Heavy metal ions, such as Cd, Hg, Pb, and As, tend to persist in soil without natural degradation and can be absorbed by crops, leading to the accumulation of agricultural products that pose a significant threat to human health. However, the development of a rapid and efficient technique for identifying heavy metals in agricultural products is essential to ensure health and safety. With the knowledge of the extent of damage caused by heavy metals, it becomes imperative to detect the presence of cadmium in the soil, water, and the environment. This study introduces a novel plate approach for quick and precise colorimetric detection of cadmium ions using the Cd(II)-Chrome Azurol S CAS-2,2 '-dipyridyl dipy-Cetylpyridinium Bromide CPB quaternary complex. Our innovative method has shown that at a reaction solution pH of 11, the optimal concentration ratio is CAS (5 x 10-3 M): dipy (0.1 M): CPB (1.0 x 10-3 M) = 4 mL: 1 mL: 1 mL. The most significant fading alert was observed when the ethylenediaminetetraacetic acid (EDTA) chelator was added dropwise to the CAS detection plate, indicating strong chelation of Cd by EDTA. This laboratory-based study established a foundation for future applications in real environmental sample analysis.
In sensitive ecosystems of the Arctic, even slight disruptions may produce serious damage. Therefore, the extent of contamination in such zones should be evaluated. A comparison was made between concentrations of metals in Sanionia uncinata in three areas of the European Arctic: (1) the vicinity of the Polish Polar Station in the SW part of Spitsbergen on Wedel Jarlsberg Land, (2) Longyearbyen (Spitsbergen) influenced by local sources of pollution and (3) Iceland relatively free from local pollution. The tested hypothesis was that S. uncinata from Iceland contains significantly lower concentrations of metals than the same moss from Spitsbergen. The maximum concentrations of metals in the examined moss from Longyearbyen reached values for Cr and Mn higher than those known as harmful for plants and for Ni and Zn values within the harmful ranges with no visible harmful effects. S. uncinata from Iceland contained significantly lower concentrations of Cd, Mn, Pb compared to this species from Spitsbergen. S. uncinata seems to be a useful indicator for metal fallout in the European Arctic. This study presents the effects of local sources of contamination on metal levels in S. uncinata from Longyearbyen, Wedel Jarlsberg Land and Iceland as well as verification of S. uncinata as a suitable bioindicator in this Arctic area. The benefit of the study is a to better understanding contamination problems of Arctic habitats.
The discharge of heavy metals (HMS) from industrial production has severely damaged the natural environment and human health. To address the challenges posed by heavy metals, a novel almond shell biochar (FeSCTS@nBC) modified with FeS and chitosan (CTS) was prepared. Scanning electron microscopy and X-ray photoelectron spectroscopy observations revealed a uniform distribution of FeS particles on the biochar. Adsorption thermodynamics experiments showed that the maximum adsorbed amounts of cadmium (Cd), lead (Pb), and chromium (Cr (VI) and Cr (III)) in FeS-CTS@nBC were 85.6, 89.63, 94.2, and 75.62 mg/g, respectively. Results of soil incubation experiments indicated that FeS-CTS@nBC had a desirable immobilization effect on heavy metals, decreasing the bioavailability of Cd, Pb, Cr (VI), and Cr (III) by 29.43%, 23.93%, 5.75% and 5.23 %, respectively. Density functional theory (DFT) calculations, revealed that the oxygen-containing functional groups on the biochar exhibited stronger adsorption capacities for heavy metals. Plant potting experiments indicated that the paddy grew well in the soil remediated with FeS-CTS@nBC. The Cd content in the roots and leaves of the paddy after nBCS2 repair was reduced by 28.01 % and 55.73 %, respectively. Overall, this work provides a promising low-cost method with a simple production process for mitigation of heavy metals from water and soil.
Rapid urbanization and industrial growth in China have increased brownfield site reclamation, the sustainable remediation for urban transformation and enhancing ecosystem services. However, traditional brownfield safety assessment strategies impose unnecessary costs since excessive remediation. Herein, a comprehensive system integrated by soil self-purification, potential ecological risks and human health risks is developed to investigate the safety of brownfield sites. Indices, including soil environmental loading capacity (SELC), and Nemerow integrated pollution index (NIPI), were introduced to assess heavy metals (HMs) pollution. Results show that 72.05% of the sites are identified as moderate pollution, where Cd, As, and Cr(VI) are at heavy pollution, incorporating soil self-purification. The average values of potential ecological risk (PERI) reached 6615.00, posing a significant damage to the local ecosystem, and Cd was identified as main ecological hazards in the study sites. Furthermore, the health risk assessment shows that children's health risks are higher than that of adults, with non-carcinogenic risk to children (2.60) and adults (0.41), and carcinogenic risk to children (2.30 x 10-3) and adults (1.12 x 10-4). Utilizing a multi-index decision-making approach, it is determined that 19.30% of the site exhibit high-risk values, between concentration screening (11.40%) and risk screening (83.30%) base on single-indices. The study sheds light on the comprehensive assessment of brownfield site safety.
Heavy metals (HMs) contamination poses a significant threat to environmental matrices, particularly soil, which is essential for food security, agricultural productivity, and key ecosystem services. Understanding how crops respond to HMs is crucial for developing biomonitoring strategies to assess soil contamination and inform remediation efforts. Plants, including crops, exhibit a range of functional traits (FT) that can indicate HMs stress and contamination levels. In this study, we investigated the response strategies of Zea mays L. var. Limagrain 31455, widely cultivated throughout the region of Land of Fires, a critically polluted area of southern Italy, to different concentrations of Zn, Pb, and Cr, corresponding to moderate to severe soil contamination. Functional traits related to the photosynthetic machinery, including gas exchange, chlorophyll fluorescence and reflectance indices, were examined. Root morpho-histochemical analysis were also conducted to correlate early root alterations with any observed changes in these photosynthetic traits. Results revealed distinct response patterns: tolerance to Zn, without adverse effects on photosynthetic traits; resistance to Pb, mediated by increased RD and photoprotection through change in reflectance indices; and sensitivity to Cr highlighted by severe functional impairments of all the studied photosynthetic traits and structural root damages. Functional traits, such as chlorophyll fluorescence parameters and the photochemical reflectance index or normalized difference vegetation index, demonstrated high potential for monitoring HMs stress responses; in addition, morpho-anatomical traits of the root system provided insights into biomass allocation and the capacity of var. Limagrain 31455 to tolerate and adapt to HMs stress. These findings underscore the importance of integrating physiological, anatomical, and spectral analyses to improve the biomonitoring and management of polluted soils and detecting spatial variability in contamination via remote sensing.
The pervasive occurrence of combined metal and antibiotic pollution (CMAP) in agricultural soils is increasingly being recognized as a novel threat to ecosystems. However, the toxicity variations of CMAP compared to single pollution and the mechanisms underlying these changes remain poorly understood. Herein in this study, the toxicities of copper (Cu)/erythromycin (ERY) and lead (Pb)/norfloxacin (NOR) to earthworms (Eisenia fetida) were investigated. These results indicated that a single exposure to ERY and NOR at environmental concentrations had negligible effects on physiological processes. Combined Cu/ERY exposure induced more significant oxidative stress, disrupted energy metabolism, and caused cellular damage than Cu alone, as indicated by altered antioxidant enzyme activities, malondialdehyde and adenosine triphosphate content, elevated reactive oxygen species levels, and apoptosis rates in coelomocytes. Conversely, these adverse effects were mitigated by Pb/NOR exposure compared to Pb treatment alone. Further analysis of the gut microbiota revealed that Cu/Pb-tolerant Bacillus spp. play a critical mediating role in the contrasting toxicity profiles. ERY reduced the abundance of Bacillus spp., diminishing their ability to secrete soluble phosphate to immobilize Cu in the gut and leading to increased Cu absorption and toxicity. NOR enriches Bacillus spp. in the gut, facilitating Pb immobilization and reducing Pb bioavailability and toxicity. The contrast toxicity profile revealed the response of the gut microbiota taxa is the primary determinant of the variation in CMAP toxicity. These findings advance our understanding of the impact of CMAP on soil organisms and highlight the need for comprehensive ecological risk assessments to inform regulatory strategies.
Industrial development has caused significant environmental damage, especially through potentially toxic element (PTE) pollution. Combining pollution indices, health risk assessment, spatial autocorrelation (Moran's I), and receptor modeling (APCS/MLR), this study quantified sources and risks of heavy metals in smelting-adjacent farmland soils, facilitating targeted PTE pollution mitigation. Soil analysis revealed significantly elevated mean concentrations of As (326 mg/kg), Cd (23 mg/kg), Cr (104 mg/kg), Cu (106 mg/kg), Ni (73 mg/kg), Pb (274 mg/kg), and Zn (660 mg/kg), all exceeding Yunnan provincial background values. The average total non-carcinogenic risk index (HIadult = 2, HIchild = 11) and total carcinogenic risk index (TCRadult = 5.52 x 10-4, TCRChild = 6.44 x 10-4) for both adults and children exceeded the threshold (HI = 1, TCR = 1 x 10-04). The results of environmental pollution evaluation show that the overall pollution in the study area is a heavy pollution level. The ACPS-MLR model showed that Cd and Zn in soil mainly came from industrial activities (37%). Cu and Pb were derived from motor vehicle emissions and agricultural activities (20%). As may be derived from agricultural and industrial activities. Furthermore, based on the combination of source apportionalization and the spatial distribution of environmental pollution, the northeastern part of the study area and transportation hubs are the key pollution areas and need to be given priority for treatment. PTEs accumulate in the soil, will be enriched through the food chain, and seriously threaten human health and soil ecological environment. Therefore, this study can provide a basis for identifying, preventing, and controlling the risk of PTEs pollution in soil.
Heavy metals (HMs) contamination is a major issue produced by industrial and mining processes, among other human activities. The capacity of fungi to eliminate HMs from the environment has drawn attention. However, the main process by which fungi protect the environment against the damaging effects of these HMs, such as cadmium (Cd), is still unknown. In this study, some fungi were isolated from HMs-polluted soil. The minimum inhibitory concentrations (MICs) and the tolerance indices of the tested isolates against Cd were evaluated. Moreover, molecular identification of the most tolerant fungal isolates (Aspergillus niger and A. terreus) was done and deposited in the GenBank NCBI database. The results showed that the colony diameter of A. niger and A. terreus was decreased gradually by the increase of Cd concentration. Also, all the tested parameters were influenced by Cd concentration. Lipid peroxidation (MDA content) was progressively increased by 12.95-105.95% (A. niger) and 17.27-85.38% (A. terreus), respectively, from 50 to 200 mg/L. PPO, APX, and POD enzymes were elevated in the presence of Cd, thus illustrating the appearance of an oxidative stress action. Compared to the non-stressed A. niger, the POD and PPO activities were enhanced by 92.00 and 104.24% at 200 mg/L Cd. Also, APX activity was increased by 58.12% at 200 mg/L. Removal efficiency and microbial accumulation capacities of A. niger and A. terreus have also been assessed. Production of succinic and malic acids by A. niger and A. terreus was increased in response to 200 mg/L Cd, in contrast to their controls (Cd-free), as revealed by HPLC analysis. These findings helped us to suggest A. niger and A. terreus as the potential mycoremediation microbes that alleviate Cd contamination. We can learn more about these fungal isolates' resistance mechanisms against different HMs through further studies.
The leaching of excessive heavy metals (HMs) from lithium slag (LS) presents a significant challenge for its use in road engineering, necessitating the development of safe treatment methods. This study employed solidification/ stabilization (S/S) technology to develop a magnesium slag-lithium slag composite solidified material (MS-LS). The deformation and displacement characteristics of MS-LS during destruction were analyzed using digital image correlation (DIC). Various microscopic analytical techniques were used to analyze the stabilization mechanisms of MS-LS towards HMs. Results indicated that adding MS significantly improved the compressive strength and resistance to cracking of MS-LS. The minimum strength of the 8 %-MS group reached 2.7 MPa, meeting the strength requirements for subgrade stabilized soil in a first-class highway under heavy traffic load conditions. The development of strength is attributed to improved structural compactness from particle micro-gradation effects and the cementitious hardening action of C-S-H gel. HMs immobilization was achieved through directional adsorption at active sites within the calcium-rich mineral phase and interlayer adsorption within the C-S-H gel, complemented by a physical encapsulation mechanism that reduces HMs leaching. The immobilization rates of Be(II) and Pb(II) in the 8 %-MS group exceeded 95 %, demonstrating the effectiveness of MS in stabilizing these HMs in LS.
The environment has been damaged due to anthropogenic activities related to the production and consumption of cattle. The present study investigated the pollution potentials of slaughterhouse effluents on groundwater qualities in Ebonyi State Southeast Nigeria, with the specific objectives to determine the effect of slaughterhouse effluents on both microbiological, physicochemical and heavy metal parameters on the quality of groundwater. Eighty-four well water samples were taken in 2022 and 2023 from slaughterhouse locations, and a control location for the determination of physicochemical properties and microbiological contents using standard analytical methods. Datasets were analyzed using Fisher's Significance Least Difference (F-LSD) at 0.05 probability level. The study recorded higher levels of physicochemical, BOD, COD, Salinity, bacterial and fungal counts in the slaughterhouses well waters when compared to the control well water. With the exception of chloride, ammonia, copper and electrical conductivity, all water parameters were significant in both years. The result of the study also demonstrated that, with the exception of ammonia, lead, biological oxygen demand, chemical oxygen demand, salinity, salmonella spp, shigella spp, E. coli, and other coliforms, the majority of the analysed parameters were within the World Health Organisation recommended standard. In addition, as compared to the first year of study, the well water parameters were generally higher in the second year. In order to prevent groundwater pollution, the present study suggests that slaughterhouse effluents be disposed of in an environmentally responsible manner through the segregation of waste materials to prevent groundwater pollution.