Journal of Water Chemistry and Technology最新文献

To investigate the hydrochemical properties, influencing factors, and travertine deposition potential of the Springs and the Secondary Conversion Springs in the Huanglong Scenic Area, 14 surface water samples were gathered from two aquifers. The composition and controlling factors of hydrochemical elements in the region’s surface water were analysed using statistical methods, Pearson correlation, Piper diagrams, Gibbs diagrams, ion ratio analysis, and principal component analysis. The findings are as follows: (1) The dominant hydrochemical classification in the region is ({text{HCO}}_{3}^{ - })–Ca²⁺. (2) The Springs exhibit significant spatial variability in hydrochemical traits, heavily influenced by factors such as temperature, aquifer materials, and terrain. In contrast, the Secondary Conversion Springs are less impacted by these variables. (3) The hydrochemical composition of the Springs and the Secondary Conversion Springs in July and September remained stable over time, primarily influenced by a single factor—water−rock interaction. The hydrochemical profile was mainly governed by the dissolution of carbonate rocks, with minor contributions from halite and gypsum dissolution. (4) The Springs in the study area are characterised by high ({{P}_{{{text{C}}{{{text{O}}}_{{text{2}}}}}}}), high ({text{HCO}}_{3}^{ - }) and high Ca²⁺, concentrations, providing the main sources of calcium and carbon for travertine deposition in the Secondary Conversion Springs, and the deposition capacity of travertine is mainly affected by Ca²⁺, ({text{HCO}}_{3}^{ - }), ({{P}_{{{text{C}}{{{text{O}}}_{{text{2}}}}}}}) and pH.

The present study investigates the degradation of tetracycline (TCH), amoxicillin (AMX), and diclofenac sodium (DCF) under ultraviolet (UV) and visible light conditions using TiO₂ and two composite nanofibers, PAN-MWCNT/TiO₂−NH₂ and PAN-MWCNT/TiO₂, as photocatalysts. The nanofiber catalysts were prepared by the force-spinning method and characterised by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). Maximum degradation percentage was achieved by optimising various parameters, in particular feed pH (3–11), concentration of feed (50–100 mg/L), and dosing of the catalyst (0.5–1.5 g/L). TiO₂-based nanofiber adjusts the band gap and increase its capability to absorb UV and visible light selectively. The effectiveness of AMX, TCH, and DCF (50 mg/L) degradation was investigated using UV and solar radiation with various photocatalysts (1 g/L) at pH 3 for AMX and DCF and pH 11 for TCH. This study revealed that PAN-MWCNT/TiO₂ was the most efficient catalyst under UV radiation, which showed the maximum degradation percentage of the pollutants, i.e., 97% for AMX, 95% for TCH, and 91% for DCF in 90 min, whereas PAN-MWCNT/TiO₂–NH₂ was highly effective in visible light and resulted in 64% for AMX, 72% for TCH, and 67% for DCF degradation in 6 h. Chemical oxygen demand (COD) analysis was performed before and after the degradation process. 70–80% COD removal efficiencies suggested partial oxidation of the pollutants (AMX/TCH/DCF). To spot the intermediate compounds produced during the degradation process, Liquid chromatography-mass spectrometry (LC-MS) analysis was also performed.

The synthesis of biohybrids is a fascinating field of study at the node of materials engineering and bioscience involving combining functional materials with biological entities. Tailoring the physicochemical properties of nanomaterials in conjunction with biological systems has been made easy by developments in novel material design and processing technologies. Because biohybrids have more active sites and a larger surface area than polycrystalline materials, they demonstrate better catalytic activity. Thus, employing microbes in nanomaterials can offer a fresh method for decontaminating and treating wastewater. Various nanomaterials have been incorporated into biological systems up to this point, ranging from essential enzymes to complex multicellular species. Here, we offer a critical review of current advancements in biohybrids, which open up new or enhanced biological applications that can potentially treat wastewater. These enticing biohybrids explore the most recent developments of integrated biotechnology and nanotechnology that may work together to transform wastewater management. An overview of the possible uses of different biohybrids in various water treatments is given in this review. Consequently, this review has also recognized and examined the drawbacks and difficulties of using biohybrids. The information presented in this review offers fresh perspectives and opportunities for further study and advancement to increase the applicability of biohybrids.

A structural model of water–oil–coal emulsions (WOCEs) based on large spherical anthracite particles dispersed in a matrix phase composed of small spherical anthracite particles, oil, industrial waste water, and an emulsifier is proposed. The model provides the calculation of average coordination numbers for both large and small particles along with the interparticle distance by using the specified or calculated coordination numbers. This makes it possible to optimize the process of achieving desirable properties, in particular, with waste water to promote more efficient utilization for water–oil–coal emulsions in the power production sector. The utilization of water–oil–coal emulsions contributes to rational resource management, reduces environment pollution, and provides a comprehensive solution for industrial wastewater disposal. Due to stable combustion within a broad range of temperatures and a high calorific value, such systems essentially reduce the thermal power production expenditures. The cost of heat production by WOCE combustion per 1 Gcal is twice lower as compared to traditional fossil fuels, so its utilization becomes economically reasonable and promising for power production industry.

This study justifies the use of biotesting methods to assess the level of toxicity in aquatic environments contaminated with pharmaceutical substances (PSs) of various origins, including diclofenac, streptocide, and paracetamol. To determine overall toxicity, we used Daphnia magna, a cladoceran crustacean, and Brachydanio rerio, a representative vertebrate aquatic organism. To assess cytotoxicity, the blood cells of zebrafish were tested. The biotesting results showed that the tested pharmaceuticals exerted varying degrees of toxicity on aquatic organisms, depending on their concentration in the water, and caused pathological changes in fish blood cells. Aqueous solutions of the pharmaceuticals at concentrations from 0.1 to 10.0 mg/dm³ caused acute toxic effects in Daphnia and chronic toxic effects in fish. In addition, cytotoxicity in the blood cells of Brachydanio rerio was detected after 10 days of exposure to the studied compounds, well before the onset of mortality in the test organisms. According to the European Directive EC 93/67/EEC, these effects correspond to “very toxic,” “toxic,” and “harmful” classifications for aquatic life. These findings indicate negative trends in the ecological status of natural water bodies that are continuously polluted by pharmaceuticals and their metabolites. Excessive contamination may lead to irreversible degradation of aquatic ecosystems.

The widespread application of pharmaceutically active compounds all over the world and the imperfection of traditional water treatment technologies lead to the appearance of these preparations and their metabolites in purified waste and surface waters. Contemporary advanced oxidation processes (AOPs) based on the generation of powerful OH radicals from environmentally friendly oxidants (O₂, O₃, H₂О₂) under UV radiation and the application of titania as a photocatalyst are able to provide the complete destruction of many ecotoxicants to CО₂, H₂О, and inorganic ions, i.e., their mineralization. A promising trend in expanding the capabilities of heterogeneous AOPs is the use of titania, which is deposited (immobilized) on solid supports to avoid the terminal nanosized powder separation stage. The kinetics of photocatalytic and heterogeneous photocatalytic destruction with hydrogen peroxide has been studied for popular cheap drugs, such as aspirin, salicylic acid, and analgin, in an aqueous medium in a reactor with TiО₂ immobilized on a large-pore ceramic support under UV-C irradiation. It has been shown that the Н₂О₂/TіО₂/UV photocatalytic system is able to provide the almost complete (96–100%) primary destruction of salicylic acid and aspirin (C₀ = 0.2 mM) and analgin (C₀ = 0.1 mM) at a maximum degree of mineralization of 85, 84, and 71%, respectively, for 3 h at an oxidant utilization rate ≥90%. The direct photolysis of all three preparations for 3 h has led their molecules only to slight initial transformation (≤41% according to spectrophotometric data) accompanied by a low degree of mineralization (≤6%).

Extracellular polymers (EPS) are critical for microbial metabolism in wastewater biological treatment processes. This study examined the impact of bisphenol A (BPA) on microbial EPS within a biological denitrification system. Results indicated that low concentrations of BPA (0.1, 0.5, and 1.0 mg/L) had minimal effects on denitrification performance. In contrast, high concentrations (3.0 and 5.0 mg/L) significantly impaired denitrification. As the concentration of BPA increased, tyrosine-like proteins content in loosely bound EPS (LB-EPS) increased while tryptophan-like proteins and humic acids content decreased. The C–(C,H) content in LB-EPS initially increased and then decreased, whereas the C–(O,N) content continuously increased. Conversely, in tightly bound EPS (TB-EPS), tyrosine and tryptophan-like proteins content decreased while humic acids content increased. The C–(C,H) content in TB-EPS continuously increased, whereas the C–(O,N) content initially increased and then decreased. The C–O–C and C=O peaks of polysaccharides and carboxylates in both LB-EPS and TB-EPS shifted, whereas the peaks corresponding to protein peptide bonds remained unchanged. BPA primarily binds to C–(C,H) and C–(O,N) components in EPS.

Wastewater treatment is an important option to reclaim treated water for countries that are facing water shortages. The availability of technical and financial factors influences the selection of treatment technology. Therefore, it is very important to choose the best-fit technology for the treatment of wastewater. The objective of this investigation was to optimize the anaerobic digestion for the treatment of slaughterhouse wastewater and to evaluate the bioenergy production potential, and chemical oxygen demand (COD) removal efficiency of residual matter. The anaerobic digestion setup was combined with the electro-coagulation technique to enhance the process optimization and recovery of bioenergy from waste. The performance of the lab scale anaerobic digester was evaluated under mesophilic environmental conditions (29 ± 1.40°C). Experimentation showed the COD removal efficiencies and methane yield of lab scale treatment system in the ranges of 58.92 to 94.54% with the maximum volumetric production of 0.158 ± 0.17 m³/day. The proposed system is efficient enough to cater not only to the high-strength slaughter-house wastewater, but it will also act as a source of generating bioenergy. Consequently, combined processes are inferred to be superior to individual techniques, for the removal of both organic and inorganic compounds from slaughterhouse wastewater.

Groundwater has been depleted much faster in recent decades due to anthropogenic activities. Many pollutants enter water bodies through domestic sewage and industrial wastewater, lowering water quality. The health risks associated with water quality are critical for long-term water management in coastal regions of India. This study analyzed groundwater quality, seawater intrusion, hydrogeochemical processes (Piper trilinear graph and Gibbs plot), and statistical data in Tiruvallur district, Tamil Nadu, India. Water quality data were collected at 58 sampling stations. The water quality index (WQI) results showed that water in 12 stations was unsuitable for drinking. 20 stations exhibited poor water quality, while 20 were very poor. The extent of seawater intrusion into the study area was calculated using the seawater mixing index (SMI), and the results indicated that only one station had an SMI value of >1. A human health risk assessment (HHRA) was performed based on the nitrate and fluoride concentrations. The results showed that 39.65% of stations posed nitrate risks to children, while 20.68% posed risks to adults. By comparison, fluoride-related risks affect 34.48% of the stations in children, but only one station in adults.