Cleaner Water最新文献

The study employs remote sensing and GIS techniques to assess the water quality dynamics of Mirik Lake, located in the Darjeeling Himalayas, West Bengal, India. To analyse the impact of land use and land cover (LULC) changes on the water quality of Mirik Lake from 1993 to 2023. Landsat imagery spanning from 1993 to 2023 was used to detect significant alterations in LULC patterns. Remote sensing and GIS techniques were utilised to analyse the data, focusing on changes in LULC and their implications for water quality. The results indicate a steady increase in total phosphorus (TP), total nitrogen (TN), and Biological Oxygen Demand (BOD) levels, attributed to anthropogenic activities such as urbanisation and tourism development. LULC change analysis highlights the expanding built-up areas and agricultural lands surrounding the lake, contributing to nutrient loading and organic pollution. The spatial distribution of pollution categories underscores the influence of tourist infrastructure on water quality degradation. Integrated watershed management and sustainable development strategies are recommended to mitigate anthropogenic impacts and preserve the ecological integrity of Mirik Lake.

This paper reveals a green chemistry approach to remove arsenic (As⁺³) from water using potassium hydroxide (KOH) modified sewage sludge-derived biochar (SSDB-KOH). Characterisation of the morphology, particle size and composition of the SSDB-KOH pre- and post-adsorption confirmed porous and heterogenous surface favouring adsorption. At ambient temperature (20 °C), the SSDB-KOH dose of 20 g/l achieved 98 % arsenite removal at nearly neutral solution pH (8). This compared favourably with pristine SSDB, where the performance was limited to 41.6 % removal. The enhanced arsenite adsorption of SSDB-KOH was informed by several mechanisms, including ionic interactions, pore filling and metal-pi interactions. The experimental data fits closely with the Langmuir isotherm and pseudo-second-order kinetic models, revealing monolayer adsorption and the chemical interaction between adsorbents and the adsorbate. The spontaneous and endothermic nature of the process was confirmed by the negative value of ΔG and the positive value of ΔH, respectively. The performance of the biochar was evaluated for four-cycle regeneration. Finally, a cost analysis was performed to demonstrate the economic feasibility of using SSDB-KOH to remove arsenic from water.

Antimicrobial resistance (AMR) stands as a critical threat to global public health. Wastewater-based epidemiology (WBE) provides health data within communities via sewage analysis. This study delved into antibiotic resistance prevalence across two sewersheds in Belo Horizonte, each with distinct health vulnerability indexes (HVI) and number of hospitals. Bacteria resistant (ARB) to amoxicillin, azithromycin, cephalexin, sulfamethoxazole + trimethoprim, meropenem and ARGs (Intl1, sul1, blaTEM, blaKPC) were quantified in sewage from the two sewersheds over the years from 2020 to 2023. Statistical analysis revealed no significant differences in median concentrations of ARBs between sewersheds, except for bacteria resistant to meropenem. ARGs Investigated exhibited similar patterns, with blaKPC showing statistical significant difference. This suggests that hospital density within a sewershed exerts a more pronounced influence on AMR dissemination than HVI. The difference found in meropenem-resistant bacteria, a hospital-prescribed carbapenem, and blaKPC concentrations underscores the impact of hospital antibiotic usage. Thus, the presence and number of hospitals emerges as a pivotal factor in AMR spread, emphasizing the need for specific treatment and management of hospital wastewater to curb antimicrobial resistance.

The world is facing an alarming situation in terms of pollution, with water contamination being a critical concern for scientists aiming to protect the ecosystem. Contaminants produced from municipal, industrial, commercial, and agricultural processes, along with domestic activities, pose serious threats to aquatic life and human welfare. Addressing these pollutants requires serious attention. Various physical, chemical, and biological approaches are used for water purification, each showing different levels of efficacy. Recent advancements in wastewater treatment techniques, such as Non-Thermal Plasma Discharge, Genetic Engineering, Nanotechnology, CRISPR-Cas9, Elimination of Emerging Organic Pollutants (EOPs), and the use of durable substrates with Metal-Organic Frameworks (MOFs) and covalent organic frameworks, have shown promising results. For example, Nanotechnology has demonstrated a removal efficiency of up to 95% for heavy metals, while MOFs have achieved over 90% efficiency in organic pollutant degradation. The effectiveness of these techniques varies depending on the pollutant type and environmental factors. Consequently, selecting the appropriate method is crucial for achieving better and cost-effective outcomes in water treatment.

Around 30 % of the world’s population lacks access to safe water despite being a critical factor that modulates the complex dynamics of ecosystems and societies. Efficient technologies to purify water to potable form are either inaccessible or economically not viable for the majority. Water poverty and scarcity can be potentially exacerbated by the recent, widespread detection of plastics in drinking water sources, tap water and groundwater. This can induce various emerging bottle necks in global drinking water quality management. One of the most affordable disinfection techniques practiced across the world is to boil the water. Plastic pollutants in potable water sources can pose emerging water quality management bottlenecks, including leaching additives and chemicals due to water boiling. Exposure to plastic leachates in drinking water can lead to potential health risks, including oxidative stress, cancers, endocrine disruption, cardiovascular diseases, and developmental effects. The current global drinking water scenario and the emerging impacts of plastic pollutants specifically micro- and nano-plastics in drinking water, are also enlisted. Further, evidence-based prospects for drinking water quality management and impacts on one health initiative in the wake of the presence of plastics are discussed. Monitoring and surveillance, improved water treatment, and infrastructure incorporating technological innovations explicitly focusing on plastic pollutants in drinking water can ensure sustainable management and mitigation of the ill effects to a satisfactory extent. The need for firm policy instruments, partnerships between various private and public stakeholders, and the judicious use and management of potable water are contented in this article, which will steer humanity and the earth system toward achieving one health mandate and a sustainable future.

Public health and the aquatic environment face significant threats from pollution originating from pharmaceutical wastewater (PhWW) containing stubborn antibiotics. Conventional treatment methods fail to fully eradicate these antibiotics and other contaminants ^{such as COD and BOD}₅ due to the complex organic compound mixtures present in PhWW. Additionally, PhWW exhibits low biodegradability and high toxicity, mainly due to the persistence of antibiotics. This pressing issue has prompted the scientific community to seek more effective and cost-efficient treatment solutions for detoxifying PhWW. Hence, this study explores the catalytic efficiency of zeolite 5 Å (Z5Å) coated with cobalt and iron (Z5Å-Co-Fe) for the abatement of one of the most persistent organic pollutants oxytetracycline (OTC) as a target pollutant. The synthesized catalyst is assessed using various analytical techniques such as FTIR, SEM, and EDX analysis. Results show that the heterogeneous catalytic ozonation using cobalt and iron-loaded zeolite (Z5Å-Co-Fe/O₃) achieves OTC removal rates of 8%, 67%, and 95% through adsorption, ozonation (O₃), and Z5Å-Co-Fe/O₃ processes, respectively, ^{at pH 6, 1.6 mg/min of O}₃ ^{flow and 15 min of treatment time}. Moreover, the Z5Å-Co-Fe/O₃ process demonstrates higher cost-effectiveness compared to other methods, and electrical energy per order (EEO) of 1.47 USD and 1.62 kWh per cubic meter of PhWW respectively. Additionally, it enhances the biodegradability of PhWW from 0.30 to 0.51, making it more suitable for further secondary treatment. Furthermore, Z5Å-Co-Fe/O₃ treated PhWW meets National Environmental Quality Standards (NEQS) and holds promise as a pretreatment option for industrial-scale conventional treatment systems. Therefore, it is concluded that the Z5Å-Co-Fe/O₃ process was found to be highly efficient for the degradation of OTC in real PhWW matrix and it may help to achieve UN sustainable development goals (SDGs)

Context

Because of the complexity of soil water distribution, accurate prediction of wetting pattern is not easily accessible and this has led to a inefficiency in some proposed models in the literature. These models do not consider the hydraulic characteristics of the irrigation system and are developed solely on the basis of the water volume or infiltration rate, soil hydrodynamic properties, and other conditions of the percolation environment.

Objective

Due to the importance of the estimation of wetting front beneath Subsurface Drip Irrigation (SDI) laterals, a semi-empirical model using easily accessible data of the SDI system is proposed to predict the wetting patterns in both distribution and redistribution phases. The aforementioned model has been developed based on a novel approach that couples the governing equations of the lateral hydraulics with empirical equations derived by dimensional analysis.

Methods

To develop the model and evaluate its performance, three 16-mm drip line pipes with 0.2, 0.4, and 0.5 m emitter spacing, and 2–5 l/h discharge were placed at 0.20 m depth in a soil box filled with clay loam soil. Water was applied for 3 hours at 50, 100, and 150 kPa operating pressures, and the wetting patterns’ geometries were measured in each lateral after 1, 2, 3, and 24 h. The performance of the model was then assessed and compared with that of three other models.

Results and conclusion

The result demonstrated that the proposed model provides the most accurate estimations of the wetting depths and widths. RMSE and MAE statistical indexes of the wetting depth were 0.001–0.002 m and 0.004–0.009 m, respectively, whereas those associated with the wetting width were 0.001–0.003 m and 0.005–0.016 m, respectively. These values resulted in the lowest error when compared with the corresponding obtained from other well-known models. Consequently, the model allows acceptable predictions of the wetting patterns using accessible hydraulic parameters of the SDI system.

Significance

Uniquely, the results of the lateral hydraulic analysis were applied to determine the wetting front dimensions in this study. Also, the results demonstrated that the model was successful in wetting pattern prediction beneath the lateral as a line source. While other models usually are used to estimate the wetting front around a point source.

Environmental sustainability has gained acceptance to achieving the goal of a secure ecosystem with a reliable management system. Heavy metal remediation of aqueous streams is of special concern due to the intractability and persistence in the environment. Adsorption is a potential alternative to the existing inefficient conventional technologies for the removal and recovery of metal ions from aqueous solutions and becomes vital to align with the Sustainable Development Goals (SDGs) and mitigate the adverse environmental and social impacts. Calcium Alginate-Graphene oxide (CA-GO) composite has been synthesized for the adsorption of heavy metals including Cr³⁺, Cu²⁺, and Cd²⁺ ions from tannery effluents. Graphene oxide is prepared from commercial graphite powder and reacted with sodium alginate and calcium chloride to form the beads of CA-GO composite. The developed composite was characterized by FTIR, elemental analysis, SEM, XRD analysis, and Raman spectroscopy. Moreover, the effect of pH, adsorbent dosage, contact time, and initial concentration of metal ions on the adsorption capacity were investigated through batch experiments. At a pH>3.0 (pHzpc), the carboxyl group of CA-GO was deprotonated to make the surface negatively charged and facilitate metal adsorption. The optimum pH and maximum adsorption capacity of CA-GO for removal of Cr(III), Cu(II), and Cd(II) were 4.5, 6.0, and 7.0, and 90.58, 108.57, and 134.77 mg g⁻¹, respectively. The kinetics, adsorption isotherms, and thermodynamics were studied to determine the adsorption mechanism. The kinetic of adsorption adopted the second-order model. Thermodynamic parameter were calculated and the adsorption process was determined to be exothermic and spontaneous at room temperature. The developed composite has been efficaciously applied for the removal of metal ions and pollution from real tannery effluents.

The most dependable source of fresh water is groundwater. Groundwater supplies are severely threatened by a number of factors, including urbanization, industrialization, and population growth. The amount, quality and variables affecting groundwater supplies are significantly impacted by climate variability. The fall in groundwater levels is often exacerbated by poor quality surface water resources and unreliable monsoons. Therefore, in order to supplement the groundwater supply, it is important to locate and define the groundwater potential zone (GPZ). The analysis is conducted for the Khordha district, where groundwater rather is a primary source for agricultural uses. In order to determine the possible groundwater zones, many factors, including geomorphology, geology, elevation, slope, precipitation, soil type, soil texture, drainage density (DD), lineament density (LD), Land use/Land cover (LULC), and lineament density (LD), are constructed as separate layers in the geographical information system (GIS) backdrop. The multi-criteria decision-making technique and the Analytic Hierarchy Process (AHP), which enable pairwise evaluation of criteria impacting the potential zone, were utilized to establish the weights for the different layers and after that, the weighted overlay analysis (WOA) tool in ArcGIS10.8 was used to produce the final groundwater potential map. The output map of specified region was delineated into five new classes-very good, good, moderate, poor, and very poor of which 12% (325.1745 km²) falls under ‘very low’, 22% (603.9765 km²) under ‘low’, 26% (700.7715 km²) under ‘moderate’, 26% (694.2591 km²) under ‘high’, 14% (376.7553 km²) under ‘very high’. Approximately 1395 km² area concerning 52% of study region, falls under ‘high’ and ‘very high’ categories of GPZ. Validation of the generated GPWZ map was done with data acquired from Central groundwater board. The accuracy assessment was done by kappa coefficient error matrix, and based on overall accuracy, the obtained map was 81.538% accurate to field value. As dependable results were produced with the proposed methodology, future management plans incorporating natural and artificial recharge practices can be created in these locations with effectiveness.

Integrated field geological and geophysical (Vertical Electrical Sounding VES and 2D Electrical Resistivity Tomography ERT) investigations were carried out in the Nnewi Industrial Zone, SE Nigeria to identify and characterize productive aquifer, aquifer hydraulic properties, and aquifer vulnerability. Data acquired from 17 VES points and across a profile line of about 800 m for the 2D ERT were processed, interpreted, and modeled. Results from the geologic mapping showed that the outcropping units are mainly the sandstone, shaly-sandstone, and less commonly shale of the Nanka and Ogwashi-Asaba Formations which are relatively permeable and offer poor protective cover to the underlying aquifer. Models from the resistivity data showed that the depth-to and thickness of the aquifer vary from 38.60 to 98.80 m and 30.10–177 m, respectively. Aquifer properties estimated from the geophysical data gave values ranging from 0.611127 m²/day to 246.6576 m²/day and 0.1609 m/day to 5.6325 m/day for transmissivity and hydraulic conductivity, respectively, and suggestive of low – moderate aquifer potential. Aquifer Protective Capacity APC distribution modeled from the longitudinal conductivity values, and the aquifer vulnerability modeled using the DRASTIC method indicate that the study area is characterized by poor – moderate APC and low – moderate – high aquifer vulnerability, respectively. Analysis shows that the modeled aquifer parameters, APC, and aquifer vulnerability have similar trend which tends to improve towards the southern and more specifically southeastern parts of the study area, suggesting that even though aquifer units were identified all through the study area, the southeastern parts are best suited for the development of groundwater exploitation schemes. Also, aquifer vulnerability model results recommend that proper and efficient waste disposal schemes are put in place to conserve groundwater quality from pollution from industrial waste since the aquifer in the area is relatively vulnerable.