Environmental Science and Pollution Research最新文献

Submarine Groundwater Discharge (SGD) constitutes a pivotal mechanism for the transference of freshwater, nutrients, and pollutants from terrestrial to marine environments, exerting a profound influence on coastal water quality and ecosystem dynamics. In this investigation, we executed an extensive field sampling campaign along the 650 km coastal expanse of southwest India, employing a 10-km sampling interval, to discern and validate the probable zones of SGD. We have utilized a transect-based methodology for the systematic collection of groundwater, porewater, and seawater samples, employing a suite of proxies to scrutinize SGD). This multifaceted approach encompassed biogeochemical, geophysical, and remote sensing techniques. The in situ physio-chemical parameters, encompassing electrical conductivity (EC), total dissolved solids (TDS), pH, dissolved oxygen (DO), temperature, and salinity, facilitated the delineation of prospective SGD sites. Adjacent continuous probable SGD sites were amalgamated into nine potential SGD zones spanning the 650 km coastal stretch. Comprehensive analyses of major ions and nutrients revealed maximum observed seawater concentrations of nitrate, phosphate, and silica at 22.11 µM/L, 12.5 µM/L, and 11.69 µM/L, respectively, underscoring the SGD signatures and the subsequent transference of nutrients from terrestrial sources to the ocean via subsurface pathways. Furthermore, geophysical investigations employing Electrical Resistivity Tomography (ERT) at the nine potential SGD zones substantiated the groundwater signatures, elucidating subsurface lithology, delineating the aquifer system, and determining the extent of the saline-freshwater interface, including discharge depth. All ERT profiles were meticulously calibrated against available lithological data. Additionally, we executed a comprehensive evaluation of Landsat-8 satellite imagery within the thermal infrared spectral domain (10.6-11.19 μm) to monitor variations in sea surface temperature (SST) and sea surface anomalies across three stratified thermal ranges (21-28 °C, 25-33 °C, and 11-23 °C) encompassing the entire study area. The visual correlation observed between lower SST values and the identified SGD probable zones further substantiates supplementary validation. Ultimately, the verification of these nine prospective SGD zones was reinforced through a meticulous comparison with groundwater level data, which ranged from 0 to 41 m above mean sea level (MSL). This extensive investigation represents the inaugural comprehensive identification and confirmation of SGD zones along the southwest coast of India, spanning a 650-km stretch, resulting in a more precise demarcation of the area into nine SGD probable zones where multiple proxies are mutually corroborative.

This study investigates the effect of temperature variation on malodor generation across different units of a wastewater treatment plant (WWTP). The results demonstrate that higher temperatures exacerbated odor emission due to increased microbial activity with all the different units showing maximum odorous gas production at the highest temperatures used (35 °C and 45 °C) in this study. The maximum total odor activity value (OAV) of 353106 was obtained for anoxic and anaerobic unit at 45 °C. The variation in composition of odor-causing gases was also dependent on wastewater characteristics than temperature alone. Volatile reduced sulfur compounds, including hydrogen sulfide and methyl mercaptan, were dominant in most wastewater samples, while units with higher dissolved oxygen (DO) content, such as aeration and sedimentation units, exhibited elevated levels of phenol and dimethyl disulfide and reduced H₂S concentration. Analysis of the liquid composition following incubations revealed presence of mainly aldehydes (> 75%) which are produced due to incomplete organic matter degradation, particularly at lower temperatures. Statistical analysis showed positive correlation between temperature and odor generation. DO had negative correlation with H₂S (r =  - 0.78, - 0.93) along with total gas concentration and total OAV, but positively correlated with other gases, namely methyl mercaptan (r = 0.22, 0.97), dimethyl disulfide (r = 0.93, 0.98), phenol (r = 0.99, 0.97), and ammonia (r = 0.99, 0.98). Solids concentration and volatile solids to total solids (VS/TS) ratio had positive correlation with H₂S, total gas concentration, and total OAV (r = 0.68, 0.54, and 0.90). These findings highlight the need for tailored odor management strategies based on temperature fluctuations and unit-specific conditions to optimize WWTP operations and reduce odor emissions effectively.

Anthropogenic activities exert significant pressures on the dynamics and health of dominant fish species in aquatic ecosystems. In this study, we evaluated how human activities impact the community structure, length-weight relationships, and condition factors of key fish species in a north-central Nigeria river. Sampling was conducted over 14 months across four sites with varying levels of disturbance: Zhabyala (minimal), Tunga Waya, Chanchaga, and Korokpan (severe). A total of 1361 fish individuals, representing diverse orders and families, were collected. Dominant species such as Tilapia zillii and Tilapia guineensis featured prominently in our analysis. Site 1 exhibited the highest abundance (n = 594), while site 4 had the lowest (n = 238). Characiformes dominated the assemblage, followed by Cypriniformes and Mormyriformes. Correlation analysis highlighted strong associations between environmental factors and the length-weight relationships of dominant species. Tilapia zillii showed the highest mean standard length and body weight at site 1, whereas Tilapia guineensis demonstrated the highest standard length at site 1 and the greatest body weight at site 3. Despite favorable health indicators for many dominant species, environmental stress was evident at specific sites. This study provides crucial insights into the condition factors and ecological dynamics of dominant fish species, serving as a valuable reference for future conservation and management efforts.

Clean water requires accurate water quality categorization. A water potability (WP) dataset with pH, hardness, solids, chloramines, sulfate, conductivity, and other metrics for 3276 water bodies was used in this paper. After median imputation for missing values, normalization for feature scaling, and class imbalance correction using SMOTE, the Kaggle public dataset was prepared. With binary particle swarm optimization (BPSO) and binary whale optimization algorithm (BWAO), feature selection (FS) was used to determine the most important features for classification. A subset of seven essential characteristics is selected with the lowest average error of 0.3745 by the BPSO. Random forest (RF), gradient boosting (GB), support vector machine (SVM), Extra Tree (ET), decision tree (DT), and XGBoost are tested for WP prediction. The ET classifier ranked first, with 70.63% accuracy and 71.17% F1-score. Predictive performance was improved by stacking random forest, extra trees, and XGBoost base learners with Logistic Regression meta-learner. The stacking model improved with 69.53% accuracy, 70.23% F1-score, and 77.62% AUC. We found that stacking uses high-performing models to create a strong and balanced categorization framework. This paper shows that ensemble learning can improve WP categorization and that stacking may be a feasible way for measuring and managing water quality.

Agro-industries generate significant volumes of wastewaters that cause environmental pollution due to they are discharged in soil or surface water. In particular, arid environments are especially vulnerable to this impact as they are characterized by water scarcity, high temperature, and unproductive soils. Thus, this study aimed to assess the comparative toxicity of winery, olive oil mill, table olive, tomato processing, and walnut shelling wastewaters from an arid region on aquatic and terrestrial organisms, and its relationship with physicochemical characteristics, and sodification and salinization indexes. The seed germination and root elongation toxicity test on Raphanus sativus and the immobilization Daphnia magna test were carried out in the whole effluent toxicity framework. Also, the salinity and sodicity risks of these wastewaters were evaluated. The most toxic wastewater was produced in the table olive industry, whereas the most harmless wastewater was produced in winery. Even after treatment, the wastewaters derived from table olive industry presented the highest risk of sodification and salinization. Toxicity was associated with high levels of sodicity, salinity, and polyphenols, but low values of BOD/COD ratio. The best wastewater quality for soil irrigation was found in the wine and tomato processing industries. Therefore, the comprehensive use of salinity and sodicity risk indicators together with toxicity tests improves the wastewater assessment to reuse them in food production systems as an alternative water source in arid lands.

Congo red, a persistent dye widely used in the textile industry, poses significant environmental hazards if not properly treated. In this study, the effectiveness of chitosan beads for removing Congo red from textile wastewater was investigated. A Box-Behnken design was utilized to optimize the degree of deacetylation (DDA) of the chitosan beads, achieving a maximum DDA of 95.79% under the optimal conditions of 100 °C, 300 min reaction time, and 45.91% NaOH concentration. Comprehensive characterization of the synthesized adsorbent was performed using FT-IR, XRD, SEM, and BET analysis, with a BET surface area of 11.5180 m²/g, indicating a substantial surface area for effective adsorption. The adsorption process followed pseudo-second-order kinetics and was best described by the Langmuir model. At pH 6, an adsorbent dose of 0.06 g, and an optimal reaction time of 80 min, a maximum adsorption capacity of 110.37 mg/g was achieved, surpassing the performance of magnetic chitosan (40.12 mg/g) and powdered chitosan (42.48 mg/g). Thermodynamic parameters (ΔH° = 10.91 kJ/mol and ΔG° < 0) indicate that the adsorption process was endothermic and spontaneous. DFT calculations were conducted to elucidate the adsorption mechanism, focusing on the role of benzene rings and oxygen atoms in Congo red as electron donors. These findings demonstrate that chitosan beads are a promising material for the removal of Congo red from contaminated wastewater.

Utilizing waste materials and reclaimed asphalt pavement (RAP) in road construction is gaining research interest. The pricey nature of building roads is attributed to the energy required for new material production and its environmental impact. The study investigated rheological and chemical properties of reclaimed asphalt pavement using PET additive as a modifier. The materials used in this study are virgin bitumen (VB), RAP bitumen (RB), and PET bottles. The synthesis of PET bottle into PET-derived additives was carried out, using aminolysis method in the presence of triethylenetriamine (TETA) as a solvent. Additionally, polymer-modified bitumen (PMB) was created by adding 2% PET additive with VB. The findings showed that utilizing PMB with RB in asphalt blend improved RB's brittle effect and has high resistance to deformation at high temperature. Moreover, the effect of the PMB on the asphalt binder did not alter the functional group while there was a reduced mass loss for PMB. Consequently, PET additives can be used to improve the quality of asphalt mixture in road construction, thus enhancing sustainability.

In recent years, peroxymonosulfate-based advanced oxidation processes (PMS-AOPs) have garnered increasing attention for their efficacy in eliminating persistent organic pollutants. Metal-nitrogen-carbon (M-N-C) materials are frequently employed as efficient catalysts for the activation of PMS, leading to the effective production of various reactive species. In this study, a novel 3D porous cobalt/nickel bimetallic-nitrogen-carbon aerogel (Co/Ni-N-C) with well-dispersed CoNi-nanosheets that enhance electron transfer and provide a large active surface area was prepared through an in situ growth and a straightforward pyrolysis procedure of 2D cobalt/nickel metal-organic framework (CoNi-MOF) which was contained by a bamboo cellulose aerogel as a precursor. Rapid tetracycline (TC) removal (efficiency of 99.83% and mineralization rate of 69.8%) was achieved via PMS activation, facilitated by a synergistic enhancement effect of well-dispersion CoNi-nanosheet array. The evenly dispersed Co/Ni-N active sites and high Co:Ni ratio (P_Co:_Ni = 0.21) producing multiple reactive oxygen species (ROS) were essential in accelerating removal of contaminant. The toxicity assessment results of the intermediates further confirmed that the catalytic degradation in the Co/Ni-N-C-800/PMS system reduced the ecological toxicity of TC through dehydroxylation, demethylation, ring-opening, and deamidation. Furthermore, the Co/Ni-N-C-800/PMS system demonstrated exceptional degradation efficiency for various aromatic compounds with diverse substituents and showed good cyclic stability. These findings offer insights into the development of highly effective bimetallic-nitrogen-carbon catalytic materials.

Freshwater biodiversity plays a pivotal role in maintaining ecological equilibrium and furnishing numerous ecosystem services to diverse organisms. However, these intricate ecosystems face imminent threats from various phenomena, including global warming and anthropogenic activities, leading to heightened occurrences of ecological disasters, notably mass mortality events among aquatic fauna. This study represents the first comprehensive investigation and high-frequency monitoring of the ecological disaster of fish mass mortalities in Africa. We focused on instances of fish mass mortality events (FMME) in North African freshwater ecosystems and estuaries in 2019, focusing on Morocco, as the country most endowed with aquatic ecosystems in North Africa. Seven aquatic ecosystems exhibited susceptibility, impacting a total of 10 species. Notably, 94.59% of the minimum estimated 171,064 deceased fish individuals belonged to non-native species. Lepomis macrochirus stood out as the species most profoundly impacted, representing a substantial 63.36% of the total mortalities, with Lepomis gibbosus following closely at 27.64%. Comprehensive measurements of water quality parameters, encompassing temperature, dissolved oxygen, pH, salinity, among others, were conducted, and their associations with the affected ecosystems were analyzed. Our findings suggest that the predominant cause of the majority of FMME was attributed to the critically low concentrations of dissolved oxygen, likely resulting from anthropogenic and climatic pressures. Overall, FMME can considered as a potential threat to Moroccan freshwater fish diversity and communities.