Assessing pesticide residues occurrence and risks in water systems: A Pan-European and Argentina perspective.

Freshwater ecosystems face a particularly high risk of biodiversity loss compared to marine and terrestrial systems. The use of pesticides in agricultural fields is recognized as a relevant stressor for freshwater environments, exerting a negative impact worldwide on the overall status and health of the freshwater communities. In the present work, part of the Horizon 2020 funded SPRINT project, the occurrence of 193 pesticide residues was investigated in 64 small water bodies of distinct typology (creeks, streams, channels, ditches, rivers, lakes, ponds and reservoirs), located in regions with high agricultural activity in 10 European countries and in Argentina. Mixtures of pesticide residues were detected in all water bodies (20, median; 8-40 min-max). Total pesticide levels found ranged between 6.89 and 5860 ng/L, highlighting herbicides as the dominant type of pesticides. Glyphosate was the compound with the highest median concentration followed by 2,4-D and MCPA, and in a lower degree by dimethomorph, fluopicolide, prothioconazole and metolachlor(-S). Argentina was the site with the highest total pesticide concentration in water bodies followed by The Netherlands, Portugal and France. One or more pesticides exceeded the threshold values established in the European Water Framework Directive for surface water in 9 out of 11 case study sites (CSS), and the total pesticide concentration surpassed the reference value of 500 ng/L in 8 CSS. Although only 5 % (bifenthrin, dieldrin, fipronil sulfone, permethrin, and terbutryn) of the individual pesticides denoted high risk (RQ > 1), the ratios estimated for pesticide mixtures suggested potential environmental risk in the aquatic compartment studied.

Distribution and diversity of aquatic insects in different water bodies of Qatar / Distribuição e diversidade de insetos aquáticos em diferentes corpos de água do Catar

Aquatic insect fauna remains an important tool for bio indication of environmental disturbance, while maintaining a healthy aquatic system. The purpose of the study was to document and to identify the diversity and distribution patterns of aquatic insect, a highly ignored aspect from the Qatar. Following the standard procedures, the samples were collected from aquatic habitats during the period October 2015 to May 2017 on monthly basis. A total of 11,287 individuals, belonging to 6 orders were captured. Dipterans were the abundant with the percentages of 71.01 (n=8,015), while the lowest percentage was observed for Coleoptera 0.04 (n=05). Twelve insects families were identified, among these five were reported under Diptera, followed by Hemiptera (03), while Coleoptera, Tricoptera, Odonata, and Ephemeroptera were represented by single families. Among the selected localities, Dipterans were collected from 10 stations, followed by Hemiptera (9), Coleoptera (4), Odonota (4), Ephemeroptera (3) and Trichoptera (1) respectively. Among the water bodies samples, streams were the most preferred habitats (n=2,767), while drinking water pools were the least (27). Moreover, the highest Simpson diversity index of 1.48 and lowest of 0.47 was recorded for flooded sewage pool and plastic containers respectively, while the low evenness values were observed for ponds, and less than 1 Margalef's diversity values were seen for all habitats. This study documents the patterns of the diversity and distribution of aquatic insects, and provides a baseline for the future studies from Qatar.

A fauna aquática de insetos continua sendo uma ferramenta importante para a bioindicação de distúrbios ambientais, ao mesmo tempo em que mantém um sistema aquático saudável. O objetivo do estudo foi documentar e identificar a diversidade e os padrões de distribuição dos insetos aquáticos, um aspecto altamente ignorado no Catar. Seguindo os procedimentos padrão, as amostras foram coletadas em hábitats aquáticos durante o período de outubro de 2015 a maio de 2017, mensalmente. Um total de 11.287 indivíduos, pertencentes a seis ordens, foram capturados. Dípteros foram os mais abundantes, com as porcentagens de 71,01 (n = 8.015), enquanto a menor porcentagem foi observada para Coleópteros 0,04 (n = 05). Doze famílias de insetos foram identificadas, destas, cinco foram registradas sob Diptera, seguido por Hemiptera (03), enquanto Coleoptera, Tricoptera, Odonata e Ephemeroptera foram representados por famílias únicas. Dentre as localidades selecionadas, Dipterans foram coletados em 10 estações, seguidos por Hemiptera (9), Coleoptera (4), Odonota (4), Ephemeroptera (3) e Trichoptera (1), respectivamente. Entre as amostras de corpos d'água, os riachos foram os hábitats mais preferidos (n = 2.767), enquanto as piscinas de água potável foram os menos (27). Além disso, o maior índice de diversidade de Simpson de 1,48 e o menor de 0,47 foi registrado para piscina de esgoto inundada e recipientes de plástico, respectivamente, enquanto os valores de baixa uniformidade foram observados para lagoas e menos de 1 valores de diversidade de Margalef foram observados para todos os hábitats. Este estudo documenta os padrões de diversidade e distribuição de insetos aquáticos e fornece uma linha de base para os estudos futuros do Catar.

Distribution and diversity of aquatic insects in different water bodies of Qatar

Abstract Aquatic insect fauna remains an important tool for bio indication of environmental disturbance, while maintaining a healthy aquatic system. The purpose of the study was to document and to identify the diversity and distribution patterns of aquatic insect, a highly ignored aspect from the Qatar. Following the standard procedures, the samples were collected from aquatic habitats during the period October 2015 to May 2017 on monthly basis. A total of 11,287 individuals, belonging to 6 orders were captured. Dipterans were the abundant with the percentages of 71.01 (n=8,015), while the lowest percentage was observed for Coleoptera 0.04 (n=05). Twelve insects families were identified, among these five were reported under Diptera, followed by Hemiptera (03), while Coleoptera, Tricoptera, Odonata, and Ephemeroptera were represented by single families. Among the selected localities, Dipterans were collected from 10 stations, followed by Hemiptera (9), Coleoptera (4), Odonota (4), Ephemeroptera (3) and Trichoptera (1) respectively. Among the water bodies samples, streams were the most preferred habitats (n=2,767), while drinking water pools were the least (27). Moreover, the highest Simpson diversity index of 1.48 and lowest of 0.47 was recorded for flooded sewage pool and plastic containers respectively, while the low evenness values were observed for ponds, and less than 1 Margalefs diversity values were seen for all habitats. This study documents the patterns of the diversity and distribution of aquatic insects, and provides a baseline for the future studies from Qatar.

Resumo A fauna aquática de insetos continua sendo uma ferramenta importante para a bioindicação de distúrbios ambientais, ao mesmo tempo em que mantém um sistema aquático saudável. O objetivo do estudo foi documentar e identificar a diversidade e os padrões de distribuição dos insetos aquáticos, um aspecto altamente ignorado no Catar. Seguindo os procedimentos padrão, as amostras foram coletadas em hábitats aquáticos durante o período de outubro de 2015 a maio de 2017, mensalmente. Um total de 11.287 indivíduos, pertencentes a seis ordens, foram capturados. Dípteros foram os mais abundantes, com as porcentagens de 71,01 (n = 8.015), enquanto a menor porcentagem foi observada para Coleópteros 0,04 (n = 05). Doze famílias de insetos foram identificadas, destas, cinco foram registradas sob Diptera, seguido por Hemiptera (03), enquanto Coleoptera, Tricoptera, Odonata e Ephemeroptera foram representados por famílias únicas. Dentre as localidades selecionadas, Dipterans foram coletados em 10 estações, seguidos por Hemiptera (9), Coleoptera (4), Odonota (4), Ephemeroptera (3) e Trichoptera (1), respectivamente. Entre as amostras de corpos d'água, os riachos foram os hábitats mais preferidos (n = 2.767), enquanto as piscinas de água potável foram os menos (27). Além disso, o maior índice de diversidade de Simpson de 1,48 e o menor de 0,47 foi registrado para piscina de esgoto inundada e recipientes de plástico, respectivamente, enquanto os valores de baixa uniformidade foram observados para lagoas e menos de 1 valores de diversidade de Margalef foram observados para todos os hábitats. Este estudo documenta os padrões de diversidade e distribuição de insetos aquáticos e fornece uma linha de base para os estudos futuros do Catar.

Influence of sewage discharge on dissolved oxygen concentration and fish diversity in the Girado stream and Chascomús lake.

Hypoxic aquatic environments have increased in recent decades mainly by human activities that generate pollution. The objective of this work was to study the influence of the discharge of sewage effluents from Chascomús city on the concentration of dissolved oxygen (DO) in the Girado stream and its connection with Chascomús lake and analyze the impact on fish biodiversity. Four sites were selected to measure DO and temperature weekly for one year: discharge of sewage effluent, union of the sewage effluent with the Girado stream, Girado stream and Chascomús lake. Also, ichthyological samplings were carried out in a presumed hypoxic zone and a normoxic zone of the Girado stream. The results showed that there were two hypoxic zones corresponding to the sewage effluent and the union of the effluent with the Girado stream (~3 mg l-1). Also, two normoxic zones were identified, the course of the Girado stream and the union with Chascomús lake (~ 8 mg l-1). In these areas the water temperature varied according to the seasonality of the region (from 10 to 30 °C) without differences between zones. It is important to note that these areas received a constant flow of sewage effluent from Chascomús city (~ 885,600 l per day). In the fish sampling carried out in the 4 seasons of the year, 14 typical species of the Pampas lakes were captured with species more tolerant to low DO. Pejerrey were captured in a small number in both sites but with no signs of abnormalities in the gonads.

Pb(II) Uptake from Polluted Irrigation Water Using Anatase TiO2 Nanoadsorbent.

The adsorption characteristics of titanium dioxide nanoparticles (nano-TiO2) for the removal of Pb(II) from irrigation water were investigated in this work. To accomplish this, several adsorption factors, such as contact time and pH, were tested to assess adsorption efficiencies and mechanisms. Before and after the adsorption experiments, commercial nano-TiO2 was studied using X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The outcomes showed that anatase nano-TiO2 was remarkably efficient in cleaning Pb(II) from water, with a removal efficiency of more than 99% after only one hour of contact time at a pH of 6.5. Adsorption isotherms and kinetic adsorption data matched the Langmuir and Sips models quite well, showing that the adsorption process occurred at homogenous sites on the surface of nano-TiO2 by forming a Pb(II) adsorbate monolayer. The XRD and TEM analysis of nano-TiO2 following the adsorption procedure revealed a non-affected single phase (anatase) with crystallite sizes of 9.9 nm and particle sizes of 22.46 nm, respectively. According to the XPS data and analyzed adsorption data, Pb ions accumulated on the surface of nano-TiO2 through a three-step mechanism involving ion exchange and hydrogen bonding mechanisms. Overall, the findings indicate that nano-TiO2 has the potential to be used as an effective and long-lasting mesoporous adsorbent in the treatment and cleaning of Pb(II) from water bodies.

Medical Household Waste as a Potential Environmental Hazard: An Ecological and Epidemiological Approach.

Nowadays, the contamination caused by emerging pollutants is a global concern due to the lack of scientific evidence to demonstrate the risk or toxicity to humans due to the presence of pharmaceutical residues in the environment. This study aimed to identify and describe the disposal practices of unused and unwanted medications, as well as to analyze and identify the most frequent drugs determined on water bodies adjacent to the biggest urban population in Mexico. A two-phase study with an epidemiological and an ecological assessment was performed. The epidemiological phase was carried out with a descriptive cross-sectional study among citizens from Mexico City and the metropolitan area using an electronic survey applied to 719 subjects aimed to assess practices in which pharmaceutical products are disposed. The ecological phase included a review of scientific reports. The results show that nearly 83.5% of those surveyed use inappropriate practices for disposal medicines, the main ones are through the municipal dump or directly in the drain. The ecological approach was carried out by a systematic literature review of original reports published between 2013 to 2023; information about the class of drugs, active substance, environmental compartments, location, and concentration was extracted and presented. Fifty-one different types of pharmaceutical residues were detected in wastewater in Mexico City in the last decade. The results of this study can contribute to the application of public policies for waste management authorities to mitigate the socio-environmental risks due to the inappropriate disposal of medicines.

An ultrasensitive LC-MS/MS method for the determination of glyphosate, AMPA and glufosinate in water - analysis of surface and groundwater from a hydrographic basin in the Midwestern region of Brazil.

The intensive use of glyphosate around the world in the last few decades demands constant monitoring of this compound and its metabolite in aquatic compartments. This work aimed to develop a sensitive method for the analysis of glyphosate, AMPA and glufosinate in water by liquid chromatography/tandem mass spectrometry (LC-MS/MS). The method involves analyte concentration by lyophilization (20×) and direct injection on the LC-MS/MS, and was satisfactorily validated at a LOQ of 0.0025 µg L-1. A total of 142 samples of surface and groundwater collected during the 2021/2022 dry and rainy seasons in the Rio Preto Hydrographic Basin were analyzed. All the 52 groundwater samples were positive for glyphosate (up to 1.5868 µg L-1, dry season) and AMPA (up to 0.2751 µg L-1, dry season). A total of 27 of the 90 surface water samples were positive for glyphosate (up to 0.0236 µg L-1), and 31 samples for AMPA (up to 0.0086 µg L-1), of which over 70 % collected during the dry season. Glufosinate was detected in only five samples, four in groundwater (up to 0.0256 µg L-1). The levels found in the samples are much lower than the maximum levels established by the Brazilian legislation for glyphosate and/or AMPA and lower than the most critical toxicological endpoints for aquatic organisms. However, constant monitoring is necessary, demanding sensitive methods to allow the detection of the very low levels of these pesticides in water.

Relationship between Pesticide Standards for Classification of Water Bodies and Ecotoxicity: A Case Study of the Brazilian Directive.

The objective of this study was to evaluate if the maximum values (MVs) for pesticides in surface freshwater included in CONAMA directive 357/2005 are safe for aquatic biota, comparing them with ecotoxicology data published in the literature. The terms "aquatic toxicity", "chronic" "acute", "LC50", "EC50", "NOEL", "NOEC" and the name of each pesticide were used for searches on the research platforms. Data from 534 tests reported in 37 published articles and three ecotoxicological databases were included in this study; 24% of the tests were carried out with producer organisms, 34% with primary consumers and 42% with secondary consumers. Microcrustaceans of the Daphnia genus and the fishes Pimephales promelas and Oncorhynchus mykiss were the organisms most used. Atrazine, alachlor and metolachlor were the most investigated pesticides. Atrazine and alachlor are approved in Brazil, with atrazine ranking fourth among the most used pesticides in the country. The results indicated that of the 27 pesticides included in the standard directive, 17 have a risk quotient (RQ) higher than the level of concern for at least one ecotoxicological parameter and may not protect the aquatic biota. The insecticide malathion, used in various agricultural crops in Brazil, was the one that presented the highest RQs (3125 and 3,125,000 for freshwaters classified as 1/2 and 3, respectively), related to a LC50 (96 h) of 0.000032 µg/L in Chironomus ramosus. The results indicate that CONAMA directive 357/2005 should be updated in line with the current use of pesticides in the country, and the MVs should be re-evaluated so that they do not represent toxicity for the aquatic biota.

Euphlyctis Cyanophlyctis Schneider, 1799 (Amphibia: Dicroglossidae) in district Lower Dir, Pakistan / Euphlyctis Cyanophlyctis (Schneider, 1799) Amphibia: Dicroglossidae no distrito de Lower Dir, Paquistão

Euphlyctis cyanophlyctis (the skittering frog) is one of the most widespread species in Pakistan. Present study was aimed to know the presence of Euphlyctis cyanophlyctis in urban and rural areas of Lower Dir, the North-western Pakistan. A total of 33 frogs were collected, including 15 from rural and 18 from urban areas. The frogs were caught by hands covered with gloves instead of using nets. The collection was managed from August to October 2016 and from April to May 2018. Morphometric analysis, coloration as well as photographs of the frogs have been provided in detail. Skittering frogs were seen frequent in swampy areas near the water bodies. These frogs were mostly seen after sunset.(AU)

Euphlyctis cyanophlyctis (a rã que desliza) é uma das espécies mais comuns no Paquistão. O presente estudo teve como objetivo conhecer a presença de Euphlyctis cyanophlyctis em áreas urbanas e rurais de Lower Dir, noroeste do Paquistão. Um total de 33 sapos foram coletados, incluindo 15 de áreas rurais e 18 de áreas urbanas. As rãs foram apanhadas com as mãos cobertas com luvas em vez de redes. A coleta foi gerenciada de agosto a outubro de 2016 e de abril a maio de 2018. Análises morfométricas, coloração e também fotografias das rãs foram fornecidas em detalhes. Rãs saltitantes foram vistas freqüentemente em áreas pantanosas próximas aos corpos dágua. Essas rãs eram vistas principalmente após o pôr do sol.(AU)

A new species of the seasonal killifish genus Moema (Cyprinodontiformes: Rivulidae) from the Piraí watershed in the Southwest Amazon basin

Moema, a genus of the Rivulidae family, currently comprises 20 valid species. Most of these species inhabit temporary pools in the Amazon basin and only one species is found in the upper Paraguay basin. A new member of this genus from the upper Río Madeira drainage is here described. Males of the new species differ from all congeners by the combination of a color pattern consisting of oblique, sometimes chevron-like, irregular rows of red and light blue double-dots on body; dark yellowish to golden pectoral fins with no visible markings; and a stripe pattern on the ventral section of caudal fin with a very narrow black marginal line, intermittent or even absent. The existence of infrageneric species groups within Moema, the geographic distribution and taxonomic aspects of the species present in the Ríos Mamoré and Iténez/Guaporé rivers drainages, and the observation of intraspecific aggression between males and amphibious lifestyle in the new species are discussed.

Moema, un género de la familia Rivulidae, actualmente comprende 20 especies válidas. La mayoría de estas especies habitan en charcos temporales de la cuenca amazónica y solo una especie se encuentra en la cuenca alta del Río Paraguay. Un nuevo miembro de este género de la cuenca alta del Río Madeira es descrito aquí. Los machos de la especie nueva se diferencian de todos los congéneres por la combinación de un patrón de color de filas irregulares oblicuas, a veces en forma de chevrón, de puntos dobles rojos y azul claro en el cuerpo; aletas pectorales de color amarillento oscuro a dorado sin marcas visibles; y un patrón de rayas en la sección ventral de la aleta caudal con una línea marginal negra muy estrecha, intermitente o incluso ausente. Se discute la existencia de grupos infragenéricos de especies dentro de Moema, la distribución geográfica y aspectos taxonómicos de las especies presentes en el drenaje de los Ríos Mamoré e Iténez/Guaporé, y la observación de agresión intraespecífica entre machos y estilo de vida anfibio en la nueva especie.

Euphlyctis Cyanophlyctis Schneider, 1799 (Amphibia: Dicroglossidae) in district Lower Dir, Pakistan / Euphlyctis Cyanophlyctis (Schneider, 1799) Amphibia: Dicroglossidae no distrito de Lower Dir, Paquistão

Euphlyctis cyanophlyctis (the skittering frog) is one of the most widespread species in Pakistan. Present study was aimed to know the presence of Euphlyctis cyanophlyctis in urban and rural areas of Lower Dir, the North-western Pakistan. A total of 33 frogs were collected, including 15 from rural and 18 from urban areas. The frogs were caught by hands covered with gloves instead of using nets. The collection was managed from August to October 2016 and from April to May 2018. Morphometric analysis, coloration as well as photographs of the frogs have been provided in detail. Skittering frogs were seen frequent in swampy areas near the water bodies. These frogs were mostly seen after sunset.

Euphlyctis cyanophlyctis (a rã que desliza) é uma das espécies mais comuns no Paquistão. O presente estudo teve como objetivo conhecer a presença de Euphlyctis cyanophlyctis em áreas urbanas e rurais de Lower Dir, noroeste do Paquistão. Um total de 33 sapos foram coletados, incluindo 15 de áreas rurais e 18 de áreas urbanas. As rãs foram apanhadas com as mãos cobertas com luvas em vez de redes. A coleta foi gerenciada de agosto a outubro de 2016 e de abril a maio de 2018. Análises morfométricas, coloração e também fotografias das rãs foram fornecidas em detalhes. Rãs saltitantes foram vistas freqüentemente em áreas pantanosas próximas aos corpos d’água. Essas rãs eram vistas principalmente após o pôr do sol.

Euphlyctis Cyanophlyctis Schneider, 1799 (Amphibia: Dicroglossidae) in district Lower Dir, Pakistan

Abstract Euphlyctis cyanophlyctis (the skittering frog) is one of the most widespread species in Pakistan. Present study was aimed to know the presence of Euphlyctis cyanophlyctis in urban and rural areas of Lower Dir, the North-western Pakistan. A total of 33 frogs were collected, including 15 from rural and 18 from urban areas. The frogs were caught by hands covered with gloves instead of using nets. The collection was managed from August to October 2016 and from April to May 2018. Morphometric analysis, coloration as well as photographs of the frogs have been provided in detail. Skittering frogs were seen frequent in swampy areas near the water bodies. These frogs were mostly seen after sunset.

Resumo Euphlyctis cyanophlyctis (a rã que desliza) é uma das espécies mais comuns no Paquistão. O presente estudo teve como objetivo conhecer a presença de Euphlyctis cyanophlyctis em áreas urbanas e rurais de Lower Dir, noroeste do Paquistão. Um total de 33 sapos foram coletados, incluindo 15 de áreas rurais e 18 de áreas urbanas. As rãs foram apanhadas com as mãos cobertas com luvas em vez de redes. A coleta foi gerenciada de agosto a outubro de 2016 e de abril a maio de 2018. Análises morfométricas, coloração e também fotografias das rãs foram fornecidas em detalhes. Rãs saltitantes foram vistas freqüentemente em áreas pantanosas próximas aos corpos d'água. Essas rãs eram vistas principalmente após o pôr do sol.

Euphlyctis Cyanophlyctis Schneider, 1799 (Amphibia: Dicroglossidae) in district Lower Dir, Pakistan / Euphlyctis Cyanophlyctis (Schneider, 1799) Amphibia: Dicroglossidae no distrito de Lower Dir, Paquistão

Euphlyctis cyanophlyctis (the skittering frog) is one of the most widespread species in Pakistan. Present study was aimed to know the presence of Euphlyctis cyanophlyctis in urban and rural areas of Lower Dir, the North-western Pakistan. A total of 33 frogs were collected, including 15 from rural and 18 from urban areas. The frogs were caught by hands covered with gloves instead of using nets. The collection was managed from August to October 2016 and from April to May 2018. Morphometric analysis, coloration as well as photographs of the frogs have been provided in detail. Skittering frogs were seen frequent in swampy areas near the water bodies. These frogs were mostly seen after sunset.

Euphlyctis cyanophlyctis (a rã que desliza) é uma das espécies mais comuns no Paquistão. O presente estudo teve como objetivo conhecer a presença de Euphlyctis cyanophlyctis em áreas urbanas e rurais de Lower Dir, noroeste do Paquistão. Um total de 33 sapos foram coletados, incluindo 15 de áreas rurais e 18 de áreas urbanas. As rãs foram apanhadas com as mãos cobertas com luvas em vez de redes. A coleta foi gerenciada de agosto a outubro de 2016 e de abril a maio de 2018. Análises morfométricas, coloração e também fotografias das rãs foram fornecidas em detalhes. Rãs saltitantes foram vistas freqüentemente em áreas pantanosas próximas aos corpos d'água. Essas rãs eram vistas principalmente após o pôr do sol.

Analysis of community-level factors contributing to cholera infection and water testing access in the Northern Corridor of Haiti.

Vibrio cholera, the bacteria that cause cholera, is endemic in Haiti with a presence in both cities and remote areas. Improved access to drinking water testing and treatment in remote areas may reduce the impact of the disease. This case study uses correlation and regression analysis to identify the main factors that hinder access to water testing and that lead to high cholera infection rates among communities in the Northern Corridor of Haiti. Poor road conditions, mountainous terrain, and limited transportation options lead to high travel times up to 5.7 min/km between remote communities and drinking water testing facilities. The presence of springs in a community has a significant positive correlation with cholera infection rates in the Northern Corridor. However, socioeconomic factors had no significant correlation with cholera infection rate. The results of this study will be used to plan the implementation of a new drinking water testing laboratory near the city of Cap-Haitian and other programs for vulnerable remote areas. PRACTITIONER POINTS: Topography and road conditions may be more important than distance in determining the accessibility of water testing facilities for rural communities. A lack of access to private vehicles is a substantial challenge for many rural communities in accessing water testing. The presence of springs in a community had a significant positive correlation with cholera infection rate.

Performance of sewage treatment plants and impact of effluent discharge on receiving water quality within an urbanized area.

In Brazil, wastewater treatment coverage is low. Even when treatment is carried out, many municipalities cannot achieve adequate levels of contaminant removal, and the usual practice of releasing raw or treated domestic effluent into water bodies remains. Thus, this pollution source puts pressure on water resources, compromising downstream uses of the disposal. This study has two aims: (1) to evaluate the performance of sewage treatment plants and (2) to determine the impact of discharging treated effluent on the water quality of receiving water bodies located within an urbanized area in the Velhas River basin, Minas Gerais State, Brazil. Monitoring data from raw wastewater were compared with typical ranges reported in literature, and effluent concentrations were compared between plants. The monitoring data of the receiving water bodies collected at points upstream and downstream of each disposal were statistically compared. Different performances between the systems and significant alterations in the receiving bodies resulting from the discharge of the treated effluents were found.

Determination of organochlorine and organophosphorus residues in surface waters from the coffee zone in Quindío, Colombia.

The aim of this study was to identify organochlorine (OC) and organophosphorus (OP) pesticides levels in water samples collected in secondary water bodies in agricultural area planted with coffee and plantain. A descriptive cross-sectional study was carried out. A validated method for microwave-assisted extraction and gas chromatography with electron microcapture detector (MAE-GC-µECD) was used to analyze pesticide residues in samples. The determinations were based on certified reference material, Organochlorine Pesticide Mix AB #3, Canadian Drinking Organophosphorus Pesticides Mix, and pentachloronitrobenzene (ISTD) Internal Standard Mix 508.1. Pesticide residues were found in 81.3% of the samples, including OCs: 4.4'-DDT (38%), endosulfan II (19.7%), endosulfan sulfate, and endrin (11.7% and 8.8%), and others identified as 4.4'-DDE, Delta-HCB, parathion, chlorpyrifos, endrin aldehyde, heptachlor, heptachlor epoxide, endrin ketone, and methoxychlor. Parathion and/or chlorpyrifos were found in 5.8-8% of samples; the water bodies most heavily affected were those in Filandia and Quimbaya in which 100% of samples were contaminated, followed by those in Calarcá, Córdoba, Pijao, and Génova, with contamination found in over 75% of samples. The results indicated that surface waters from Quindío municipalities are contaminated with pesticide residues hazardous to human health, which are still in use despite being either restricted or prohibited.

Laccases: structure, function, and potential application in water bioremediation.

The global rise in urbanization and industrial activity has led to the production and incorporation of foreign contaminant molecules into ecosystems, distorting them and impacting human and animal health. Physical, chemical, and biological strategies have been adopted to eliminate these contaminants from water bodies under anthropogenic stress. Biotechnological processes involving microorganisms and enzymes have been used for this purpose; specifically, laccases, which are broad spectrum biocatalysts, have been used to degrade several compounds, such as those that can be found in the effluents from industries and hospitals. Laccases have shown high potential in the biotransformation of diverse pollutants using crude enzyme extracts or free enzymes. However, their application in bioremediation and water treatment at a large scale is limited by the complex composition and high salt concentration and pH values of contaminated media that affect protein stability, recovery and recycling. These issues are also associated with operational problems and the necessity of large-scale production of laccase. Hence, more knowledge on the molecular characteristics of water bodies is required to identify and develop new laccases that can be used under complex conditions and to develop novel strategies and processes to achieve their efficient application in treating contaminated water. Recently, stability, efficiency, separation and reuse issues have been overcome by the immobilization of enzymes and development of novel biocatalytic materials. This review provides recent information on laccases from different sources, their structures and biochemical properties, mechanisms of action, and application in the bioremediation and biotransformation of contaminant molecules in water. Moreover, we discuss a series of improvements that have been attempted for better organic solvent tolerance, thermo-tolerance, and operational stability of laccases, as per process requirements.

Isolation and identification of Vibrio species in the Rio Bravo/Grande and water bodies from Reynosa, Tamaulipas.

The Rio Bravo (Rio Grande) adjoins various states in the Mexican region and has a great importance in water distribution in the northeast Tamaulipas (Mexico). In this work 161 strains were isolated, identified and characterized from the water samples taken from the flow of the Rio Bravo and the two inner canals that cover Reynosa city. The strains were identified as Vibrio cholerae (74·5%), Vibrio spp. (1·2%) and Vibrio mimicus (0·6%). Furthermore, the detected virulence genes in the V. cholerae strains, were the hlyA, ompU, tcpA, toxR genes in 78·3, 62·5, 15·8 and 90·8% respectively. Only the ompU and vmh genes were detected in the V. mimicus strain. These results indicate the presence of multi-toxigenic V. cholerae strains in the Rio Bravo/Grande and in the water bodies from Reynosa city, which could represent a risk for the exposed population. SIGNIFICANCE AND IMPACT OF THE STUDY: Water quality is associated with public health, as it plays an important role in the transmission and epidemiology of pathogens such as Vibrio, since this species have been responsible for human diseases around the world. This study demonstrated the presence of toxigenic Vibrio species in water bodies in Reynosa surroundings, indicating that water bodies may be a source of public health risk.

Monitoramento e modelagem da qualidade de água em uma bacia hidrográfica semiárida / Monitoring and modeling of water quality in a semiarid watershed

RESUMO O artigo teve como objetivo apresentar uma metodologia para caracterização da qualidade de água na Bacia Hidrográfica do Açude Acarape do Meio, no semiárido brasileiro. O mapeamento do uso do solo e o monitoramento de parâmetros de qualidade de água possibilitaram a identificação de fontes poluidoras e a construção do diagnóstico da bacia. A partir da modelagem da qualidade de água, 37 km do Rio Pacoti foram classificados como classe 4, exceto sua nascente, que ficou na classe 2. As principais fontes poluidoras para a degradação dos corpos hídricos foram as deficitárias Estações de Tratamento de Esgoto (ETEs), a falta de saneamento básico na zona rural, a pecuária e a atividade agrícola. O modelo QUAL-UFMG estimou a carga de entrada de fósforo no açude em 13,7 ton.ano-1 para uma concentração de 0,56 mg.L-1 e vazão média em 1,48 m³.s-1. Os coeficientes calibrados K1, Ks, Kd, Kb, Kspo, Koi e K2 foram iguais a 0,45 d-1, 0,29 d-1, 0,68 d-1, 0,65 d-1, 0,1 d-1, 0,01 d-1 e 5,4 d-1, respectivamente. Avaliaram-se as intervenções políticas e infraestruturais na bacia em dois cenários: melhoria na eficiência de operação das ETEs e efetivação de políticas públicas, que reduziram consideravelmente a carga de fósforo.

ABSTRACT This paper aimed at presenting a methodology for evaluating the water quality at the Acarape do Meio catchment, in the Brazilian semiarid. The land use mapping and monitoring of water quality parameters enabled the identification of main polluting sources and the construction of a catchment diagnosis. According to the water quality modelling, a stretch of 37 km along the Pacoti River was classified as class 4, except for those ones located at the catchment headwater, which was classified as class 2. The main polluting sources contributing to the water degradation were the inefficient Sewage Treatment Plants, the lack of basic sanitation in rural areas, livestock and agriculture activities. The QUAL-UFMG model estimated an affluent phosphorous load at the reservoir entrance of 13.7 ton.year-1 for the concentration of 0.56 mg.L-1 and mean water discharge of 1.48 m³.s-1. The K1, Ks, Kd, Kb, Kspo, Koi and K2 coefficients were 0.45, 0.29, 0.68, 0.65, 0.1, 0.01 and 5.4 d-1, respectively. The impacts of political and infrastructural measures over the catchment were evaluated taking into account two scenarios: improvement of efficiency at Sewage Treatment Plants and implementation of effective public policies, which reduced significantly the affluent phosphorous load into the reservoir.

Nutrient loads in the river mouth of the Río Verde basin in Jalisco, Mexico: how to prevent eutrophication in the future reservoir?

Since nutrients are emitted and mobilized in river basins, causing eutrophication of water bodies, it is important to reduce such emissions and subsequent nutrient loads. Due to processes of attenuation, nutrient loads are reduced during their mobilization in river basins. At the mouth of the Río Verde basin in western Mexico, the El Purgatorio dam is being constructed to supply water to the metropolitan area of the second most populated city in the country, Guadalajara. To analyze situations that allow protecting this future dam from eutrophication, nutrient loads in the mouth of the river basin were determined and their reduction scenarios evaluated by using the NEWS2 (Nutrient Export from Watersheds) model. For this, a nutrient emissions inventory was established and used to model nutrient loads, and modeling results were compared to an analysis of water quality data from two different monitoring sites located on the river. The results suggest that 96% of nitrogen and 99% of phosphorus emissions are attenuated in the watershed. Nutrient loads reaching the mouth of the river basin come mainly from wastewater discharges, followed by livestock activities and different land uses, and loads are higher as emissions are located closer to the mouth of the river basin. To achieve and maintain mesotrophic state of water in the future dam, different nutrient emission reduction scenarios were evaluated. According to these results, the reduction of 90% of the phosphorus loads in wastewater emissions or 75% of the phosphorus loads in wastewater emissions and at least 50% in emissions from livestock activities in the river basin are required.