Journal of Water Chemistry and Technology最新文献

Two samples of Algerian clay were collected for preparing ceramic membranes that can be used for water filtration. The membrane support was prepared from mountain clay from El Outaya mountains, Biskra province, Algeria, using calcium carbonate and methocel additive via extrusion method. The membrane was deposited using slip-casting method and the precursor slurry was based on polyvinyl aniline (PVA) and clay from Constantine mountains. The supports exhibited proportional evolution of mechanical resistance with sintering temperature, so the 1150°C support was selected for membrane deposition due to its porosity, which yielded optimal mean flux values (30 002.082, 21 559.54, and 16 511.71 L h^–1 m^–2 for 3 × 10⁴, 6 × 10⁴, and 9 × 10⁴ Pa pressure, respectively). The selected support possessed optimal permeability suitable for membrane deposition (factor k = 0.25679 L h^–1 m^–2 Pa^–1) because of necks and bridges formation made of mainly Gehlenite–Anorthite with some traces of Mullite. The cast membrane displayed low porosity and very high filtration performance since the Scanning electron microscope (SEM) image revealed a clean side section of the membrane with good homogeneity and low porosity rate. Moreover, the application of the cast membrane for filtration resulted in a very good filtration rate under high-pressure filtration when comparing the polluted water sample and the filtrate, showing the applicability of the designed membrane for microfiltration.

The analysis of correlations between the quality indicators of water resources is carried out for the Dnipro River representing a strategic water resource of Ukraine as an example. The studies show an increase in the concentrations of contaminants, such as ammonium ions, nitrates, nitrites, and chlorides due to excessive water discharge and climate changes. In particular, significant distinctions in the dynamics of water quality indicators on the left and right banks of the Kremenchuk Reservoir are observed to evidence a nonuniform character of load on the water resources. The objective of this study is to determine the effect of climate changes and anthropogenic load on the quality indicators of surface water in the Kremenchuk Reservoir. Mathematic modeling by means of regression analysis, statistical data processing, and analysis of trends in water quality indicators for the period from 2016 to 2024 are performed. It has been revealed that most of the studied indicators do not correspond to the normal distribution law due to a complex effect of climatic and anthropogenic factors. Correlation analysis results evidence that temperature cycle has an essential effect on the organic water parameters and the seasonal character of their change. At the same time, chlorides and dissolved oxygen remain stable and independent of temperature fluctuations. The conclusions of this papers emphasize importance of adaption to European standards, introduction of advanced water treatment methods, and reformation in the water supply and sewage infractructure. A key problem in attaining the sustainable development and European integration goals of Ukraine is to preserve the qualitative state of water resources.

Among the physicochemical and biological methods of water purification from organic and inorganic contaminants, adsorption is the most suitable and advanced technique due to the high removal efficiency, easy operation, economic availability, and reusability of adsorbents. The removal of organic contaminants from water sources can be improved by using appropriate target adsorbents. Currently, much attention is paid to the production of carbon-containing sorbents from biorenewable raw materials (agro-industrial residues, wood processing products, wastes from various industries). The structural and sorption properties of fruitstone activated carbon from apricot kernels (FAC) and its modified sample obtained by impregnation with iron salts (Fe-FAC) have been studied. It has been shown that FAC modification leads to an increase in the total specific surface area, the surface of meso- and micropores, and the volume of pores. An increase in the static cation- and anion-exchange capacities was observed. The adsorption of p-chloroaniline, p-nitroaniline, and m-nitroaniline was studied under steady-state conditions at temperatures of 5, 20, and 40°C. In all the cases, adsorption is better on the modified adsorbent. The obtained results were described by the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models. Thermal studies allowed us to calculate thermodynamic parameters, such as the Gibbs free energy change and process enthalpy and entropy. It has been revealed that the adsorption of the studied compounds occurs as a spontaneous exothermal process.

The adoption of water-saving technologies in dairy industry facilities has created a challenge in effectively treating their high-strength wastewater. One approach to addressing this issue involves the implementation of integrated treatment technologies. This study aimed to identify the most effective wastewater pretreatment solutions for discharge into municipal sewer systems or natural water bodies. We analyzed current methods and technologies for treating high-strength effluents generated by dairy plants, proposed, and experimentally validated the performance of a custom-designed aeration-settling tank with increased hydraulic height and jet aeration for use at dairy wastewater treatment facilities. For high-strength effluents with chemical oxygen demand (COD) values ranging from 2000 to 5000 mg/dm³, where discharge into municipal sewer systems is intended, the proposed technology and proprietary infrastructure proved suitable. These include flotation-settling tanks and aeration-settling tanks with increased hydraulic height (6–10 m) equipped with surface jet aeration. When discharging into natural water bodies, a two-stage biological treatment process is necessary, utilizing the same aeration tank configuration followed by post-treatment through polystyrene-based filtration systems. Field testing of the proposed system demonstrated its capacity to increase the concentration of activated sludge in the aeration zone to 5–6 g/dm³ and to efficiently separate sludge mixtures. This results in high oxidative capacity of the treatment infrastructure, with COD removal rates reaching up to 2200 g/(m³ day), and enables effective nitrogen compound removal via simultaneous biological nitrification−denitrification. This is achieved by forming an aerobic zone in the upper part and an anoxic (anaerobic) zone in the lower part of the unit. The authors also investigated the flocculating and disinfecting properties of polyhexamethylene guanidine salts, confirming their applicability at various stages of wastewater treatment. These compounds neutralize potentially harmful microorganisms, promote the sedimentation of suspended solids, and eliminate residual odors and coloration. Based on these findings, the authors propose a treatment technology for high-strength dairy wastewater (COD 2000–5000 mg/dm³) that combines physical and biological methods. This integrated approach ensures efficient treatment before discharge into either municipal sewer systems or open water bodies.

Anthropogenic pressure alters the hydrochemical regime of surface water sources, thereby degrading water quality and limiting its suitability for aquaculture. This issue underscores the critical need for continuous monitoring and comprehensive environmental assessment of surface water quality in aquaculture contexts. The present study aims to evaluate seasonal fluctuations—during spring and autumn—in the water quality index (WQI) of surface water sources within the Mohyliv-Podilskyi district of Vinnytsia oblast. The analysis focuses on the Kotlubaivka River basin, a left-bank tributary of the Dniester River, and the Dniester River itself, both upstream and downstream of the municipal wastewater treatment facilities operated by the municipal enterprise “Vodokanal” utility (Mohyliv-Podilskyi). This region exemplifies areas vulnerable to surface water contamination due to intensive agricultural practices, affecting rivers and ponds that are otherwise suitable for fish farming. The WQI was determined based on analytical measurements of hydrochemical parameters, including dissolved oxygen, pH, total (bicarbonate) alkalinity, total mineralization, nitrate concentration, and ammonium nitrogen. During the spring season, water samples from all five sampling points exhibited WQI values corresponding to the Good category. In contrast, in the autumn season, the water sample from Kotlubaivka River fell under the Satisfactory category, while the remaining samples remained Good. These findings indicate that spatial and seasonal variability in hydrochemical parameters significantly constrains the suitability of aquatic environments for aquacultural use.

The purpose of this study is to perform a comprehensive radioecological assessment of Okchuchay and Basitchay rivers in Zangilan region of Azerbaijan. The main objective of the article and research is to assess the level of radioactive contamination, as well as the amount of heavy metal pollutants and organochlorine pesticides in water, sediment and soil samples taken from these major transboundary rivers, which are important for agriculture and drinking water. Samples were taken from six zones of Zangilan region. Laboratory analyzes were performed using gamma spectrometry for radionuclides, atomic absorption spectrometry for heavy metals, and gas chromatography for pesticide residues. The study used rigorous sampling and analytical procedures to ensure accurate and reliable data. Additionally, the parameters of the water samples collected were measured using appropriate devices, and all the results are presented in tables. This study highlights the urgent need for effective environmental management and restoration strategies to address pollution in the Okchuchay and Basitchay basins. Urgent measures must be taken to reduce pollution and protect the health of ecosystems and local populations that depend on these water resources. It is important to implement complex monitoring and remediation programs for sustainable environmental management in Zangilan region.

Photocatalysts are emerging as promising materials for various photolytic chemical reactions for the applications ranging from fuel generation to pollutant degradation. In this study, we synthesized ZnO and Ti doped ZnO (Ti:ZnO) nanoparticles using sol-gel method with 2–12.8 at % in ZnO. The chemical composition and optical response of the nanoparticles were studied using energy dispersive spectroscopy (EDS) and diffuse reflectance spectroscopy (DRS) respectively. The morphological and crystalline properties of the nanoparticles were characterised using high resolution scanning electron microscopy (HRSEM) and X-ray diffraction (XRD) respectively. The role of Ti doping on crystallinity, photocatalytic response and anti-microbial activity is addressed. Using ZnO nanoparticles, degradation rate constant of Methylene Blue (MB) about 4.6 × 10^–2 min^–1 occurred which was found to increase by 20% for 12.8% Ti in Ti:ZnO photocatalyst. For other Ti dopant concentrations, the degradation rate constant decreased due to lower crystallite size with higher grain boundaries leading to charge carrier recombination and suppressed formation of reactive oxygen species. By addition of varying concentration of isopropyl alcohol, the suppressed degradation process revealed the role of hydroxyl radicals in this low power UV light assisted photocatalysis. This was further confirmed with controlled experiments through generation of photoluminescence in terephthalic acid induced by the hydroxyl radicals. Ti:ZnO nanoparticles also showed significant anti-bacterial activity towards the Gram-positive (Staphylococcus aureus, Streptococcus mutans) and Gram-negative (Pseudomonas aeruginosa, Klebsella pneumonia) organisms. In addition, these nanoparticles also showed remarkable activity against fungi Candida albicans and Aspergillus flavus due to their greater surface area leading to generation of hydrogen peroxide. This study reveals the role of grain size in dye degradation process and anti-bacterial activity. The Ti:ZnO nanoparticles obtained using a simple and scalable synthesis route are highly efficient photocatalyst material and anti-microbial agent for application of waste water treatment in industrial effluents and bacterial killing.

The escalating presence of harmful dyes in industrial wastewater is a critical issue, with textiles, food, paper, and pharmaceutical industries identified major contributors. This study enhances the adsorption capabilities of Mg/Fe layered double hydroxide (LDH), a recognized adsorbent, by incorporating jute charcoal. Resulting hybrid, created with a 3 : 1 Mg/Fe molar ratio using co-precipitation, proves more efficient in removing Methylene Blue (MB) dye than pristine Mg/Fe LDH. Described by the Freundlich model, the hybrid displays a higher K value (0.87) than Mg/Fe LDH (0.13), indicating enhanced adsorption capacity. The pseudo-second-order kinetic model identifies chemisorption as the rate-determining step. Across temperatures (10 to 60°C), equilibrium MB removal reaches 343–454 µmol/g (Mg/Fe LDH) and 528–666 µmol/g (hybrid Mg/Fe LDH). The activation energy is significantly lower for the hybrid (18.63 kJ/mol) than Mg/Fe LDH (111.33 kJ/mol), signaling a favorable process. The hybrid’s efficacy in MB removal is attributed to π–π interactions, cation–π interactions, H-bonding, and electrostatic forces. Spontaneous adsorption is confirmed by negative ∆G° values (–5.5 to –9.69 kJ/mol for Mg/Fe LDH and –4.7 to –5.5 kJ/mol for the hybrid), exothermic reactions (∆H° values –5.5, –8.5 kJ/mol), and increased disorderliness (∆S° values 7.39, 11.71 kJ/molK), underscoring the hybrid’s potential in combating textile pollution.

Constructed wetlands are engineered systems, constructed and designed to employ the natural functions of emerging macrophytes, soils, and microbial populations to remove multiple contaminants from raw wastewater to reduce environmental deterioration and increase water availability by improving the wastewater quality. To practically develop artificial wetlands in Algeria and especially in the Saharan zone with an arid climate, locally available macrophyte species (Phragmites australis and Acacia) were tested. To evaluate the treatment efficiency of each macrophyte and especially Acacia in this arid region compared to the control, the experiments were carried out for 3 months (February, March, and April) with measurements taken at the beginning of each month for untreated water and every 10 days for treated water. Therefore, the main objective of this review article is to judge the performance of two aquatic plants (Phragmites australis and Acacia) regarding the domestic wastewater pollutants removal under arid climate conditions. It was found in the work that the wastewater treatment efficacy of the two aquatic macrophytes was very remarkable. The overall results show that the pH values recorded before and after treatment are lower than the limit values of Algerian discharge standards and the World Health Organization (WHO) standards (8.5). The electrical conductivity (EC) values recorded in treated water strongly exceed those before treatment. The bed grown with Phragmite australis achieves the highest oxygen concentration (4.29 mg/L) as compared to the Acacia filter (1.97 mg/L) and even to raw wastewater (1.28 mg/L). Obtained findings also indicated that Phragmites australis donated the upmost achieving the highest removal rate for biological oxygen demand (BOD₅) (97%). Additionally, it showed superior removal efficiency for total nitrogen (TN) (89%) and total phosphorus (TP) (99.65%) in domestic wastewater samples, compared to the Acacia plant, which exhibited removal rates of 95.26, 96.79, 87.7, and 99.38% for the same parameters, respectively. The unplanted bed (no plants), on the other hand, showed lower removal efficiencies of 91.58, 95.46, 72.60, and 95.50% for the same parameters, respectively. The higher performance in removing TN after wastewater treatment may be due to the absorption of nitrates (({text{NO}}_{3}^{ - })) and ammonium (({text{NH}}_{4}^{ + })) by macrophyte plants for the growth of their tissues. On the other hand, total suspended solids (TSS) removal, the Acacia filter showed the greater removal percentage compared to that found via the Phragmite australis bed and unplanted filter respectively.