Groundwater quality assessment is a crucial factor in ensuring sustainable water resources for drinking and irrigation. This study evaluates the hydrochemical characteristics of groundwater from the Sebdou and Hennaya aquifers in northwestern Algeria, using key physicochemical parameters and water quality indices (WQI) such as drinking water quality index (DWQI), the irrigation water quality index (IWQI) and the nitrate pollution index (NPI). The analysis focused on parameters including temperature, pH, electrical conductivity, chloride, sulfate, and nitrate concentrations to determine the suitability of groundwater for human consumption and agricultural use. The results indicate that while the Sebdou aquifer generally provides water of excellent to good quality for drinking purposes, irrigation remains restricted due to elevated salinity levels. Specific points exhibit severe restrictions, whereas others present only moderate limitations. In contrast, the Hennaya aquifer demonstrates poor water quality, with electrical conductivity exceeding the Word Health Organization standards in all sampled locations and nitrate concentrations consistently surpassing the recommended limit of 50 mg L–1. In both aquifers, the NPI highlights significant nitrate contamination, particularly in the Hennaya region, where pollution levels remain critically high throughout both wet and dry seasons. This high nitrate pollution could be attributed to the discharge of wastewater and the intensive use of fertilizers, especially in the Hennaya region, which is an agriculturally oriented plain. The study underscores the pressing need for sustainable groundwater management strategies to mitigate pollution, regulate nitrate sources. Without proper intervention, continued degradation of water quality may threaten public health and agricultural productivity in the region. These findings provide a scientific basis for policymakers to develop targeted measures that ensure the long-term viability of groundwater resources in northwestern Algeria.
In this study, an iron−manganese double oxide containing wood fiber-based nanomaterial was synthesised for enhanced removal of organic dyes and toxic metals from contaminated water using a modified hydrothermal technique. This adsorbent was formed in situ within the porous structure of wood fibers after a portion of the lignin was removed. Analytical methods, in particular: scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), derivative thermogravimetric (DTG) and energy-dispersive X-ray spectroscopy (EDX) were used to characterise the synthesised nanomaterial. UV-visible spectroscopy and atomic absorption spectroscopy (AAS) were utilised for the investigation of the kinetics of adsorption and adsorption isotherms of organic dye Methylene Blue (MB) and metal pollutant Cr(VI). From the analysis of kinetics data, it is observed that in both cases the adsorption exhibited a superior fit to the pseudo-second-order kinetics model of non-linear form. The Langmuir adsorption isotherm model demonstrated a better fit for the adsorption of MB, displaying a maximum adsorption capacity of approximately 92
The importance of a comprehensive assessment of the quality of surface water environments as sources of drinking water, especially in conditions of global ecological disasters, is shown by the example of pollution by heavy metals (by Cr(III) and Cr(VI), in particular) as ecotoxicants. The solution to this problem is successfully achieved through complex biotesting, which provides an integral assessment of the danger of contaminated water for living organisms, including man. Daphnia magna is used among standardized test organisms to assess the quality of natural waters as sources of drinking water supply. Some aspects of the toxic effect of chromium ions on daphnia have been established: the greatest toxicity effect depends on the degree of chromium oxidation, which corresponds to its MPC for drinking water. Chromium(VI) compounds are characterized by a significantly higher acute toxicity than chromium(III) compounds; and their concentration in aqueous solution, the duration of impact on test organisms, and the presence of complexing ligands (shown by the example of EDTA as an analogue of natural humic acids) also exert a significant effect. The death of Daphnia magna significantly increases with the rise in the concentration and the duration of exposure to chromium ions.
Natural organic matter (NOM) negatively affects water purification quality and leads to the formation of disinfection by-products that exhibit carcinogenic, teratogenic, and mutagenic effects. In addition, biodegradable natural organic matter enhances the growth of microorganisms in the distribution network and causes problems with taste and odor. This necessitates the improvement of existing water treatment methods and the search for more efficient technological solutions, one of which is the use of an integrated coagulation−ultrafiltration process. In this study, the optimal conditions of an integrated coagulation−ultrafiltration process using aluminum sulfate as a coagulant for the purification of Dnipro River water were established. It was shown that, at pH of 6.0–6.5 and a coagulant dose of 2 mgAl/L, the obtained filtrate quality meets the existing regulatory requirements for drinking water. Water quality was evaluated by turbidity, color, residual aluminum concentration, total organic carbon TOC, UV254, UV364, and SUVA parameters. The mechanism of membrane fouling was determined as a gradual transition from the blocking of pores by multiple particles to intermediate filtration with the further formation of a cake layer on the membrane surface. Membrane regeneration was carried out by direct washing with distilled water, which restored the specific permeate flux by 62.0
The traditional 5-Br-PADAP (2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol) spectrophotometric method for determining antimony in water involves the use of highly toxic Sb(III) standards, requires large volumes of chemical reagents, and exhibits low sensitivity. To overcome these drawbacks, this paper couples cloud point extraction (CPE) with complexation colorimetry for the determination of trace antimony in water. This approach enables simultaneous enrichment and high-precision determination of trace pentavalent antimony [Sb(V)]. The effects of various parameters on CPE efficiency were systematically investigated, and the method performance was evaluated in the concentration range of 1–25 μg/L. The results show that under the optimized conditions (4.0 mol/L HCl; 2 mL of 2
