mini-cuttings planted in substrate composed of carbonized rice husk and vermiculite (1:1). Cuttings and mini-cuttings were planted in conical plastic tubes containing treated and untreated (control) substrate and kept under intermittent mist irrigation at 26-28°C. After 35 days, rooting percentage and dry root matter of cuttings were evaluated. Ten isolates capable of providing gains of up to 110 percent in root formation and up to 250 percent in root biomass over non-inoculated control cuttings were selected. Gains in rooting varied according to clone and isolate tested. The greatest gains were obtained for the mini-cuttings exhibiting the lowest rooting efficiency. Among the ten isolates tested, only 3918 (code R98) and MF4 (code R87), produced 3-indole-acetic acid in vitro, at concentrations of 0.7 and 0.67 µg ml-1, respectively. Significant increases in rooting and root dry matter of cuttings grown on rhizobacteria-inoculated substrate were found when compared to untreated or indole-butyric acid (IBA) treated mini-cuttings.

Neste trabalho, testaram-se 107 rizobactérias, isoladas da rizosfera de mudas de clones de eucalipto, quanto ao seu potencial como promotoras de enraizamento de estacas e miniestacas de eucalipto, em substrato à base de casca de arroz carbonizada e vermiculita (1:1). Estacas e miniestacas foram plantadas em tubetes cônicos contendo substrato tratado e não tratado (testemunha) e foram mantidas sob nebulização intermitente de água a 26-28°C. Aos 35 dias, avaliou-se a porcentagem média de estacas enraizadas e a massa seca do sistema radicular. Dez isolados destacaram-se como indutores de enraizamento e crescimento, propiciando ganhos de até 110 por cento e de 250 por cento, respectivamente. Esses isolados também foram eficientes no enraizamento de miniestacas, cujos ganhos variaram de acordo com o clone e isolado testado. Os maiores incrementos obtidos no enraizamento de estacas foram superiores aos observados para miniestacas. Em geral, quanto menor o índice de enraizamento do clone, maior foi o ganho médio obtido com a inoculação. Apenas os isolados 3918 (código R98) e MF4 (código R87) foram capazes de produzir ácido indol-acético (AIA) in vitro, em quantidades equivalentes a 0,7 e 0,67 µg/ml de suspensão, respectivamente. Quando comparados ao tratamento de miniestacas em ácido indol butírico (AIB), estes isolados promoveram incrementos significativos na porcentagem de enraizamento e na massa seca do sistema radicular de miniestacas.

Molecular diversity of mesophilic and thermophilic bacteria in a membrane bioreactor determined by fluorescent in situ hybridization with mxaF- and rRNA-targeted probes.

An evaluation of the efficiency of treatment of kraft mill foul condensates in a membrane bioreactor was carried out in the laboratory. Efficiency and rate of methanol removal were quantified at operating temperatures of 35, 45 and 55 degrees C. The structure of the bacterial community present in the reactor biomass at the different operating temperatures was evaluated by in situ hybridization of the biomass samples with fluorescently-labelled probes (FISH) targeting the Eubacteria, the alpha, beta and gamma subclasses of the Proteobacteria, the low G + C content Gram-positive bacteria (Bacillus spp.), while community function was evaluated by in situ hybridization with a methanol dehydrogenase gene (mxaF) probe. Methanol removal efficiency decreased from 99.4 to 92%, and removal rate from 2.69 mg MeOH/l x min to 2.49 mg MeOH/l x min when the operating temperature was increased from 35 to 55 degrees C. This decrease in methanol removal was accompanied by a decrease (from 58% to 42%) in the relative proportion of cells that hybridized with the mxaF probe. The relative proportion of Bacillus spp. increased from 5 to 20% while the proportion of members of the alpha subclass of Proteobacteria decreased from 16% to 6% when the bioreactor operating temperature was raised from 35 to 55 degrees C. The relative proportions of bacteria belonging to the beta (22-25%) and gamma (18-20%) subclasses of the Proteobacteria remained relatively constant regardless of operating temperature. Proteobacteria (alpha, beta and gamma subclasses) and Bacillus spp. represented 61, 67 and 71% of the Eubacteria in the biomass sampled at 35, 45 and 55 degrees C, respectively. The FISH technique was shown to be an efficient method for detection of both structural and functional changes in the bacterial communities that could be related to efficiency of methanol removal in a membrane bioreactor operating at different temperatures.

Detecting structural and functional differences in activated sludge bacterial communities originating from laboratory treatment of elementally and totally chlorine-free bleaching effluents.

The ability to differentiate functional and structural diversity of bacterial communities present in activated sludges adapted to elementally (ECF) and totally (TCF) chlorine-free bleaching effluents was evaluated. Community function was evaluated through substrate utilization patterns in BiologGN microplates, and taxonomic structure was evaluated by fluorescent in situ hybridization using probes targeting the Eubacteria; the alpha, beta, and gamma subclasses of the Proteobacteria; and gram-positive bacteria with high GC content. Over 6-week sampling periods, ECF-and TCF-adapted sludge bacterial communities presented reproducible substrate utilization patterns that through principal components (PCs) analysis, separated the ECF samples from the TCF samples. Application of the fluorescent in situ hybridization technique was complicated by the intense autofluorescence of the bleaching effluent sludge samples that interfered with detection of specific hybridization signals. The most notable difference in community structure detected using the chosen set of probes was the relatively greater proportion of cells of the alpha subclass in TCF sludge (27%) than in ECF sludge (6%). Nonspecific hybridization with beta and gamma probes was relatively high, but both sludges appeared to have similar proportions of cells of the beta (20-22%) and gamma (11-12%) subclasses. The two sludges presented relatively few gram-positive cells with high GC content (<0.2% of eubacterial counts). Differences in both metabolic potential and taxonomic structure of the microbial communities in the ECF- and TCF-activated sludges were detected. The kinetics of the development of these differences in treatment plants and their relationships with treatment efficiency and production process conditions should now be evaluated.