Approaches to Evaluation of Self-Purification in Estuarine Rivers of Souhteast of Amapá State - Brazil

There are a number of reasons that make Amazon estuary an important natural water resource. First, it is biologically productive being the spawning and nursery ground for many important aquatic biota. Second, it serves as receiving waters for wastewater discharges and for navigation use. Third, it has been demonstrating its elevated dilution and self-purification capacity for constituents of the water, principally bacteria, toxic substances, organic material and nutrients. Many cities and small ports of the State of the Amapá located on estuaries and coastal zones are ready affecting their quality through runoff, domestic and industrial wastewater. So, the present research evaluated the water quality in four rivers located close to the periurban areas of Macapá and Santana and rural area of Mazagão municipality. The main objective is to diagnostic the spatial-temporal distribution of some variables and parameters of the water quality, considering important factors as atrophic, hydrologic and climatologic effects in streams sanitation

Deoxygenation in surface water of lotic environment (doi:10.4136/ambi-agua.127) (Portuguese)

The mathematical models are gaining increasing importance in the evaluation and comparison of alternative management of natural water bodies. One of the difficulties of using models of water quality for oxygen is the absence of data on kinetic parameters of reactions of biochemical processes. This study aimed to evaluate the processes of temporal processing of oxygen in surface water of lotic environment. The study was conducted in the Meia Ponte River, Goiás, one of the main rivers of the state. Water samples were collected in the urban area of Goiânia, Goiânia New District 2, which shows apparent anthropogenic interference with the natural environment. After corrected to the standard temperature of 20°C, the BOD varied between 4.11 and 21.24 mg L-1 and during the process of biological oxidation, the deoxygenation coefficient (Kd20) varied from 0.12 to 1.05 d- 1, and an increase of organic matter in the dry season was observed

Environmental impacts of dairy effluent on waterway in the Pomba River Basin

<p></p><p>ABSTRACT Dairy activity has economic and environmental importance in the Pomba River Basin. Aiming to check for possible environmental impacts of dairy effluents on watercourses, five dairy effluents were characterized during the production cycle. To select the variables important for the characterization of effluents, it was applied a principal component analysis (PCA). Data obtained were compared with official regulations and it was simulated the impact of the discharge of effluents, treated or non-treated, on a waterway. The most significant variables in the effluent analysis were conductivity, biochemical oxygen demand (BOD), total phosphorus, turbidity, temperature and pH. Dairy plants do not comply with legal standards for effluent discharge, even with treatment plants installed. The main reason is the low use of whey, associated with inefficient treatment of effluents. By simulating the discharge of effluents, it can be concluded that the reduction of BOD should be 60-70% for the river water did not exceed the standard limits for BOD. The simulation was important to determine the impacts of dairy effluents and can be applied to other dairy plants in order to ensure that effluent cause no environmental damage. Developing products or technology for the better use of whey in small dairy plants, adequately treat the effluents, and reduce water consumption are considered important actions to reduce environmental impacts on water resources.</p><p></p