Identification of enteric viruses from raw water using fluoro-immuno-magnetic separation coupled to RT-PCR / Identificación de virus entéricos en aguas crudas usando separación inmuno-magnética acoplada a RT-PCR

Abstract | Introduction: Enteric viruses have been associated with the production of a variety of diseases transmitted by the fecal-oral route and carried through contaminated food and water. Given their structure and composition, they are highly resistant to environmental conditions and most of the chemical agents used in the purification processes. Therefore, the systematic monitoring of raw water is necessary to ensure its quality especially when it is used for producing drinking water for human consumption. Objective: We identified the presence of rotavirus and hepatitis A virus by means of the fluoro-immuno-magnetic separation technique (FIMS) in raw water taken from four purification plants and their water supplies in the department of Norte de Santander. Materials and methods: The viruses were captured and separated from the water samples using magnetic microparticles functionalized with monoclonal anti-Hepatitis A and anti-Rotavirus antibodies. Confocal microscopy was used to monitor the viral concentration process and transmission electron microscopy for the morphological visualization of the separated viruses. The reverse transcriptase-coupled polymerase chain reaction (RT-PCR) was applied to confirm the presence of pathogens. Results: The two enteric viruses were identified in the majority of the analyzed water samples including water supply sources. Conclusion: We determined that the FIMS technique together with RT-PCR is highly effective for the detection of viral pathogens in complex matrices such as raw water.

Resumen | Introducción. Los virus entéricos se asocian con una serie de enfermedades transmitidas por vía fecal-oral en alimentos o agua contaminada. Dada su estructura y composición, son muy resistentes a las condiciones ambientales y a la mayoría de los agentes químicos empleados en los procesos de potabilización, por lo cual es necesario un monitoreo sistemático del agua cruda para asegurar su calidad, máxime cuando se emplea como materia prima en la producción de agua potable para consumo humano. Objetivo. Determinar la presencia de rotavirus y del virus de la hepatitis A mediante la técnica de separación fluoro-inmuno-magnética en agua cruda procedente de cuatro plantas de potabilización y sus fuentes hídricas en el departamento de Norte de Santander. Materiales y métodos. Los virus fueron capturados y separados a partir de las muestras de agua, empleando micropartículas magnéticas funcionalizadas con anticuerpos monoclonales anti-hepatitis A y anti-rotavirus. Se empleó microscopía confocal para hacer el seguimiento del proceso de concentración viral y, microscopía electrónica de transmisión, para la visualización morfológica de los virus separados. La reacción en cadena de la polimerasa acoplada a transcriptasa inversa (RT-PCR) se utilizó para confirmar la presencia de los patógenos. Resultados. Los dos virus entéricos se detectaron en la mayoría de las muestras de agua analizadas, incluidas las de sus fuentes hídricas. Conclusión. La técnica de separación fluoro-inmuno-magnética acoplada a RT-PCR fue altamente efectiva en la detección de patógenos virales en matrices complejas como el agua cruda.

Recomendaciones sobre el consumo de agua y alimentos en circunstancias especiales

El agua de uso y consumo humano debe reunir ciertas características de potabilidad para evitar que causen enfermedades, los gobiernos de los países son responsables de la calidad del agua, la purificación se realiza por varios procesos que aseguran que esté libre de patógenos, de sustancias químicas, físicas y radiológicas, siguiendo pautas de la Organización Mundial de la Salud (OMS). Las diarreas infecciosas son causadas por diferentes patógenos y muy frecuentemente asociadas al consumo de agua no potable. Desde hace varios años, en Venezuela, se presentan fallas en el suministro regular de agua potable intra-domiciliario, por fallas en la cadena de distribución y almacenamiento, además son frecuentes problemas deficitarios del suministro de energía eléctrica. Más reciente, en marzo de 2019, se presentó a escala nacional un colapso total del suministro de energía eléctrica que duró de 3 a 7 días, lo cual dejó a los ciudadanos sin el suministro de agua en sus hogares, además de fallas del transporte, colapso hospitalario, colocando en riesgo socio-sanitario a millones de personas. El objeto del documento es servir de guía e informar a la comunidad sobre las enfermedades más frecuentes asociadas al consumo de agua no potable; aconsejar sobre los cuidados especiales en los niños y, brindar medidas preventivas prácticas recomendadas para la purificación del agua de uso y consumo humano.

Water use and human consumption must meet certain characteristics of drinking to avoid causing diseases, the Governments of the countries are responsible for the quality of the water, purification is performed by several processes which ensure that it is free of pathogenic substances chemical, physical and radiological, following guidelines of the World Health Organization (WHO). Infectious diarrhea are caused by different pathogens and often associated with the consumption of non-potable water. For several years, in Venezuela, failures occur at regular drinking water supply intra-household, for failures in the chain of distribution and storage, they are also frequent electricity supply deficit. Most recently, in March 2019, arose nationwide a total collapse of the supply of electrical energy that lasted from 3 to 7 days, which left the people without water in their homes, in addition to transport, hospital collapse in putting at risk health to millions of people. The object of the document is to guide and inform the community about the most frequent illnesses associated with the consumption of non-potable water; advise on special child care and, provide preventive measures recommended for purification practices water use and human consumption.

Effectiveness of vertical subsurface wetlands for iron and manganese removal from wastewater in drinking water treatment plants / Eficacia de humedales subsuperficiales verticales en la remoción de hierro y manganeso de aguas residuales de plantas potabilizadoras / Eficácia das zonas úmidas subsuperficiais verticais na remoção de ferro e manganês das águas residuais de estações de tratamento de água potável

Abstract Population growth and urbanization pose a greater pressure for the treatment of drinking water. Additionally, different treatment units, such as decanters and filters, accumulate high concentrations of iron (Fe) and manganese (Mn), which in many cases can be discharged into the environment without any treatment when maintenance is performed. Therefore, this paper evaluates the effectiveness of vertical subsurface wetlands for Fe and Mn removal from wastewater in drinking water treatment plants, taking a pilot scale wetland with an ascending gravel bed with two types of plants: C. esculenta and P. australis in El Hormiguero (Cali, Colombia), as an example. The pilot system had three upstream vertical wetlands, two of them planted and the third one without a plant used as a control. The wetlands were arranged in parallel and each formed by three gravel beds of different diameter. The results showed no significant difference for the percentage of removal in the three wetlands for turbidity (98 %), Fe (90 %), dissolved Fe (97 %) and Mn (98 %). The dissolved oxygen presented a significant difference between the planted wetlands and the control. C. esculenta had the highest concentration of Fe in the root with (103.5 ± 20.8) μg/g; while P australis had the highest average of Fe concentrations in leaves and stem with (45.7 ± 24) μg/g and (41.4 ± 9.1) μg/g, respectively. It is concluded that subsurface wetlands can be an interesting alternative for wastewater treatment in the maintenance of drinking water treatment plants. However, more research is needed for the use of vegetation or some technologies for the removal or reduction of the pollutant load in wetlands, since each drinking water treatment plant will require a treatment system for wastewater, which in turn requires a wastewater treatment system as well

Resumen El crecimiento de la población y la urbanización imponen una mayor presión al tratamiento de agua potable. Por otra parte, las diferentes unidades de tratamiento, como decantadores y filtros, acumulan altas concentraciones de hierro (Fe) y manganeso (Mn), las cuales, en muchos casos, son descargadas en el ambiente sin ningún tratamiento cuando se hace mantenimiento. Este artículo evalúa la efectividad de humedales subsuperficiales de flujo vertical para la remoción de Fe y Mn provenientes de agua residual en plantas de tratamiento de agua potable, tomando como ejemplo un humedal de flujo ascendente a escala piloto, con un lecho de grava y dos tipos de plantas: C. esculenta y P. australis en El Hormiguero (Cali, Colombia). El sistema piloto consistió en tres humedales verticales de flujo ascendente, dos de ellos plantados y el tercero sin plantas, como control. Los humedales se organizaron en paralelo, cada uno formado por tres lechos de grava de diferente diámetro. Los resultados mostraron que no hubo diferencia significativa en el porcentaje de remoción en los tres humedales para turbidez (98 %), Fe (90 %), Fe disuelto (97 %) y Mn (98 %). El oxígeno disuelto presentó una diferencia significativa entre los humedales plantados y el control. C. esculenta tuvo la concentración más alta de Fe en la raíz, con (103.5 ± 20.8) μg/g; mientras que P. australis tuvo el promedio más alto de concentraciones de Fe en hojas y tallos, con (45.7 ± 24) μg/g y (41.4 ± 9.1) μg/g, respectivamente. Se concluye que los humedales subsuperficiales pueden ser una alternativa interesante para el tratamiento de aguas residuales en el mantenimiento de plantas de tratamiento de agua potable. Sin embargo, se requiere más investigación sobre el uso de vegetación u otras tecnologías para la remoción o reducción de la carga contaminante en humedales, ya que cada planta de tratamiento de agua potable o su sistema de tratamiento de aguas residuales con humedales mantendrá el contaminante en el sistema.

Resumo O crescimento da população e da urbanização impõem uma maior pressão ao tratamento de água potável. Adicionalmente, as diferentes unidades de tratamento, como decantadores e filtros, acumulam altas concentrações de ferro (Fe) e manganês (Mn), as quais, em muitos casos, são liberadas no ambiente durante a manutenção, sem receber nenhum tipo de tratamento. Este artigo avaliou a eficácia de zonas úmidas subsuperficiais de fluxo vertical na remoção de Fe e Mn provenientes das águas residuais de estações de tratamento de água potável, usando como exemplo uma zona úmida a escala piloto com fluxo ascendente, leito de cascalho e dois tipos de plantas, C. esculenta e P. australis, localizada em El Hormiguero (Cali, Colombia). O sistema piloto usou três zonas úmidas verticais de fluxo ascendente, duas delas com plantas e a terceira sem plantas, como controle. As zonas húmidas foram organizadas em paralelo, cada uma sendo formada por três leitos de cascalho de diferente diâmetro. Os resultados mostraram que não houve diferença significativa na porcentagem de remoção das três zonas úmidas em termos de turbidez (98 %), Fe (90 %), Fe dissolvido (97 %) e Mn (98 %). O oxigênio dissolvido apresentou uma diferença significativa entre as zonas úmidas plantadas e a controle. C. esculenta teve a concentração mais alta de Fe na raiz, (103.5 ± 20.8) μg/g, em quanto P. au tralis teve a maior média de concentrações de Fe nas folhas e nos talos, (45.7 ± 24) μg/g e (41.4 ± 9.1) μg/g, respetivamente. Concluiuse que as zonas úmidas subsuperficiais podem ser uma alternativa interessante para o tratamento de águas residuais durante a manutenção de estações de tratamento de água potável. No entanto, mais pesquisa é necessária para determinar a importâncias do uso da vegetação ou outras tecnologias para a remoção ou diminuição da carga contaminante nas zonas úmidas, pois cada estação de tratamento de água potável ou sistema de tratamento de águas residuais com zonas úmidas irá manter oconaminante no sistema.

Nitrate detoxification using antioxidants and probiotics in the water for rabbits / Detoxificación de nitrato usando antioxidantes y probióticos en el agua para conejos / Detoxificação de nitrato usando antioxidantes e probióticos na água para coelhos

Abstract Background: Agricultural practices increase groundwater pollution from nitrate. High nitrate intake could negatively affect animal growth. Objective: To determine the effects of different levels of nitrate in drinking water on digestive, liver, and kidney functions, and on water and feed intake, and to determine the ability of vitamin C, vitamin E + selenium (Se) or probiotics to overcome the effects of nitrate in New Zealand White rabbit bucks. Methods: Forty-two male rabbits were randomly distributed into six treatment groups: 1) control group (with no nitrate); 2) 350 ppm nitrate; 3) 700 ppm nitrate; 4) 700 ppm + 200 ppm vitamin C; 5) 700 ppm + 200 ppm vitamin E + Se; and 6) 700 ppm + 1000 ppm probiotic. Productive performance, digestive, liver, and kidney functions, and hepatic and renal histology were evaluated. Results: Water intake was reduced (p<0.05) by the 350 ppm nitrate treatment. Rabbits given 700 ppm nitrate showed lower (p<0.05) dry matter intake, nutrient digestibility, and increased (p<0.05) water and nitrate intake, as well as urea concentration, and aspartate aminotransaminase (AST) and alanine aminotransferase (ALT) activity. Vitamin C, vitamin E + Se and probiotics improved (p<0.05) feed intake and nutrient digestibility, and reduced (p<0.05) water and nitrate intake, urea concentration, and AST and ALT activities. Conclusion: Rabbits may tolerate up to 350 ppm of nitrate, but 700 ppm of nitrate negatively affect digestive, liver, and kidney functions, which are improved by vitamin C, vitamin E + Se and probiotic supplementation.

Resumen Antecedentes: Las prácticas agrícolas aumentan la polución de aguas subterráneas con nitratos. Una alta ingestión de nitratos posiblemente afecta negativamente el crecimiento animal. Objetivo: Determinar los efectos de diferentes niveles de nitrato en el agua de bebida sobre las funciones digestivas, hepáticas y renales, ingestión de agua y alimento, y determinar la habilidad de la vitamina C, vitamina E + Selenio (Se) o probióticos en superar los efectos del nitrato en conejos Nueva Zelanda Blanco. Métodos: Cuarenta y dos conejos machos se distribuyeron al azar entre seis tratamientos: 1) grupo control (sin nitrato), 2) 350 ppm nitrato, 3) 700 ppm nitrato, 4) 700 ppm + 200 ppm vitamina C, 5) 700 ppm + 200 ppm vitamina E + Se, y 6) 700 ppm + 1000 ppm probiótico. Se evaluó el desempeño productivo, las funciones digestivas, hepáticas y renales, y la histología renal y hepática. Resultados: La ingestión de 350 ppm de nitrato disminuyó (p<0,05) la ingestión de agua. Los conejos que consumieron 700 ppm de nitrato presentaron menor (p<0,05) ingestión de materia seca y digestibilidad de nutrientes, y mayor (p<0,05) ingestión de agua y nitrato, concentración de urea, y mayores actividades de aspartato aminotransferasa (AST) y alanina aminotransferasa (ALT). Las vitaminas C, E + Se y el probiótico mejoraron (p<0,05) el consumo de alimento y la digestibilidad de nutrientes, y redujeron (p<0,05) la ingestión de agua y nitrato, la concentración de urea, y las actividades de AST y ALT. Conclusión: Los conejos pueden tolerar hasta 350 ppm de nitrato, pero 700 ppm de nitrato afectan negativamente las funciones digestivas, hepáticas y renales, las cuales mejoran con la suplementación de vitamina C, vitamina E + Se y del probiótico.

Resumo Antecedentes: As práticas agrícolas aumentam a contaminação de águas subterrâneas a partir de nitrato e a alta ingestão desta substância pode afetar negativamente o crescimento animal. Objetivo: Determinar os efeitos de diferentes níveis de nitrato na água de bebida sobre as funções digestivas, hepáticas e renais, ingestão de água e ração e determinar a habilidade da vitamina C, vitamina E + Selênio (Se) ou probiótico em sobrepor os efeitos do nitrato em coelhos Nova Zelândia Branco. Métodos: Quarenta e dois coelhos machos foram distribuídos ao acaso em seis tratamentos: 1) grupo controle (sem nitrato), 2) 350 ppm de nitrato, 3) 700 ppm de nitrato, 4) 700 ppm + 200 ppm de vitamina C, 5) 700 ppm + 200 ppm vitamina E + Se e 6) 700 ppm + 1000 ppm de probiótico. Foram avaliados o desempenho produtivo, as funções digestivas, hepáticas e renais além da histologia hepática e renal. Resultados: A ingestão de 350 ppm de nitrato diminuiu (p<0,05) a ingestão de água. Coelhos que receberam 700 ppm de nitrato apresentaram menor (p<0,05) ingestão de matéria seca, menor digestibilidade de nutrientes, e maior (p<0,05) ingestão de água e de nitrato, maior concentração plasmática de ureia e maiores atividades de aspartato aminotransferase (AST) e alanina aminotransferase (ALT). A adição de vitaminas C ou vitamina E + Se e probiótico melhorou (p<0,05) o consumo de ração, a digestibilidade de nutrientes e reduziram (p<0,05) a ingestão de água e de nitrato, a concentração de ureia e as atividades de AST e ALT. Conclusão: Coelhos podem tolerar até 350 ppm de nitrato, mas 700 ppm de nitrato afeta negativamente as funções digestivas, hepáticas e renais, as quais são melhoradas a partir da suplementação de vitamina C, vitamina E + Se ou ainda probiótico.

Limitaciones del IRCA como estimador de calidad del agua para consumo humano / Limitations of the Water Quality Risk Index as an estimator of quality for human consumption

RESUMEN Objetivo Analizar los resultados del Índice de Riesgo de la Calidad del Agua para Consumo Humano (IRCA) para los 116 municipios del Departamento de Cundinamarca, del año 2007 a 2013. Materiales y Métodos Información recolectada de los 116 municipios del Departamento de Cundinamarca, seleccionados y clasificados en función de los datos porcentuales del IRCA. Resultados Se observa una disminución del promedio anual del IRCA, lo cual refleja un mejoramiento de la calidad del agua entregada en el departamento; sin embargo, un 26,7% de municipios no reportan información de la zona rural y un 56,9% de los municipios reportan un IRCA superior a 5, que aunque se ubican en Riesgo Bajo, son un agua no apta para consumo humano. Conclusiones Se propone una nueva ponderación de los parámetros evaluados en el IRCA, con el fin de permitir que este índice sea más representativo del riesgo a la salud y, como estudios futuros un análisis estadístico concienzudo sobre el tamaño de la muestra que permita que los resultados obtenidos sean confiables para los tomadores de decisiones sobre el mejoramiento de la calidad del agua potable.(AU)

ABSTRACT Objective To analyze the results of the Water Quality Risk Index (IRCA) in the 116 municipalities of the department of Cundinamarca, between 2007 and 2013. Materials and Methods Information collected from the 116 municipalities of the department of Cundinamarca, selected and classified according to the percentage data retrieved by IRCA. Results A decrease of the annual IRCA average is observed, which reflects an improvement of the water quality delivered in the department. However, 26.7% of the municipalities do not report information from their rural areas, and 56.9% of the municipalities report IRCA figures over 5, which means that even though they are at low risk, they receive water unfit for human consumption. Conclusions A new weighting method for the parameters evaluated with the IRCA is proposed to make this index more representative of the risk to health. In addition, future studies should carry out a thorough statistical analysis on the size of the sample that allows the obtained results to be reliable for decision makers to improve the quality of drinking water.(AU)

The transformation of microcystin-LR during tap water treatment process and analysis of its degradation products / 中华预防医学杂志

Objective@#To establish a liquid chromatography-tandem mass spectrometry (LC/MS/MS) method for the determination of microcystin-LR (MC-LR) in drinking water, investigate its removal efficiency during tap water advanced treatment process and analyze its degradation products in the tap water.@*Methods@#Two parallel water samples were collected from each point of tap water advanced treatment process in September 2015, November 2015 and January 2016, respectively, and treated by mixing, filtration, concentration, elution, nitrogen blow and re-dissolvement. The samples were analyzed by LC/MS/MS to determine the MC-LR concentration and its removal efficiency during treatment process. The combination of actual water enrichment (including source water enrichment of 50 times and 1 500 times concentrated, finished water enrichment of 50 times and 2 500 times concentrated) and laboratory simulated water (including the mixture of MC-LR and liquid chlorine in the mass ratio of 1∶10, 1∶20, 1∶100 and 1∶1 000, respectively) were used to qualitative analyze the MC-LR degradation products by Orbitrap mass spectrometry.@*Results@#The linearity of MC-LR ranged from 2 to 200 μg/L with the detection limit of 0.007 9 μg/L and the limit of quantification of 0.026 3 μg/L. The recovery rate of MC-LR from different contration in drinking water were from 94.88%-101.47%. The intra-day precision was 2.51%-7.93% and the intra-day precision was 3.24%-8.41%. The average concentration of MC-LR in source water was (0.631±0.262) μg/L, 94.0% of which can be removed by ozone exposure while the concentrate was (0.038±0.016) μg/L, biological pre-treatment and chlorination. The remaining can hardly be removed by sand filtration, ozone exposure, activated carbon, ultrafiltration and other processes. The MC-LR average concentration in the finished water maintained at about (0.036±0.016) μg/L. Degradation products including hydroxy-microcystin, methyl-hydroxy-microcystin, methyl-microcystin were identified in the laboratory simulated water of the mixture of MC-LR and liquid chlorine in the mass ratio of 1∶10.@*Conclusion@#The established MC-LR detection method can be well applied to the monitoring of MC-LR in drinking water due to its simple pre-treatment process and good methodological validation parameters. The degradation products of treatment processes was different.

Agua segura para comunidades rurales a partir de un sistema alternativo de filtración / Safe water for rural communities from an alternative filtration system

RESUMEN Objetivo Proponer un prototipo de sistema de tratamiento de agua para zonas rurales colombianas. Materiales y Métodos El prototipo consta de cuatro compartimientos en los cuales se adelantan procesos de clarificación del agua con piedra de alumbre y filtración, utilizando materiales granulares como: arenas de distinta granulometría, piedra pómez, carbón activado y gravilla. El agua problema se emuló siguiendo las características del agua encontrada en la zona rural del país y su monitoreo se realizó siguiendo la normatividad vigente en Colombia. Resultados Hubo reducción en coliformes fecales y totales del 99,9 %, turbiedad del 98 % y color del 83 %. En todos los casos los registros obtenidos permiten catalogar el agua tratada como apta para el consumo humano. El pH presentó un ligero aumento debido a la presencia de piedra pómez y otras calizas en el material filtrante, pero el valor medido, está dentro del límite máximo aceptado para agua potable. Conclusiones El sistema de tratamiento (purificación) evaluado en el presente estudio, produjo un agua apta para consumo humano a partir de agua con características promedio de zonas rurales semi-templadas del país. La tecnología propuesta es de fácil adaptación y difusión, y permite el control de enfermedades de origen hídrico en zonas desprovistas de sistemas de acueducto.(AU)

ABSTRACT Objective Propose a prototype system for safe water treatment in Colombian rural areas. Materials and Methods The prototype consists of four chambers working on a water -clarification process using alum stone, also working on a filtration processes using granular materials such as different grain sizes of sand, pumice stone, activated carbon and gravel. The water problem was emulated based on the average water features found in the countryside and its monitoring mechanism tracked the current regulations in Colombia. Results There was a reduction of the fecal and total coliform of the 99.9 %, a reduction of the 98 % of turbidity, and of an 83 % of color. In all the cases, the records obtained enable to catalog the treated water as fit for human consumption. The pH, presented a slight increment due to the presence of pumice and other limestone in the filter material, but the measured value was included under the upper limit accepted for potable water. Conclusions The treatment (purification) system evaluated in this study produced suitable water for human consumption obtained from countryside average water. The proposed technology is easy for adoption and diffusion and contributes to prevent water-borne diseases in areas without water systems.(AU)

Parâmetros operacionais na remoção biológica de nitrogênio de águas por nitrificação e desnitrificação simultânea / Operating parameters on biological nitrogen removal of water by simultaneous nitrification and denitrification

RESUMO O nitrogênio é um dos contaminantes mais importantes presentes nas águas residuais. As alternativas tecnológicas mais usuais para o tratamento de águas contendo esse composto lançam mão do ciclo bioquímico do nitrogênio, o qual se sustenta em dois processos, a nitrificação e a desnitrificação. Dentre os parâmetros que influenciam na remoção de nitrogênio, podemos citar a concentração de oxigênio dissolvido, relação carbono/nitrogênio, temperatura, pH entre outros. Este trabalho apresenta uma revisão sobre a remoção biológica de nitrogênio das águas e os principais parâmetros que influenciam na sua remoção, dando ênfase ao processo de nitrificação e desnitrificação simultânea.

ABSTRACT Nitrogen is one of the most important contaminants present in wastewater. The most common alternative technologies for the treatment of waters containing this compound lay hold of the biochemical cycle of nitrogen, which is based on two processes, nitrification and denitrification. Among the parameters that influence the removal of nitrogen, we can mention the concentration of dissolved oxygen, carbon/nitrogen ratio, temperature, pH, and other relationships. This paper presents an overview of the biological nitrogen removal of water and the main parameters that influence the removal, emphasizing the simultaneous nitrification and denitrification process.

Dental unit water lines decontamination with the aid of nanotechnology.

Aim: This article reviews the issue of dental unit waterline (DUWL) contamination which affects all the clinical and hospital settings. The contaminating microorganisms commonly isolated from these settings and the most pathogenic among them have serious consequences. Over the years several measures are inculcated for decontamination of water, their advantages and shortcomings have been addressed. Options using nanotechnology which are available in the market are described briefly. Materials and Methods: A manual and electronic search was conducted. Google and PubMed were searched for relevant material from studies up to 2013. Medical Subject Headings words looked for were “Nanotechnology,” “Water purification,” and “Biofilms.” Reviewed findings were summarized by topic, using the Preferred Reporting Items for Systematic Reviews and Meta‑analyses statement for reporting. Seventy articles were shortlisted for articles pertaining to our topic of discussion. A systematic approach was followed by two independent reviewers and included eligibility criteria for study inclusion, data extraction, data synthesis, and drawing of conclusion. Results: Dental waterline contamination is widespread in any type of dental setting having serious implications on clinicians and patients alike, especially elderly and immune‑compromised. Hence, international bodies like center for disease and control and American Dental Association have come up with stringent measures for maintenance of water quality. A gamut of procedures has been tried to overcome this problem ranging from chlorinated products, water filters to the usage of distilled water. The use of nanoemulsions, nanofilters, nanomembranes, etc., and their applicability for routine usage is discussed. Conclusions: Biofilm formation in DUWLs is inevitable with the subsequent release of part of microbiota into the otherwise sterile dental settings. These consequences can be quite serious on clinicians and dental patients. Though conventional measures in water decontamination have been partly successful, the quest for more foolproof methods has led to the use of latest technology, i.e., nanotechnology. The most practical option has to be chosen based on the ease of their usage.

Metodología rápida y sencilla para la determinación de colifagos somáticos como indicadores de contaminación fecal en una planta de tratamiento de agua localizada al noreste colombiano / Quick and easy methodology to determine somatic coliphages as indicators of fecal contamination in a water treatment plant located in northeastern Colombia

Introducción: En el presente artículo se propone una metodología rápida y sencilla para determinar colifagos sómaticos en las diferentes etapas del tratamiento de agua de una planta del Nordeste Colombiano, con el fin de verificar la calidad del proceso de potabilización. Materiales y métodos: Se empleó la técnica de filtración por membrana para obtener el contenido fágico y posteriormente se cuantificó la presencia de los virus a través de la metodología de capa simple usando agar tripticasa de soya modificado. Resultados: El 88% de las muestras de agua analizadas resultaron ser positivas en alguna de las etapas del proceso de potabilización. La presencia de fagos aumentó en época de lluvias con recuentos máximos de 1310 UFP/100mL en la etapa de captación del agua y de 2,5 UFP/100mL en la etapa de cloración. La prueba no-paramétrica Chi cuadrado de homogeneidad en distribución corroboró estadísticamente la igualdad en distribución de las muestras positivas encontradas en cada una de las etapas de potabilización (p>5%) pues el muestreo fue fijado por indicador. Conclusión: La metodología empleada permitió en tan solo 12 horas determinar la presencia de colifagos somáticos en las diferentes etapas de tratamiento de agua de la planta objeto de estudio. Además, se comprobó la elevada resistencia de estas nanomáquinas naturales a los procesos de desinfección, que mostraron persistencia en etapas de almacenamiento y distribución, especialmente en época de lluvias.

Introduction: In this article a quick and simple method is proposed to determine somatic coliphages in the different stages of water treatment in a plant in the northeast of Colombia, in order to verify the quality of the treatment process. Materials and methods: The technique of membrane filtration was used to get the phage content and subsequently through the methodology of single layer using tryptic soy agar modified, the presence of the virus was quantified. Results: 88% of the water samples analyzed were found to be positive in any of the stages of purification. The presence of phages increased during the rainy season with maximum counts of 1310 UFP / 100 mL at the stage of uptake of water and 2.5 UFP / 100 mL in the chlorination stage. Non-parampetrica Chi square homogeneous distribution test confirmed statistically equal distribution of positive samples found in each of the stages of purification (p> 5%) because the sample was determined by indicator. Conclusion: The methodology allowed to determine the presence of somatic coliphages at different stages of water treatment in the plant under study in only 12 hours. In addition, the high resistance of these natural nanomachines to the processes of disinfection was found, which showed persistence in warehousing and distribution stages, especially in the rainy season.

Prevalence of household drinkingwater contamination and of acute diarrhoeal illness in a periurban community in Myanmar.

Background: A major health consequence of rapid population growth in urban areas is the increased pressure on existing overstretched water and sanitation services. This study of an expanding periurban neighbourhood of Yangon Region, Myanmar, aimed to ascertain the prevalence of acute diarrhoea in children under 5 years; to identify household sources of drinking-water; to describe purification and storage practices; and to assess drinking-water contamination at point-of-use. Methods: A survey of the prevalence of acute diarrhoea in children under 5 years was done in 211 households in February 2013; demographic data were also collected, along with data and details of sources of drinking water, water purification, storage practices and waste disposal. During March–August, a subset of 112 households was revisited to collect drinking water samples. The samples were analysed by the multiple tube fermentation method to count thermotolerant (faecal) coliforms and there was a qualitative determination of the presence of Escherichia coli. Results: Acute diarrhoea in children under 5 years was reported in 4.74% (10/211, 95% CI: 3.0–9.0) of households within the past two weeks. More than half of the households used insanitary pit latrines and 36% disposed of their waste into nearby streams and ponds. Improved sources of drinking water were used, mainly the unchlorinated ward reservoir, a chlorinated tube well or purified bottled water. Nearly a quarter of households never used any method for drinking-water purification. Ninety-four per cent (105/112) of water samples were contaminated with thermotolerant (faecal) coliforms, ranging from 2.2 colony-forming units (CFU)/100 mL (21.4%) to more than 1000 CFU/100 mL (60.7%). Of faecal (thermotolerant)-coliform-positive water samples, 70% (47/68) grew E. coli. Conclusion: The prevalence of acute diarrhoea reported for children under 5 years was high and a high level of drinking-water contamination was detected, though it was unclear whether this was due to contamination at source or at point-of-use. Maintenance of drinking-water quality in study households is complex. Further research is crucial to prove the cost effectiveness in quality improvement of drinking water at point-of-use in resource-limited settings. In addition, empowerment of householders to use measures of treating water by boiling, filtration or chlorination, and safe storage with proper handling is essential.

Prevalence of Cryptosporidium Infection among Inhabitants of 2 Rural Areas in White Nile State, Sudan

Cryptosporidium, a protozoan parasite that causes watery diarrhea, is found worldwide and is common in areas with low water hygiene. In February 2014, 866 stool samples were collected from the inhabitants of 2 rural areas in White Nile State, Sudan. These stool samples were assessed by performing modified acid-fast staining, followed by examination under a light microscope. The overall positive rate of Cryptosporidium oocysts was 13.3%. Cryptosporidium oocysts were detected in 8.6% stool samples obtained from inhabitants living in the area having water purification systems and in 14.6% stool samples obtained from inhabitants living in the area not having water purification systems. No significant difference was observed in the prevalence of Cryptosporidium infection between men and women (14.7% and 14.1%, respectively). The positive rate of oocysts by age was the highest among inhabitants in their 60s (40.0%). These findings suggest that the use of water purification systems is important for preventing Cryptosporidium infection among inhabitants of these rural areas in Sudan.

A importância da qualidade da água reagente no laboratório clínico / The importance of water quality in clinical laboratory reagent

A água é um reagente utilizado na maioria dos testes laboratoriais e por isso deve seguir um padrão de controle de qualidade rigoroso. O fornecimento urbano de água apresenta moléculas orgânicas, íons inorgânicos, partículas, coloides, gases, bactérias e seus produtos, que podem alterar os resultados dos exames laboratoriais e causar eventuais erros e falhas mecânicas em equipamentos analíticos. Para remover essas impurezas, é necessário recorrer a uma combinação de tecnologias de purificação. Há várias organizações que especificam normas sobre a água reagente, a fim de minimizar sua interferência nos ensaios laboratoriais. A maioria dos laboratórios utiliza as normas estabelecidas pelo Clinical and Laboratory Standards Institute (CLSI) que classifica a água em: clinical laboratory reagent water (CLRW), special reagent water (SRW) e instrumental feed water (IFW). O monitoramento da qualidade é realizado pela determinação de resistividade, condutividade, carbono orgânico total (TOC), controle microbiológico e endotoxinas. Os parâmetros são avaliados de acordo com a periodicidade estabelecida pela norma utilizada. Neste artigo, discutem-se a importância da água utilizada nos procedimentos laboratoriais, o controle da qualidade e as interferências nos ensaios laboratoriais.

Water is a reagent used in most laboratory tests and, therefore, must follow stringent quality control standards. The urban water supply has organic molecules, inorganic ions, particles, colloids, gases, bacteria and their products, which may alter laboratory test results and cause occasional errors and mechanical failures in diagnostic equipment. To remove these impurities, it is necessary to use a combination of purification technologies. There are several organizations that specify reagent water standards to minimize its interference in laboratory assays. Most laboratories set standards established by the Clinical and Laboratory Standards Institute (CLSI), which classifies the type of water as follows: clinical laboratory reagent water (CLRW), special reagent water (SRW) and instrumental feed water (IFW). The quality monitoring is performed by means of assessing the resistivity, conductivity, total organic carbon (TOC), microbial control and endotoxins. The parameters are evaluated in accordance with the frequency determined by the standard used. In this article we discuss the importance of water employed in laboratory procedures, its quality control and its interference in laboratory assays.

Avaliação do teor de flúor na água de abastecimento e sua retenção pelos filtros domésticos / Evaluation of the fluoride level on the water of supplying and its retention by domestic filters

O objetivo deste trabalho foi verificar o teor de flúor da água de abastecimento que chegava nas residências e analisar se ocorria alteração no nível de flúor após a água passar pelos reservatórios e filtros domésticos. As coletas de amostras de água foram feitas em residências do município de São José dos Campos, SP, e os resultados foram submetidos à análise estatística. Da análise dos resultados, pode-se concluir que 70% das amostras apresentaram nível de acordo com o preconizado como ideal para a localidade analisada e não houve evidência de alteração significativa dos níveis de flúor da água de abastecimento durante a passagem pelos reservatórios e filtros domésticos.

This study tried to verify the fluoride level in water that supplies residences, if water has any fluoride level changes after passing to the domestic reservoirs domestic filters. Water samples had been obtained in São José dos Campos city. Results were submitted to statistical analysis. The results showed that 70% of the analyzed samples had its fluoride level according to what is recommended. There was not any evidence of significant alteration in fluoride levels of public supplied water in the reservoirs and domestic filters.

Adsorption Performance of Chitosan in Printing and Dyeing Wastewater Treatment / 环境与健康杂志

Objective To study the adsorption performance of chitosan in printing and dyeing wastewater treatment.Methods The influence factors such as chitosan concentrations(0-500 mg/L),pH value(1-13),temperatures(20-50 ℃)and time(0.5-2.5 h) were considered in the test.Results When the concentration of chitosan was 200 mg/L,pH value was 2-5,time was 0.5 h and at the room temperature,the absorption could show a good result.The deeolorizing rate could reach above 90%.Conclusion The chitosan concentrations,pH value,time and temperature affect the adsorption performance of chitosan in printing and dyeing wastewater treatment.

Synergistic Effect of Purified Water and Magnesium Deficiency Food on Learning and Memory of Offspring of Rats / 环境与健康杂志

Objective To study the effect of purified water on the neurobehavioral development of the offspring and the synergistic effect of the magnesium deficiency in food. Methods SD rats were divided into four groups,control food plus control water (control group),control food plus purified water,magnesium deficiency food plus control water,magnesium deficiency plus purified water,from five weeks of age of the F0 generation to five weeks of the F1 generation respectively. Morris water maze (MWM) was used to test the spatial learning and memory ability of offspring of rats. Results In the early training days of the place navigation,control group offspring of rats showed a shorter swimming time than the other groups. There were no significant differences among all experimental groups in the later training days of the place navigation,spatial probe test and visible platform trial,however the tendency was still to remain. Conclusion Purified water can damage the learning ability of offspring of rats and the learning ability delay will be more obviously when magnesium is deficient in food.

Efficiency of Ozone in Inactivation of f_2 Phage in Water / 环境与健康杂志

Objective To observe the efficacy of ozone in the inactivation of f2 phage in water. Methods The concentration of ozone in water was measured by iodometry. During the experiment,the suspension of f2 phage was added in the ozonized water, at 5,15,30 min, the f2 phage inactivation rate was calculated. Results Under the same condition of ventilation,in the range of pH regulated in the drinking water sanitary standard,the effect of pH on the inactivation of f2 phage was not obvious, while the chromaticity of water could remarkably influence the inactivation of f2 phage. Conclusion The higher chromaticity of water can interfere the inactivation of f2 phage in water by ozone.

Control of Sediment Phosphorus Release in Lakes Adding Chemical Reagents / 环境与健康杂志

Objective To study the inhibit efficiency of lake sediment phosphorus release by adding chemical reagents and to provide the technical basis for the comprehensive management of city lake.Methods In May 20,2008,Mochou Lake upper sediment and water samples were collected.The phosphorus forms of sediments,total phosphorus(TP),NaOH-P,HCl-P,inorganic phosphorus(IP),organic phosphorus(OP) were analyzed and the pH value and content of TP in water samples were determined.Each water(250 ml)-sediment(10 g) system was respectively added by 0-1 000.0 mg/L of Ca(OH)2,2.0-10.0 mg/L of A12(S04)3 and 0-25.0 mg/L of FeCl3.The pH value and content of TP in water were determined,then the control rate of TP release were calculated.Results The pH values were between 7.6-8.0,TP content was 2.0 mg/L in water of Mochou Lake.The contents of TP,HCl-P,NaOH-P,IP,OP were 2 187.06,1 383.89,526.48,1 910.37 and 276.69 mg/kg respectively.With the increase of Ca(OH)2 concentration,pH value of water increased rapidly,content of TP showed a decreasing trend,control rate of TP release was increased.With the increase of A12(SO4)3 or FeCl3 concentration,pH value of water declined slightly,content of TP showed a decreasing trend,control rate of TP release was increased.Conclusion Ca(OH)2,A12(SO4)3,FeCl3 can significantly inhibit the phosphorus release of sediments in Mochou Lake.

Avaliação de técnica eletroquímica na remoção de resíduos orgânicos em água com emprego de unidade em escala de laboratório / Evaluation of electrochemical technique for removal of organic waste from water by using a laboratory scale unit

Neste trabalho são apresentados os resultados preliminares da avaliação de técnica eletroquímica na remoção de compostos orgânicos em água, em escala laboratorial. Cela eletroquímica simples foi construída para os testes e uma metodologia básica foi empregada. O método consiste em provocar a migração de espécies polares ou ionizadas em direção ao eletrodo de carga oposta. Fenol e o herbicida atrazina foram os contaminantes avaliados. Os ensaios foram realizados em função do tempo de aplicação de carga, acompanhada a evolução do pH entre os eletrodos e as concentrações relativas avaliadas por medidas de absorbância na região do ultra-violeta. Os melhores resultados foram conseguidos para operações acima de 30 minutos, indicando migração proporcional a 62% para o fenol, mas inferior a 30% para a atrazina.

In this work the preliminary results of a lab scale evaluation of electrokinetic technique for the removal of organic contaminants in water are presented. A simple cell was constructed and a basic methodology was followed. The method consists in provoke the migration of ionized or polar specimens solved in aqueous solution in direction of the opposite charged electrode. Phenol (C6H5OH) and herbicide atrazine (6-chlorine-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4 diamine), was chosen as standard contaminants. The testes were performed in function of charge application time, mapping the pH between electrodes and the concentration assessed by absorbance measurements in ultra-violet region. The best results were attained after 30 minutes operation, showing migration proportional to 62% for phenol, but inferior to 30% atrazine.

Investigation of Deep Treatment System for Drinking Water in Guangdong / 环境与健康杂志

Objective To know the quality of drinking water produced by deep treatment systems in Guangdong Province.Methods The unified investigation form was used,the water supply systems were selected from 4 cities,Guangzhou,Shenzhen,Zhuhai,Dongguan.pH value,conductivity,ozone,COD,TOC,heavy metals,bacteria were determined in 2004.Results Having investigated 169 systems,reverse osmosis,nanofiltration and ultrafiltration equipment used to treat water accounted for 74.40%,19.05% and 6.55 % respectively.The use of ozone disinfection was 70.7%.45.8% of the systems,the water cycled twice per day,and 29%,no water quality test was conducted according to the regulation.The quality of water with deep treatment was satisfactory compared with the common tap water.Conclusion The quality of water produced by deep treatment systems is considered better than the common tap water and the applicable water treatment units should be selected,the routine water quality test and management should be conducted.