Water, Air, & Soil Pollution最新文献

The land use/land cover pattern of a region is an outcome of natural and socioeconomic factors and the utilisation by humans in time and space. This study aims to model the marine water quality using the relative impact of land use on marine water quality of selected river estuary between 2006-2013, Geographical Information System (GIS) and Cellular Automata (CA)-Markov method as a planning tool in evaluating Marine Water Quality Index (MWQI) were applied. The CA-Markov model revealed agricultural land use changes from 2006-2013 using land use land cover (LULC) in GIS as Setiu and Semerak River basins have 5.72% and 2.75%, respectively. The result indicated the impact of agricultural lands on MWQI, which is very low, according to projections of land use in 2020. Thus, the MWQI value in 2020 (Setiu 76.27 and Semerak 67.64) will be higher than MWQI mean value for 2006-2013.

Geochemical reactions and anthropogenic activities are a source of heavy metal concentration in aquatic bodies leading to serious detrimental effect to the environment because of its non-biodegradability. Bentonite, a smectite group of minerals has layered structure based on sheets having 2:1 structure i.e. one octahedral sheet sandwiched by 2 tetrahedral sheets. The bentonite was characterised by PXRD, FTIR, TGA and DSC experiments and the surface area was known by BET analysis. A weight loss of 14% and diffraction pattern of PXRD confirmed presence of Montmorillonite unit in the inner part. Bentonite acts as a natural scavenger of heavy metal toxicants .Owing to high cation exchange capacity, high surface area and intercalation properties, bentonite mineral has been used as a potential remover of heavy metals. The kinetic and thermodynamic studies were done in order to determine the remediation potential at pH 2 to 8. Langmuir, Freundlich and Temkin adsorption isotherms were employed to give an insight into the adsorption mechanism. The experimental data revealed that first order kinetics was followed during the adsorption of heavy metals onto modified bentonite. Maximum percentage removal of Cr(VI) and Mn(VII) was 80 and 55.5 respectively. Thus locally available bentonite may be utilised as a low cost and eco-friendly alternative of heavy metal removal.

Biochar-zero-valent iron composites are promising materials for the removal of heavy metals from aqueous solution, but further research is still required on the co-removal of multiple heavy metals. This paper presents the performance, effects and mechanisms of peanut shell biochar (BC)-supported zero-valent iron (ZVI) composites in the co-removal of Cd(II) and Cr(VI) from aqueous solution. Samples were subjected to the isotherm test, the kinetic test, the adsorption performance test and microscopic tests, and impact factors such as initial pH, reaction time, dosage and BC/ZVI mass ratios were considered. The results show that the removal efficiency of biochar-zero-valent iron composites for Cd(II) and Cr(VI) co-removal is significantly higher compared to individual applications of zero-valent iron and biochar. Under the condition of dosage of 0.2 g, initial pH = 4.0, and BC/ZVI mass ratio of 4:1, the removal efficiency of Cd(II) and Cr(VI) can reach 98.66% and 98.45%, respectively. In this case, the maximum adsorption capacity of Cd(II) and Cr(VI) can reach 20.44 mg/g and 3.70 mg/g. The removal of Cd(II) follows the pseudo-second-order and Freundlich model, whereas the removal of Cr(VI) is better fitted by pseudo-first order and Langmuir model. The co-removal process of Cd(II) and Cr(VI) can be divided two phase, and the mechanisms of Cd(II) and Cr(VI) are also remarkably distinct. The reduction, adsorption, complexation or co-precipitation are the dominant mechanisms for Cr(VI) removal, while the complexation of biochar and adsorption of the iron oxyhydroxide layer predominate for Cd(II) removal.

This work is concerned with the cyanide removal from aqueous solution by oxidation with hydrogen peroxide H₂O₂ catalyzed by copper zinc oxide (CuO-ZnO) nanoparticles prepared by co-precipitation method. The influences of catalyst dose, hydrogen peroxide concentration, temperature, and catalyst stability on cyanide removal were examined. The use of CuO-ZnO nanoparticles made it possible to increase the reaction rate, thus showing good catalytic activity. The cyanide removal percentage was increased after 75 minutes of reaction time from 70% to 100% by raising the catalyst dose from 0.25 g/L to 1.0 g/L. Increasing the temperature from 24 °C to 35 °C enhanced cyanide removal rate, the apparent activation energy was then found to be equal to 48 KJ/mol. The nanocatalyst was used again for four successive times and exhibited good stability. The kinetics of cyanide elimination was found to be pseudo-first order with respect to cyanide.

The widespread use of fossil fuels in daily commuting vehicles poses a significant health risk to urban populations. This study aims to quantify the escalation of black carbon (BC) emissions from traffic and assess their environmental impact. BC monitoring was conducted using a motorcycle to estimate mobile concentrations emitted by vehicles along two distinct routes during three phases (M-period, A-period, and E-period). The average mobile BC concentration (± SD) was found to be 32.57 ± 22.78 μg m-3, with the highest average value observed during the E-period at 34.1 μg m-3 for route-1. In route-2, BC concentration was 29.12 ± 21.08 μg m-3, with the mean highest at 33.4 during the E-period. The likelihood of increased BC emissions is evident when individuals venture out to markets in the evening. Weekend BC concentrations (25.76 μg m-3) were generally lower than weekdays (39.38 μg m-3) during the analysis of route-1. A similar trend was observed in route-2, attributed to reduced traffic volume and vehicular emissions resulting from the closure of schools and offices on weekends. Throughout the study, BC levels ranged from 10.91 to 149 μg m-3 in TR-1 and 9.76 to 114 μg m-3 in TR-2. Notably, at five intersection points on TR-1, BC concentrations at T102 were 34% higher during evening times than at T105. Similarly, among the four intersection points on TR-2, BC levels at T201 were 55% higher than T203 during the evening. Our analysis also showed that inhalation doses (IDOSE) were highest during peak traffic times, with motorcyclist IDOSE ranging from 15.29 to 25.01 µg. This study highlights the concerning levels of BC exposure during daily commuting, emphasizing the need for measures to mitigate the health impacts associated with urban traffic emissions and promote a safer environment for urban populations.

Limited data on rural Poland's atmospheric ion concentrations exists, with no publicly available monitoring data in urban areas. These knowledge gaps hinder the comparison of concentrations across environments and the identification of their sources. This study examines water-soluble ions across five rural locations in Poland over four years to investigate their concentrations and sources in the atmosphere. This study explores aerosol origins, performing a four-year correlation analysis across five locations to reveal ion relationships. Notably, sulfate (SO₄²⁻), nitrate (NO₃⁻), and ammonium (NH₄⁺) exhibit significant correlations ranging from 0.3 to 0.8, suggesting a common pollution source in all analyzed rural locations. Interestingly, magnesium (Mg²⁺) and sodium (Na⁺) in two locations demonstrated a strong correlation, ranging between 0.4 and 0.9, suggesting the influence of sea spray on these sites. Principal component analysis is used to investigate the factors influencing ion concentrations, revealing distinctive patterns for each location and explaining the total variances ranging from 74.9% to 84.8%. This underscores the significance of geographical and environmental factors. The study's novelty lies in its thorough and long-term analysis of water-soluble ion concentrations across rural Poland, providing an extensive dataset for the region. The study fills a data gap on rural pollution sources and reveals consistent ion patterns across different sites and seasons. The findings emphasize geographical and environmental impacts on aerosol composition and suggest common pollution sources for all areas. This research encourages further investigations into the stability and origins of ions in rural environments, providing valuable insights for local and broader atmospheric studies.

In order to control the eutrophication of rivers or lakes by dredging, a large amount of sediment has been generated, making the treatment of dredged sediment a challenging issue. In response to this problem, we have successfully synthesized an innovative composite amendment for reusing dredged sediment, which included Fe-loaded biochar (Fe@BC), clinoptilolite, wheat straw, and 3,4-dimethylepyrazole phosphate (DMPP). Tests for adsorption and characterization showed that Fe@BC and clinoptilolite, as the main components of the amendment, have excellent adsorption performance for orthophosphate (Ortho-P) and ammonium nitrogen (NH₄⁺-N)/potassium ions (K⁺), respectively. The results of column leaching experiment demonstrated that the addition of 4%-5% amendment of the sediment mass could not only significantly reduce the leaching of nitrogen (N), phosphorus (P), and potassium (K), but also effectively slowed down the movement of N, P, and K in the sediment profile. Moreover, the bulk density, moisture retention, and particle size of sediment were simultaneously improved.

Urban areas worldwide face significant challenges from increasing air pollution, posing health risks and environmental concerns. Lahore, a major city in Pakistan, is particularly affected by severe air pollution due to rapid industrial growth, high vehicle emissions, and various human activities. Traditional air quality monitoring methods, while effective, are often costly and complex, limiting their widespread use. This study investigates a dual monitoring system combining passive biomonitoring with spider web silk and active measurements using portable instruments to assess airborne pollutants in urban environments. Spider webs, collected from various sites in Lahore, were analyzed for heavy metals, while portable instruments simultaneously measured PM_2.5, PM₁₀, total volatile organic contents, formaldehyde, and carbon monoxide at the same locations. A spatial distribution analysis using GIS and statistical analysis revealed a pattern with significant changes as per land use in the urban environment related to anthropogenic activities. The Principal Component Analysis revealed three distinct clusters of pollutants origins consisting of: I) effluent drains and landfills, II) construction sites, and III) residential areas. The concentrations of Hg in spider silk (average ~ 2.66 mg/kg) were found to be significantly higher in the northeastern part of Lahore, with a similar trend observed in Cd, Cu, Ni, and As levels (average ~ 15.45, 102.87, 31.72, and 6.64, respectively). Several-fold changes in levels and spatial distribution of Pb (15.12 to 356.41 mg/kg) showed a higher concentration in the northern and northeastern parts of Lahore. The spatial variation pattern of Cr (average~ 57.04 mg/kg) registered a higher concentration in southwestern Lahore. Ambient air levels of measured pollutants followed almost similar patterns in spatial distribution. PM_2.5 and PM₁₀ measured higher levels (195 and 226 μg/m³, respectively) in the southwestern and northwestern areas, with a similar pattern of variation observed in TVOC (average ~ 0.14 μg/m³). The concentration of HCHO (average ~ 0.003 μg/m³) was higher in the southwest of Lahore. All measured pollutants registered higher values than air quality standards. Particulate matter is the most dominant pollutant contributing to air pollution (up to 20x higher than WHO guidelines). The findings support the use of a dual monitoring system, integrating passive spider web silk biomonitoring and active portable instruments, as a scalable and sustainable solution for air quality management. This approach holds potential for global application in diverse urban environments, with future research focusing on further validation and integration with advanced remote sensing technologies to enhance air quality monitoring and contribute to improved public health and environmental management worldwide. Hence, this research work points to the pote

Microplastics (MPs) are greatly released into soils in different ways, specifically through mulching practices in irrigated loess soils in northern Iran as the fertile and susceptible soils to water erosion. This study was conducted to examine the effects of Polyethylene (PE) (a common kind of MPs used in mulching farming in loess soils of north Iran), in a Loess soil under an experimental study. A loess soil was collected from 0- 30 cm surface and incubated at two levels of PE (2.5 and 5 % by weight) in two sizes (1-2 mm and >2mm) for 60 days, at 70% of field capacity moisture and temperature of 25-28 ° C. Soils samples were collected in 1, 15, 30, 45 and 60 days after incubation and different soil chemical, physical, mechanical and biological properties were measured. The results showed that soil pH was significantly (P<0.05) reduced by timing (time after incubation), and application rate of MPs. Inclusion of MPs led to increasing bulk density significantly (P<0.05) and also led to reducing aggregation and mean weight diameter (MWD) compared to control soil. The rate of MWD decreasing varied from 79 % to 87 % in different rates of MPs application. Among the mechanical attributes, liquid limit, plastic limit, and plastic index, all were reduced significantly (P<0.05) after mixing up and incubation with MPs. Reducing aggregation and aeration in treated soils compared to control soils, led to lowering soil microbial respiration, especially with timing. As our results about the effects of MPs in loess soils in a few cases were contrary to other soils studied worldwide, further studies are recommended to perform in loess soils in northern Iran, where receive considerable MPs by farming and open landfill practices in the studied region.