Clean-soil Air Water最新文献

The disposal of spent coffee grounds (SCG) not only represents a significant waste of resources but also poses environmental challenges, highlighting the need for effective pretreatment strategies to mitigate potential adverse effects. Incorporating metal oxides into biomass-based adsorbents can enhance their adsorption capacity for heavy metal ions by enhancing electrostatic attraction and increasing the number of accessible active sites. In this study, KMnO₄-modified spent coffee grounds (KMnO₄-SCGS) were successfully synthesized and applied for the removal of Cd(II) from aqueous solution. Key process parameters, including contact time, pH, initial Cd(II) concentration, temperature, and adsorbent dosage, were systematically investigated. Characterization using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and x-ray photoelectron spectroscopy (XPS) confirmed that KMnO₄ treatment increased the abundance of oxygen-containing functional groups and promoted the deposition of manganese oxides (MnO_x) on the adsorbent surface. The adsorption isotherm followed the Langmuir model, and the kinetics were well fitted by the pseudo-second-order model. The maximum Langmuir adsorption capacity of KMnO₄-SCGS for Cd(II) was determined to be 49.54 mg/g at pH 5.0, and 298 K. Thermodynamic analysis indicated that the adsorption process was spontaneous and endothermic. The enhanced Cd(II) uptake was primarily attributed to the synergistic effect of MnO_x and oxygen-containing functional groups, which facilitated the formation of surface complexes. In conclusion, KMnO₄ modification represents an effective strategy for developing high-performance adsorbents for Cd(II) removal.

Nonsteroidal anti-inflammatory drugs are a group of analgesic and anti-inflammatory drugs widely used around the world. These drugs are very important for humans; however, when they end up in the environment, they cause pollution. One of the drugs belonging to this group is indomethacin (INDO). In the study presented in this article, the effects of INDO on spring barley, Heterocypris incongruens, and the water flea Daphnia magna were evaluated. The tested drug, at a concentration of 1000 mg kg⁻¹ of soil dry weight (DW), induced oxidative stress in spring barley seedlings, as indicated by a statistically significant rise in hydrogen peroxide, proline, and ascorbic acid levels, and an increase in DW content. A statistically significant increase in the activities of enzymes such as superoxide dismutase and guaiacol peroxidase was also observed, accompanied by a reduction in the content of chlorophyll and carotenoids and a decline in chlorophyll fluorescence. The presence of INDO in the soil caused faster root growth when the drug was used at concentrations from 0.1 to 100 mg kg⁻¹ of soil DW. In contrast, INDO at a concentration of 1000 mg kg⁻¹ of soil DW caused growth inhibition of both aboveground parts and the roots of barley. In the case of H. incongruens, INDO caused increased mortality of these crustaceans, and at high concentrations of the drug, mortality was 100%. INDO also proved to be harmful to D. magna causing its 100% mortality after 48 h of exposure to INDO applied at a concentration of 50 mg L⁻¹.

The present study explores the use of scrap iron—a waste by-product from steel manufacturing—as a heterogeneous catalyst in Fenton and photo-Fenton processes for treating coke-oven wastewater (COW). The concept of exploiting waste (scrap iron) to treat liquid waste in the context of more sustainable procedures within a circular economy is the main idea for this study. Elementary composition and morphological analysis of scrap iron have been mapped using scanning electron microscopy and energy-dispersive x-ray spectroscopy (SEM/EDX). Brunauer–Emmett–Teller (BET) was used to determine the absorption characteristics of scrap iron. The impact of catalyst loading, solution pH, and H₂O₂ on phenol degradation in COW wastewater was elucidated. Under ideal circumstances, kinetic studies have been conducted for phenol's degradation. Scrap iron effectively eliminates 73.39% and 81.97% of phenol in the Fenton and photo-Fenton processes, respectively, under optimum conditions. This study revealed that scrap iron is a potential material for treating highly polluted wastewater streams. Given the massive production of scrap iron debris and its possible use as a catalyst in a highly polluted liquid waste treatment process, these discoveries appear extremely important from the standpoint of the circular economy.

This study evaluated halotolerant microbial formulations for mitigating salinity stress and improving chilli (Capsicum annuum) growth in pulp and paper mill-contaminated soil. Formulations combining Bacillus velezensis, Kocuria rhizophila, and Kosakonia radicincitans were applied as carrier-based (CBHF, 4 kg ha⁻¹) and liquid-based (LBHF, 1500 mL ha⁻¹) treatments, selected through statistically significant improvements in yield and soil fertility. Experiments were conducted with sterile carrier and buffer controls. CBHF and LBHF significantly enhanced organic carbon, nitrogen, and microbial diversity. Metabolomic profiling of root exudates revealed increased osmoprotectants, sugars, and GABA, indicating improved rhizosphere resilience. Metagenomic analysis showed enrichment of salt-tolerant and plant growth–promoting taxa (Actinobacteria, Firmicutes) and functional genes linked to osmoregulation and phosphate solubilization. Field ECE fluctuations were attributed to continuous effluent irrigation. Overall, halotolerant microbial formulations improved soil–plant–microbe interactions and nutrient cycling, demonstrating sustainable potential for bioremediating saline effluent-irrigated soils.

Monsoon fluctuation and agricultural land use systems were revealed to have a critical impact on soil hydrological characteristics in a comprehensive 2-year study (2020–2021) across microwatersheds in West Bengal, India. Twenty different cropping systems were evaluated, with the groundnut-rice-potato rotation (C10) proving to have better performance, showing high infiltration (2.03–2.06 cm h⁻¹) and permeability (0.22 cm s⁻¹) through varying monsoon years. The 2021 monsoon (1674 mm rainfall) revealed the resilience of biologically-managed systems, with C10 retaining 95% permeability post-monsoon, while conventional systems (e.g., C5, C7) showed 15%–20% declines. Principal component analysis identified soil organic carbon (SOC), aggregate stability, and porosity as key drivers of hydraulic function, with C10's success attributed to groundnut-derived biopores (1.5–2.0 m depth) and SOC-mediated aggregate stability (0.36%–0.84%). Systems with shallow-rooted crops (C7, C8) performed poorest (0.01–0.33 cm h⁻¹ infiltration), particularly in clay-rich soils. The study demonstrates that strategic crop diversification—particularly pre-monsoon legumes with deep root systems—can overcome textural limitations, enhancing monsoon resilience. The results offer practical recommendations for climate-adaptive agriculture in rainfed regions, highlighting groundnut-based rotations as nature-based solutions for sustainable soil health and water management.

Groundwater contamination by ammonia is an emerging environmental and public health concern in arid regions that depend heavily on groundwater. This study evaluates groundwater quality in the Northwestern Gulf of Suez, examining chemical characteristics, governing geochemical processes, and noncarcinogenic health risks associated with ammonia. Groundwater was sampled from 12 industrially influenced locations. The water showed near-neutral pH (7.0–7.9), high electrical conductivity (5310–10 300 µS/cm), and elevated total dissolved solids (3690–6130 ppm), indicating substantial mineralization. Urea concentrations were low (0.12–1.6 ppm), whereas chemical oxygen demand (COD) ranged from 25 to 161 ppm, reflecting variable organic loads. Ammonia reached 277 mg/L in areas adjacent to industrial discharge, far exceeding permissible limits. Principal component analysis revealed that groundwater chemistry is shaped by both natural geochemical processes and anthropogenic inputs, including fertilizer leaching and saline intrusion. Noncarcinogenic health risks from ammonia were assessed for adults, children, and infants across inhalation, dermal, and oral exposure pathways. Hazard quotient values were highest for the oral route, reaching 46.54 for children and 101.19 for infants; dermal exposure also posed significant risk, whereas inhalation was minimal. Most samples—particularly Sample 3—exceeded the safe Hazard Index (HI) threshold (HI > 1), with newborns exhibiting HI values above 100. Overall, groundwater in the study area shows marked chemical deterioration and presents substantial health risks, especially to vulnerable populations. The findings underscore the need for effective mitigation measures, including pollution control, water treatment, and sustained monitoring, to support safe and sustainable groundwater management in ammonia-affected regions.

Pseudomonas putida is a multifaceted bacteria with the capability of doing bioremediation for various compounds present in the environment or released through different industrial processes. This review presents the degradation pathway of many noxious acyclic, homocyclic, and heterocyclic compounds, which have serious adverse effects. Some of these hydrocarbons can cause harm to humans by either being carcinogenic, like naphthalene, nitrobenzene, and carbazole, or being addictive, like nicotine. Even the simplest of the hydrocarbons like alkanes are capable of causing pneumonia or simply dryness and irritation to the human body. In addition, the acyclic isoprenoids are known to act as a skin irritant or a respiratory and Central nervous system (CNS) depressant. Plasmids, which are small, extrachromosomal deoxyribonucleic acid (DNA) molecules present inside the cell, have the power to replicate independently. This review focuses on the participation of the different active genes of individual plasmids of P. putida responsible for the degradation of different compounds. It also gives a proper degradation pathway for each toxic compound stated above. In this article, the knowledge available in research papers about the compounds and the advantage of using P. putida for its removal for a better, safer, and sound environment is presented in simple language understandable to an initiator, as well as providing comprehensive information for the seasoned researcher in the field.

This study introduces a novel strategy to enhance the removal of polyethylene microplastics (PE-MPs) from wastewater by integrating natural clay minerals into the electrocoagulation (EC) process. The innovation lies in leveraging clay as a synergistic agent to address the inherent challenge of poor floc sedimentation. Experimental results demonstrated that all tested clays significantly improved PE-MP removal, with montmorillonite (0.5 g/L) exhibiting the highest performance. By reducing the absolute zeta potential from −22.67 to +9.85 mV within 3 min of addition, montmorillonite promoted charge neutralization and facilitated the formation of larger, denser flocs via a “net capture and sweeping” mechanism. Under optimal conditions, this synergistic process achieved a high PE-MP removal efficiency of 84.4%. Kinetic and isotherm analysis revealed that the adsorption process followed pseudo-first-order kinetics and the Langmuir monolayer adsorption model. This study confirms that the integration of low-cost natural clay with EC is a highly efficient and promising technology for microplastic remediation.

Pesticide contamination in hospital effluents poses a significant threat to environmental and public health. First-time demonstration of sponge gourd as a low-cost, natural bio-adsorbent for sustainably remediating pesticide-contaminated hospital effluents in West Bengal, India. This study evaluates the concentrations of chlorpyrifos (CPF) and cypermethrin (CPM) residues in hospital effluents and surrounding environments in West Bengal, India, highlighting the urgent need for mitigation. CPF levels were detected between 43.33 and 343.3 µg/L in wastewater, and 6.33 and 61 µg/L in soil, whereas CPM concentrations ranged from 8.66 to 80 µg/L in water and 0 to 300 µg/L in soil. These values surpass the FAO/WHO maximum residue limit (MRL) standards, with pond water being significantly affected. Gas chromatography (GC) was employed to quantify pesticide levels accurately. To address contamination, the study explored the potential of low-cost natural bio-adsorbents, such as sponge gourd, for decontamination. Following 72 h of incubation with sponge gourd (Luffa cylindrica), clearance rates of 51.33% for CPF and 82.5% for CPM were observed, demonstrating its efficacy as a sustainable remediation method. The findings underscore the harmful impacts of pesticide pollution on aquatic ecosystems and public health, emphasizing the importance of developing effective, eco-friendly solutions. This study is the first to demonstrate the use of sponge gourd (L. cylindrica) as a low-cost, natural bio-adsorbent for sustainably removing pesticide contamination from hospital effluents in West Bengal, India.

The co-contamination of cadmium (Cd) and lead (Pb) in paddy soil poses a significant threat to rice safety. While interactions between Cd and Pb are well-documented, no prior study has systematically examined their tissue-specific accumulation and transport dynamics across rice organs. Through pot experiments with varying Cd (1.14, 1.95, and 3.87 mg kg⁻¹) and Pb (55.75, 105.71, and 244.59 mg kg⁻¹) treatments, we demonstrate that Pb250 (244.59 mg kg⁻¹) substantially enhanced Cd accumulation in all rice tissues. Notably, brown rice Cd reached 0.51 mg kg⁻¹ under Cd2Pb250, exceeding China's safety limit (0.2 mg kg⁻¹) by 155%. Root Cd content peaked at 51.02 mg kg⁻¹ under Cd4Pb250, while Pb increased Cd transport in vascular tissues (internodes/nodes) by 54%. In contrast, Pb accumulation was concentrated in the roots (1125 mg kg⁻¹ under Pb250) but remained below 0.15 mg kg⁻¹ in grains. This study represents the first comprehensive quantification of Cd–Pb antagonism and synergism effects across 14 rice tissues, providing critical mechanistic insights into Pb's role in exacerbating Cd grain translocation and informing targeted remediation strategies for co-contaminated paddies.