Location and characterisation of pollution sites by principal component analysis of trace contaminants in a slightly polluted seasonal river: a case study of the Arenales River (Salta, Argentina)

Abstract

Principal component analysis (PCA) was used to deduce the common origin of trace contaminants in a slightly contaminated, strongly seasonal river of low-average discharge, aiming to ascertain the type of the pollution. Splitting of data into categories according to specific conductance was essential to reach conclusions. Dry-season data allowed the pinpointing of polluting sites by means of the biplots resulting from the representation of the scores on the components. Concentrations corresponding to the wet seasons yielded no useful results probably due to the high percentage of data below detection limits for 2 of the 6 variables. The Arenales River in NorthWest Argentina was monitored by means of 19 sampling campaigns between 2003 and 2005 comprising two hydrological cycles, at seven locations along a 25 km section of the river course across the city of Salta. Pollution of the river was not severe, overall mean values in µg/ℓ being: As 1.2; B 490; Cu 4; Fe 92; Pb 13; Zn 83. Simple correlation analysis revealed no significant correlation between these elements. The high positive loadings of variables B and As concentrations on the first principal component and the biplots indicate that their main common point sources are boron mineral deposits still existing in the urban area. Interpretation of the biplots shows that Cu, Fe and Zn contamination also originated at point sources, the contribution of the sewage treatment plant being negligible.

Heavy metal assessment and water quality values in urban stream and rain water

“…Recently, water quality monitoring has become a matter of concern in stream and river water systems affected by careless disposal of urban effluents. Runoff, atmospheric deposition and domestic and industrial effluent discharges are the major sources of aquatic pollution (Wasswa, 1997;Linnik and Zubenko, 2000;Campbell, 2001;Lwanga et al, 2003 andLomniczi et al, 2007) and physicochemical characteristics such as dissolved oxygen and the pH of aquatic ecosystems may determine stream water ecosystem integrity. Monitoring of stream water physico-chemical characteristics and heavy metal concentration is necessary to establish the levels of contamination in wastewater.…”

Tracking SARS-CoV-2 in rivers as a tool for epidemiological surveillance

“…The copyright holder for this preprint this version posted June 29, 2021. ; https://doi.org/10.1101/2021.06.17.21259122 doi: medRxiv preprint located 0.7 km upstream and 0.7 km downstream the southern wastewater treatment plant (WWTP-S) and the municipal landfill, respectively. Despite the chemical and microbiological contamination of this river (Lomniczi et al, 2007;Poma et al, 2012;Prez et al, 2020), it is used for domestic irrigation of vegetables and for recreational purposes. River before (AR-1) and after (AR-2) the discharge of the southern wastewater treatment plant (WWTP-S); Mojotoro River before (MR-1) and after (MR-2) the discharge of the northern wastewater treatment plant (WWTP-N), and La Caldera River (CR).…”

Seasonal variations in the level of heavy metals in the water of minor rivers

“…Як результат важкі метали спричинюють мутагенний і тератогенний ефекти, проявляють синергізм, посилюючи дію інших токсикантів на біоту (Sudha et al, 2013;Klymenko et al, 2016). Хімічний склад природних водойм неоднорідний, а специифічність геохімічних процесів зумовлює різноманіття співіснуючих форм важких металів і певні закономірності їх міграції у водному середовищі (Lomniczi et al, 2007;Reza and Singh, 2010;Chandra et al, 2015). З огляду на зазначене вище мета цього дослідження -визначити ступінь забруднення води мАлих річок Рівненщини важкими металами (Zn, Mn, Fe, Cu, Pb, Co, Ni, Cd) залежно від рівня антропогенного навантаження на типу гідроекосистеми.…”