Índices de qualidade da água no sistema de captação de água da região amazônica (Brasil)

Abstract

Os lagos Bolonha e Água Preta são utilizados para abastecer parte da população da Região Metropolitana de Belém. O estudo visou avaliar a qualidade da água durante um ano, em cinco pontos distribuídos ao longo do sistema de captação. O valor da média do IQA classificou a qualidade das águas como regulares e, os valores da média do IET entre eutrófico e supereutrófico. Apesar dos fortes impactos ambientais que ocorrem na área dos mananciais que são utilizadas no abastecimento público da Região Metropolitana de Belém, observa-se que a capacidade de autodepuração e renovação ainda são mantidos. No entanto, é necessário que os órgãos responsáveis, juntamente com a sociedade, continuem trabalhando para torná-la uma fonte viável de água. Ações de educação ambiental para a população devem ser adotadas para promover a conscientização ambiental e mitigar os impactos causados pelo avanço da urbanização.

Characterization of dissolved inorganic carbon and dissolved oxygen in two impacted Amazonian lakes.

“…According to the estimates of the parameters of the carbonate system, the pH showed a strong positive correlation with DO and negative with CO2aq (r 2 = 0.82 and r 2 = -0.93, respectively; Table II). The range of observed values is also in agreement with the values observed by other authors (Brito et al 2020;Vasconcelos & Souza 2011;Silva et al 2020). The work of Vasconcelos & Souza (2011), carried out between 2007 and 2009 showed average values in the range of 1.5 to 4.5 mg l -1 in the lakes.…”

Ecological indexes and phytoplankton structure of urban reservoirs supplied by estuarine waters and under the effects of seasonality (Belém, Pará, Brazil)

“…Climatic factors are important for phytoplankton development [58], where periods of high rainfall can provide nutrient inputs to aquatic ecosystems [59], as observed by Silva et al ( 2019) [12] in the rainy season, the highest values of nitrogen and phosphorus occur in the reservoirs, providing the development of phytoplankton, such as the species Gonyostomum sp., which benefits from this condition [59]. Transparency limits the development of phytoplankton, as it is associated with the entry of light into the water column, mainly grouping species of freshwater chlorophytes, generally related to naturally clear environments [15], in this way, the high productivity of these organisms can act in the increase in dissolved oxygen concentration, as this variable is directly dependent on the photosynthetic process [9].…”

“…According to Zaghloul et al (2020) [69], a low amount of species present in the environment demonstrates a high degree of stress to which the system is subjected. Due to the disorderly advance of urbanization around the reservoirs and allied to the low coverage of basic sanitation present in the region [8,10], the supply reservoirs of Belém are in the process of eutrophication [5,12,70], which has contributed to the gradual decrease in the diversity of the aquatic environment [71], mainly in the Bolonha reservoir, which is dominated by aquatic macrophytes, and their proliferation is mainly associated with the increase of nutrients in the water [72], and this increase is possibly associated with the contribution of sewage discharges without prior treatment.…”

“…In this scenario, sewage is discharged without prior treatment into rivers and the contaminated water is the main cause of several processes of ecological imbalance due to the loss of its quality and biodiversity [10]. The reservoirs of this supply system are dominated by aquatic macrophytes and their waters are eutrophic, with records of cyanobacteria blooms, which makes them unsafe for human consumption [11][12][13][14]. Due to the increasing scarcity of water, existing aquatic environments must be monitored in order to ensure safe water for supply and to predict processes that impact these environments and may endanger their ecological integrity.…”