Qualidade da água e composição fitoplanctônica de um viveiro de piscicultura utilizado para fins de pesca esportiva e irrigação

Water quality of a fish pond used by UNESP, at Jaboticabal, SP, Brazil, for both fishing and irrigation has been evaluated according to certain limnological parameters and to its phytoplankton composition. During the year, four sampling sites were assigned at the pond: P(1)=inlet water in the pond; P(2)=inlet water from a shrimp pond; P(3)=irrigation spot; and P(4)=outlet water (water flowing directly into another pond). The collected data show a water pond with high concentration of nutrients and chlorophyll-a, and high values of electrical conductivity, total hardness and total dissolved solids, proceeding from the above pond. These factors affected substantially some biological parameters, such as chlorophyll-a and phytoplankton. In P(3), whereas class Zygnematophyceae showed the highest specimens richness, with 34.01%, the Chlorophyceae, that had the highest number of genera, comprehended 33.52% of the total number of individuals. The use of the water fish pond for irrigation must be re-evaluated, due to eutrophic conditions of the water, the presence of potentially toxic cyanobacteria, so as the proper management employed.

Efeitos do manejo de Eichhornia crassipes sobre a qualidade da água em condições de mesocosmos

As macrófitas, apesar da enorme importância na dinâmica do ambiente aquático, quando formam extensas e densas colonizações, promovem uma série de prejuízos ao ambiente e aos usos múltiplos dos reservatórios. Nessas situações, há necessidade de redução de seu tamanho populacional, seja reduzindo as condições favoráveis ao crescimento, seja por meio do controle direto das plantas. Dentre as macrófitas aquáticas que promovem esses tipos de problema, o aguapé (Eichhornia crassipes) é considerada a mais importante. Seu controle é praticado em todo o mundo. O diquat tem sido bastante utilizado para o controle desta planta, em razão de seu baixo custo, eficácia, rapidez de controle e baixa toxicidade no ambiente aquático. O objetivo do presente trabalho foi avaliar os possíveis impactos causados pelo controle de Eichhornia crassipes sobre algumas características de qualidade da água em mesocosmos. Para isso, cinco situações experimentais foram estudadas: CPCH - mesocosmo colonizado por aguapé, o qual foi controlado pela aplicação do herbicida diquat; CPCG - mesocosmo colonizado por aguapé, o qual foi morto por congelamento; CPSH - mesocosmo colonizado com aguapé, sem controle; SPCH - mesocosmo sem macrófitas e com aplicação de diquat na superfície da água; e SPSH - mesocosmo sem macrófitas aquáticas e sem aplicação. O herbicida diquat foi utilizado na dose de 7,0 L da formulação comercial Reward/ha. A temperatura foi mais elevada nos mesocosmos sem plantas, devido à maior incidência de raios solares na coluna d'água. As concentrações de oxigênio dissolvido foram menores nos mesocosmos colonizados pelo aguapé e também tiveram rápida queda após o controle das plantas tanto com diquat como por congelamento. O pH da água foi maior nos mesocosmos sem a cobertura da macrófita. Os valores de sólidos totais dissolvidos (STD) e de condutividade elétrica foram maiores nos tratamentos com morte por congelamento e pelo diquat e em mesocosmos colonizados sem controle da macrófita. Esse efeito pode ser devido à presença de material orgânico em suspensão e à maior concentração de nutrientes presentes na água. Comparando os mesocosmos sem plantas, sem e com a aplicação de diquat na superfície da água, os valores das características avaliadas foram estatisticamente similares, levando à conclusão de que as alterações observadas nos fatores analisados decorrem principalmente da decomposição das plantas.

Sistema com aeração, decantação e filtragem para a melhoria da qualidade de água em irrigação localizada

A qualidade da água é muito importante para irrigação por gotejamento, pois ela escoa por pequenos bocais dos emissores, podendo ocorrer obstrução devido à deposição dos sólidos em suspensão. Portanto, antes da instalação do projeto, devem-se avaliar parâmetros de qualidade da água, para adotar medidas preventivas, evitando o risco de entupimento do sistema. Este trabalho teve como objetivo avaliar um sistema composto por aeradores com aspersores, sobre leito de pedra, para a precipitação dos íons Fe+2e Mn+2 em tanque de decantação, e um conjunto de filtragem composto por três filtros de areia e um de disco, em sistema de irrigação localizada. O trabalho foi realizado na Fazenda Alvorada, no município de Nova Granada - SP, no período de março a outubro de 2008. Foram realizadas determinações de variáveis físicas e químicas da água, ao longo do sistema de aeração, decantação e filtragem, o qual foi eficiente para a melhoria da qualidade de água, reduzindo os níveis de risco de entupimento de severo para médio e de médio para baixo. Oxigênio dissolvido, condutividade elétrica, pH, Fe+2e Fe+3 não diferenciaram a qualidade de água entre os pontos do sistema de tratamento, porém a turbidez, sólidos dissolvidos, sólidos em suspensão, ferro total e manganês total reduziram-se significativamente pelo uso do sistema proposto, melhorando a qualidade da água.

Efficiency of a constructed wetland for wastewaters treatment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Performance of the constructed wetland system for the treatment of water from the corumbataí river

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Implications of groundwater weathered profile interactions to the mobilization of radionuclides

This study reports the nature and extent of open-system interaction between groundwater and a weathered profile developed in the high grade thorium and REE ore body in Morro do Ferro, Pocos de Caldas plateau. The radioelement mobility in the shallow oxidizing environment was considered by using chemical data in conjunction with U-234/U-238, Ra-226/Th-230, Th-230/U-234, Th-228/Th-232, Ra-228/Th-232 and Th-230/Ra-228 activity ratios (AR's) for borehole spoil and groundwater samples.Recharging groundwater from the studied borehole has low salinity values, with total dissolved solids content of 14.7 mg/l and total ionic strength of 0.00018. The ratio of the weight of dissolved radioelement per unit volume of solution to the weight of radioelement in solid phase per unit weight of solid phase showed that the radioelement solubility in the studied waters varied according to the following order: radium> uranium >thorium.U-234/U-238 AR's less than 1 were measured in solid phase and can justify the enhancement of U-234 in solution. Ra-226/Th-230 AR's greater than 1 and Th-230/U-234 AR'S less than 1 were evaluated between 20 and 27 m in depth, where a 2.1-m thick magnetite dike was intersected. These ratios could be justified by deposition of U and Ra associated with Fe-Mn oxides and kaolinite, where mineral saturation indices evaluated from the available data confirm this possibility. Covariations among disequilibria involving Th-228/(228) Ra and Ra-228/Th-232 AR's showed the preferential removal of Ra-228 relative to Tn isotopes, Th-228 and Th-232. The recent deposition of radium within the timescale of at least the last 35 years also is suggested. (C) 1998 Elsevier B.V. Ltd. All rights reserved.

The natural radioactivity in water by gross alpha and beta measurements

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da qualidade da água e autodepuração do ribeirão do meio, Leme (SP)

This investigation utilized hydrochemical relations to evaluate possible anthropogenic inputs at Meio Stream, São Paulo State. Realized three sampling of water during the months of February, April and July/2005, in five sampling points analyzing: discharge, temperature, turbidity, pH, electrical conductivity (EC), dissolved oxygen ( DO), TDS (total dissolved solids), TSS (total suspended solids), Ca(2+), Mg(2+), Na(+), K(+), HCO(3)(-), Cl(-), SO(4)(2-), PO(4)(3-) and NO(3)(-). The characteristics of water close to spring until Leme city allow concluding that there is a small interference in its quality, however the absence of treatment of domestic wastewater at Leme city reduced its quality. It was applied the QUAL 2K modeling to evaluate the Meio Stream auto-purification identified the auto-purification zones and indicated the necessity of secondary wastewater treatment, with 76% of efficiency.

Relações entre condutividade hidráulica, transmissividade, condutância longitudinal e sólidos totais dissolvidos para o aquífero livre de Caçapava do Sul (RS), Brasil

A água subterrânea é um importante recurso ao abastecimento público, principalmente para comunidades periféricas em grandes cidades ou pequenos municípios, onde a instalação ou prolongamento de sistemas de distribuição são economicamente inviáveis. Estudos voltados à análise da vulnerabilidade de aquíferos são relevantes para subsídio a políticas públicas em saneamento básico e preservação ambiental. Este estudo contou com o cadastro de 23 poços rasos localizados no município de Caçapava do Sul (RS), onde foram realizadas medidas de resistividade elétrica e cargabilidade por meio de geofísica, e medidas diretas de condutividade hidráulica e sólidos totais dissolvidos. A análise estatística dos dados demonstrou diversos graus de correlação entre parâmetros, basicamente condicionados a fatores geológicos como porosidade, permeabilidade e sólidos totais dissolvidos.

Hydrochemical relationships in groundwater from central São Paulo State, Brazil

Groundwater samples from different aquifers occurring at center/northeast portion of São Paulo State, Brazil, were collected and chemically analyzed. The waters leaching Mesozoic sediments are generally more acid (pH(average) = 5.9) and have lower values for total dissolved solids (TDSaverage = 105 mg/L) than those obtained for waters leaching Paleozoic sediments of Tubarao Group. First-degree trend surfaces revealed that the deeper tubular wells occur towards east/southeast and exploit Paleozoic sediments as well fractured/fissured diabases/basalts, whereas the tubular wells in the west/northwest region are shallower. Piper diagrams indicated that the majority of the waters are a blend of waters from different lithologies. Significant correlations were found among nitrate, chloride and bicarbonate, suggesting the occurrence of some anthropogenic inputs, whereas elevated alpha activity of geogenic Ra-226 indicated the need of a broad radiometric survey in the area.

ENHANCEMENT OF U-234 IN SPRINGWATERS OF AGUAS-DA-PRATA, SAO-PAULO, BRAZIL

Springwater samples were collected at Aguas da Prata, an important spa in São Paulo State, Brazil. The U-238 and U-234 isotopes were evaluated for Platina, Paiol, Villela, Prata-Radioativa, Prata-Nova, Boi, Vitoria, and Prata-Antiga springs. An inverse logarithmic correlation was found between U-234/U-238 activity ratio and Rn-222 content of the studied waters, which was related to different solution mechanisms of Rn-222 and U-234 nuclides at the rock-water interface. A linear correlation also exists between the U-234/U-238 activity ratios of the studied waters and total dissolved solids, ionic strength, CO2 partial pressure, and index of base exchange, which indicates that the enhancement of U-234 in solution increases with the degree of weathering in the aquifers, A higher U-234/U-238 activity ratio was found to be directly related to a higher value of dissolution rate.

Performance of constructed wetland system for public water supply

The project is being conducted in the town of Analândia, São Paulo, Brazil. The constructed wetlands system for water supply consists of a channel with floating aquatic macrophytes, HDS system (Water Decontamination with Soil - Patent PI 850.3030), chlorinating system, filtering system and distribution. The project objectives include investigating the process variables to further optimize design and operation factors, evaluating the relation of nutrients and plants development, biomass production, shoot development, nutrient cycling and total and fecal coliforms removal, comparing the treatment efficiency among the seasons of the year; and moreover to compare the average values obtained between February and June 1998 (Salati et al., 1998) with the average obtained for the same parameters between March and June 2000. Studies have been developed in order to verify during one year the drinking quality of the water for the following parameters: turbidity, color, pH, dissolved oxygen, total of dissolved solids, COD, chloride, among others, according to the Ministry of Health's Regulation 36. This system of water supply projected to treat 15 L s-1 has been in continuous operation for 2 years, it was implemented with support of the National Environment Fund (FNMA), administered by the Center of Environmental Studies (CEA-UNESP), while the technical supervision and design were performed by the Institute of Applied Ecology. The actual research project is being supported by FAPESP.

Possible effects of sodium chloride treatment on quality of effluents from Alabama channel Catfish ponds

Channel catfish ponds are treated with salt (sodium chloride) to increase chloride concentration and prevent nitrite toxicity in fish. A survey indicated that most farmers try to maintain chloride concentration of 50 to 100 mg/L in ponds by annual salt applications. Averages and standard deviations for selected water quality variables in salt-treated ponds were as follows: chloride, 87.2 ± 37.5 mg/L; total dissolved solids (TDS), 336 ± 96 mg/L; specific conductance, 512 ± 164 μmhos/cm. Maximum values were 189 mg/L for chloride, 481 mg/L for TDS, and 825 μmhos/cm for specific conductance. Good correlations between specific conductance values and both chloride and TDS concentrations suggest that specific conductance can be a rapid method for estimating concentrations of these two variables in surface water. The maximum limit for chloride concentration in Alabama streams allowed by the Alabama Department of Environmental Management is 230 mg/L. The usual recommended upper limit of TDS for protection of aquatic life in freshwater streams is 1,000 mg/L. Based on the observed relationship between TDS concentration and specific conductance in Alabama catfish ponds, 1,000 mg/L TDS corresponds to 1,733 μmhos/cm specific conductance. It is unlikely that effluents from salt-treated catfish ponds would violate the in-stream chloride standard of 230 mg/L or harm aquatic life in streams. Nevertheless, chloride concentrations in ponds should be measured before salt application as a safe guard against excessive salt application and chloride concentrations above the in-stream chloride standard.

Análise das condições hidrológicas em bacias hidrográficas com differentes uso e ocupação do solo

The analysis of the physical medium in hydrographic basins requires knowledge of the processes involved and characteristics of variables at different geographic scales. Considering the principle that the micro-basins can be categorized, they are then considered territorial units of ideal work for the analysis of hydrologic conditions. The objective of this work was to compare water resources of four hydrographic basins' with different land use and occupation. Five sampling points along the drainage network of hydrographic basins of first order of magnitude and a sampling point in the river mouth of M1 and M4 micro-basins were established. The water collections occurred at monthly intervals from August, 2006 to August, 2007. Temperature (°C), turbidity (NTU), odor, pH, electric conductivity (μS cm-1), dissolved oxygen (mg/L), total dissolved solids (ppm) and total phosphorous (mg/L) were the variables evaluated in the study. The highest variability of the parameters was found in hydrographic basins M2 and M3. The characterization of the hydrologic conditions of the hydrographic micro-basins indicated that agricultural activities, including cultural practices of anthropic activities affect water resources.

Qualidade da água para irrigação na microbacia do Coqueiro, Estado de São Paulo

The aim of this study was to evaluate the physico chemical characteristics of water quality for irrigation purposes in the micro basin of Coqueiro, a tributary on the right bank of the São José dos Dourados river, located between the municipalities of Jales, São Francisco, Palmeira d'Oeste and Dirce Reis, in the state of São Paulo, Brazil. Water samples were collected at five geo-referenced points along the stocam and analysed monthly for one year. The parameters analysed were: suspended and dissolved solids, turbidity, electrical conductivity, pH, calcium, magnesium, hardness and total iron. The result showed that the physico chemical parameters had the classification of medium potential for damage to the irrigation system, except total iron, which was classified as having medium to high potential for damage by clogging for localized irrigation systems.