Sediment pollution in an urban water supply lake in southern Brazil

Temporal variation and risk assessment of heavy metals and nutrients from water and sediment in a stormwater pond, Brazil

“…TP concentrations during the dry season exceeded the permissible limit by an average of 1.73 times. These results had similar findings in previous studies performed in Brazil in Pampulha Lake, Belo Horizonte (Friese et al 2010), Guanabara Bay, Rio de Janeiro (Abreu et al 2016), and Lake Gauíba, Porto Alegre (De Andrade et al 2019).…”

Tributary contributions to sediment deposited in the Jacuí Delta, Southern Brazil

“…11). The higher content of these metals in sediments of Caí and Sinos rivers can be explained by the historical occurrence of tannery (leather and footwear industry) activities in these subcatchments (de Andrade et al, 2019). The low content of Zn and Cr clearly indicates that the sediment sampled on the Ilha da Pintada Channel has great similarity to the bed sediment sampled at the mouth of the Jacuí River (Fig.…”

“…11). This is likely due to the fact that the river flows through the metropolitan region between the cities of Gravataí, Porto Alegre, and Canoas, where a large amount of untreated sewage is discharged into the river (de Andrade et al, 2019Andrade et al, , 2018b.…”

“…It a covers a surface area of 482 km 2 and is fed by water coming from four main rivers: the Jacuí River, the Sinos River, the Caí River, and the Gravataí River. Those rivers converge and flow into the Jacuí Delta, forming a transitional environment (from fluvial to lacustrine), and this water then flows through the lake until it reaches the Patos Lagoon (de Andrade et al, 2019). In the last several decades, episodes of water quality problems in Lake Guaíba have become increasingly frequent, mainly due to eutrophication (Andrade and Giroldo, 2014;Ribeiro et al, 2012).…”

“…Recent studies have shown that the sediment of Lake Guaíba is contaminated with high levels of heavy metals (de Andrade et al, 2019) and phosphorus (de Andrade et al, 2018b) due to the pollution originating from the different tributaries. This may increase water treatment costs and significantly decrease the quality of the water supplied to a large metropolitan region (McDonald et al, 2016).…”