Spatial distribution of major and trace elements in artificial lakes in Serbia: health risk indices and suitability of water for drinking and irrigation purposes.

Lakes and reservoirs are the main water resources for household, irrigation, and industrial use. Hence, it is necessary to control water pollution and have reliable information on water quality, which refers to its suitability for a particular purpose. The main objective of this study was to evaluate the suitability of water for drinking and irrigation purposes from ten artificial lakes on the territory of the Republic of Serbia. The physicochemical parameters were determined using standard analytical methods, whereas the optical emission spectrometry with inductively coupled plasma, ICP-OES, was used to determine the concentrations of 23 macro-, micro-, and trace elements in water. Health risk indices of drinking water and its suitability for irrigation purposes were evaluated. The results of physicochemical parameters, except for total organic matter, indicated that most samples were within the recommended values. Among analyzed elements, the concentration of Mg was elevated in the water of the lakes Srebrno and Prvonek. The results of health risk assessment clearly showed that there was no acute health risk (HQA < 1), whereas long-term risk (HQL) in the studied lakes was observed with respect to As (lakes Grliste and Srebrno), Mn (lakes Srebrno and Prvonek), Ni (Lake Vrutci), and Sr (Lake Grliste). The irrigation criteria indicated that the water from the examined lakes had satisfactory quality for this purpose, except for residual sodium carbonates (RSC). This criterion indicated low quality or unsuitability of the water in 7 lakes. The main outcomes provided valuable information on the suitability of water from the artificial lakes for intended uses.

Hydrochemistry of groundwater contaminated by petroleum hydrocarbons: the impact of biodegradation (Vitanovac, Serbia).

Aquifer contamination by petroleum hydrocarbons leads to measurable changes of groundwater hydrochemistry, primarily due to the microbiological activity. This study analyzes this phenomenon at an historical kerosene-contaminated site in Vitanovac (central Serbia). Due to the long-term hydrocarbon contamination and exposure to aerobic and anaerobic biodegradation mechanisms, the lowest concentrations of O2, NO3-, and SO42- (electron acceptors) and the highest concentrations of Mn and Fe (products of microbial metabolic activity) overlap. The terminal redox-accepting processes in groundwater ranged from oxygen reduction to sulfate reduction. The most anoxic processes were registered in piezometers closest to the source of contamination, as was also confirmed by the redox potential (Eh) measurements. High electrical conductivity values and the highest TOC, SiO2, and Al concentrations also overlap in the contaminated zone close to the source of contamination. Scanning electron microscopy study of quartz grains from the zone undergoing the impact of biodegradation confirmed the occurrence of weathering microscale processes on mineral surfaces. Taking all these factors together, it seems reasonable to assume that microbiological activity has caused the enhanced weathering of silicate minerals.

Assessment of spa mineral water quality from Vrnjacka Banja, Serbia: geochemical, bacteriological, and health risk aspects.

The goal of this study is to evaluate the quality of seven natural mineral water sources in the Vrnjacka Banja area used in the treatment of various diseases. The 24 macro- and microelements were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The results show that element content was within allowed limits of concentration, except for B, As, and Se. The evaluated content of these elements can be associated with geological and anthropogenic factors. The sample S6 contains more than twice the concentration of As, meaning that the use of water from this source should be limited due to the negative impact of this element on human health. The calculated values of weekly (EWI) and oral (OI) intakes as well as the acute hazard quotient (HQA) of selected toxic and potentially toxic elements indicate no health risks to the consumers. The highest hazard quotient (HQL) observed for As in sample S6 (2.0·10-1) demonstrated a significant risk of carcinogenic diseases in long-term consumption from this source. The estimated non-carcinogenic (DIA) and carcinogenic (DIL) dermal intakes with acute (HQA) and long-term (HQL) hazard quotient values for sample S3 show that there is no health risk to those who use the water from this thermal source for bathing. The presence of aerobic mesophilic bacteria at 22 °C and 37 °C in samples S3, S6, and S7 as well as sulphite-reducing Clostridia species in sample S5 were detected, potentially indicating some non-faecal or faecal contamination.