Seawater quality conditions of the south Andaman Sea (Bay of Bengal, Indian Ocean) in lustrum during 2010s decade

Faecal bacteria density in tropical seawater: The Itanemas' cove case study, Angra dos Reis, Brazil

Angra dos Reis can receive up to 1.3 million tourists in the summer season. The lack of an adequate sanitary system makes sewage contamination a growing concern in Ribeira Bay, Angra dos Reis, Brazil. This study aims to investigate the seasonal variation of faecal indicator bacteria (FIB) and abiotic variables in Itanema cove situated within Ribeira Bay. Despite the seasonal population increase (>80 individuals) and the absence of an integrated sanitary system, our results indicate that Itanema is still a stable estuarine environment. From 2017 to 2019, the mean salinity was 27.91, pH was 7.82, and water temperature was 25.01 °C. However, the FIB number was 10⁵, suggesting the absence of sewage treatment in Itanema's outfall. Following current conservation status, baseline studies are mandatory for background references of endangered coastal areas such as Itanema cove. These studies are crucial for future governance decisions and sustainable tourism implementation in Angra dos Reis.

Assessment of the Bulgarian Wastewater Treatment Plants' Impact on the Receiving Water Bodies

Deterioration of water quality is a major problem world widely according to many international non-governmental organizations (NGO). As one of the European Union (EU) countries, Bulgaria is also obliged by EU legislation to maintain best practices in assessing surface water quality and the efficiency of wastewater treatment processes. For these reasons studies were undertaken to utilize ecotoxicological (Microtox^®, Phytotoxkit F^TM, Daphtoxkit F^TM), instrumental (to determine pH, electrical conductivity (EC), chemical oxygen demand, total suspended solids (TSS), total nitrogen (N) and phosphorus (P), chlorides, sulphates, Cr, Co, Cu, Cd, Ba, V, Mn, Fe, Ni, Zn, Se, Pb), as well as advanced chemometric methods (partial least squares-discriminant analysis (PLS-DA)) in data evaluation to comprehensively assess wastewater treatment plants' (WWTPs) effluents and surface waters quality around 21 major Bulgarian cities. The PLS-DA classification model for the physicochemical parameters gave excellent discrimination between WWTP effluents and surface waters with 93.65% correct predictions (with significant contribution of EC, TSS, P, N, Cl, Fe, Zn, and Se). The classification model based on ecotoxicological data identifies the plant test endpoints as having a greater impact on the classification model efficiency than bacterial, or crustaceans' endpoints studied.