Temporal and spatial variation of limnological variables and biomass of different macrophyte species in a Neotropical reservoir (São Paulo - Brazil)

Aim: This study reports an investigation of limnological characteristics and aquatic macrophyte occurrence in a neotropical reservoir in order to assess the spatio-temporal variation of water and sediment variables and their influence on plant distribution. Methods: Macrophytes, water and sediment samples were collected from a Brazilian reservoir in different seasons from four main arms of the reservoir. In total sixteen water-sediment variables were analyzed including N:P ratio and Trophic State Index. The plants were collected using a quadrat sampling procedure and the dry weight per sample was measured. MANOVA was performed to evaluate spatial and temporal variation of environmental variables as well as seasonal biomass differences. To assess the relationship among environmental variables and macrophytes an ordination analysis (using Canonical Correspondence Analysis: CCA) was carried out. Results: The spatial and temporal variation of limnological variables generated a heterogeneous system which supports the presence of different species of macrophyte. pH, dissolved oxygen and sediment composition were important predictors of Polygonum lapathifolium occurrence while nutrients were associated with Eichhornia crassipes and Pistia stratiotes. Inorganic substances were related to biomass variation of Eichhornia azurea and Myriophyllum aquaticum. Conclusions: The spatial variation of the environmental variables has caused heterogeneity in the reservoir and it may support the occurrence of different species of macrophyte. Limnological variables highlighted in CCA are important to predict the species occurrence and their control in the study area

Application of sustainability indicators to stabilization ponds

A escolha de uma alternativa tecnológica para tratamento de efluentes, assim como o local para implantação deve ser precedida de um estudo de sustentabilidade do ambiente. Foi proposto um método para avaliação da sustentabilidade de estações de tratamento de esgoto, baseado nas características ambientais, sociais e econômico-financeiras dessas unidades. O método foi aplicado em três ETE, constituídas por lagoas de estabilização, localizadas nos municípios de Cajati, Jacupiranga e Pariquera-Açu, todas pertencentes à bacia do Baixo Ribeira de Iguape (SP). A falta de dados para alguns parâmetros considerados na composição dos indicadores prejudicou a obtenção de valores mais realistas. O método proposto mostrou-se de fácil visualização da condição de sustentabilidade das ETE constituídas por lagoas de estabilização.The choice of an alternative technology for effluent treatment as well as the location for deployment must be preceded by a study of environmental sustainability. A method for assessing the sustainability of wastewater treatment plants, based on environmental, social and economic-financial characteristics was proposed. The method was applied to three wastewater treatment plants using stabilization ponds, located in the municipalities of Cajati, Jacupiranga and Pariquera-Açu, all belonging to the Lower Ribeira de Iguape River basin, in the state of São Paulo, Brazil. The lack of values for some parameters considered in the formulation of indicators undermined the achievement of more realistic values. The proposed method proved to be easy to visualize the condition of sustainability of wastewater treatment stations using stabilization ponds.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Probabilistic analysis of the occurrence of incompatibility of the water quality with the legal framework of aquatic systems - case study of Pariquera-Açu River (SP, Brazil)

Embora relativamente comuns no Brasil, programas de monitoramento da qualidade da água frequentemente não transformam os resultados em elementos que norteiem o poder público para a recuperação dos sistemas aquáticos. Assim, a presente pesquisa teve por objetivo discutir a utilização das curvas probabilísticas de incompatibilidade da qualidade da água com o enquadramento legal dos corpos de água como ferramenta complementar ao monitoramento. As probabilidades de inconformidade com a resolução CONAMA 357/05 (Classe 2) para o rio Pariquera-Açu (SP) em 2007 foram de 35, 8, 44, 1, 0, 0 e 0%, respectivamente para oxigênio dissolvido, turbidez, fósforo, nitrogênio amoniacal, nitrito, nitrato e clorofila-a. Concluiu-se que o grau de condensação de informações gerado pelas curvas probabilísticas representa uma contribuição para a gestão da qualidade de água.Although relatively common in Brazil, water quality monitoring programs usually do not organize the results in a way that they are able to guide local authorities for reclamation of aquatic systems. Therefore, this research aimed to discuss the use of probabilistic curves of water quality incompatibility with Brazilian legal framework of water bodies as a complementary tool for monitoring. The incompatibility probabilities with CONAMA 357/05 (framework for Class 2) for Pariquera-Açu river (São Paulo, Brazil) were 35, 8, 44, 1, 0, 0 and 0%, respectively, for dissolved oxygen, turbidity, phosphorus, nitrogen-ammonia, nitrite, nitrate and chlorophyll-a. We concluded that the condensation level of information achieved by probabilistic curves represents an important contribution for management of quality of the water

Calibração do modelo QUAL2K em uma micro bacia brasileira: efeitos do uso e ocupação do solo na qualidade da água

AIM: This study aimed to evaluate the water quality of Canha River micro watershed (Ribeira de Iguape Valley, São Paulo State, Brazil) and to calibrate the QUAL2K model with field data; METHODS: Five variables of water quality were analyzed (water temperature, dissolved oxygen, pH, electric conductivity and turbidity), as well as flow and velocity, in eight sampling stations from September, 2006 to July, 2007. It was performed a correlation test between observed data and simulated data; RESULTS: The dissolved oxygen concentration was high (over than 5.0 mg.L-1) during sampling period. The headwater presented the lowest concentrations of this variable. The electric conductivity did not exceed 80 µS.cm-1 and the pH did not range (0.5-1). The hydraulic variables were in agreement with River Continuum Concept. Although correlation test was not successful for some variables, the simulated data followed observed data; CONCLUSIONS: The rainfall linked to land use was important for obtained results. The watershed characteristics, as high slope, for example, were essential mainly to dissolved oxygen concentrations. Even though QUAL2K has some limitations its use is recommended for water resources management and future purposes.OBJETIVO: O presente estudo teve por objetivo avaliar a qualidade da água da microbacia do rio Canha (Baixo Ribeira de Iguape, São Paulo, Brasil) e calibrar o modelo QUAL2K com os dados obtidos em campo; MÉTODOS: Foram analisadas cinco variáveis de qualidade da água (temperatura da água, oxigênio dissolvido, pH, condutividade elétrica e turbidez), bem como vazão e velocidade de escoamento, em oito pontos amostrais durante setembro de 2006 a julho de 2007. A comparação entre os dados simulados e observados foi feita através de um teste de correlação simples; RESULTADOS: As concentrações de oxigênio dissolvido foram altas (acima de 5,0 mg.L-1) durante todo o período de amostragem, sendo que na nascente observaram-se as menores concentrações. A condutividade elétrica não ultrapassou 80 µS.cm-1 e o pH teve uma pequena faixa de variação (0,5 a 1). As variáveis hidráulicas seguiram a teoria do Continuum fluvial. Os dados simulados seguiram a mesma tendência dos dados observados, embora o teste de correlação não tenha sido satisfatório para todas as variáveis; CONCLUSÕES: A precipitação pluviométrica aliada à modificação do tipo de uso e ocupação do solo foram os principais responsáveis pelos resultados obtidos. As características da bacia, como alta declividade, por exemplo, também foram importantes, principalmente para as concentrações de oxigênio. Embora o modelo QUAL2K tenha algumas limitações, seu uso para gerenciamento dos recursos hídricos e propostas de cenários futuros é recomendado

Associations between a one-shot delay discounting measure and age, income, education and real-world impulsive behavior

There has been discussion over the extent to which delay discounting – as prototypically shown by a preference for a smaller-sooner sum of money over a larger-later sum – measures the same kind of impulsive preferences that drive non-financial behavior. To address this issue, a dataset was analyzed containing 42,863 participants’ responses to a single delay-discounting choice, along with self-report behaviors that can be considered as impulsive. Choice of a smaller-sooner sum was associated with several demographics: younger age, lower income, and lower education; and impulsive behaviors: earlier age of first sexual activity and recent relationship infidelity, smoking, and higher body mass index. These findings suggest that at least an aspect of delay discounting preference is associated with a general trait influencing other forms of impulsivity, and therefore that high delay discounting is another form of impulsive behavior

Integration between cumulative frequency curves for water quantity and quality as a tool for effective water resources management

A garantia dos usos múltiplos da água, dos serviços ambientais e do equilíbrio ecológico depende de uma combinação adequada entre aspectos quantitativos e qualitativos dos rios. A presente pesquisa descreve aplicações de uma nova abordagem das curvas de permanência de vazões, que foram associadas a curvas de frequência acumulada de qualidade da água. Foram compilados dados de fósforo total (2005 a 2009) e vazão média mensal (1959 a 2003) dos rios Paraíba do Sul e Sorocaba para ilustrar o conceito. A integração entre as curvas de quantidade e qualidade se mostrou desejável por oferecer subsídios a concessões de outorga, à cobrança pelo uso da água, ao monitoramento ambiental e ao enquadramento dos cursos de água. Outro aspecto positivo é que essas curvas podem incorporar variações no clima e no uso e ocupação do solo, o que permite o estabelecimento de cenários ambientais

Horizontal subsurface flow constructed wetlands for mitigation of ametryn-contaminated water

The feasibility of using constructed wetlands (CWs) for the mitigation of pesticide runoff has been studied in the last decade. However, a lack of related data was verified when subsurface flow constructed wetlands (SSF CWs) are considered for this purpose. In the present work, SSF CWs were submitted to continuous ametryn addition and evaluated during an I I-week period, with the aim of determining the feasibility of these systems for mitigation of contaminated water. Ametryn was not added to one CW cell in order to provide a control for the experiments. Monitoring of treatment performance was executed by standard water quality parameters, ametryn chromatography quantification and macrophyte (Typha latifolia L) nutritional and agronomic property analysis. Results indicated that 39% of the total initially added amount of ametryn was removed, transferred or transformed. Herbicide metabolism and mineralisation were carried out by chemical and biological mechanisms. No statistic differences were observed in nutritional contents found in the T. latifolia crops of the CWs after the experimental period. Moreover, the biomass production (one valuable source of renewable energy) was equal to 3.3 t.ha(-1) (dry matter) in wetland cells. It was concluded that constructed wetland systems are capable of mitigating water contaminated with ametryn, acting as buffer filters between the emission sources and the downstream superficial water bodies

Dinâmica espaço-temporal de variáveis limnológicas em uma área alagada localizada no Vale do Ribeira do Iguape (São Paulo, Brasil) em diferentes períodos hidrológicos

AIM: The main goal of this research was to investigate the influence of the hydrological pulses on the space-temporal dynamics of physical and chemical variables in a wetland adjacent to Jacupiranguinha River (São Paulo, Brazil); METHODS: Eleven sampling points were distributed among the wetland, a tributary by its left side and the adjacent river. Four samplings were carried out, covering the rainy and the dry periods. Measures of pH, dissolved oxygen, electrical conductivity and redox potential were taken in regular intervals of the water column using a multiparametric probe. Water samples were collected for the nitrogen and total phosphorus analysis, as well as their dissolved fractions (dissolved inorganic phosphorus, total dissolved phosphorus, ammoniacal nitrogen and nitrate). Total alkalinity and suspended solids were also quantified; RESULTS: The Multivariate Analysis of Variance showed the influence of the seasonality on the variability of the investigated variables, while the Principal Component Analysis gave rise in two statistical significant axes, which delimited two groups representative of the rainy and dry periods. Hydrological pulses from Jacupiranguinha River, besides contributing to the inputs of nutrients and sediments during the period of connectivity, accounted for the decrease in spatial gradients in the wetland. This "homogenization effect" was evidenced by the Cluster Analysis. The research also showed an industrial raw effluent as the main point source of phosphorus to the Jacupiranguinha River and, indirectly, to the wetland; CONCLUSIONS: Therefore, considering the scarcity of information about the wetlands in the study area, this research, besides contributing to the understanding of the influence of hydrological pulses on the investigated environmental variables, showed the need for adoption of conservation policies of these ecosystems face the increase anthropic pressures that they have been submitted, which may result in lack of their ecological, social and economic functions

In situ Remediation Technologies Associated with Sanitation Improvement: An Opportunity for Water Quality Recovering in Developing Countries

The access to safe water is of great importance to reduce the spread of diseases caused by water-related pathogens and to assure the life quality to the human-beings. According to the World Health Organization (WHO, 2011), diarrhea, for example, is responsible for two million deaths every year, mainly among children under the age of five. The environmental effects of some pollutants (e.g. endocrine disruptors, organic compounds) remain unclear and the harmful consequences of the exposure to contaminated water are certainly an important issue for the next decades. Moreover, many research have linked water quality to health problems, such as cancer (Rodrigues et al., 2003; Han et al., 2009), insufficient uptake of nutrients and trace-metals (Lind & Glynn 1999), diabetes, cerebrovascular and kidney disease (Meliker et al., 2007). The costs and benefits of water quality have been the topic of stimulating discussion in the scientific community (Isaac, 1998; Hajkowicz et al., 2008; Saz-Salazar et al., 2009) because water quality decrease implies not only loss of lives, but also economic damages. The costs of the anthropogenic eutrophication reach US$2.2 billion in the United States (Dodds et al., 2009) and US$187.2 million in England and Wales every year (Pretty et al. 2002). The reduction of nutrient loading to the aquatic systems worldwide is the cornerstone of artificial eutrophication control (Smith et al., 1999), with repercussions in other fields like public health and economics. The anthropogenic impacts on the quality of urban water bodies in developing countries are frequently exacerbated by poor levels of sanitation and inadequate water and wastewater management. Pressure from urban areas on the water quality was reported in Argentina (Almeida et al., 2007), Brazil (Jordão et al., 2007), India (Suthar et al., 2010) and Mexico (Bravo-Inclan et al., 2008). Rapid shifts in the land use patterns, unplanned urbanization and inefficient resources allocation are further aggravating environmental problems in such 256 Ecological Water Quality - Water Treatment and Reuse nations. Restrictions to the water uses are increasing as the pollution of rivers and lakes is offering more risks to the human health and to the maintenance of the ecological balance. Within this context, the water resources management plays an important role in the conciliation of the water uses and the long-term sustainability. The in situ remediation of rivers, lakes and reservoirs is a decentralized alternative that may be convenient in some cases in comparison to off-site solutions. The main advantages of the in situ approach are, besides the relative small period of time required to its implementation, the suitability of the in situ facilities to the regions with lack of available areas to build off-site treatment plants (e.g. highly urbanized areas) and the lower expenses with pumping structures. Although it takes more time and requires more investments, the implementation of sanitation infrastructure is also necessary. With the increase of the negative environmental impacts induced by the anthropogenic activities, the remediation of aquatic systems became an alternative to restore the ecological functions of the ecosystems and accelerate their recovery. The first and most important step in a remediation project is to define the remedial action aims to be accomplished at the site, involving the desirable mechanisms of treatment - biological (e.g. phytoremediation), physical and/or chemical (e.g. oxidation, air stripping, ion exchange, precipitation). Most of the current technologies for aquatic systems remediation were adapted from unitary processes used for drinking water production, industrial purposes or wastewater treatment. The flotation, for example, has been used in mining activities to separate the mineral of interest from the gangue since 1893 (Hoover, 1912). The technology was then adapted to treat water and wastewater through dissolved air flotation (e.g. Heinänen et al., 1995). Ultrafiltration membranes in turn have been mainly used for drinking water production (2 million m3 /day worldwide according to Laîné et al., 2000). According to the same authors, the oldest water industry with ultrafiltration plant started to operate in 1988 in France. The membranes are becoming cheaper over the years and the technology is more attractive for remediation of surface waters at the present time

Linkages between Water and Forests in South American Watersheds under Restoration

Water security is threatened by the rapid growth of the human population in areas where there were native forests before coupled with climate change scenarios. One of the main elements which ensures water security is water stored in soil, which is fundamental for maintaining ecohydrological processes at the watershed scale under forest land-use change. In South America, aiming to restore and recover changing catchment areas, best management practices (BMP) have been widely proposed as a strategy for water-forest resource sustainability. Based on forest evapotranspiration demand, this chapter presents fundamental concepts related to soil-water-forest cycles, watershed restoration, and case studies of BMPs in South American watersheds (e.g., Brazilian and Colombian projects for watershed conservation or restoration). It has become clear that there is an opportunity in setting baseline data and quantifying the effectiveness of these BMPs. By using ecohydrological monitoring and suitable indicators of these BMPs in the long term, an integrated understanding of water-forest relationships is needed. Furthermore, the more successful watershed management projects are, the more effective decision-making regarding BMP linking water and forests is