Nitrogen distribution in a tropical urbanized estuarine system in northeastern Brazil

Abstract

Nitrogen enters estuaries mostly through fluvial discharge and tide, although anthropogenic sources are known to influence the amount of this element in these aquatic ecosystems. Thus, the objective of this work was to verify which river (Cachoeira, Fundão, and/or Santana) exerts greater influence on the distribution of dissolved N forms (Dissolved Organic Nitrogen and Dissolved Inorganic Nitrogen = NH/NH, NO, and NO) along a tropical urbanized estuarine system in northeastern Brazil. The studies estuarine system lies with in urban municipality, and the upper portion of the Cachoeira river estuary receives the treated effluent from this municipality through a sewage treatment station and untreated effluents from nearby villages. The selected sampling stations were located near the outfall of the rivers in the estuaries to the treatment plant and the villages. Of all the nitrogen forms, dissolved organic nitrogen (DON) prevailed in the estuarine system, followed by nitrate (NO) as the main inorganic form. The highest concentrations were recorded in the fluvial portion and upper estuary of Cachoeira river in the dry season. Based on the N concentrations found in the estuarine system, Cachoeira river has the greatest anthropogenic influence due to the amount of untreated effluents from the villages and treated effluents from the sewage treatment plant (STP) in the upper portion of the estuary.

Environmental Violation Fines Growth in the Northern Region of Santa Catarina State, Brazil

“…However, it is important to highlight that IMA and PMA are unable to promote intensive supervision on the industries regarding to the pollution violations in both air and water levels. In general, this responsibility is provided to the local goverments that should promote frequent monitoring (Simonassi et al, 2010;Pereira & Röring, 2016;Santos et al, 2018). According to Kelly & Fussell (2015) and Sîrbu et al (2015), pollution was considered a major environmental risk factor in the incidence and progression of some diseases.…”

Nutrient dynamics in a tropical estuary: a microcosm approach

“…In this case, the Cachoeira River estuary is a typical tropical estuary dominated by mangroves, located on the Eastern Brazilian Coast (Silva et al 2015), that faces anthropogenic eutrophication. Several anthropic activities have developed along the Cachoeira River hydrographic basin, which contribute to increasing concentrations of N and P in many forms (Souza 2005, Souza et al 2009, Lima et al 2010, Lucio et al 2012, Silva et al 2013, Silva et al 2015, Santos et al 2018. The activities include pasture, agriculture, cacao crop cultivation as an agroforest system, and wastewater release of untreated domestic and industrial effluents in the riverbed (Cerqueira et al 2020).…”