环境•农林最新文献

Water pollution caused by the dye industry is a major environmental concern, particularly in regions where textile and dye production are prevalent. Wastewater from dyeing operations is typically characterized by high concentrations of dyes, salts, heavy metals, and other harmful chemicals, making it highly toxic to aquatic ecosystems and human health. Our work deals with the minimization of two commonly used dyes. First is Congo Red, despite its popularity in industrial applications, Congo Red is known for its toxicological and environmental risks, particularly in water pollution. Congo Red (CR) and Rose Bengal (RB) in water bodies can cause significant contamination due to their persistence and difficulty in degradation. These organic contaminants (dye) are carcinogenic and mutagenic, posing potential risks to both aquatic organisms and humans. Also, it has low lipid solubility, which can limit its ability to cross cell membranes and accumulate in tumors. Newly synthesised of ruthenium-doped titanium dioxide nanoparticles have been successfully obtained and demonstrated to be extremely efficient photocatalysts for the photodegradation of dye wastes in water samples. This study employs a sol–gel route, which provides fine control over particle size, dopant dispersion, and material uniformity, all while operating under mild conditions and avoiding the use of harmful substances. A variety of features confirm the production of Ru@TiO₂. Analyses are performed using XRD, FTIR, SEM–EDS, and HR-TEM to understand the composition of the composite. The photocatalytic effectiveness of Ru@TiO₂ photocatalyst is measured using various factors such as pH, contact time, photocatalyst dose, and dye concentration. Ru@TiO₂ is an excellent photocatalyst for dye degradation from wastewater under optimal conditions, with 94 and 96% elimination of CR and RB, respectively, within 100 min of reaction time. In addition, more than 92.0% of total organic carbon was eliminated. Furthermore, the reusability test demonstrated the extraordinary stability of Ru@TiO₂ after five cycles, with just a tiny decrease ( < 16%) in dye degradation efficiency.

Due to human activities, large quantities of dyes, represented by methylene blue, have been discharged into aquatic ecosystems, posing a global threat. The lignite residue (Lig) produced during humic acid extraction requires appropriate valorization or treatment to prevent potential environmental impacts. To develop a modified material with enhanced uptake performance for the effective removal of methylene blue (MB), Lig was functionalized with Fe₃O₄ to form Lig-Fe. The underlying adsorption mechanisms were systematically investigated through comprehensive characterization. Results revealed that Lig was transformed into a mesoporous composite with enhanced surface functionality. The maximum uptake amount and removal effciency of Lig-Fe was 189.91 mg/g and 98.05%. Kinetic analysis indicated that the adsorption process followed a pseudo-second-order model, suggesting chemisorption as the dominant mechanism. Adsorption equilibrium was reached within 150 min for Lig-Fe, compared to 180 min for unmodified Lig. Isotherm modeling revealed hybrid mechanisms that vary with temperature, involving both Langmuir-type monolayer adsorption and Freundlich-type multilayer physisorption. Analyses confirmed chemisorption pathways involving Fe–O coordination, π-π interactions, and actions with oxygen functionalities. The outstanding adsorption performance of Lig-Fe provides insights for further optimizing its modification parameters. This work also provides a technical pathway for simultaneous lignite residue valorization and industrial wastewater remediation, supporting China's dual carbon strategy through circular economy implementation.

Graphic Abstract

Industrial wastewater from oil refining processes poses significant environmental challenges due to the high concentration of petroleum hydrocarbons and increased chemical oxygen demand (COD), where conventional treatment methods fail due to severe membrane fouling in treatment systems. This study introduces a novel and stable green catalyst (GC) derived from calcium oxide (CaO) prepared from tomato sepal biomass, which is integrated as an efficient visible light photocatalyst with a polyacrylonitrile (PAN) membrane in a photocatalytic membrane reactor (PMR). The main objective was to optimize the PMR to maximize oil and COD removal while minimizing permeate flux (PF) reduction using synthetic wastewater simulated from industrial petroleum effluents. For this purpose, PAN membrane was fabricated via phase inversion and both GC and PAN were characterized using several techniques. Performance evaluation was performed under visible LED light irradiation with 14 W intensity, neutral pH and flow rate of 0.6 L/min, at membrane pressure of 2 bar, with different parameters through central composite design (CCD) in response surface methodology (RSM). The results of the experiments showed the outstanding performance of the PMR membrane with a one-hour treatment, which produced a wastewater flux of 74.34 L/m²h. At a concentration of 100 ppm, the oil and COD removal efficiencies were determined to be 99.20% and 97.15%, respectively. In addition, the PAN membrane showed remarkable self-cleaning performance, achieving a flux recovery ratio (FRR) of 96.24% when operating with industrial wastewater. The results showed the high potential of the PMR system in advancing industrial wastewater treatment by significantly reducing membrane fouling and increasing effluent quality, and achieving compliance with World Health Organization (WHO) standards through residual oil and COD concentrations of 5 and 100 ppm, respectively.

It is important for snowmelt runoff pollution management to recognize the snow pollution characteristics from different underlying surfaces. The underlying surfaces are categorized into five main groups in this study: residential communities, parks, squares, urban roads, and snow dump sites, sampling process was followed a five-point sampling method, to investigate the natural and deposited snow pollution characteristics, the results showed that the land type has an important effect on snow pollution, the deposited snow in urban road and snow dump sites were polluted more seriously. Significant correlation among different pollutants was also founded: chloride ions (Cl⁻) serve as a biomarker for the use of deicing agents, and their peak concentration are significantly positively correlated with total phosphorus (TP), chemical oxygen demand (COD), total nitrogen (TN), as well as various pollutants such as copper (Cu), iron (Fe), and zinc (Zn), indicating the synergistic input mechanism of snow melting activity with nutrients, oxygen consuming substances, and some heavy metal pollution. The dissolved organic matter (DOM) is influenced by both endogenous and terrestrial inputs, with endogenous contributions being more prominent. This provides a new perspective for understanding the biogeochemical processes of organic pollutants in urban environments, and also provides important basis for accurately identifying pollution sources and developing collaborative control strategies.

Graphical Abstract

In bilaterians, particularly arthropods, body segments are often functionally differentiated along the anterior-posterior axis, resulting in lineage-specific morphologies. Although the acquisition of novel traits in body segments or appendages is considered a key driver of animal evolution, the loss or reduction of these structures has also contributed to the adaptation to new environments and emergence of novel body plans. Members of the family Caprellidae (Caprelloidea: Amphipoda: Crustacea), commonly known as skeleton shrimps, exhibit an unusual body plan characterized by highly elongated thoracic segments (pereonites) and a markedly reduced abdomen derived from the pleon (pleonites and urosomites). Caprellids also lack most appendages that are retained on the pleon in non-caprellid amphipods. Despite these distinctive features, the internal organization of organs within the reduced body segments of caprellids remains poorly understood. In this study, we conducted histological observations of Caprella scaura and found that organs essential for survival and reproduction, particularly the digestive and reproductive systems, are entirely located within the pereonites. Comparative observations of a related non-caprellid amphipod Podocerus sp., revealed a similar distribution of reproductive organs in the pereonites, whereas the pleon contained only extensions of the digestive organs. These results suggest that, in the common ancestor of Caprelloidea, essential organs were already positioned within the pereonites. Furthermore, previous studies indicate that pleonal appendages became functionally reduced in caprellids in association with specialization for an epiphytic lifestyle. The anatomical organization, together with functional changes in appendages, may have facilitated the evolution of the highly degenerated body plan characteristic of caprellids.

Beneficial plant–microbe interactions are essential for sustainable agricultural practices while mitigating environmental stress. This study examines the role of the bacterial strain Allorhizobium borbori in alleviating cadmium contamination by demonstrating positive effects on plant growth-promoting attributes, including starch hydrolysis, phosphate solubilization, indole-3-acetic acid (IAA) production, hydrogen cyanide (HCN) production, and urease activity. These characteristics are critical for a bacterial strain to function effectively as a bioinoculant under stress conditions. Cadmium contamination poses a significant threat by impairing plant growth and yield, as well as disrupting the rhizosphere and its microbial diversity, ultimately destabilizing the entire rhizospheric environment. The studied isolate showed the maximum tolerance concentration (MTC) at 25 mg/l. Experiments including pot assay and PREP assay also showed a significant(p < 0.05) increment in the shoot growth, root elongation, and overall biomass under the different cadmium concentrations. The strain also showed the stress tolerance index (STI) of 30%, an 8.89% decrement in heavy metal tolerance, declining from 453.68% at 15 mg/l Cd with A.borbori to 413.33% at 25 mg/l, compared to the control (100%), showing the inhibition of growth at higher concentration. Moreover, under the same treatment, the growth recovery index declined from 313.14% to 283.98%, reflecting its regenerative capacity of the bacterial strain, which decreased with higher concentration. The decline in GRR, which is the growth reduction ratio from 1.55 at 15 mg/l along with A.borbori to 1.01 at 25 mg/l with A.borbori, both compared to the control, which was 1, indicated growth was inhibited at high concentrations of cadmium. The value of 3.2 Shannon diversity (H’ = 3.2) indicated the enriched robust microbial diversity in the stressed environment, reflecting its importance in restoring the functional resilience and stability. Its environmental application is confirmed by the antibiotic susceptibility profile, which further ensures its biosafety and highlights its role as a green rhizobioinoculant for enhancing crop growth, health, and productivity in stressed agroecosystems.

Graphical Abstract

Urban rivers worldwide face severe contamination from anthropogenic activities; yet, comprehensive assessments of micropollutants (MPs) remain limited. This study investigates water quality degradation and MP contamination in the River Musi as it traverses Hyderabad, India. Eight strategic sampling sites (S1–S8) were analyzed for conventional water quality parameters and MPs using non-targeted Liquid Chromatography-Quadrupole Time-of-Flight (LC-QToF) analysis. Results revealed critical ecosystem stress, with dissolved oxygen levels below 1.5 mg/L at all urban sites. Key pollution indicators showed alarming ranges: COD (26 ± 2.17 to 112 ± 6.2 mg/L), TOC (12.3 ± 0.21 to 37.7 ± 0.24 mg/L), total nitrogen (2.10 ± 0.28 to 27.80 ± 0.21 mg/L), and phosphate (0.63 ± 0.05 to 4.03 ± 0.41 mg/L). Electrical conductivity reached 1274 ± 225 μS/cm with turbidity up to 165 ± 6 NTU. Notably, pollutant concentrations increased 1.5- to 5-fold within city limits compared to upstream sites. BOD/COD ratios consistently below 0.5 indicated predominant non-biodegradable contamination. The LC-QToF analysis identified 404 distinct MPs—substantially exceeding previous regional studies. Pharmaceuticals (31.36%) and agrochemicals (24.2%) dominated the MP profile, representing over 55% of detected compounds. This expanded MP inventory reveals previously uncharacterized contamination patterns in urban river systems. These findings demonstrate severe anthropogenic impacts on urban river health and emphasize the urgent need for enhanced wastewater treatment infrastructure. The study contributes critical data for achieving Sustainable Development Goal 6 (clean water and sanitation) and provides a comprehensive baseline for urban river restoration strategies in rapidly developing regions.