Journal of Water Chemistry and Technology最新文献

This review deals with contemporary methods and technologies for the removal of pollutants from natural waters with emphasis on the integration of physicochemical and biological methods with advanced oxidation processes (AOPs). In the introduction, the urgency of this problem is substantiated with consideration for the significant accumulation of organic and inorganic contaminants (ammonium nitrogen, phosphorus, phenols, surfactants, chlorinated organic compounds) as a result of anthropogenic burden on natural waters and insufficient efficiency of traditional treatment technologies. The method implies the comprehensive analysis of conventional approaches (biological and aerated filters, floatation, adsorption) and the empirical evaluation of AOP schemes with UV, O₃, and H₂O₂ with consideration for efficiency, power consumption, and economic viability. Results indicate that optimal combinations, in particular, O₃ + H₂O₂ + UV provide essential disinfection and degradation of persistent pollutants at a lower power consumption as compared to simpler schemes, (e.g., UV + H₂O₂), though require high-power UV sources. Biological methods (based on natural conditions or bioplateau systems) are more environmentally promising and less power consumptive, but slower and depend on pH, temperature, and availability of biogenic chemical elements. The discussion highlights the necessity of using AOPs and biotechnologies for maximum synergetic clean-up effect. Contemporary wastewater treatment technologies are described. In the conclusions, it is pointed out that the future development of treatment systems must be based on the rational combination of physicochemical and biological methods with AOP technologies with consideration for water characteristics, energy efficiency, and economic viability.

The Triund trek near McLeodganj, India, attracts a significant influx of tourists annually. However, the lack of sanitation facilities has led to rampant open defecation at and around the campsite, resulting in fecal contamination of water sources. In the present study, we have used drainage basin classification to identify water sources in the Bhagsunag region that could be a potential sink for the fecal contamination passing through surface runoff from Triund. The analysis shows that Bhagsunag waterfall, the primary water source for the region, is a part of the drainage basin receiving this contaminated runoff, further exacerbating the risk. Water samples collected from the Triund campsite and Bhagsunag area revealed exceptionally high total dissolved solute (TDS) values and elevated conductivity and coliform levels. The snowline water, initially fresh, accumulates fecal matter as it flows downstream, primarily due to open defecation at the campsite. This results in pathogen load in lower-altitude water sources. Water quality index (WQI) values for most samples were >100, making them unfit for consumption or domestic use. To effectively address the contamination issue, implementing Eco-San toilets at the Triund campsite is recommended due to their water-efficient, closed-system design, making them a superior alternative to other options. The findings underscore the urgent need for sanitation infrastructure improvements and policies to mitigate open defecation, which poses a direct threat to both ecological integrity and public health in the Bhagsunag region. Immediate action is critical to prevent further environmental degradation and health hazards in this high-altitude ecosystem.

Heavy metals (HMs) form a distinct group within the vast range of organic and inorganic ecotoxicants. Because of their high solubility, heavy metals can exert mutagenic and toxic effects on all components of the biosphere. Among the most hazardous heavy metals is cobalt. In trace amounts, cobalt is an essential element for humans and animals; however, excessive cobalt intake can cause serious health disorders. Prolonged exposure to cobalt may lead to carcinogenic, teratogenic, or mutagenic effects in living organisms. Developing modern, efficient, and economically feasible methods for removing heavy metals, including cobalt, from contaminated water, therefore, remains a critical and urgent challenge. Adsorption using natural or synthetic, modified or unmodified adsorbents represents one of the most effective approaches for removing heavy metal ions from polluted water. This study examines the adsorptive removal of Co(II) ions from aqueous solutions using Filtrasorb 300 activated carbon premodified with Fe(III) oxide. This adsorbent shows high magnetic sensitivity, enabling a convenient and efficient separation from aqueous media. The study also demonstrates the potential of polymeric complexing agents—water-soluble polyethylenimines—to enhance the efficiency of Co(II) removal. The effects of several adsorption parameters, including pH, initial Co(II) concentration, polyethylenimine (PEI) concentration, and PEI molecular weight, on the adsorption capacity and removal efficiency of Co(II) were investigated. The results show that the extraction of Co(II) by the modified adsorbent depends on the stability and concentration of its complexes with PEI, which are influenced by both the molecular weight and the concentration of PEI in solution. Furthermore, the equilibrium adsorption data were analyzed using the Langmuir and Freundlich isotherm models.

One of the major problems which the world faces today is water scarcity, as every life needs it for their day-to-day activity. Pollution and salinity are the two major causes of most waterbodies being unfit for use. Removing pollutants or salt from water became essential for overcoming the water shortage. Desalination technology is being used to achieve this, but the major disadvantage is its lower production. Applying solar energy and nanofluids may tackle the problem and increase the production. In this work, some physical and chemical parameters, in particular isoelectric point (pH), total dissolved solids (TDS), electric conductivity (EC), chloride (Cl^–), fluoride (F^–), iron(II) (Fe²⁺) content, were studied before and after desalination. Also, the influence of various water nanofluids (WNF) on increasing the output of glass-made double slope solar stills was studied. Physical and chemical parameter analysis revealed a reduction in values after desalination. Single and double-basin glass solar stills of 0.81 m² basin area were fabricated, and the experiments were conducted at Kovilpatti. The experiments were carried out at a depth of 1 cm with borewell saline water and nanofluids under insulated conditions. A maximum productivity of 4350 mL per 0.81 m²/day (5405 mL/m²/day) was obtained while using Al₂O₃ nanofluid in a double basin glass solar still, which was higher than that obtained using water, SnO₂ and ZnO WNF. This confirms the efficiency of Al₂O₃ aqueous nanofluid, which yielded more distillate than other two nanofluids used.

This study aims to evaluate the current knowledge about the biological effects and the sources responsible for drinking water contamination in Khyber Pakhtunkhwa (KP), Pakistan. For this purpose, this review article has summarized data extracted from various national and international journals and relevant reports published by government and non-governmental organizations. The KP province faces water pollution as a major public health problem. This review shows a detailed layout of the water quality with special emphasis on major pollutants, pollution sources, and their impacts on public health. The study revealed that drinking water sources in KP province are highly polluted with microbes and heavy metals. The physicochemical parameters were noted above the World Health Organization’s permissible limits. The trend of toxic metals has been reported as Fe > Ni > Pb > Cd > Cr in the drinking water of KP. An overview of relevant reports and published articles reported the presence of Coliform bacteria (CB) in the drinking water of Peshawar (1740 MPN/100), Abbottabad (2–600 MPN/100), Nowshera (2–1800 MPN/100), Charsadda (5–1600 MPN/100), Swabi (21 MPN/100), and the Northern Areas (38 MPN/100). The study highlighted those key sources responsible for water contamination are anthropogenic activities such as improper waste handling and agricultural inputs. Various health problems, such as diarrhea, dysentery, other gastrointestinal problems, and skin diseases, have been reported due to waterborne diseases. To shrink the risk of waterborne diseases, it is important to enhance the monitoring and sustainable techniques for the effective management of water resources.

Metal oxide impregnated activated carbon (IAC) has good affinity for heavy metals present in water. Zinc/copper impregnation by imbibing method was executed for the purpose of optimum tailoring of activated carbon (AC) for water purification purposes. Calcination of these samples was carried out to convert metals into their respective oxides in an inert atmosphere using a tube furnace. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The results helped to explore metal loading, metal dispersion and the final metal form onto AC. The surface area available for incoming metals was studied by Brunauer−Emmett−Teller (BET) theory. Heavy metal ions were analyzed using inductively coupled plasma atomic emission spectrometry (ICP-AES) and studied by applying adsorption models, a variety of isotherms and altering various conditions. The system was feasible, spontaneous, had a major chemisorption mechanism and was overall endothermic. Adsorption studies make it clear that dual metals impregnation helped in maximizing active sites as compared to the same concentration of single metal. Weber and Morris model was used to find that intra particle diffusion and film diffusion, both processes occur during adsorption while Boyd model confirmed that film diffusion was rate determining phenomenon. 0.33 mmol/g of each zinc and copper IAC showed 96% removal efficiency of chromium(VI) and 98% for lead(II) at 30°C for 10 mg/L concentration, pH 3 and a dose of 4 g/L. Hence, imbibed AC is efficient, safe and economical adsorbent for water purification.

Inorganic membrane was prepared from local raw materials using slip casting technique. Characterizations of prepared tubular samples have been made by mercury inclusion porosimetry (MIP), scanning electron microscopy (SEM), UV-visible spectrometer, water permeability plant and stream potential measurements. The obtained values are mean pores radius (10 nm), water permeability (1000 L m^–2 h^–1 MPa^–1) and stream potential (–52 mV); these values clearly indicate the possibility of using this inorganic membrane in microfiltration, ultrafiltration and/or pre-nanofiltration processes. Results from filtration operation applied to chromium (Cr(III)) contaminated water: retention R(%) = 82% and estimated surface charge –66.7 mC m⁻² show the important capacity of membrane to separate chromium ions from contaminated waters. Donnan equilibrium mechanism between membrane surface charge and solute ions has been proposed to explain the selective rejection behaviour of ions by inorganic membrane.

The present work focuses on the treatment of model wastewater that simulates industrial pharmaceutical effluent. Paracetamol (PCT) is the most widely consumed medicine, particularly during the fight against the Corona virus disease-2019 (COVID-19) pandemic and is therefore one of the most persistent contaminants in aquatic ecosystems. In this study, the degradation of PCT was investigated using the conventional homogeneous Fenton reaction (H₂O₂/Fe²⁺) in a batch reactor operating at an ambient temperature with a degradation time of 60 min. The effectiveness of the treatment was assessed by monitoring the removal of total organic carbon (TOC). The study investigated the effect of the key process variables: A: pH, B: [H₂O₂]/[PCT], and C: [H₂O₂]/[Fe²⁺]. The influence of these variables was systematically examined utilizing a Box−Behnken design (BBD) with a 3-level 3-factor configuration and response surface methodology. The analysis of variance (ANOVA) for TOC removal efficiency by BBD model shows that the model is significant. The model F-value is 41.71 and the p-value is 0.0004. The model was fit with an R² of 0.9869 and an adjusted R² of 0.9632. The ideal process conditions were determined as pH = 3, [H₂O₂]/[PCT] = 15, [H₂O₂]/[Fe²⁺] = 16, with a TOC elimination rate of 33.40%. The results show how to make the Fenton process work better and how to get rid of PCT more efficiently. This research could lead to new ways to treat wastewater and clean up the environment.

In classical chemistry, a chemical bond arises from the distribution of electron density between atoms. However, quantum-mechanical models suggest that vibrational states of nuclei also play an active role in forming stable structures. Atomic nuclei in a molecule undergo quantum oscillations within potential wells shaped by the electron cloud and neighboring nuclei. These oscillations exhibit characteristic frequencies that depend on the nuclear mass and the form of the potential, as well as a spatiotemporal structure expressed through vibrational wave functions. When two or more nuclei in a system possess similar or commensurate vibrational frequencies, resonance interaction between them can emerge. This resonance may increase coherence time, minimize the energy of the vibrational subsystem, and induce effective interactions without electron participation. In a water molecule, nuclear coherence plays a key role in enhancing the stability of its geometry. This property of the water molecule becomes especially significant under conditions of strong ionization, when electrons are almost absent and classical orbital models lose applicability. In high-temperature environments, water maintains structural integrity through harmonic nuclear oscillations with phase coherence. In biomolecular systems, water provides the background of coherent vibrations that sustain the stability of complex biochemical structures. Thus, the water molecule serves as a universal model that demonstrates the action of the nuclear vibrational resonance mechanism as one of the fundamental principles of chemical bonding. Water not only preserves coherence under the destabilization of electron clouds but also gives a platform for energetic interactions between molecules.