Occurrence and removal of drugs and endocrine disruptors in water supply systems in the metropolitan region of Belo Horizonte (Minas Gerais State, Brazil)

This study evaluates both the occurrence and removal of 24 compounds, including drugs and endocrine disruptors, in 8 water treatment plants (WTP) located in the metropolitan region of Belo Horizonte (Minas Gerais State, Brazil). The compounds 4-nonylphenol, 4-octylphenol, 17α-ethinylestradiol, 17β-estradiol, acyclovir, bisphenol A, bezafibrate, caffeine, dexamethasone, diclofenac sodium, diltiazem, estrone, estriol, gemfibrozil, ibuprofen, linezolid, loratadine, losartan, metformin, naproxen, paracetamol, promethazine, propranolol and sulfamethoxazole were monitored at 3 sampling points (raw water, filtered water, treated water) over 10 or 12 collection campaigns for each WTP. The results showed that bisphenol A occurred at higher concentrations during the dry period with a maximum concentration of 3257.1 ng L^-1, while the compounds 4-nonylphenol and losartan exhibited higher concentrations in the rainy period with maximum concentrations of 8577.2 ng L^-1 and 705.8 ng L^-1, respectively. Regarding the removal of compounds in the monitored WTPs, the clarification step demonstrated better removals for 4-nonylphenol, bisphenol-A, paracetamol, and sulfamethoxazole, whereas the disinfection step mainly removed the compounds 4-octylphenol and estrone. Margin of exposure (ME) assessment results indicated that only dexamethasone, ethinyl estradiol, diclofenac, estradiol, and estrone were classified as imminent risk or alert considering the 95th percentile concentration found in the samples of treated water.

Occurrence of contaminants of emerging concern in surface waters from Paraopeba River Basin in Brazil: seasonal changes and risk assessment

This study describes the application of gas chromatography coupled to mass spectrometry (GC-MS) to evaluate the occurrence of 12 CECs-contaminants of emerging concern (bisphenol A, diclofenac, 17β-estradiol, estriol, estrone, 17α-ethinylestradiol, gemfibrozil, ibuprofen, naproxen, 4-nonylphenol, 4-octylphenol, and acetaminophen) in surface waters from Paraopeba River Basin, Minas Gerais State, Brazil. The analytical procedure was validated and applied to 60 surface water samples collected across four sampling campaigns along the upper and middle watershed. Methods for CECs determination involved sample filtration, and solid-phase extraction (SPE) with subsequent derivatization of the target compounds prior to their analysis by GC-MS. The LOQ varied from 3.6 to 14.4 ng/L and extraction recoveries ranged from 46.1 to 107.1% for the lowest spiked concentration level (10 ng/L). The results showed a profile of spatial distribution of compounds, as well as the influence of rainfall. Ibuprofen (1683.9 ng/L), bisphenol (1587.7 ng/L), and naproxen (938.4 ng/L) occurred in higher concentrations during the rainy season, whereas during the dry season, the concentrations of bisphenol (1057.7 ng/L), estriol (991.0 ng/L), and estrone (978.4 ng/L) were highlighted. The risk assessment of human exposure shows that for most contaminants, the concentration is well below the estimated thresholds for chronic toxicity from water intake. However, estradiol and 17α-ethinylestradiol showed concentrations in the same order of magnitude as the guide values estimated for babies.

Occurrence and removal of drugs and endocrine disruptors in the Bolonha Water Treatment Plant in Belém/PA (Brazil)

This study aimed to investigate the occurrence of drugs and endocrine disrupters in water supplies and in water for human consumption. Twelve sampling campaigns were carried out during the rainy and dry season at four sampling points in the Bolonha Complex, in the city of Belém, northern region of Brazil: Bolonha reservoir (catchment) and Water Treatment Plant (WTP) Bolonha (filtered water chamber, treated water tank, and washing water from the filters). The determination of the compounds was performed by solid phase extraction followed by gas and liquid chromatography coupled to mass spectrometry. The results confirmed the anthropic influence that the reservoir and WTP-Bolonha have been suffering, as consequence of the discharge of domestic sewage in natura. Among 25 microcontaminants analyzed, 12 were quantified in raw water and 10 in treated water. The antiallergic Loratadine (LRT) was the contaminant that occurred most frequently in all sample points, having been poorly removed (median 12%) in the conventional treatment used. Losartana (LST), 4-octylphenol (4-OP), and Bisphenol A (BPA) also occurred very frequently in raw water with concentrations ranging from 3.7 to 194 ng L^-1. Although such contaminants occurred in treated water in concentrations varying from 4.0 to 135 ng L^-1, the estimated margin of exposure ranged from 55 to 3333 times which indicates low risk of human exposure to such contaminants through ingestion of treated water.

Impact of microaeration bioreactor on dissolved sulfide and methane removal from real UASB effluent for sewage treatment

Two bioreactors were investigated as an alternative for the post-treatment of effluent from an upflow anaerobic sludge blanket (UASB) reactor treating domestic sewage, aiming at dissolved sulfide and methane removal. The bioreactors (R-control and R-air) were operated at different hydraulic retention times (HRT; 6 and 3 h) with or without aeration. Large sulfide and methane removal efficiencies were achieved by the microaerated reactor at HRT of 6 h. At this HRT, sulfide removal efficiencies were equal to 61% and 79%, and methane removal efficiencies were 31% and 55% for R-control and R-air, respectively. At an HRT of 3 h, sulfide removal efficiencies were 22% (R-control) and 33% (R-air) and methane removal did not occur. The complete oxidation of sulfide, with sulfate formation, prevailed in both phases and bioreactors. However, elemental sulfur formation was more predominant at an HRT of 6 h than at an HRT of 3 h. Taken together, the results show that post-treatment improved the anaerobic effluent quality in terms of chemical oxygen demand and solids removal. However, ammoniacal nitrogen was not removed due to either the low concentration of air provided or the absence of microorganisms involved in the nitrogen cycle.

Oxidative treatments for atenolol removal in water: Elucidation by mass spectrometry and toxicity evaluation of degradation products

RATIONALE

The presence of pharmaceuticals in water is a worldwide concern due to potential damage to human and environmental health. For example, compounds such as the β-blocker atenolol (ATE), widely used for the treatment of cardiac disease, are detected in drinking water since conventional water treatment plants are not designed to remove them. Thus, the evaluation of ATE removal at different water oxidative treatment processes, identification of its degradation products and evaluation of their toxicity is necessary.

METHODS

Aqueous solutions of ATE (10 mg/L) were submitted to oxidative treatments of chlorination ([NaClO] = 10 mg/L), ozonation ([O₃ ] = 8 mg/L), photocatalysis ([TiO₂ ] = 120 mg/L and UV-C light) and photolysis (UV-C light). The removal of ATE and formation of degradation products (DPs) were monitored by mass spectrometry. To assess acute cytotoxicity, DPs were submitted to colorimetric MTT assay using HepG2 cells. The Ecological Structure Activity Relationships (ECOSAR) software was applied to estimate the acute and chronic toxicity of identified DPs at different trophic levels.

RESULTS

Photocatalysis was the treatment that demonstrated greater efficiency, removing 94% of the initial ATE. For the four tested treatments, 12 DPs were confirmed after 30 min. Moreover, some of the identified DPs were unpublished in the literature. Through high-resolution mass spectrometry (HRMS), it was possible to elucidate the structure of the DPs. Solutions of DPs were not considered to be toxic to HepG2 cells. Only the DP with a molecular formula of C₁₃ H₁₉ NO₃ (m/z 238.1438) could be considered detrimental to daphnid and green algae.

CONCLUSIONS

Low rates of organic matter removal and high rates of ATE degradation were obtained in the applied treatments after 30 min. Although the treated solutions were not toxic to HepG2 cells, one of the degradation products can be considered an environmental concern since it presents chronic toxicity to daphnid and green algae.

Quality improvement and geographical indication of cachaça (Brazilian spirit) by using locally selected yeast strains

AIMS

In order to improve the quality and to create a biological basis for obtainment of the protected denomination of origin (PDO), indigenous yeast were isolated and characterized for use in Salinas city (the Brazilian region of quality cachaça production).

MATERIAL AND METHODS

Seven thousand and two hundred yeast colonies from 15 Salinas city distilleries were screened based on their fermentative behaviour and the physicochemical composition of cachaça. Molecular polymorphic analyses were performed to characterize these isolates.

RESULTS

Two Saccharomyces cerevisiae strains (nos. 678 and 680) showed appropriate characteristics to use in the cachaça production: low levels of acetaldehyde and methanol, and high ethyl lactate/ethyl acetate ratio respectively. They also presented polymorphic characteristics more closely related between themselves even when compared to other strains from Salinas.

CONCLUSIONS

The application of selected yeast to cachaça production can contribute for the improvement of the quality product as well as be used as a natural marker for PDO.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study suggests that the use of selected yeast strains could contribute to obtain a cachaça similar to those produced traditionally, while getting wide acceptation in the market, yet presenting more homogeneous organoleptic characteristics, and thus contributing to the PDO implementation.

Comparison between two forms of granular activated carbon for the removal of pharmaceuticals from different waters

The aim of this study was to evaluate the performance of two forms of basic granular activated carbon (GAC), mineral (pH = 10.5) and vegetal (pH = 9), for the removal of three pharmaceuticals, as sulphamethoxazole (SMX), diclofenac (DCF) and 17β-estradiol (E2), from two different matrices: fortified distilled (2.4-3.0 mg L(-1) and pH from 5.5 to 6.5) and natural (∼1.0 mg L(-1) and pH from 7.1 to 7.2) water in a bench scale. The Rapid Small-Scale Column Test used to assess the ability of mineral and vegetal GAC on removal of such pharmaceuticals led to removal capacities varying from 14.9 to 23.5 mg g(-1) for E2, from 23.7 to 24.2 mg g(-1) for DCF and from 20.5 to 20.6 mg g(-1) for SMX. Removal efficiencies of 71%, 88% and 74% for DCF, SMX and E2, respectively, were obtained at breakthrough point when using mineral GAC, whereas for the vegetal GAC the figures were 76%, 77% and 65%, respectively. The carbon usage rate at the breakthrough point varied from 11.9 to 14.5 L g(-1) for mineral GAC and from 8.8 to 14.8 L g(-1) for vegetal GAC. Mineral CAG also exhibited the best performance when treating fortified natural water, since nearly complete removal was observed for all contaminants in the column operated for 22 h at a carbon usage rate of 2.9 L g(-1).

Behaviour of pharmaceuticals and endocrine disrupting chemicals in simplified sewage treatment systems

This work assessed the behaviour of nine pharmaceuticals and/or endocrine disrupting chemicals (EDCs) in demo-scale upflow anaerobic sludge blanket reactors (UASB reactors) coupled to distinct simplified post-treatment units (submerged bed, polishing ponds, and trickling filters) fed on raw sewage taken from a municipality in Brazil. The dissolved concentration of the studied micropollutants in the raw and treated sewage was obtained using solid phase extraction (SPE) followed by analysis in a liquid chromatography system coupled to a hybrid high resolution mass spectrometer consisting of an ion-trap and time of flight (LC-MS-IT-TOF). The UASB reactors demonstrated that they were not appropriate for efficiently removing the assessed compounds from the sewage. Furthermore, this study demonstrated that the hydraulic retention time (HRT) was an important parameter for the removal of the hydrophilic and less biodegradable compounds, such as trimethoprim and sulfamethoxazole. The post-treatment units substantially increased the removal of most target micropollutants present in the anaerobic effluents, with a greater removal of micropollutants in simplified systems that require a large construction area, such as the submerged bed and polishing ponds, probably because of the higher HRT employed. Alternatively, compact post-treatment systems, such as trickling filters, tended to be less effective at removing most of the micropollutants studied, and the type of packing proved to be crucial for determining the fate of such compounds using trickling filters.

Occurrence of pharmaceuticals and endocrine disruptors in raw sewage and their behavior in UASB reactors operated at different hydraulic retention times

This work investigated the occurrence of pharmaceuticals and endocrine disrupting compounds (EDCs) in raw sewage (from Belo Horizonte city, Minas Gerais state, Brazil) and assessed their behavior in demo-scale upflow anaerobic sludge blanket reactors (UASB reactors) operated at different hydraulic retention times (HRT). The dissolved concentration of the studied micropollutants in the raw and treated sewage was obtained using solid phase extraction (SPE) followed by analysis in a liquid chromatography system coupled to a hybrid high resolution mass spectrometer consisting of an ion-trap and time of flight (LC-MS-IT-TOF). The natural (estradiol) and synthetic (ethinylestradiol) estrogens were hardly detected; when present, however, their concentrations were lower than the method quantification limits. The concentrations of bisphenol A and miconazole in raw sewage were similar to that reported in the literature (around 200 ng L⁻¹ and hardly detected, respectively). The antibiotics sulfamethoxazole (median 13.0 ng L⁻¹) and trimethoprim (median 61.5 ng L⁻¹), and the other pharmaceutical compounds (diclofenac and bezafibrate, with median 99.9 and 94.4 ng L⁻¹, respectively) were found in lower concentrations when compared with reports in the literature, which might indicate a lower consumption of such drugs in Brazil. The UASB reactors were inefficient in the removal of bisphenol A, and led to an increased concentration of nonylphenol in the effluent. The anaerobic reactors were also inefficient in the removal of diclofenac, and led to a partial removal of bezafibrate; whereas, for sulfamethoxazole there seemed to be a direct relationship between the HRT and removal efficiencies. For trimethoprim the sludge retention time (SRT) seemed to play an important role, although it was only partially removed in the UASB reactors.

Occurrence of endocrine disrupting compounds in water sources of Belo Horizonte Metropolitan Area, Brazil

Endocrine disrupting compounds (EDCs) have attracted the attention of the scientific community because of the effects of EDCs on aquatic fauna and the potential threat they pose to human health. There are a handful of papers on the monitoring of EDCs in Brazilian surface waters, hence this research was aimed at assessing, by using liquid chromatography coupled to mass spectrometry (LC-MS), the presence of 17 beta-estradiol, 17 alpha-ethynylestradiol and 4-nonylphenol in surface waters used for supplying the Belo Horizonte Metropolitan Area, Minas Gerais state, Brazil. The one-year monitoring period of three water sources showed that 4-nonylphenol was detected in all samples in a concentration range of 44 to 1918 ng L(-1), whilst the natural and synthetic estradiols were hardly detected (only in approximately 15% of samples) and always in low concentrations (2 to 54 ng L(-1)). Samples of partially treated water, collected in three water treatment plants before the chlorination step, showed that the steps of prechlorination, flocculation-sedimentation and sand filtration did not efficiently remove the EDCs studied.