Revista de Gestão de Água da América Latina (Water Management Journal in Latin America)

NATURAL AND ANTHROPIC EFFECTS ON THE QUALITATIVE ASPECTS OF WATER IN THE NIQUIM RIVER BASIN

2024-12-19T11:08:43-03:00

The natural and anthropogenic effects on the water quality of the Niquim River, located in the São Miguel Hydrographic Region, were analyzed with the aim of developing a classification proposal. Qualitative water monitoring was carried out in the Niquim River Lagoon (RNL), the second near the city's water intake (RNC) and the third near the mouth (RNF). The results of the analyses were compared with the limits established by CONAMA Resolution No. 357/05. In the classification proposal, the basin was divided into 3 sections, for which classes 1 and 2 were suggested, but it was found that some parameters do not meet their predominant uses. In section 1, the aim is to increase DO and reduce BOD_5,20 and ammoniacal N, through the preservation of forest formations to reduce the organic load in this section. In section 2, it is necessary to reduce the BOD_5.20 and ammonia-N parameters by preserving vegetated areas, mainly riparian forests, to reduce the organic load in this section. In section 3, the BOD_5.20, ammonia-N, DO and E. coli parameters are above the levels established in the Resolution. In order to reach the limits of the proposed classification in all sections, it is necessary to correctly dispose of effluents, preserve green areas, and plan land use and occupation.

Changes in Water Color Related to Mining in Rivers of Southwestern Amazon Observed by Satellite

2025-01-21T10:45:13-03:00

Given the importance of water resources, their monitoring is essential. Considering the size of Brazilian river basins, especially the Amazonian ones, the use of remote sensing tools becomes feasible, allowing for the monitoring of surface water quality, particularly color characteristics and total solids. The components present in the water alter its reflectance according to their characteristics, enabling the study and tracking of water quality. The main objective of this work was to identify changes in the water color of rivers in the Southwestern Amazon, within the sub-basins of the Ji-Paraná, Canumã, and Amaná rivers, mapping evidence of interactions and the impacts of mining and gold panning. This was achieved through reflectance angles and dominant wavelengths, understanding the formation of water color in the basins and the influence of mining and human activities. A statistical analysis of the average values of dominant wavelengths and suspended material data provided by ANA was conducted to verify whether the variations were significant between 1994 and 2021. Through statistical analyses, significant changes were demonstrated for higher average dominant wavelengths in most sections of the Ji-Paraná and Amaná basins, while for the Canumã River, the changes were mostly toward shorter wavelengths.

A MULTIOBJECTIVE AND MULTICRITERIA METHODOLOGY FOR SUPPORT TO THE PROCESS OF CONCESSION OF WATER USE RIGHTS

2025-02-21T11:39:49-03:00

We proposed a methodology to assist in the granting of water use rights, using multi-objective and multi-criteria methods, and its application to the Preto River basin. We divided the basin into five zones, and we identified water demands and availability in them. We defined eight different development scenarios for the basin, taking into account aspects such as the location of irrigators in the basin, the type of irrigator, and their growth rate. From the interviews with experts, we established seven criteria, covering environmental, social, technical, and economic aspects. We evaluated these criteria using GIS and water balance using Acquanet. We applied three multi-objective methods (Compromise Programming - CP, PROMÉTHÉE-II, and TOPSIS) to four different sets of weights, defined by consulting experts and simulating “policies” to guide the granting process in the Preto River basin. The “policies” aimed to give priority to social, environmental, and economic aspects, in addition to a “neutral policy,” with all weights equal. The results for the different “policies”, after being normalized, produced an aggregated classification and established the concession scenario to be implemented in the basin. The methodology made it possible to define a water granting policy capable of considering conflicts and articulated with social policies.

MINEIRO WATER RESOURCES POLICY

2025-01-21T10:50:22-03:00

The management of Brazilian water resources is conducted through a system that possesses a holistic perspective on all aspects involving water management. Additionally, this system seeks to reconcile strategically important sectors of the country for the sake of water management. Minas Gerais is a state that plays a crucial role in the country when considering economic, social, and environmental aspects. Thus, understanding the water resources management system in Minas Gerais is fundamental for achieving cohesion in the management process at the national level. That said, this study evaluates the relationship between the water resources regulations in force at the aforementioned levels, traversing certain fields of water management in Minas Gerais and Brazil. It is evident that Minas Gerais plays a significant role in the management of water resources under its jurisdiction.

Use and occurrence of 2,4-D in Brazil: emphasis on drinking water quality

2025-01-21T16:19:42-03:00

This study aims to provide a diagnosis of 2,4-D in Brazil, based on its environmental fate, sales, spatial distribution, and concentrations in raw and drinking water. An estimate of 2,4-D sales in Brazilian municipalities and states was conducted, considering data on planted area, sales, and authorized use in the country. The concentration of 2,4-D was analyzed through a systematic literature review and data processing from SISAGUA. It was found that 2,4-D shows a tendency for increased commercialization, with an annual average of 43,267 tons and an average usage rate per planted area of 0.65 kg/ha, with some notable regions. 2,4-D showed a high detection frequency, with values that, overall, did not exceed the maximum acceptable value (MAV) for drinking water in Brazil. It is concluded that 2,4-D is widely used and detected, however, this fact does not currently reflect a risk to human health through drinking water consumption.

Influence of seasonality on the characteristics and biological pre-treatment of landfill leachate

2025-02-19T15:33:23-03:00

Factors such as climate, waste characteristics, age and operation of the landfill influence the flow and composition of landfill leachate, which must be monitored as they interfere with the treatment process. Although anaerobic and aerated lagoons are unable to bring the treated leachate into line with release standards, they function as pre-treatment and amortise its variability, preparing it for post-treatment. This study assessed the influence of seasonality on the flow, composition and biological pre-treatment of leachate generated in a landfill in a tropical region, by means of physico-chemical and flow analyses of the raw and pre-treated leachate. The influence of precipitation on the increase in flow and the variability of COD and BOD was confirmed5,20. Pre-treatment removed 60.8% and 36.6% of COD; 74.7% and 79.4% of BOD5.20, and 94.6% and 76.8% of N-NH4, respectively, in the dry and rainy seasons, but with remaining concentrations still high for direct use in post-treatment.