Influência de actividades antropogénicas sobre alguns parâmetros da qualidade de agua da lagoa azul – Nicoadala

Abstract

Hydrological information is important for the planning of society's activities and for the management of water resources, as well as for reducing the risks to water quality. This research was carried out in the blue lagoon, Nicoadala District, Zambézia Province, on 28 May and 4 October 2017. However, fishing, bathing, laundry, water supply to fish tanks and practice are the main activities practiced and dependent on the lagoon. In this context the principle emerges that the work was elaborated with the general objective of to study the influence of anthropogenic activities on some parameters of the quality of Water of the Blue Lagoon - Nicoadala. In order to reach this objective, it was possible to board an artisanal boat, where the parameters Temperature, Dissolved Oxygen and Hydrogenionic Potential were measured by the Multi-parameter OxyGuard instrument and pH meter. Water samples were collected at three seasons, respectively in the mouth (P1), in the middle (P2) and at the end of the pond (P3) during the less rainy and dry seasons. The phosphate was analyzed in the laboratory of Chemistry of the School of Marine and Coastal Sciences - EMU and determined by the photometer Multidirect 7, and the ammonium was analyzed in the laboratory of Water quality of the Fund of Investment and Heritage of Water Supply - Quelimane and (23.6 ° C and 27.25 ° C), OD (2.72 m / l and 2.86 m / l), respectively, were determined by the HACH DR 900 spectrophotometer. The average values for the two seasons (rainy and dry) L), PO43- (2.68 m / L and 1.9 m / L), pH (6.7 and 6.55) and NH4 + (2.7 m / L). We conclude that the activities performed in the lagoon, although contributing in small proportions in the concentrations of ammonium, phosphate, dissolved oxygen and pH, indicated less harmful influences to this medium, since the lagoons do not have abrupt variations in the parameters of water quality.