The large-scale dredging of lake sediments generates substantial sludge, presenting both environmental challenges and opportunities for agricultural reuse. This study evaluated the effects of blended sediment on crop growth and soil heavy metal safety using sediments from Gehu Lake, China. A field experiment employing a rice-wheat rotation compared three treatments: a control (CK, no sediment), raw sediment (Sed), and blended sediment (B-Sed: 90% sediment, 5% compost, and 5% river sand), all applied at 60 t ha-1. The blended sediment significantly enhanced crop performance: Wheat and rice yields increased by similar to 26% and 52% compared with CK, without elevating grain sterility. Both sediment treatments improved soil quality, elevating soil organic matter (by 17% in Sed and 61% in B-Sed), nutrient availability, and soil structure. Concentrations of heavy metals (Cd, Pb, As, Hg, Cu, Ni, Zn, and Cr) in soils and grains remained below China's national safety standards (GB 15618-2018, GB 2762-2022). Risk assessments confirmed low environmental ecological risk. A USEPA-model-based health risk assessment indicated that the total hazard index (THI) and total carcinogenic risk (TCR) for both adults and children were within acceptable limits, with the B-Sed treatment posing the lowest risk. In conclusion, blended dredged sediment effectively enhanced soil fertility and crop yields in a rice-wheat enhance soil fertility and crop yields, supporting its sustainable reuse in agriculture.
This innovative waste management strategy examines a triad mixture of laterite soil (LS), peat soil (PS), and rice husk (RH) for managing heavy metal migration in landfill daily covers. Heavy metal contamination in groundwater presents significant environmental challenges in Malaysia, highlighting the need for effective remediation. The research evaluates the LS-PS-RH mixture's ability to mitigate leachate generation and reduce metal contamination. Laboratory assessments, including surface physical morphology and adsorption tests, were performed to determine the mixture's effectiveness. Using Central Composite Design (CCD) for optimization, optimal conditions for maximum heavy metal removal at an initial concentration of 5.76 mg/L were identified. Validation experiments confirmed the model's predictions, with error ranges of 0.54%-4.74%. Although Ni removal showed a slightly higher error at 6.75%, the model remains valid. The 50LS:40PS:10RH mixture demonstrates promise as a sustainable solution for landfill daily covers, effectively controlling heavy metal migration and ensuring environmental protection.
This study numerically investigates the three-dimensional flow characteristics within a hybrid spur dike field to evaluate how alternating impermeable (I) and pile (P) spur dikes influence channel hydraulics and sediment transport potential. Using ANSYS Fluent with the standard k - epsilon model, six geometric configurations (each maintaining identical first and last impermeable spur dikes) and three discharges were simulated to analyze the effects of permeability ratio and spatial arrangement on internal circulation and velocity distribution. Results show that impermeable spur-dike field systems generate a single compact recirculation cell extending over approximately 4-5 m, with near-bank velocity reductions exceeding 70%, leading to strong stagnation and sediment-deposition potential. In contrast, hybrid configurations (particularly the balanced 3I-2P and fully hybridized 4I-3P layouts) develop multiple smaller vortices that enhance shear-layer instability and fluid exchange between the main flow and the inner zone. The 4I-3P configuration achieved the most favorable hydraulic performance, shortening the reattachment length to 3.3 m (50% reduction relative to the impermeable case) and increasing near-bank velocities to 0.12-0.15 m s-1. These results indicate a 40%-65% improvement in momentum redistribution and a 60% reduction in stagnation area compared to impermeable layouts. Overall, the findings demonstrate that an equal or well-distributed combination of impermeable and pile spur dikes provides the optimal balance between flow conveyance and morphological stability. The proposed hybrid system offers a hydraulically efficient and sustainable approach for enhancing flood-carrying capacity and reducing sediment accumulation in long river reaches.
Cropland is a significant source of nitric oxide (NO) in rural areas. We extracted field measurement data from peer-reviewed publications and conducted a pairwise meta-analysis, with major objectives (1) to quantify the variations of NO emissions and direct emission factors (EFds) across Chinese cropland, and (2) to evaluate the impacts of various mitigation strategies on NO emissions and EFds. Cropping systems included paddy rice-winter wheat, vegetables, maize-winter wheat, orchards, and tea plantations. The dataset comprised 650 and 427 records of NO emissions and EFds, respectively, from 71 publications (2006-2026). Mean seasonal NO emissions were 0.49, 2.23, and 1.71 kg N ha-1 for paddy rice, winter wheat, and vegetables, respectively. Mean annual NO emissions were 1.33, 1.78, and 5.89 kg N ha-1 for maize-winter wheat, orchards, and tea plantations, respectively. Mean EFds were 0.16%, 0.70%, 0.79%, 0.31%, 0.17%, and 1.47% for paddy rice, winter wheat, vegetables, maize-winter wheat, orchards, and tea plantations, respectively. Tea plantations and vegetable systems were identified as major sources of NO emissions. Reducing nitrogen input rates significantly decreased NO emissions by 33% on average, but had nonsignificant effects on EFds. Organic amendments, straw retention, and the application of biochar or enhanced-efficiency fertilizers reduced NO emissions (ranging from -37% to -16%) and EFds (ranging from -49% to -13%). These findings provide a basis for effectively mitigating NO emissions from Chinese cropland.
Toxic elements (arsenic, cadmium, lead, and mercury) are public health concerns and listed as priority pollutants for their severe toxic effects, especially in children, whose biological systems are developing. The aim of this study was to determine the concentrations of toxic elements (As, Cd, Pb, and Hg) in plastic utensils using x-ray fluorescence and specific migration tests. The utensils were cleaned with an Extran detergent and analyzed using a portable XRF analyzer. Specific migration tests were conducted using water and 3% acetic acid as food simulants under two test conditions: rapid (2 h at 40 degrees C) and long (10 days at 25 degrees C), followed by inductively coupled plasma mass spectrometry analysis. A total of 54 utensils were analyzed, revealing mean concentrations of Cd, Pb, As, and Hg of 20.9, 31.3, 10.4, and 14.45 mg kg-1, respectively. Alarmingly, Cd, Hg, and Pb exceeded specific migration limits on the rapid tests by factors of 18.6, 34.5, and 5027, respectively, whereas Hg and Pb exceeded limits on the long tests by factors of 2 and 22, respectively. Statistical analyses confirmed significant associations between utensil type/color and element concentrations. The high levels of toxic elements found underscore the urgent need for coordinated action to protect health and ensure food and environmental safety.
A comprehensive investigation was conducted to evaluate the levels of radon (Rn-222), thoron (Rn-220), and their offspring in the interior habitats of Moga District, Punjab, India. SSNTD-based progeny sensors (DRPS/DTPS) and single-entry pinhole dosimeters following the standard approach advised by BARC, Mumbai, India, were used. The measured annual average Rn-222 level ranged from 16 to 65 Bq m(-3) with an average of 33 +/- 4 Bq m(-3), which was found well below the recommended level of 300 Bq m(-3). Annual Rn-220 concentration varied from 17 to 114 Bq m(-3), with an average of 47 +/- 12 Bq m(-3) exceeding 10 Bq m(-3) (worldwide thoron average) suggested by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Seasonal variation was observed as rainy > winter > summer. The Rn-222 progeny annual average level (EERC) falls short of the UNSCEAR-recommended global threshold of 15 Bq m(-3), with values ranging from 7 +/- 0.8 to 22 +/- 1.5 Bq m(-3) and a mean of 12 +/- 1.0 Bq m(-3). The Rn-220 progeny yearly average concentration (EETC) is higher than the UNSCEAR-recommended worldwide value of 0.5 Bq m(-3), ranging from 0.39 +/- 0.06 to 2.45 +/- 0.14 Bq m(-3) with a 0.88 +/- 0.09 Bq m(-3) mean value. The average yearly effective dose was 0.94 mSv year(-1), well within the International Commission on Radiological Protection (ICRP)-recommended safety limits of 14 mSv year(-1) for houses. The results highlight the necessity of ongoing surveillance and preventative measures to guarantee indoor air quality and protect public health.
Interfacial solar vapor generation presents a promising avenue for sustainable freshwater production. However, its practical implementation is impeded by high energy cost, salt accumulation, and unstable water supply. Inspiration, drawn from natural reeds, effectively transports water across long distance. The evaporator utilizes the hierarchical and porous vascular bundles as optimal channels for spontaneous water pumping. Various reeds are systematically evaluated before and after delignification. These findings show that the reeds with hollow structure facilitate thermal localization through their internal air gaps while enabling rapid vapor escape via its central cavity. This innovative design yields the superior evaporation performance that significantly exceeds that of solid reeds, exhibiting a distinctive and positive size effect up to a certain scale. Microscopic characterization indicates that the microstructures of hollow reeds, coupled with enhanced hydrophilicity resulting from delignification, collectively ensure rapid capillary water transport. Furthermore, numerical simulations confirm that the evaporation performance can be further optimized by adjusting wall thickness. This work introduces a bio-inspired structural prototype spanning both micro- and macroscales for water evaporation. It demonstrates the substantial potential of engineered natural materials for automatic pumping, structural stability, and resistance to salt fouling within sustainable water purification technologies.
The lack of fresh water is a global issue that affects the survival of living beings. An effective way to address the impending water issue is to collect fresh water from the atmosphere. This study focuses on developing a sustainable and eco-friendly atmospheric water harvesting system utilizing a polydimethylsiloxane (PDMS) elastomeric network. The water harvesting system was fabricated by dip-coating cotton mesh with PDMS and PDMS-tetraethyl orthosilicate (TEOS). The water accumulation capability of the PDMS elastomeric mesh (PEM) and TEOS-modified PEM were evaluated over 7 h, and the volume of water collected during each hour was quantified. The physicochemical and mechanical characterizations of the PDMS and PDMS-TEOS films were also performed. The PEM demonstrated the capability to gather 2.71 +/- 0.22 kg m(-2) water, and the addition of TEOS increased the water collection to 4.09 +/- 0.16 kg m(-2). Modifying elastomeric mesh with TEOS significantly improved the water harvesting rate by 50.92% (p < 0.05). The hydrophobicity of the PDMS and PDMS-TEOS films are assessed by static contact angle measurements, and there is a significant reduction in the hydrophobicity of PDMS from 115.47 degrees +/- 2.05 to 106.9 degrees +/- 3.33 with the addition of the TEOS (p < 0.05).
This study systematically investigates how ferrihydrite (Fh) amendment influences enrofloxacin (ENR) sorption in northwest China's agricultural soils, addressing the critical gap in understanding Fh-antibiotic interactions under realistic field conditions. Our results reveal that Fh amendment exerts a conditional dual effect on ENR sorption in soils: Under acidic to neutral conditions (approximately pH 4-6) and low ionic strength, low Fh dosages enhance sorption, whereas under alkaline conditions (pH > 8) or at high Fh dosages (>= 6%), sorption is inhibited, likely due to competitive sorption and site blocking. Maximum enhancement (8.24%) occurred with 4% Fh. Both pristine and Fh-amended soils reached equilibrium within 2 h, with pseudo-second-order kinetics providing the best fit. Linear models effectively characterized the thermodynamic sorption process. Analysis of sorption affinity at different temperatures showed both low and high temperatures reduced promotional effect of Fh on ENR sorption in soils. Under acidic conditions, protonation of the hydroxyl functional groups of Fh alters surface charge, decreasing the ENR sorption capacity of soil. Fh exhibits optimal enhancement of ENR sorption in weakly alkaline soil conditions. Notably, Fh addition strengthens the sorption-promoting effect of low-concentration cations, primarily through cation-bridging mechanisms. However, Fh reduces the NH4+-enhanced sorption effect due to weakened electrostatic sorption and intensified competitive sorption. The sorption-enhancing capability of Fh originates from its abundant surface functional groups and pH-dependent charge characteristics. These findings demonstrate that appropriate Fh addition can effectively improve ENR immobilization, offering insights for agricultural soil management strategies.
Groundwater contamination by arsenic (As) and related hydrochemical components poses major threats to human health and food safety in South Punjab, Pakistan. To assess aquifer susceptibility and establish the relatively safest groundwater source for domestic use in Multan City, this study methodically assessed depth-dependent variation in arsenic and important physicochemical properties. Sixty-four groundwater samples at four urban areas at three depth intervals (100, 200, and 300 ft) were measured and analyzed on 12 physicochemical parameters. The obtained results were compared with drinking water recommendations by the World Health Organization (WHO) to find out the level of compliance and risk exposure. The contamination was more prevalent in shallow aquifers (100-200 ft) with electrical conductivity (323-1193 & micro;S/cm), alkalinity (2.22-5.77 mmol/L), calcium (28.75-73.7 mg/L), bicarbonate (111-288 mg/L), and potassium (2.16-20.35 mg/L) above the WHO limits, but chloride, hardness, magnesium, total dissolved solids, and pH remained within safe limits. The level of contamination of arsenic (28.75-48.75 & micro;g/L) was higher than the WHO recommended value of 10 & micro;g/L in all the depth ranges, which proves the consistent geogenic contamination regardless of the aquifer depth. Sodium levels (38.25-101.75 mg/L) were less than 200 mg/L but greater in the shallow areas. The overall quality of groundwater improved with depths, with the safest being 300 ft, followed by 200 and 100 ft. This depth-sensitive evaluation presents new data on aquifer-specific contamination trends in Multan and confirms the increased risk of chronic exposures in shallow aquifers, supporting the selective groundwater abstraction and targeted treatment of the shallow aquifers along with risk-informed water resource management approaches in arsenic-prone areas.
Composting of municipal solid waste (MSW) is a sustainable approach for organic waste management; however, the performance of different methods varies considerably in terms of nutrient recovery and heavy metal stabilization. Integrated comparative studies that simultaneously evaluate nutrient quality, heavy metal behavior, seasonal variability, and overall compost suitability under identical conditions remain limited. In this study, source-segregated MSW was collected from an urban residential area and processed under controlled conditions using windrow composting (WC), vermicomposting (VC), and inoculated microbial composting (IMC). Compost quality was evaluated through physicochemical parameters and composite quality indices within a multi-parameter assessment framework. Fertilizing parameters, heavy metal concentrations, nutrient enrichment index (NEI), clean index (CI), fertilizing index (FI), and removal efficiencies were determined, and differences among treatments were statistically analyzed using one-way analysis of variance (ANOVA) (p < 0.05). The results demonstrated that VC achieved the most balanced compost quality, recording the highest FI score (6/6) due to optimal carbon-to-nitrogen (C:N) ratio, enhanced nutrient retention (N approximate to 1.9%, P approximate to 0.6%, K approximate to 1.6%), and biological stability. IMC exhibited rapid decomposition and exceptional removal efficiencies (>95%) for Pb, Cr, Cu, and Ni, resulting in the lowest CI value; however, substantial organic carbon depletion and reduced phosphorus levels led to a lower FI score (3/6). WC, although cost-effective and operationally simple, showed moderate performance in both nutrient recovery and heavy metal stabilization. All composts complied with Indian regulatory standards, whereas comparative benchmarking against international standards indicated superior agronomic suitability for VC. Seasonal evaluation further revealed that the composting method exerted a stronger influence on final compost quality than climatic variability. Overall, the integrated assessment identifies VC as the most reliable technique for producing nutrient-rich and agronomically valuable compost, whereas IMC shows strong potential for heavy metal remediation but requires nutrient optimization. WC remains a practical option for large-scale municipal waste stabilization.
This study examined the influence of leisure activities on the aquatic quality of lakes within Yedig & ouml;ller National Park. Beginning in May 2022, a systematic collection of water samples was conducted on a monthly basis throughout a year-long period, wherein a multitude of parameters, including water temperature, dissolved oxygen, conductivity, pH, turbidity, suspended solids, total nitrogen, total phosphorus, chlorophyll-a, and Secchi depth, were meticulously analyzed. The findings indicated that recreational activities had no statistically significant influence on the examined water quality parameters. Moreover, no significant variations in water quality parameters were identified between regions with high levels of recreational use and those with low levels of participation. This finding suggests that the current level of recreational activity does not negatively influence the aquatic quality of lakes in the Yedig & ouml;ller Region. However, it has been observed that seasonal variations have a significant impact on specific water quality parameters. This finding emphasizes the importance of considering seasonal dynamics for the effective management and preservation of lake ecosystems.
A recyclable magnetic nano-bio composite based on NiFe2O4, halloysite nanotubes (HNTs), and chitin was synthesized and applied for Zn2+ removal from aqueous media. The composite was systematically characterized by Fourier-transform infrared (FT-IR), x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), BET, vibrating sample magnetometry (VSM), and energy-dispersive x-ray spectroscopy (EDS) and exhibited rapid adsorption kinetics (equilibrium was reached within 10 min) with a maximum uptake of 357.14 mg/g at pH 6 and 25 degrees C. Adsorption followed the pseudo-second-order and Langmuir models, indicating a chemisorption-controlled monolayer process. Thermodynamic parameters confirmed that the adsorption process was spontaneous and exothermic. The material showed high reusability over 10 consecutive regeneration cycles, underscoring its stability. To demonstrate its environmental relevance, Zn2+ monitoring data from the Persian Gulf Special Economic Zone (PGSEZ) demonstrated that shoreline concentrations frequently exceed international guideline values, highlighting urgent need for effective remediation strategies. Overall, the proposed composite thus represents not only a high-performance sorbent for aqueous Zn2+ removal but also a practical and sustainable option for coastal management strategies aimed at mitigating heavy metal pollution in marine ecosystems such as the Persian Gulf.
The transportation sector is one of the major potential contributors to air pollution in urban regions, which is more harmful to human health. The concentration of quasi-ultrafine particles is found to be higher in terms of number concentration but lower in terms of mass concentration. Delhi is known for its frequent pollution events, and various mitigation measures have been implemented over time to reduce the pollution load. The odd-even scheme for vehicular movement is one among several mitigation measures introduced for the third time in Delhi. Particle number concentration (PNC) variation during the implementation of the scheme was measured and analyzed in three major locations: Najafgarh, Pitampura, and Panchkuian. The study revealed that the quasi-ultrafine PNC was reduced by around 30.4%, 30%, and 28.4%, respectively, in all three monitoring locations. The total vehicle count (TVC) showed a 26.7% reduction on odd days and a 24.9% reduction on even days, whereas reductions of 27.4% and 24.8% occurred in cars and taxis, respectively, for both odd and even days. In all locations, the concentration reduction obtained was greater on the odd days compared to the even days. Introducing such schemes will be beneficial in mitigating air pollution during extreme events, and source-specific actions are necessary to achieve and maintain good air quality in the long run.
Microbial inoculation represented a promising strategy for mitigating ammonia emissions during kitchen waste composting. Herein, two strains of thermophilic deodorizing bacteria (Bacillus licheniformis and Bacillus subtilis) were isolated and formulated as thermophilic microbial (TM) agent. During the 30-day composting process, compared to control group (CK), the TM agent extended the high-temperature period in the composting process by 2 days. TM agent significantly reduced the concentrations of NH3 and H2S by 38.88% and 17.47%, whereas the nitrate nitrogen (NO3 --N) and total nitrogen (TN) content increased by 15.44% and 6.69%, respectively. Furthermore, the application of TM significantly increased humus content by three-dimensional fluorescence spectroscopy and humus analysis. Additionally, the inoculation of TM agent enriched chitin-decomposing (Chitinophaga) and ammonia-assimilating (Streptomyces) bacteria. From the perspective of nitrogen cycling, the transformation of ammonium nitrogen (NH4 +-N) was the key process for promoting nitrogen retention. The redundancy analysis (RDA) indicated that the transformation of NH4 +-N was the key process for promoting nitrogen retention during the TM agent inoculation. Therefore, thermophilic deodorizing bacteria were identified as a potential inoculant to improve humus formation and enhance nitrogen conservation during kitchen waste composting.
Access to safe drinking water remains a major challenge in Sub-Saharan Africa, where surface water is frequently contaminated. This study evaluates the effectiveness of local charcoal from avocado trees (Persea americana), corn cobs, and eucalyptus (Eucalyptus spp.) in improving the potability of river water, with a view to proposing simple and accessible solutions for rural communities. The charcoals were obtained by pyrolysis of local biomass, then crushed, sieved, washed, dried, and sterilized. The physicochemical composition of the coals was evaluated using standard methods: thermogravimetric analysis, x-ray fluorescence, and pH measurement. Low-flow filtration devices, such as gravity-fed packed columns, were set up in the laboratory, with each material being tested in triplicate. Physicochemical and bacteriological parameters were analyzed before and after filtration using standard APHA methods. The data were processed using the Kruskal-Wallis test (alpha = 0.05). Filtration led to an overall decrease in microbial load. Avocado charcoal showed the best bacteriological performance, with total elimination of fecal coliforms and more than 98% elimination of total coliforms and Escherichia coli. Eucalyptus charcoal particularly reduced fecal streptococci (96.78%). All charcoals significantly reduced turbidity (82%-90%), with values compliant with World Health Organization (WHO) standards. However, an increase in conductivity, total dissolved solids, and potassium was observed. Avocado charcoal is the most suitable material, thanks to its overall superior effectiveness in removing bacteriological contaminants and reducing turbidity. It is a simple and promising local solution for improving water potability.
Although nutrient dynamics in temperate watersheds are well-documented, the mechanisms governing nonpoint source (NPS) pollution in tropical agricultural catchments remain poorly understood, particularly regarding the interplay between monsoonal transitions and diverse crop layouts. This study investigates the spatiotemporal dynamics of nitrate (NO3) and phosphate (PO4 3-) in the Machap Dam catchment, Malaysia, to bridge the gap between land-use intensity and reservoir water security. Utilizing an integrated approach of hydrological monitoring and spatial interpolation across seven strategic sites, the research identifies critical nutrient hotspots primarily driven by oil palm and tapioca cultivation. Findings reveal that early wet-season transitions trigger significant nutrient surges through fertilizer mobilization, surpassing baseline levels and challenging the catchment's natural attenuation capacity. Rather than steady-state pollution, the study identifies "episodic pulses" as the primary threat to water quality. These results provide a transferable framework for managing humid tropical watersheds, suggesting that water security strategies must transition from general oversight to targeted upstream interventions synchronized with seasonal hydrological cycles.
The illicit use of synthetic dyes, which are harmful to humankind's health and aquatic ecosystems, highlights the urgent need for efficient adsorbents in wastewater treatment. This work investigates the adsorption performance, kinetics, and thermodynamics of anionic Congo red (CR) dye removal, using oxidized carbon nanoplatelets (OCNPs). Optimal adsorption was achieved at pH 2.25, 25 degrees C, initial CR concentration of 30 mg L-1, adsorbent dose of 10 g L-1, after 1 h. Fourier transformation infra-red spectroscopy (FTIR) analysis before and after adsorption suggested a predominantly physisorption mechanism, and this trait enhances reusability, thus indirectly supporting the practical applicability of OCNPs. The adsorption data follow the pseudo-second-order kinetic model (R 2 = 0.9998), suggesting adsorption rates governed by adsorption capacity. The negative Gibbs energy at all temperatures and enthalpy changes confirm spontaneous and exothermic processes, respectively, whereas a positive entropy change indicates increased energy dispersal at the solid-liquid interface. Notably, OCNPs achieved high decontamination efficiency under both acidic and basic conditions, demonstrating strong affinity toward CR molecules. These findings position oxidation-tailored OCNPs as effective and low-cost adsorbents with oxidation-induced surface chemistry for the remediation of anionic dye-contaminated wastewater at low adsorbent doses and operational at room temperature. The material demonstrated high adsorption performance without the need for composite formation across a wide pH range or additional functionalization. Furthermore, its surface properties can be systematically controlled with oxygen content/species, providing a straightforward route to tailor adsorption behavior. This approach also reduces production complexity and cost, particularly given the potential derivation of the precursor from renewable biomass sources.
This study examined the influence of conservation agriculture (CA) practices and weed management strategies on productivity, profitability, soil health, and sustainability in a cotton-babycorn-sunnhemp cropping system. A strip plot design comprising 12 treatment combinations was adopted, involving three tillage practices conventional tillage (CT), zero tillage (ZT), and residue retention (R) and four weed management strategies, including recommended herbicides, integrated weed management (IWM), and an unweeded control. Among the treatments, the CT-ZT-ZT system (T-2) combined with preemergence (PE) pendimethalin at 680 g/ha followed by a directed spray of paraquat at 0.6 kg/ha at 20-25 DAS in cotton (T2W1) and early postemergence (EPOE) of topramezone at 12.5 g/ha + 2,4-D at 500 g/ha in babycorn (T2W3), consistently recorded the lowest weed density and dry weight and the highest weed control efficiency (>70% at 30 DAS). These treatments resulted in significantly higher crop productivity, profitability, and postharvest soil microbial populations. The treatment W-2: PE pendimethalin 680 g/ha + brush cutter on 60 DAS registered the lowest total weed seed density (1.33 Nos./pot) and notably lower BLW numbers (0.26 Nos./pot), indicating effective pre-sowing suppression of BLWs. These findings indicate that practicing ZT combined with residue retention and IWM enhance agro-ecosystem sustainability, improve soil biological health, and support efficient and environmentally sound weed control in cotton-babycorn-sunnhemp systems.
Hydrogen sulfide (H2S) is a toxic air pollutant with significant implications for environmental quality and human health. This study assessed ambient H2S concentrations across five selected industrial and urban sites in Nigeria, examined their relationships with meteorological parameters, and evaluated potential noncarcinogenic health risks for adults and children. Measurements were conducted over a 6-month period using a portable gas analyzer, with sampling performed at 3-4 h intervals and averaged over 5 min readings. Mean H2S concentrations varied markedly across sites, ranging from 0.93 +/- 0.76 ppm at petroleum filling stations to 9.31 +/- 1.40 ppm at pig steads, with elevated levels also observed near pig farms and dumpsites. A notable negative correlation was observed between H2S concentration and ambient temperature (r = -0.645), suggesting reduced accumulation at higher temperatures, while wind speed and relative humidity showed no statistically significant influence. Health risk assessment revealed pronounced age-related differences, with hazard quotient (HQ) values for children consistently higher than adults near pig farms and dumpsites. Although HQ values remained below unity across all sites, the elevated relative risk for children indicates potential vulnerability to noncarcinogenic health effects, whereas adult HQ values were lower. Petroleum filling stations recorded the lowest H2S levels and posed negligible health risks. These findings highlight localized H2S pollution hotspots and underscore the need for enhanced air quality monitoring, targeted mitigation strategies, and regulatory interventions, particularly to protect vulnerable populations such as children in high exposure environments.
