Abstract This study provides a comprehensive assessment of surface water quality in the Mexa and Cheffia dams located in the El Tarf region, northeastern Algeria. The work focuses on evaluating pollution levels, organic contamination, and nutrient status using several indices. Sampling was carried out at two different sites over a 12-month period (May 2024 to April 2025). The Water Pollution Index ( WPI ) classified all seasons in both reservoirs as “very highly polluted”, reflecting strong mineralisation and ionic enrichment. The Organic Pollution Index ( OPI ) indicated predominantly high to very high organic pollution, with Cheffia showing 91.7 % high organic pollution and 8.3 % very high organic pollution, and Mexa presenting 100 % high organic pollution. The Nutrient Pollution Index ( NPI ) revealed strong seasonal contrasts, ranging from moderate pollution (0.66-2.47) in summer-autumn to extremely high nutrient enrichment (up to 7.44) in winter and spring. Trophic evaluation based on the TN : TP ratio showed seasonal variability, with 50 % of the observations corresponding to oligotrophic conditions, while the remaining observations exhibited eutrophic to hypertrophic states, especially in Mexa. Overall, the integrated index assessment highlights that both reservoirs are subjected to substantial mineral, organic, and nutrient pressures, with Mexa displaying greater variability and Cheffia showing relatively more stability across indices.
This study investigates the nonlinear effects of socioeconomic, pollution control, and technological innovation factors on seawater pollution using a Generalised Additive Model (GAM) and panel data from 11 Chinese coastal provinces (2018-2023). Key findings indicate: (1) Chemical Oxygen Demand Emissions (CODE) from direct marine discharge sources showed a temporal pattern of "initial increase, subsequent decrease, and gradual stabilisation", with significant spatial heterogeneity - Zhejiang recorded the highest emissions, Tianjin the lowest; (2) GAM revealed significant nonlinear relationships between most variables and CODE; (3) Factor impacts exhibited distinct range-dependent characteristics. These findings provide a scientific basis for identifying key pollution sources and formulating differentiated control strategies, leading to targeted policy recommendations.
Advanced oxidation processes employing sulphate radicals (SO4 circle-) are effective techniques to degrade trace organic pollutants in wastewaters. Herein, SO4 circle- are generated from peroxymonosulphate (PMS) and peroxydisulphate (PDS) via UV-Vis activation for the degradation of Acid blue 129 (AB 129) dye. The activation was performed using four different UV-Vis lamps, TQ-150, HG-Z1, HG-Z2 and HG-Z3, which emit different electromagnetic radiation wavelengths. Degradation of AB 129 was performed at various conditions, including different oxidant concentrations. In order to evaluate the efficiency of the processes, the kinetic rate constant was calculated via a pseudo-first-order kinetics model. In addition, the detailed oxidative degradation pathway of AB 129 induced by SO4 circle- was determined for the first time to the best of our knowledge. Finally, the ECOSAR model indicates that the toxicity of the treated solution of Acid blue 129 initially increases and then decreases across daphnids, fish, and green algae during degradation.
As a result of industrial development, many types of waste are generated, some of which are discharged into water, causing water pollution and having a negative impact on life. The electro-Fenton process (EF) has verified high efficiency in treating pollutants with low cost, ease of handling and operation, and this technology is one of the more efficient advanced oxidation technologies. The main objective of this present work is to explore the efficiency of a three-dimensional Electro-Fenton system (3DEF) in removing eosin, methylene blue, and methylene violet from simulated wastewater using graphite as anode, nickel foam as the cathode, and alum sludge as the third particle and as the source of catalyst. The study investigated the effect of operating parameters such as current density, J, catalyst concentration, and Na2SO4 concentration as supporting electrolyte, at a pH of 3, a temperature of (28 +/- 1) degrees C, an air flow rate of 20 L/h, and a treatment time of 30 minutes. Response surface methodology (RSM) was used to design and analyse experimental data. Based on the results of RSM, the best removal efficiency was achieved at J = 4.2 mA/cm2, [Fe2+] = 0.2 mM, and [Na2SO4] = 0.05 M, where the Re and chemical oxygen demand (COD) removal was 95.76 % and 100 %, respectively. The alum sludge was a very excellent choice as a primary source of Fe catalyst and the 3DEF process is an effective system that can eliminate many types of dyes.
Government environmental audits play a critical role in strengthening ecological governance and supporting China's "dual-carbon" objectives. This study evaluates the pollution control performance of Hebei, Guangdong, and Zhejiang Provinces from 2013 to 2022 through the lens of government environmental auditing. Based on the PSR (Pressure-State-Response) framework, an audit-oriented evaluation index system was constructed and weighted using the analytic hierarchy process (AHP). Grey relational analysis (GRA) was then employed to calculate provincial performance scores and examine temporal trends. The results show that all three provinces exhibit an overall upward trend in pollution prevention and control performance, although with clear regional disparities. Zhejiang performs consistently well, achieving "excellent" ratings after 2020, while Guangdong shows steady improvement with periodic fluctuations. Hebei, despite high investment in pollution-control funding, demonstrates limited progress and remains under the greatest environmental pressure. These findings reveal that environmental governance performance is not strictly proportional to financial input, and that administrative capacity, industrial structure, and policy implementation intensity play decisive roles. The study contributes new comparative evidence on regional differences in the effectiveness of government environmental audits and offers policy implications for enhancing pollution control and achieving low-carbon development goals.
Air Gap Membrane Distillation (AGMD) is an emerging and promising technology in separation processes, but its industrial adoption is limited by relatively low permeate flux. Conventional AGMD systems typically utilise thin film-cast polymeric membranes. However, electrospun nanofibrous membranes have become more popular since they possess a highly interconnected porous structure, which is able to increase mass transfer performance and availability. In this study, recycled acrylic (RA) waste powder was used to prepare a precursor solution to fabricate two types of membranes: thin film-cast membranes and electrospun nonwoven nanofibrous membranes to be evaluated in the AGMD process for water desalination application. The fabricated RA-based membranes underwent characterisation by scanning electronic microscopy (SEM), mechanical properties, water contact angle (WCA), and Fourier transform infrared spectroscopy (FTIR). Based on the results obtained, the nanofiber membrane exhibited a higher contact angle, porosity, and elasticity than the thin film cast membrane. RA-based membranes were tested in the AGMD system at different feed temperatures (45 degrees C, 55 degrees C, and 65 degrees C). The electrospun nanofibrous membrane performed better than the thin-film cast membrane in both permeate flux and salt rejection. The temperature of the feed increased correspondingly with the flux of permeate as well as the salt rejection. The cast membrane of thin film attained a flux of permeate of 1.48 kg/(m2.h) with 99.98 % salt rejection. Conversely, the electrospun nanofibrous membrane had better performance with a significantly higher permeate flux rate of 7.69 kg/(m2.h) and an almost ideal salt rejection of 99.99 %.
The regulations in force in the European Union require the thermal pre-treatment of substrates containing animal by-products prior to the anaerobic digestion (AD) process. Expired food products (EFP) belong to this category of substrates. Traditionally, the requirement for thermal pre-treatment has been met with waste heat from combined heat and power plants (CHP). However, due to the increasing trend towards biomethane production and the move away from CHP, alternative heating methods need to be explored. The main objective of this study was to evaluate the impact of the dual synergistic effect achieved by ultrasonic-thermal pre-treatment of EFP on the kinetics, efficiency and energy balance of AD. The combined thermal treatment and ultrasonic disintegration at 90 degrees C resulted in an increase in dissolved phase chemical oxygen demand (COD) by (84.4 +/- 3.9) % and total organic carbon (TOC) by (56.8 +/- 6.2) %, leading to final concentrations of (33010 +/- 1280) mg O-2/L and (10710 +/- 670) mg Corg/L, respectively. After thermal pretreatment of EFP at 70 degrees C, the methane yield reached (515 +/- 24) mL/g VS, while at 90 degrees C it increased to (525 +/- 22) mL/g VS. The application of ultrasonic thermal pretreatment resulted in a positive net energy gain, with the most efficient variant yielding (4.20 +/- 0.23) Wh, which was (0.37 +/- 0.17) Wh higher than the control sample. In contrast, a negative energy balance was observed in the variants where conventional heating methods were used.
Particles with at least one dimension in the nanoparticle range (1 nm to 100 nm) known as nanoparticles. These materials have an important role in chemistry, medicine, pharmacy, physics, biology, biotechnology, environment and other fields. Nanoparticles are classified in various types on the basis of material nature, dimensions and sizes. Nanoparticles can be prepared by a variety of methods, including chemical vapour deposition, co-precipitation, chemical reduction, laser ablation, sol-gel, sputtering, and biological methods. In medicine nanoparticles can be used as drug delivery system, as contrast imaging, and for targeted therapy. Apart from this, it can also be used in agriculture sector, catalysis, biosensor, solar cell etc. These applications are currently being explored, and research is ongoing. The future of nanoparticle application is promising as new nanomaterials and methods of synthesis are being developed. Research is also focusing on understanding the environmental impact of nanoparticles and improving safety protocols in their use. With the development of new and improved nanoparticles, the potential for applications in medicine, environment, and agriculture, will continue to expand.
For the experimental study, solutions of EDTMP, NTA, and TA were selected for HM extraction. The influence of extraction time and the ratio of extractant concentrations on extraction efficiency was evaluated. The analysed soil was artificially contaminated with selected HM (Cu, Zn, Pb). Chemical extraction of HM using chelating agents resulted in a reduction of HM concentrations in the soil to the permissible limit values set by the Council Directive 86/278/EEC. The most suitable chelating agents under the conditions of this experiment were the combined chelating agents NTA and TA with an extraction time of 60 minutes. Cu and Zn concentrations were reduced to permissible limits even when using the lowest concentration of NTA and TA (0.1 M), while the 0.5 M concentration and 60-minute extraction time resulted in the lowest concentrations of Cu, Zn, and Pb in the soil - 48 mg/kg, 74 mg/kg, and 78 mg/kg, respectively - and the highest extraction efficiencies of 93.3 %, 91.1 %, and 95.2 %, respectively. The combined chelating agents NTA and TA showed higher extraction efficiencies than the synthetic organic chelating agent NTA alone at different extraction times. The variation in extraction efficiency for the different combined chelating agents is presented as follows: for NTA and TA (0.5 M:0.5 M), Pb > Cu > Zn, and for EDTMP and TA (0.5 M:0.5 M), Cu > Pb > Zn. For chelating agents of synthetic origin only, the series were: NTA - Cu > Zn > Pb, and EDTMP - Cu > Pb > Zn.
Electrochemical, biological, adsorption, and oxidative methods can be applied for the treatment of synthetic wastewater containing methyl orange (MO). In this study, MO was catalytically oxidised using ferrous sulphate (FeSO4) and hydrogen peroxide (H2O2). The effects of reagent concentrations, initial dye concentration, contact time, and pH on treatment efficiency were investigated, and the optimal process conditions were identified. FeSO4 and H2O2 are cost-effective and environmentally benign reagents: excess hydrogen peroxide decomposes into water, while the small amount of iron introduced does not significantly impair the quality of the treated effluent. The results showed that increasing the FeSO4 concentration from 0.02 % to 2.00 % enhanced the removal efficiency of C-MO from 81.5 % to 98.7 %, as the higher availability of Fe2+ ions accelerates the formation of HO circle radicals. Increasing the H2O2 concentration from 0.6 % to 24 % raised the efficiency from 81.1 % to 94.5 %, and the highest degradation efficiency was achieved at pH 2.00 - 3.00, confirming that optimal Fenton reaction performance occurs under mildly acidic conditions. Investigation of the initial dye concentration revealed that the efficiency ranged from 80.4 % to 89.1 % when the dye concentration increased from 50 mg/L to 750 mg/L, while the reduction at higher concentrations indicates an insufficient amount of HO circle radicals. Contact time studies showed that the efficiency increased from 39.8 % to 97.1 %, with the optimal reaction time being 2 hours. Overall, the findings demonstrate that the Fenton process is a highly effective method for the degradation of azo dyes and holds strong potential for application in wastewater treatment systems.
To address the challenges associated with the fragmented distribution of scenic attractions, the ever-evolving nature of user preferences, and the suboptimal performance of multi-objective optimisation in rural tourism settings, this research introduces an innovative route recommendation approach that synergistically combines the greedy algorithm with an attention mechanism. The methodology involves the development of a dual-channel attention framework, which dynamically assigns weights to user behaviour patterns and textual semantic features. Additionally, a multi-constraint path-generation architecture, grounded in the greedy algorithm, is engineered to harmonise conflicting objectives, including time expenditure, alignment with attraction preferences, travel distance, and financial limitations. The results show that when recommending 20 scenic spots, the average absolute error decreases to 0.6921, the running time is only 0.1762 seconds, the coverage of scenic spot types increases to 6.5, and the recommended diversity index increases to 0.85. Compared with mainstream recommendation algorithms, this method significantly leads in total route revenue, accuracy of 0.83, and F1 score of 0.80, and has the lowest computation time. Application analysis shows that the recommended route has a high coverage rate, and the time consumption slows down with the increase of the number of scenic spots, taking into account personalised needs and diversity of scenic spot types. The method proposed by the research can effectively balance the real-time and personalised needs of route planning, while reducing path redundancy and enhancing the interpretability of recommendations, providing a new technological path for rural tourism route recommendations.
Green bonds have emerged as a crucial instrument in achieving dual carbon development goals. This study explores the carbon emission reduction effects and mechanisms of green bonds from an innovative local-neighbouring regional perspective, offering vital insights into realising comprehensive low-carbon transformation at the regional level. Utilising panel data from 30 Chinese provinces (including autonomous regions and municipalities directly under the central government) from 2007 to 2022, we investigate the mechanisms through which green bonds influence carbon emission intensity. Our findings demonstrate that green bonds significantly reduce carbon emission intensity, a conclusion that remains robust under Spatial Durbin Model testing. Upon decomposing the total effect, we reveal a nuanced impact: while green bonds effectively reduce local carbon dioxide intensity, disparities in environmental regulations and incentive policies across regions lead to the relocation of polluting enterprises to neighbouring areas. This study argues that while promoting the development of green bonds, it is imperative to strengthen inter-provincial communication and collaboration. Breaking down regional barriers and achieving coordinated development of green financial resources among regions is essential for reducing carbon emission intensity not only locally but also in neighbouring areas. These findings underscore the need for a holistic approach to green finance policy implementation to ensure widespread and equitable carbon reduction across China.
This study explores how environmental, social, governance (ESG) principles enhance low-carbon environmental management systems (LC-EMS), using 2015-2024 panel data from Chinese A-share firms. Fixed-effects models show that all ESG dimensions, environmental, social, and governance, significantly improve carbon reduction rates, with synergistic interactions. Mediation analysis identifies green technology innovation as the primary mechanism, supported by energy efficiency and supply chain collaboration. Heterogeneity tests reveal stronger effects in high-pollution industries, large enterprises, and state-owned enterprises. Findings are validated via robustness and endogeneity tests. We recommend tailored ESG strategies focusing on green R&D and sector-specific policy incentives to accelerate corporate low-carbon transformation.
As a first study, soil and water properties of the Oum Souid wetland, a lake far west of the Gharda & iuml;a region (Algeria), were investigated. Despite its ecological, tourist, and socio-economic importance, the wetland is little known, as it is situated in a biotope with an arid bioclimate among dune formations. Flora and avifauna inventories were conducted in the wetland to assess the studied site's characteristic biodiversity. Vertical profiles from 0 cm to 90 cm deep were sampled. Fifty samples from each soil were prospected for organic matter, electrical conductivity (EC) and pH. Additional characteristics describing neighbouring water samples, including dissolved oxygen (DO), electrical conductivity (EC), and pH, were also determined in situ. The census of bird and plant species revealed a biological richness, with 12 families of migratory birds and 21 botanical families identified. Soil analysis indicated a sandy-clay texture with little silt for all the profiles. However, some profiles were marked by a sandy-clay-loamy texture. The assessment of spatial variation revealed a moderately alkaline soil pH, high electrical conductivity, and fairly organic matter content. Water samples were characterised by a strongly alkaline pH, slight salinity, and a high dissolved oxygen rate. These findings underline the crucial role of the Oum Souid wetland as a biodiversity refuge within the Saharan environment and highlight the need for integrated, sustainable land management strategies to ensure the long-term conservation of its ecological functions and natural heritage.
In order to understand the comprehensive assessment of urban ecological environment, the author proposes a study on the comprehensive assessment of urban ecological environment based on multi-source data integration analysis. The author first analysed that remote sensing and geographic information systems are effective means for resource and environmental research. Secondly, using remote sensing and GIS technology to conduct surveys and evaluations of regional ecological environment quality at different scales can make up for the shortcomings of traditional methods that require a lot of manpower, material resources, and time to obtain ecological environment background data. It has the advantages of relatively easy data acquisition, rich information, and fast analysis. Finally, taking a certain city as an example, establishing a scientific evaluation system to comprehensively evaluate the ecological environment of the city, understanding its current situation and spatial distribution characteristics, is of great significance for promoting the construction of ecological cities, coordinating human land relations, and achieving sustainable economic and social development. The experimental results show that the urban area (with a comprehensive environmental evaluation index of 7.16) is mainly hilly and plain, with most areas having relatively flat terrain. In recent years, with the increase in urban green area and the increase in environmental protection and governance efforts, the environmental quality of the city has shown a trend of improvement.
This study proposes a framework for tracing carbon footprints and allocating emission reduction responsibilities in green supply chains by integrating Product Lifecycle Management (PLM) with a Discrete Hopfield Neural Network-based Analytic Hierarchy Process (DHNN-AHP). By constructing an integrated "trace-evaluate-allocate" model, it achieves systematic tracking of carbon footprints across the entire chain of raw material acquisition, production, distribution, usage, and recycling, while introducing DHNN-AHP for dynamic low-carbon performance evaluation of suppliers. Based on this, a responsibility allocation mechanism is proposed, grounded in carbon contributions and performance results, to promote overall carbon efficiency coordination in the supply chain. A case study using cathode material suppliers as an example demonstrates that this method enhances the accuracy of supply chain carbon management while balancing environmental and economic benefits, providing methodological support for the governance and policy coordination of green supply chains under carbon neutrality goals.
This study evaluates different options for the valorisation of olive cake waste in Jordan, focusing on direct combustion, gasification, and composting. Physical/chemical, biological/ecological, sociological/cultural, and economic/operational aspects of each option are assessed using the Rapid Impact Assessment Matrix (RIAM) procedure. The findings indicate that composting of olive cake emerges as the most favourable option, offering positive impacts on soil quality, minimal environmental and social risks, and economic benefits through job creation and value-added products. Gasification and direct combustion also show potential but may require further consideration of local context and stakeholder preferences. Overall, the study provides valuable insights for decision-makers in selecting the most suitable olive cake valorisation option in Jordan.
An efficient and sustainable method was developed for the N-formylation of primary and secondary amines using formic acid in dichloromethane at room temperature over zeolite H-ZSM-5 and ion-exchanged forms (Zn-ZSM-5, Cu-ZSM-5, Ag-ZSM-5, and Cd-ZSM-5). The catalysts were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area, ammonia temperature-programmed desorption (NH3-TPD), and inductively coupled plasma-optical emission spectrometry (ICP-OES) analyses, revealing a regular hexagonal plate-like morphology and high surface area. H-ZSM-5 exhibited the largest surface area (248.2 m2/g) and total acidity (0.109 mmol NH3/g), while ion exchange slightly modified these properties. The catalytic system achieved excellent yields (up to 99 %) for various amines, demonstrating high efficiency and reusability. This study highlights the potential of zeolite-based catalysts as effective, recyclable materials for N-formylation processes.
With the acceleration of urbanisation, waterspace faces many challenges and problems. This study aims to explore the integration and system optimisation strategy of waterspace based on the overall development model of landscape system. Through the study of related theories and practical cases, the current problems of waterspace are analysed, and the principles and methods of integration and optimisation are proposed. Taking specific waterspace as an example, an empirical study was conducted and the optimisation effect was evaluated. The results show that the integration and optimisation of waterspace based on the overall development model of landscape system can effectively enhance the ecological, social and economic values of waterspace and promote the sustainable development of cities.
Biostalactite produced as a result of the activities of the insectivorous bat species Eptesicus serotinus is described. A guano (bat faeces) deposit was found in Poland, which suggests the possibility of creating such structures not only in warm and arid climatic zones but also outside caves in temperate climate countries. The research revealed that the temperate climate bat stalactite is made of urea, accompanied by a small and variable amount of non-crystalline organic substance that comes from bat guano. Lack of contact with cave minerals is a way to save the original composition without intrusions of calcite or other minerals which come from the bottom or vault of the cave. An X-ray diffractometric analysis shows a number of dominant minerals in crystalline form present in the examined material. Detected minerals are mainly taranakite H6K3Al5(PO4)818H2O, urea crystals and ammonium aluminium hydrogen phosphate Al2(NH4)OH(PO4)2H2O. Formation of bat biostalactites is often observed in hot and dry caves, but the temperate climate in Poland eliminates this phenomenon due to high air moisture and quick microbiological digestion processes.
