ABSTRACT
O monitoramento da qualidade da água destinada ao consumo humano é imprescindível. Desta forma, objetivou-se com este trabalho caracterizar as amostras de águas de abastecimento de escolas públicas de tempo integral no município de Teresina-PI, por meio das análises de pH, turbidez e alcalinidade. As coletas de água foram realizadas em cinco escolas (zonas Sul, Sudeste, Leste, Norte e Centro) da cidade de Teresina - PI. Foram coletadas durante três meses, perfazendo 42 amostras de águas no total. As análises foram efetuadas conforme os métodos prescritos pela APHA. Os parâmetros pH, alcalinidade e turbidez das amostras coletadas em escolas de diferentes zonas da cidade de Teresina PI, encontram-se conforme o estabelecido pelos padrões de potabilidade da Portaria nº 2.914/2011.
Subject(s)
Water Alkalinity/analysis , Hydrogen-Ion Concentration , Water Quality/standards , Water Turbidity/analysis , Water Supply , SchoolsABSTRACT
INTRODUCCIÓN: El pH es una propiedad básica del agua potable y cuyos valores extremos pueden originar reacciones secundarias dañinas, entendiéndose por agua potable aquel que puede ser consumido sin restricción para el consumo humano, OBJETIVO: Determinar el valor del pH de agua potable que consumen los estudiantes de segundo año de la carrera de medicina de la Universidad Mayor de San Andrés (UMSA). MATERIAL Y MÉTODOS: Se analizaron 388 muestras de agua potable del domicilio de estudiantes regulares de segundo año cátedra de bioquímica entre los meses de julio y agosto del 2017, realizándose un estudio de tipo descriptivo con un enfoque transeccional. RESULTADOS: Se obtuvieron los siguientes resultados, 1) la media del pH total fue de 7,24; con x=7,22 en la ciudad de la Paz y x=7,28 en la ciudad de el Alto. 2) en cuanto al sistema de potabilización se obtuvo: x=7,34 en la planta el Alto, x=7,21 en la planta de Tilata, x=7,15 en la planta de Achachicala y de x=7,20 en la planta de Pampahasi. CONCLUSIONES: El pH del agua potable consumida se encontró dentro de parámetros establecidos con un valor medio de 7,24.
INTRODUCTION: The pH is a basic property of potable water and whose extreme values may cause harmful secondary reactions. It is understood that potable water can be consumed without any restriction by human beings. OBJECTIVE: To determine the pH value of potable water consumed by medicine students of second year at UMSA university. MATERIAL AND METHODS: 388 samples of potable water were analyzed which were taken from the homes of the second year students of the biochemistry department between July and August 2017, developing a descriptive study with a cross-sectional approach. RESULTS: The following results were obtained: 1) the average of the pH was 7.24; with x = 7.22 in La Paz city and x = 7.29 in El Alto city. 2) in relation to the drinking water was obtained: x=7.34 in El Alto plant, x=7.21 in Tilata plant, x=7.16 in Achachicala plant and x=7.21 in Pampahasi plant. CONCLUSION: The pH of the drinking water drunk is established within parameters with an average value of 7.24.
Subject(s)
Drinking Water , Water Alkalinity , Water Purification/statistics & numerical data , Water Treatment Plants/analysis , Drinking Water/analysisABSTRACT
The Gulf of Papagayo, Pacific coast of Costa Rica, is one of the three seasonal upwelling areas of Mesoamerica. In April 2009, a 29-hour experiment was carried out at the pier of the Marina Papagayo, Culebra Bay. We determined sea surface temperature (SST), dissolved oxygen concentration, salinity, pH, and the partial pressure of CO2 (pCO2). The aragonite saturation state (Ωa) as well as the other parameters of the marine carbonate system such as the total dissolved inorganic carbon (DIC) and the total alkalinity (TA) were calculated based on the measured pH and the pCO2. The entrainment of subsurface waters raised the pCO2 up to 645 µatm. SSTs, dissolved oxygen concentrations decreased form 26.4 to 23.7°C and from 228 to 144 µmol l-1. Ωa dropped down to values of 2.1. Although these changes are assumed to reduce the coral growth, the main reef building coral species within the region (Pocillopora spp. and Pavona clavus) reveal growth rates exceeding those measured at other sites in the eastern tropical Pacific. This implies that the negative impact of upwelling on coral growth might be overcompensated by an enhanced energy supply caused by the high density of food and nutrients and more favorable condition for coral growth during the non-upwelling season.
El Golfo de Papagayo, costa Pacífica de Costa Rica, es una de las tres regiones de afloramiento estacional de Mesoamérica. Las características físicas y químicas del agua que aflora no habían sido estudiadas. Durante 29 horas en Abril 2009, se estudiaron la temperatura superficial del mar (TSM), la concentración de oxígeno disuelto, salinidad, pH y la presión parcial de CO2 (pCO2), en la Marina Papagayo, Bahía Culebra. Con base en las mediciones de pH y pCO2 se calculó el estado de saturación de la aragonita (Ω) y otros parámetros del sistema de carbonatos como lo es el carbono orgánico disuelto (COD) y la alcalinidad total (AT). Los resultados indican que el arrastre por convección del agua sub-superficial durante los eventos de afloramiento aumenta la pCO2 y disminuye la TSM, la concentración de oxígeno disuelto y Ω. Aunque se asume que estas condiciones reducen el crecimiento coralino, las principales especies constructoras de arrecife en la región de Papagayo (Pocillopora spp. y Pavona clavus) tienen las mayores tasas de crecimiento en el Pacífico Tropical Oriental. Esto posiblemente implica que el efecto negativo del afloramiento es compensado por el crecimiento durante la época de no afloramiento.
Subject(s)
Oxygen/analysis , Carbon/analysis , Carbon Dioxide/analysis , Water Alkalinity/analysis , Anthozoa/growth & development , Costa Rica , Coral ReefsABSTRACT
Alkaliphilic cyanobacterial cultures were isolated from Lonar lake (MS, India). Among the set of cultures, Synechocystis sp, was studied for phycocyanin production. A maximum yield was obtained in BG-11 medium at optimized conditions (pH 10 and 16 h light). In order to increase the phycocyanin yield media optimization based on the eight media components a Plackett-Burman design of the 12 experimental trials was used. As per the analysis CaCl2.2H2O and Na2CO3 have been found to be the most influencing media components at 95% significance. Further the optimum concentrations of these components were estimated following a Box Wilson Central Composite Design (CCD) with four star points and five replicates at the center points for each of two factors was adopted for optimization of these two media components. The results indicated that there was an interlinked influence of CaCl2.2H2O and Na2CO3 on 98% significance. The maximum yield of phycocyanin (12% of dry wt) could be obtained at 0.058 g/l and 0.115 g/l of CaCl2.2H2O and Na2CO3, respectively.
Subject(s)
Water Alkalinity/methods , Cyanobacteria/isolation & purification , Phycocyanin , Phycomyces/isolation & purification , Sodium Carbonate , Data Interpretation, Statistical , Synechocystis/isolation & purification , Bacterial Physiological Phenomena , Fluorescence , Coastal Lagoon , Methods , Methods , Water SamplesABSTRACT
O controle de pH de efluentes industriais, para fins de descarga, é estabelecido por leis estaduais e federais. Devido ao não conhecimento da incerteza de suas medições e principalmente não se conhecendo sua rastreabilidade a padrões nacionais e/ou internacionais, pode ocorrer não conformidade ao se permitir a descarga de efluente ao meio ambiente. Este trabalho enfoca a qualidade das medições de pH, através dos aspectos da rastreabilidade e da incerteza de medição, seguindo os conceitos introduzidos pela ISO GUM. O experimento foi realizado com amostra de efluente alcalino coletado de uma indústria têxtil, envolvendo a reação de neutralização usando o dióxido de carbono. Resultados de pH acompanhados de suas incertezas oferecem informação mais completa na prevenção contra descargas impróprias de efluentes ao meio.
State and federal laws rule the control of pH of industrial effluents aiming discharge and environmental protection. Improper effluent discharges can occur if obtained pH measurements do not meet traceability to national and/or international standards and are not associated with their uncertainties. This work focuses the quality of the pH measurements and follows the ISO GUM instructions by demonstrating the traceability and estimating the uncertainty of the measurements. The experiment was carried out using an alkaline effluent sample of a textile industry, involving the neutralization reaction with carbon dioxide. Having pH measurements associated with its uncertainty can prevent risks of improper discharge of effluent to the environment.