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High lead (Pb) levels in agricultural soil and wastewater threaten ecosystems and organism health. Microbial remediation is a cost-effective, efficient, and eco-friendly alternative to traditional physical or chemical methods for Pb remediation. Previous research indicates that micro-organisms employ various strategies to combat Pb pollution, including biosorption, bioprecipitation, biomineralization, and bioaccumulation. This study delves into recent advancements in Pb-remediation techniques utilizing bacteria, fungi, and microalgae, elucidating their detoxification pathways and the factors that influence Pb removal through specific case studies. It investigates how bacteria immobilize Pb by generating nanoparticles that convert dissolved lead (Pb-II) into less harmful forms to mitigate its adverse impacts. Furthermore, the current review explores the molecular-level mechanisms and genetic engineering techniques through which microbes develop resistance to Pb. We outline the challenges and potential avenues for research in microbial remediation of Pbpolluted habitats, exploring the interplay between Pb and micro-organisms and their potential in Pb removal. [ABSTRACT FROM AUTHOR]

Malang City, located in Java, Indonesia, faces significant anthropogenic pressures but remains an important habitat for the endangered Java sparrow (Lonchura oryzivora). Understanding how Java sparrows adapt to environments with high levels of human activity is essential for their conservation. This study focused on identifying the distribution of Java sparrows and investigating their habitat selection within Malang City. The bird positions were recorded within the tree canopy, and the frequency of canopy use by the birds was determined. Living in the middle of the city impacts the metabolism of birds, as indicated by taking samples and measuring the levels of lead found in their droppings and vegetation used. Encounters near the center of human activity show they can utilize buildings and vegetation they utilize. The Java sparrows predominantly utilize plant parts at the tree level, particularly focusing on the middle canopy part of the edge (TTt) and the middle part (TT). Laboratory tests revealed that the plants utilized by the Java sparrow contain high lead levels. Therefore, to conserve the Java sparrow, it is crucial to improve the quality of their habitat to make it more natural and conduct regular health monitoring to ensure their well-being. [ABSTRACT FROM AUTHOR]

The environmental justice literature demonstrates consistently that low‐income and minority communities are disproportionately exposed to environmental hazards. In this case study, we examined cumulative multipollutant, multidomain, and multimatrix environmental exposures in Milwaukee County, Wisconsin for the year 2015. We identified spatial hot spots in Milwaukee County both individually (using local Moran's I) and through clusters (using K‐means clustering) across a profile of environmental pollutants that span regulatory domains and matrices of exposure, as well as socioeconomic indicators. The cluster with the highest exposures within the urban area was largely characterized by low socioeconomic status and an overrepresentation of the Non‐Hispanic Black population relative to the county as a whole. In this cluster, average pollutant concentrations were equivalent to the 78th percentile in county‐level blood lead levels, 67th percentile in county‐level NO2, 79th percentile in county‐level CO, and 78th percentile in county‐level air toxics. Simultaneously, this cluster had an average equivalent to the 62nd percentile in county‐level unemployment, 70th percentile in county‐level population rate lacking a high school diploma, 73rd percentile in county‐level poverty rate, and 28th percentile in county‐level median household income. The spatial patterns of pollutant exposure and SES indicators suggested that these disparities were not random but were instead structured by socioeconomic and racial factors. Our case study, which combines environmental pollutant exposures, sociodemographic data, and clustering analysis, provides a roadmap to identify and target overburdened communities for interventions that reduce environmental exposures and consequently improve public health. Plain Language Summary: Our study focused on Milwaukee County, Wisconsin, where we examined how people in this region were exposed to different types of pollutants. We found that areas with the highest levels of pollution (e.g., lead, nitrogen dioxide) had a higher proportion of Black residents and residents that experienced social and economic challenges (e.g., unemployment, poverty, and low education). Our work adds to the growing evidence that patterns of pollution and economic challenges are not random, but rather, racially and socially structured. By understanding these patterns, we can develop policies that reduce pollution in these areas and improve the health for residents in these overburdened communities. Key Points: We examine cumulative exposures to multiple pollutants and their association with socioeconomic and racial disparities in Milwaukee CountyWe highlight census block groups that are most vulnerable to pollution and low socioeconomic status (SES), which can be prioritized for regulatory interventionsPeople of color in Milwaukee County are not just exposed to high pollution, they are often exposed within the context of low SES [ABSTRACT FROM AUTHOR]

High lead (Pb) levels in agricultural soil and wastewater threaten ecosystems and organism health. Microbial remediation is a cost-effective, efficient, and eco-friendly alternative to traditional physical or chemical methods for Pb remediation. Previous research indicates that micro-organisms employ various strategies to combat Pb pollution, including biosorption, bioprecipitation, biomineralization, and bioaccumulation. This study delves into recent advancements in Pb-remediation techniques utilizing bacteria, fungi, and microalgae, elucidating their detoxification pathways and the factors that influence Pb removal through specific case studies. It investigates how bacteria immobilize Pb by generating nanoparticles that convert dissolved lead (Pb-II) into less harmful forms to mitigate its adverse impacts. Furthermore, the current review explores the molecular-level mechanisms and genetic engineering techniques through which microbes develop resistance to Pb. We outline the challenges and potential avenues for research in microbial remediation of Pb-polluted habitats, exploring the interplay between Pb and micro-organisms and their potential in Pb removal.

Organic materials, such as straw, animal manure, and their processed product biochar, are known to exhibit agronomic effects and the ability to remediate heavy metal contamination. However, knowledge regarding the relative effects of different organic amendments in soils on heavy metal immobilization and phytoavailability remain limited. Consequently, the effects of maize straw (MS), chicken manure (CM), mushroom cultivation waste (MW), and sawdust biochar (SB) on the immobilization and phytoavailability of lead (Pb) in wheat plants were investigated in this study using pot experiments. The results showed that the artificial application of Pb reduced soil pH, while increasing the total organic carbon (TOC) and cation exchange capacity (CEC) to various extents. Furthermore, the Pb treatment increased the adsorption of Pb by wheat grains (0.83 mg∙kg−1), resulting in decreased above-ground dry biomass (43.16 g∙pot−1) during the maturity growth period when compared with the control check (CK) treatment. The MS + Pb and CM + Pb treatments increased the exchangeable Pb fractions in the soil, but had a limited effect on Pb accumulation in wheat grains compared with the Pb treatment. In contrast, the SB + Pb treatment effectively increased soil pH and TOC, while decreasing the fraction of exchangeable Pb forms and increasing the oxidizable and residual Pb fractions, compared with the Pb treatment. Moreover, the MW + Pb treatment also increased the soil pH and CEC, displaying the potential to increase soil TOC, in addition to substantially modifying the portioning of Pb from exchangeable forms to less bioavailable fractions. Both the MW and SB amendments significantly reduced Pb concentrations in wheat grains (0.49 and 0.70 mg∙kg−1,∙respectively), resulting in increased above-ground dry biomass (51.59 and 54.12 g∙pot−1, respectively). In summary, the application of organic amendments, especially MW, could be an effective measure for enhancing Pb immobilization in polluted soils, thereby reducing its uptake and translocation to crops. [ABSTRACT FROM AUTHOR]

Abstract The environmental justice literature demonstrates consistently that low‐income and minority communities are disproportionately exposed to environmental hazards. In this case study, we examined cumulative multipollutant, multidomain, and multimatrix environmental exposures in Milwaukee County, Wisconsin for the year 2015. We identified spatial hot spots in Milwaukee County both individually (using local Moran's I) and through clusters (using K‐means clustering) across a profile of environmental pollutants that span regulatory domains and matrices of exposure, as well as socioeconomic indicators. The cluster with the highest exposures within the urban area was largely characterized by low socioeconomic status and an overrepresentation of the Non‐Hispanic Black population relative to the county as a whole. In this cluster, average pollutant concentrations were equivalent to the 78th percentile in county‐level blood lead levels, 67th percentile in county‐level NO2, 79th percentile in county‐level CO, and 78th percentile in county‐level air toxics. Simultaneously, this cluster had an average equivalent to the 62nd percentile in county‐level unemployment, 70th percentile in county‐level population rate lacking a high school diploma, 73rd percentile in county‐level poverty rate, and 28th percentile in county‐level median household income. The spatial patterns of pollutant exposure and SES indicators suggested that these disparities were not random but were instead structured by socioeconomic and racial factors. Our case study, which combines environmental pollutant exposures, sociodemographic data, and clustering analysis, provides a roadmap to identify and target overburdened communities for interventions that reduce environmental exposures and consequently improve public health.

Abstract Lead (Pb) pollution is a major concern in many developing nations of the world. Hence, there is a need for the development of an environmentally safe and cost-effective method for the clean-up of contaminated environments. The present study investigated the tolerance of presumptively identified fungal species isolated from 5 different dumpsite soils to Pb concentrations 200, 400, 600, 800, 1000, 1500, 5000, and 10000 mg/L. The identity of strains exhibiting outstanding tolerance was confirmed using molecular technique, and their biosorption capacity at 10000 mg/L was evaluated. FTIR and SEM analyses were performed on the Pb2+ untreated and treated fungal biomasses. A total of 17 fungal isolates belonging to the genera Aspergillus Alternaria, Chrysosporium, and Penicillium were obtained. All the fungi were resistant to the test concentrations of Pb2+ except Chrysosporium sp. (at 5000 mg/L and 10000 mg/L) and Alternaria sp. (at 1500 mg/L, 5000 mg/L, and 10000 mg/L). Four isolates molecularly identified as A. awamori OP341445 and OP341446 and A. niger OP342447 and OP341448 recorded outstanding tolerance (> 1). Biosorption capacity was at its peak on day 5 except in OP34148, day 10 with a value of 97.82 mg/g. The Pb2+ removal rate was at equilibrium on day 5 (≈86%) except for OP41447 and OP41448 (≈87%) on day 15. FTIR analysis reveals the involvement of functional groups O-H, C-H, N-H, O=C=O, C≡C, N=C=S, C=C, N-O, C-N, and S=O in the biosorption process. SEM showed distortion in the cellular structure of the fungi. These results indicated the lead remediation potential of the fungal strains.

Our objective was to determine the effect of lead (Pb) on the behavior of the Mexican mojarra, which is native to the Balsas River basin, and the convict cichlid, which is an exotic invasive there. Both fish species were exposed to Pb, followed by Pb depuration, to evaluate its impacts on behavior. We evaluated swimming activity, predation attempts, prey consumed, foraging efficiency, and aggressive behaviors. The behavioral effects of Pb differed between the two species. While swimming activity decreased in both species during Pb exposure, swimming activity recovered during the Pb depuration period in the convict cichlid, but not in the Mexican mojarra. In both species, the total predation attempts and prey consumed increased during exposure to Pb and remained elevated during Pb depuration. Pb did not affect the foraging efficiency or number of aggressive behaviors of the convict cichlid. In contrast, the foraging efficiency of the Mexican mojarra decreased with Pb exposure and remained low during Pb depuration, and the number of aggressive behaviors increased under Pb exposure and remained elevated during Pb depuration. Pb exposure affected Mexican mojarra more strongly than the convict cichlid, which could induce changes in the ecological relationships between these species. [ABSTRACT FROM AUTHOR]

Lead (Pb) pollution is a major concern in many developing nations of the world. Hence, there is a need for the development of an environmentally safe and cost-effective method for the clean-up of contaminated environments. The present study investigated the tolerance of presumptively identified fungal species isolated from 5 different dumpsite soils to Pb concentrations 200, 400, 600, 800, 1000, 1500, 5000, and 10000 mg/L. The identity of strains exhibiting outstanding tolerance was confirmed using molecular technique, and their biosorption capacity at 10000 mg/L was evaluated. FTIR and SEM analyses were performed on the Pb2+ untreated and treated fungal biomasses. A total of 17 fungal isolates belonging to the genera Aspergillus Alternaria, Chrysosporium, and Penicillium were obtained. All the fungi were resistant to the test concentrations of Pb2+ except Chrysosporium sp. (at 5000 mg/L and 10000 mg/L) and Alternaria sp. (at 1500 mg/L, 5000 mg/L, and 10000 mg/L). Four isolates molecularly identified as A. awamori OP341445 and OP341446 and A. niger OP342447 and OP341448 recorded outstanding tolerance (> 1). Biosorption capacity was at its peak on day 5 except in OP34148, day 10 with a value of 97.82 mg/g. The Pb2+ removal rate was at equilibrium on day 5 (≈86%) except for OP41447 and OP41448 (≈87%) on day 15. FTIR analysis reveals the involvement of functional groups O-H, C-H, N-H, O=C=O, C≡C, N=C=S, C=C, N-O, C-N, and S=O in the biosorption process. SEM showed distortion in the cellular structure of the fungi. These results indicated the lead remediation potential of the fungal strains. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Inorganic Analytical Chemistry / Zhongguo Wuji Fenxi Huaxue is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Lead (Pb) pollution is a major concern in many developing nations of the world. Hence, there is a need for the development of an environmentally safe and cost-effective method for the clean-up of contaminated environments. The present study investigated the tolerance of presumptively identified fungal species isolated from 5 different dumpsite soils to Pb concentrations 200, 400, 600, 800, 1000, 1500, 5000, and 10000 mg/L. The identity of strains exhibiting outstanding tolerance was confirmed using molecular technique, and their biosorption capacity at 10000 mg/L was evaluated. FTIR and SEM analyses were performed on the Pb2+ untreated and treated fungal biomasses. A total of 17 fungal isolates belonging to the genera Aspergillus Alternaria, Chrysosporium, and Penicillium were obtained. All the fungi were resistant to the test concentrations of Pb2+ except Chrysosporium sp. (at 5000 mg/L and 10000 mg/L) and Alternaria sp. (at 1500 mg/L, 5000 mg/L, and 10000 mg/L). Four isolates molecularly identified as A. awamori OP341445 and OP341446 and A. niger OP342447 and OP341448 recorded outstanding tolerance (> 1). Biosorption capacity was at its peak on day 5 except in OP34148, day 10 with a value of 97.82 mg/g. The Pb2+ removal rate was at equilibrium on day 5 (≈86%) except for OP41447 and OP41448 (≈87%) on day 15. FTIR analysis reveals the involvement of functional groups O-H, C-H, N-H, O=C=O, C≡C, N=C=S, C=C, N-O, C-N, and S=O in the biosorption process. SEM showed distortion in the cellular structure of the fungi. These results indicated the lead remediation potential of the fungal strains. [ABSTRACT FROM AUTHOR]

Due to its low cost and rarity of secondary pollutants, phytoremediation has long ago emerged as a crucial clean-up technology for the remediation of heavy metal-polluted soil. Brassica juncea was a popular plant employed for the purpose of phytoextraction due to its high tolerance for metallic constituents and extreme soil conditions; however, the extraction efficiency was low. In an approach to boost the efficacy of phytoextraction, numerous studies have been conducted. The current study used ethylenediaminetetraacetic acid as a chelating agent to enhance the phytoextraction of Lead in contaminated soil using Brassica juncea. The effect of Pb concentration on remediation efficiency was investigated with and without ethylenediaminetetraacetic acid addition, and some valuable findings were reported. The results show that adding ethylenediaminetetraacetic acid in the treatment can significantly increase the phytoextraction potential of Brassica juncea by 37.35% extraction efficiency. Additionally, a substantial amount of lead up to 12,893 mg/kg was accumulated in the roots, and about 7,493.33 mg/kg was transported to the leaves of the experimental plants. The findings also confirm that Brassica juncea could endure Lead stress even at a higher level of 1000 mg/kg without manifesting phytotoxic symptoms. [ABSTRACT FROM AUTHOR]

Phytoremediation of lead (Pb) in contaminated soils using hyper-enriched plants is an important task. It is a green and sustainable measure. Studies have revealed that three ornamental plants, Tagetes patula (T. patula), Solanum nigrum (S. nigrum), and Mirabilis jalapa (M. jalapa), have the ability to enrich for Pb; however, studies on difference between them and root morphology and the relationship between tolerance and capacity are lacking. The ability of three lead-enriching plants, T. patula, S. nigrum, and M. jalapa, to cope with Pb stress was assessed in hydroponic experiments using five Pb stress concentrations (0–1000 mg/L). Under different Pb stress conditions, the growth of the shoots and roots of three tested ornamental plants was inhibited to varying degrees. In the three tested ornamental plants, Pb mainly accumulated in the roots, and the highest levels of Pb observed in the shoots of T. patula, S. nigrum, and M. jalapa were 1074.1 mg/kg, 958.7 mg/kg, and 975.3 mg/kg, respectively. All plants reached a critical level of Pb hyperaccumulation. Redundancy analysis showed that changes in the root architecture of the three tested ornamental plants were significantly and positively correlated with tolerance as well as the enrichment and transfer ability of the heavy metal Pb. Therefore, these three ornamental plants have the potential to remediate Pb-contaminated water and soil and can increase the tolerance and enrichment characteristics of Pb by regulating the root biomass and root length of the three test ornamental plants via various agronomic measures. In addition, more research should be conducted to assess their effectiveness as phytoextractants under field conditions. [ABSTRACT FROM AUTHOR]

Operational small-scale coal mining (OSCM) is one of the most significant sources of chromium (Cr) and lead (Pb) pollution in Bangladesh. Attempts to minimize or lessen the use of Cr and Pb in OSCM have shown unsatisfactory results, mainly because they need to address the sociotechnical complexity of pollution concerns in OSCM. This research adopts a multidisciplinary, sociotechnical approach to addressing Cr and Pb problems, coupling soil sampling for Cr and Pb with questionnaires of miners' and inhabitants' perceptions of pollution and its distribution. The study was undertaken in the Barapukuria coal basin in northwest Bangladesh. Except for mining areas (average of 49.80 ± 27.25 mg/kg), Cr levels in soils exceeded the world average in the periphery (73.34 ± 24.39 mg/kg, ~ 1.2 times) and residential areas (88.85 ± 35.87 mg/kg, 1.5 times the world standard of 59.5 mg/kg). Pb levels in soils exceeded national and global averages in mining (53.56 ± 37.62 mg/kg, ~ 1.9 times), periphery (35.05 ± 21.77 mg/kg, ~ 1.3 times), and residential areas (32.14 ± 26.59 mg/kg, ~ 1.2 times) when compared to Bangladesh and global standards of 20 and 27 mg/kg. Pb levels were highest in mining areas, while Cr concentrations were highest in residential areas. The questionnaire findings indicated that miners and inhabitants did not correctly assume that the highest levels of Cr and Pb pollution would be found in these areas. Among all respondents, 54% are unaware of the health impacts of prolonged Cr and Pb exposure. They face respiratory problems (38.6%), skin diseases (32.7%), and other health issues. A large number of people (66.6%) agreed with the fact that Cr and Pb contamination has an impact on drinking water. Cr and Pb pollution has caused 40% crop loss and a 36% decrease in productivity in the agricultural sector. However, respondents underestimated the level of Cr pollution in mining areas, and most assumed that only individuals working directly with mines were impacted by the Cr and Pb content. Participants also rated the reduction of Cr and Pb contamination as of low importance. There is less awareness of Cr and Pb pollution among miners and inhabitants. Sincere efforts to reduce Cr and Pb pollution will likely be met with extra attention and hostility. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ecology & Rural Environment is the property of Journal of Ecology & Rural Environment Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the rapid development of synthetic biology, various whole-cell biosensors have been designed as valuable biological devices for the selective and sensitive detection of toxic heavy metals in environmental water. However, most proposed biosensors are based on fluorescent and bioluminescent signals invisible to the naked eye. The development of visible pigment-based biosensors can address this issue. The pbr operon from Klebsiella pneumoniae is selectively induced by bioavailable Pb(II). In the present study, the proviolacein biosynthetic gene cluster was transcriptionally fused to the pbr Pb(II) responsive element and introduced into Escherichia coli. The resultant biosensor responded to Pb(II) in a time- and dose-dependent manner. After a 5-h incubation with Pb(II), the brown pigment was produced, which could be extracted into n-butanol. Extra hydrogen peroxide treatment during n-butanol extract resulted in the generation of a stable green pigment. An increased brown signal was observed upon exposure to lead concentrations above 2.93 nM, and a linear regression was fitted from 2.93 to 3,000 nM. Extra oxidation significantly decreased the difference between parallel groups. The green signal responded to as low as 0.183 nM Pb(II), and a non-linear regression was fitted in a wide concentration range from 0.183 to 3,000 nM. The specific response toward Pb(II) was not interfered with by various metals except for Cd(II) and Hg(II). The PV-based biosensor was validated in monitoring bioaccessible Pb(II) spiked into environmental water. The complex matrices did not influence the regression relationship between spiked Pb(II) and the dual-color signals. Direct reading with the naked eye and colorimetric quantification enable the PV-based biosensor to be a dual-color and low-cost bioindicator for pollutant heavy metal. [ABSTRACT FROM AUTHOR]

As agroecology deteriorates, agricultural production is threatened by the combined stressors of exposure to environmental pollutants and pathogenic microbes. Proper agronomic practices for crop growth management and fertilization require understanding plant tolerance strategies. Both rice blast and heavy metals substantially impair rice crops, while silicon (Si) is an effective amendment to alleviate the combined stressors. Herein, this study was conducted to investigate the rice physiology and pathology perspective on the mechanism of Si alleviation against both lead (Pb) toxicity and Magnaporthe oryzae infection, utilizing pot experiments with inoculation of the virulent Magnaporthe oryzae strain. Exogenous Si reduced the phyto-availability and plant absorption of Pb, resulting in a 73.5% reduction in exchangeable Pb concentration in soil and a 40.23% reduction in rice plants. Furthermore, Si addition boosted the plant antioxidant system by increasing the activities of related enzymes, as the activities of catalase, superoxide dismutase, and polyphenol oxidase were significantly improved while the activity of peroxidase in rice panicles decreased. As a result, an improvement in dry matter quantity by 19.19% was observed compared to treatments without Si application, and the panicle blast severity (PBS) was reduced by 0.4–37.52%. Notwithstanding the interaction between the combined stressors, this study revealed that the speciation of Pb formation in the rhizosphere was the primary contributor to the alleviation of abiotic stresses, whereas the regulation of oxidative stress by enzymatic antioxidants played a dominant role in alleviating Magnaporthe oryzae colonization and impairments. The regulation process may reveal the mechanism of siliceous fertilizer functioning in the paddy system. Thereby the role of exogenous Si in anti-fungal, heavy metal toxicology, and plant physiology needs further study to fully elucidate the role of Si amendment, which is proposed to be considered from the perspective of soil chemistry and plant physiology.

In the present study, the aluminum-containing wastewater treatment residue was modified at 400 °C and 2.5 mol/L HCl and used in the removal of Pb and Cd from an aqueous solution for the first time. The modified sludge was characterized by SEM, XRD, FTIR, and BET. Under the optimized conditions, including pH 6, adsorbent dose 3 g/L, Pb/Cd reaction time 120 and 180 min, and Pb/Cd concentration 400 and 100 mg/L, Pb/Cd adsorption capacity was obtained as 90.72 and 21.39 mg/g, respectively. The adsorption process of sludge before and after modification is more consistent with the quasi-second-order kinetics, and the correlation coefficients R2 are all above 0.99. The fitting of data with the Langmuir isotherm and pseudo-second-order kinetics showed that the adsorption process is monolayer and chemical in nature. The adsorption reaction included ion exchange, electrostatic interaction, surface complexation, cation-π interaction, co-precipitation, and physical adsorption. This work implies that the modified sludge has greater potential in the removal of Pb and Cd from wastewater relative to raw sludge. [ABSTRACT FROM AUTHOR]

Although the birth of Classical Greece is often attributed to the constitutional reforms of Cleisthenes (508/507 BCE), the achievement of an economically minded government under the Peisistratid tyrant Hippias (527–510 BCE) potentially paved the way by advancing Athenian silver for exportation in international trade. It is proposed here that new silver technology, which initiated the transition from acquiring silver from 'dry' silver ores to silver‐bearing lead ores, was introduced to Greece during the time of the Peisistratids (561–510 BCE). Massive exploitation of silver‐bearing lead ores at Laurion in Attica, which later financed the construction of a war navy, appears evident in the lead pollution records of Greenland ice, lead isotopic analyses of sixth‐century BCE Attic silver coins and late Iron Age Levantine hacksilver, and is reflected in the numbers of lead votive figurines at sanctuaries in Sparta. Against the backdrop of the threat of war with Persia and an imminent Spartan invasion which resulted in the overthrow of Hippias (510 BCE), it is considered that a political transition occurred because Greece was both geologically and politically disposed to adopt this labour‐intensive silver technology which helped to initiate, fund and protect the radical social experiment that became known as Classical Greece. [ABSTRACT FROM AUTHOR]

This study was conducted in order to study the effect of different concentrations of lead pollution on the photosynthetic characteristics and growth of Miscanthus floridulus, and to reveal its photosynthetic adaptability to lead stress. The differences of gas exchange parameters, chlorophyll fluorescence characteristics and photosynthetic pigment of two Miscanthus floridulus populations, one population from Boluo an uncontaminated site, and another population from Dabaoshan, a mine site, were compared and studied through nutrient solution culture experiments treated with heavy metal lead (Pb) in green house. The results showed that (1) under Pb stress, the net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), intercellular carbon dioxide concentration (Ci), and chlorophyll content (Chl) of the leaves of the two populations decreased in different amplitude. Under moderate and severe Pb stress (80 mg·L−1, 120 mg·L−1, 240 mg·L−1), the plant biomass of non-mining population and mining population plants were 54.5%, 39.7%, 29.4% and 70.4%, 54.7%, 50.9% of the control, respectively. (2) Stomatal restriction was the main factor for the Pn's decrease in the leaves of the non-mine population under light Pb stress, while the non-stomatal restriction was the main factor for Pn's decrease in the leaves of the non-mine population under middle and high Pb stresses. (3) Under Pb stress, the maximum photochemical efficiency (Fv/Fm) and potential activity (Fv/Fo) of PS II reaction centers in the two populations of M. floridulus decreased. However, Fv/Fm and Fv/Fo showed a smaller decrease, but the capability to utilize light and the potential to activate PSII of the mine population remained higher than that of the non-mine population. The changes of photochemical quenching coefficient (qP) and non-photochemical quenching coefficient (NPQ) of PSⅡ showed that qP value decreased and NPQ value increased in the two populations under Pb stress. On the whole, the resistance mining area population had a low qP reduction and a large increase in NPQ. Electronic transfer rate (ETR) and PSII actual fluorescence efficiency (ΦPSII) of the mine population changed slightly under Pb stress. These results indicated that when under Pb stress, the electron transport activity and photosynthetic apparatus were damaged less in the mine population with high resistance than in the non-mine population with low resistance. Conclusion: the mining population of M. floridulus has strong tolerance to Pb, which is suitable for the pioneer species of gramineae in vegetation restoration construction in metal mining area. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cow manure derived biochar (CMBC) can serve as a promising functional material, and CMBC can be regarded as an ecofriendly approach compared to conventional ones. CM bioadsorbent can be employed for heavy metal immobilization (such as for lead) as well as an amendment to increase soil fertility (e.g., phosphorus). Few studies have examined the surface interactions between pollutants and bioadsorbents when inherent nutrient release is present. In this work, CMBC was prepared and applied for Pb(II) removal, and the vital roles of released phosphorus from CMBC were comprehensively disclosed. Furthermore, CMBC could immobilize part of the Pb(II) in soil and promote plant growth. CM400 was an effective adsorbent whose calculated Qe reached 691.34 mg·g−1, and it rapidly adsorbed 98.36 mg·g−1 of Pb(II) within 1 min. The adsorption mechanisms of Pb(II) by CMBC include ion exchange, physical adsorption, electrostatic attraction, chemical precipitation, surface complexation, and cation–π bond interaction. Based on the residual phosphorus content and adsorption effect, complexation rather than the chemical precipitation had a greater contribution toward adsorption. Besides, as the concentration of Pb(II) increased, the main adsorption mechanisms likely transformed from chemical precipitation to ion exchange and complexation. CMBC not only had a good effect on Pb(II) removal in the solution, but also immobilized the Pb(II) in soil to restrain plant uptake as well as promote plant growth. The main novelty of this work is providing more insights to the cow manure bio adsorbent on Pb immobilization and phosphorus release. This study is expected to serve as a basis and reference for analyzing the release effects of inherent nutrients and the interfacial behaviors with heavy metals when using CMBC and other nutrient–rich carbon–based fertilizers for pollution control. [ABSTRACT FROM AUTHOR]

Through hydroponic experiments, seven lead (Pb) pollution concentrations ranging from 0 to 1000 mg/L were used to study the ability of three kinds of ornamental plants, Commilina communis (C. communis), Hosta ventricose (H. ventricosa) and Bryophyllum pinnatum (B. pinnatum), to purify Pb-contaminated water with different mass concentrations. The results showed that the biomass of the shoots and roots of the three ornamental plants decreased to different degrees with increasing Pb concentrations, showing an inhibitory effect of Pb on plant growth. Under different Pb pollution concentrations, the distribution trend of Pb content in the tested ornamental plants showed that the roots had more Pb content than the shoots, and the Pb content in the shoots of all three plants exceeded 1000 mg/kg. C. communis was the most tolerant among the three tested ornamental plants. The effective concentration (EC50) value of the shoots of B. pinnatum was the highest at 714.2 mg/kg. The EC50 value of the roots of C. communis was the highest at 563.1 mg/kg. Therefore, both C. communis and B. pinnatum have strong potential to remediate Pb-contaminated water and soil. [ABSTRACT FROM AUTHOR]

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In this research, we collected 10 samples, 2 soil and 8 vegetables cultivated in orchard area allowing district agricultural land in Al-Khatib at a few distances from Kadhimiya district, and adjacent to the area Al-Huria samples are congested as in table 2 after the chemical digestion of the seamount by using the atomic absorption technique, we found the following results: The highest value of Cadmium in A5 sample was 0.0436 ppm and 0.026933 ppm, the highest value of Lead in the sample A1 (soil of Kadhimiya) was 0.07345 ppm average and the highest value of Brass in A2 was 1.1176 ppm and 0.1762 ppm. The highest value of Cadmium in B4 (Rashad) was 0.0514 ppm and 0.04303 ppm, and the highest value of Lead in B5 (Kirath) was 0.365 ppm and on average 0.2293 ppm, the value of Copper in B4 (Rashad) was 1.1491 ppm and 0.20185 ppm in seriously. The limits are permitted within the WHO (World Health Organization), and therefore, there is no contamination of these items in these regions A and B (allows bastinade Kadhimiya, Khatib) respectively.

Phytoremediation of lead (Pb) in contaminated soils using hyper-enriched plants is an important task. It is a green and sustainable measure. Studies have revealed that three ornamental plants, Tagetes patula (T. patula), Solanum nigrum (S. nigrum), and Mirabilis jalapa (M. jalapa), have the ability to enrich for Pb; however, studies on difference between them and root morphology and the relationship between tolerance and capacity are lacking. The ability of three lead-enriching plants, T. patula, S. nigrum, and M. jalapa, to cope with Pb stress was assessed in hydroponic experiments using five Pb stress concentrations (0–1000 mg/L). Under different Pb stress conditions, the growth of the shoots and roots of three tested ornamental plants was inhibited to varying degrees. In the three tested ornamental plants, Pb mainly accumulated in the roots, and the highest levels of Pb observed in the shoots of T. patula, S. nigrum, and M. jalapa were 1074.1 mg/kg, 958.7 mg/kg, and 975.3 mg/kg, respectively. All plants reached a critical level of Pb hyperaccumulation. Redundancy analysis showed that changes in the root architecture of the three tested ornamental plants were significantly and positively correlated with tolerance as well as the enrichment and transfer ability of the heavy metal Pb. Therefore, these three ornamental plants have the potential to remediate Pb-contaminated water and soil and can increase the tolerance and enrichment characteristics of Pb by regulating the root biomass and root length of the three test ornamental plants via various agronomic measures. In addition, more research should be conducted to assess their effectiveness as phytoextractants under field conditions.

Raw canola stalk (RCS) and water vapor–activated biochar (B35, B36, B37, ..., B57) adsorbents were utilized to remove lead (Pb) from polluted solutions. The water vapor–activated biochar adsorbents were prepared in three carbonization temperature levels and three activation temperatures. The best water vapor–activated biochar adsorbent (B57) was selected for carrying out adsorption isotherm experiments on the lead at 25 °C. Experiments were then conducted to determine the best pH level and the best adsorbent dosage, which were found equal to 6 (pH), and 0.3 g sorbent per 30 mL of pollutant, respectively. Next, both RCS and B57 were modified to obtain 5%, 10%, and 15% sorbents using magnetic iron oxide nanoparticles (Fe3O4). The lead adsorption isotherm experiments were carried out using the new modified adsorbents. The results indicated that the water vapor–activated biochar adsorbent modified with Fe3O4 (B57 5%) are the best adsorbents for the lead pollutants' removal. The results were compared within a 5% significance level. TEM, BET, VSM, FT-IR, and XRD analyses were undertaken for sample specification. The analyses showed that the Fe3O4 nanoparticles are modified on the adsorbents. [ABSTRACT FROM AUTHOR]

Microbially induced calcium carbonate precipitation (MICP) can transform free lead ions into stable precipitation.In this study, a lead-tolerant and urease-positive SHT17 strain was screened, which was identified as Streptomyces mutabilis (Accession No.OL677072)by 16 S rRNA sequences.The removal ability of Pb2+from water was researched by Streptomyces-induced precipitation of calcium carbonate.The Pb2+concentration was measured by inductively coupled plasma optical emission spectrometry (ICP-OES). The microbial-induced precipitation was analyzed by scanning electron microscopy (SEM), X-ray energy distribution (EDS), X-ray diffraction (XRD)and fourier transform infrared spectroscopy (FTIR). The results showed that Streptomyces mutabilis possessed the highest Pb2+removal ability.The Pb2+removal rate reached 99.66% (with initial Pb2+concentration 200 mg/L), and removed Pb2+was fixed in the Streptomyces-induced carbonate precipitation.Furthermore, with the increase of the initial Pb2+concentration, the removal rate of Pb2+was above 65%,and showed a general downward trend.Different calcium sources affect the morphology of the Streptomyces-induced precipitations. [ABSTRACT FROM AUTHOR]

Pomegranate is very favored but highly susceptible to lead contamination that threatens consumer health, and thereby it is essential to establish efficient modes to monitor lead level in pomegranate. A specific and sensitive electrochemical sensor was developed for assessing lead pollution in pomegranate based on Pb2+-dependent DNAzyme as recognition receptor and metal-organic frameworks (MOFs) for signal output. Particularly, the used MOFs exhibited Fenton-like catalytic functions toward methylene blue (MB) as electroactive medium. Integrating with gold nanoparticles (AuNPs), the Fenton-like MOFs showed high sensitivity for electrochemical detection of Pb2+ in pomegranate. Moreover, benefiting from the specific recognition of DNAzyme to Pb2+, the adjustable strategy was achieved, in which the approaching MB led to a higher signal with the absence of Pb2+ while the detached MB gave rise to a lower signal with the presence of Pb2+. With the use of Fenton-like catalytic MOFs driving electrochemical aptasensing interface, this simplified detection pattern was endowed with sensitive assessment of lead pollution level in pomegranate, highlighting its promising potential in evaluating the safety of foodstuffs. • MIL-88(Fe) with Fenton-like catalytic functions is designed as sensing interface. • Methylene blue as electroactive medium promotes MIL-88(Fe) for signal output. • DNAzyme as recognition receptor exhibits high selectivity toward Pb2+. • The strategy greatly enhances anti-interference ability and temporal efficiency. • The pattern is well qualified for evaluating lead pollution in pomegranate. [ABSTRACT FROM AUTHOR]

Lead-contaminated water, soil, and air have been perceived as potential sources of lead exposure for a considerable length of time, which continues to threaten human health; particularly that of young children. An Integrated Exposure, Uptake, and Biokinetic (IEUBK) as a human health risk model were applied to predict the Blood lead levels (BLLs) in children. A variety of data for air, soil, and water were obtained from the industrial region in Al-Dorah city in Baghdad for the period 2012- 2014. The result found that the predicted BLLs value of 11.17 μg/dL obtained from the IEUBK model was exceeding the agency’s threshold of concern of 10 μg/jdL which was considered as the lowest level of concern for BLL in children, this result of the IEUBK model was in agreement with the actual value of BLLs which were taken from previous literature for 24 blood samples of school children matched for age curried out in the same Al-Dorah region. This technique propels logical comprehension of the connection between BLLs in children and environmental media in both air and soil for the pollute condition. It can control national health-based benchmarks for lead and related community public health decisions.

Understanding the emission characteristics of particulate matter and associated heavy metals is essential for assessing their environmental and health impacts post-emission, as well as for identifying potential control technologies for the sources. Here, a field test was conducted at two advanced smelting plants equipped with comprehensive air pollution control devices. The particles emitted from different stages of lead and zinc smelting exhibited bi-modal size distributions, with peaks observed in PM 0.1–1.0 and PM 2.5–10 , respectively. Particulate-bound Pb was identified as the predominant Pb species in the flue gas, primarily originating from ore crushing. Consequently, over 80 % of Pb was emitted in the form of coarse particles, a marked contrast to coal-fired power plants where Pb concentrated on fine particles. High efficiencies in Pb removal were achieved by dust collectors, flue gas purification systems, and acid plants with desulfurization systems, resulting in overall Pb emission factors in lead and zinc smelting were only 89.3 and 2.60 g t-1 (of metal production), respectively. Importantly, the contribution of gas-phase Pb, which accounts for approximately 16.6 % of total emissions, must not be neglected in future emission monitoring and control efforts. [Display omitted] • Emission factors (EFs) and relative enrichment factors (REFs) for Pb in lead and zinc smelting were updated. • In contrast to coal-fired power plants, more than 80 % of smelting particulate-bound Pb emissions were found in coarse particles (PM>10). • Gas-phase lead constitutes a significant portion of total emissions, indicating the need for careful monitoring. • Advanced technologies could significantly reduce Pb emissions by 24.3 % and 48.6 % from lead and zinc smelters. [ABSTRACT FROM AUTHOR]

Lead (Pb) pollution in sediments remains a major concern for ecosystem quality due to the robust interaction at the sediment/water interface, particularly in shallow lakes. However, understanding the mechanism behind seasonal fluctuations in Pb mobility in these sediments is lacking. Here, the seasonal variability of Pb concentration and isotopic ratio were investigated in the uppermost sediments of a shallow eutrophic drinking lake located in southeast China. Results reveal a sharp increase in labile Pb concentration during autumn-winter period, reaching ∼ 3-fold higher levels than during the spring-summer seasons. Despite these fluctuations, there was a notable overlap in the Pb isotopic signatures within the labile fraction across four seasons, suggesting that anthropogenic sources are not responsible for the elevated labile Pb concentration in autumn-winter seasons. Instead, the abnormally elevated labile Pb concentration during autumn-winter was probably related to reduction dissolution of Fe/Mn oxides, while declined labile Pb concentration during spring-summer may be attributed to adsorption/precipitation of Fe/Mn oxides. These large seasonal changes imply the importance of considering seasonal effects when conducting sediment sampling. We further propose a solution that using Pb isotopic signatures within the labile fraction instead of the bulk sediment can better reflect the information of anthropogenic Pb sources. [Display omitted] • Larger, 3-fold, seasonal fluctuations were observed in the labile Pb concentration. • Pb sources were not responsible for the elevated labile Pb concentration during autumn-winter seasons. • Fe/Mn oxides dominated the seasonal variations of labile Pb concentration. • Algal bloom can increase Pb mobility in sediments. [ABSTRACT FROM AUTHOR]

Lead (Pb) is a widely occurring heavy metal employed in industrial products and hence released into the environment, causing several environmental health risk concerns. This study comprehensively surveyed the literature on Pb contamination in different agricultural foods and food products commonly consumed by Bangladeshi inhabitants and assessed associated cancer and non-cancer health risks. Cereals (i.e., rice, wheat and maize) contained very high concentrations of Pb among the selected food items, the highest was found in wheat (4.04 µg g−1), while rice and maize were 2.22 and 1.43 µg g−1, respectively, that exceeded the maximum allowable concentration (MAC, 0.20 µg g−1) for cereals. Vegetables contained higher Pb than the MAC of 0.01 µg g−1, except for mushroom, green banana, cauliflower and arum. In addition, pulses also contained a moderate amount of Pb; however, fruits contained a low level of Pb, except for mangoes. When examining spatial differences in Pb contamination, most districts exhibited high Pb content in cereals; however, vegetables of the Tangail district exhibited the highest Pb concentrations (2.17 µg g−1), originating from industrial operations and vehicular emissions. In terms of human health risk assessment, it was observed that consumption of rice, zucchini, tesla gourd, sponge gourd, okra, drumstick lib, chili and cabbage might pose non-cancer health risks (THQs > 1); however, fruits and pulses do not pose any non-cancer health risks to Bangladeshi residents. Most of the cereals and vegetables showed a higher value than 10−6, indicating a potential cancer risk; however, fruits and pulses showed lower risk only marginally exceeding the lower allowable limit (i.e., 10−6). [ABSTRACT FROM AUTHOR]

In order to study the classification method of incomplete eggshells and the food safety problems in some egg products, laser-induced breakdown spectroscopy (LIBS) and back propagation neural network (BPNN) were combined to explore the elements of eggshells, to distinguish different types of eggshells, and to detect pollution elements in eggshells, respectively. The results show that the duck eggshell contains Si, Cu, Ca, Mg, C, Na, Al and other elements. LIBS was applied to measure and calibrate the element composition in contaminated preserved eggshells, and the obvious lead characteristic peaks were successfully detected. LIBS and BPNN were combined to quickly distinguish eggshell, duck eggshell, and quail eggshell, and an accuracy rate of 94.167% was obtained. The same method was employed to study on duck eggshell and preserved eggshell to explore the classification of eggshells with different production methods, and an accuracy rate of 97.5% was obtained. The combination of LIBS and BPNN provides a new research method for egg classification and distinguishing. [ABSTRACT FROM AUTHOR]

Following the high rate at which many drinking water sources are polluted globally, an adequate evaluation of the potential hazards posed by polluted water systems is essential. In Nnewi urban (southeastern Nigeria), inhabitants indiscriminately dispose municipal solid wastes into streams and rivers, thereby exposing the surface water quality to deterioration. The aim of this study was to assess the pollution status, ecological risks, and probabilistic health risks of surface waters in this area using integrated study approach. Several heavy metal pollution indices used in this study showed that the waters generally have low pollution. However, Pb was identified as the priority pollutant. Ecological risk assessment revealed that the samples pose low ecological risk. Furthermore, non-carcinogenic risk assessment revealed low chronic risk; but children are more exposed to chronic risk due to ingestion than adults. However, with respect to dermal contact, all the samples pose negligible risks to both populations, as their hazard indices were <0.1. The probability of cancer risk, when compared to the acceptable range of ≤1 × 10−6 to 1 × 10−4, revealed that many of the samples pose carcinogenic risk due to Pb ingestion to adults (75%) and children (100%). However, all the samples pose negligible cancer risk due to dermal contact. Water quality index revealed that majority (75%) of the samples are poor quality water, and thus not recommended for drinking purpose. Correlation and factor analyses showed that both geogenic and anthropogenic factors influence the presence of the analytes in the surface waters. [ABSTRACT FROM AUTHOR]

Accelerated soil erosion and trace metal pollution in aquatic environments have become a pervasive aspect of global environmental changes during the Anthropocene, threatening food security and ecosystem viability. Long-term records of these processes can promote an improved understanding of their timing, amplitude, and environmental impacts. Here we present a sedimentary record from Lake Jian in Yunnan Province, southwestern China, which shows that land-use changes affected the lake watershed by at least 1200 CE, and that the intensity of soil erosion increased from 1450 CE onwards, as evidenced by increases in magnetic susceptibility and high concentrations of trace metals. The timing of the increase in atmospheric lead (Pb) transport, which was possibly related to the growth of metallurgical activity in the region, occurred ~250 years earlier than the anthropogenic soil erosion. Pb emissions resulting from the mining and smelting industry, coal burning, and the use of leaded gasoline led to enhanced Pb pollution in the area since the 1950s CE. Comparison of the results with geochemical records from lakes in northwestern Yunnan reveals that environmental disturbances were relatively limited during the intervals of the Nanzhao and Dali Kingdoms. However, enhanced human disturbances of lake watersheds in Yunnan occurred from the Yuan dynasty onwards, as a result of population increases caused by immigration to the area, which was followed by the changes in the type and intensity of human activity, with an enhanced anthropogenic impact after the middle twentieth century. Overall, our study provides a case study for understanding the historical background of the Anthropocene. [ABSTRACT FROM AUTHOR]

Protecting soil from Pb contamination has been a programme for a long time in China. However, research on lead pollution in wetlands remains rare. To understand the characteristics of Pb pollution in Beijing and the sources of contamination of different soil samples in wetlands, we collected samples during all four seasons from two soil horizons and analyzed their Pb concentrations and Pb isotope ratios. The average concentrations of Pb varied from 65.44 mg/kg in spring to 106.11 mg/kg in winter. Concentrations in autumn were significantly lower than those in spring and summer and were notably different between A and B Horizons (59.42 and 71.47 mg/kg, respectively). The Pb isotopic compositions show that Pb pollution results from a mixing of geogenic and anthropogenic materials. The ratios of 206Pb/207Pb and 206Pb/208Pb evidenced that coal combustion and vehicle exhaust are the main sources of lead contamination in the two horizons. These results will help in reducing lead contamination in soil by knowing the temporal and spatial variations and sources of lead in Beijing. [ABSTRACT FROM AUTHOR]

Plasmonic nanoparticles are of great importance owing to their highly responsive 'localized surface plasmon resonance' (LSPR) behaviour to self-agglomeration/aggregation leading to the development of various nanosensors. Herein, we demonstrated the definite self-assembly of citrate functionalized silver nanoparticles (AgNPs) into a one-dimensional linear chain in presence of charged lead ions (Pb2+), one of the most toxic heavy metal pollutants. We have explored detail mechanism using a variety of spectroscopic tools and electron microscopy. The self-aggregation of AgNPs leads to the generation of new LSPR modes due to coupling of nearby existing modes. The conclusion of our experimental findings is duly supported by our developed numerical modelling based on the quasi-static approximation that the generated new LSPR modes are solely due to formation of chain-like aggregation of AgNPs. We have also monitored the LSPR spectra in the presence of other metal ions; however, only Pb2+ found to give such unique self-assembled geometry may due to its high interaction affinity with citrate. These findings play a key role for citrate functionalised AgNPs to be used as a low cost highly selective and sensitive lead ion sensor for potential application in industrial lead pollution monitoring. We have further varied several sensor parameters such as AgNPs size, concentration, and the allowed reaction time for it to be practically implemented as an efficient lead sensor meeting the Environmental Protection Agency recommendations. The possible sensing mechanism of citrate-functionalized silver nanoparticles towards Pb2 + followed by unique chain-like aggregation for potential atmospheric and industrial lead pollution monitoring. [ABSTRACT FROM AUTHOR]

Although the hierarchical manganese dioxide film electrode shows promise as a durable and catalytically active anode for zinc electrowinning, it often fails and deactivates when it is exposed to fluoride-rich environments. The lack of understanding regarding the mechanism behind fluoride-induced irreversible interface reconstruction hinders their practical application in large-scale energy-saving and pollution-reduction efforts. Here, we conducted multidimensional operando investigations to gain insights into the dynamic evolution across the film electrode interface with temporal and spatial resolution. Our findings reveal that electroosmosis of F - initially triggers structural collapse and subsequent reconstruction of [MnO 6 ] units, followed by interaction with the spontaneous oxide film at the surface of lead substrate. Experimental studies and theoretical calculations indicate that F - facilitates the irreversible transformation of γ-MnO 2 into more stable yet protective catalytic dual-defective α-MnO 2 . Additionally, lower levels of F - at the interface promote a change in microenvironmental pH within porous PbSO 4 , triggering the development of microporous corrosion-resistant β-PbO 2 as the dominant phase. The combined effects of MnO 2 and interphase evolution effectively explain the abnormally elevated oxygen evolution overpotential. Then, the proposed appropriate application scenarios based on the corrosion behavior will serve as a practical guide for the implementation of the hierarchical manganese dioxide film electrode.

The study was carried out to investigate the remediative capacity of Eleusine indica in lead-polluted soil. Soil samples were collected near student hostel (hall 5) in the University of Benin. The soil samples were sun dried to constant weight and was pulverized with wooden roller and sieved with a hand sieve of 2 mm mesh size. The sieved soil was spiked with 0.625 g lead nitrate (PbNO3), lead sulphate (PbSO4), lead carbonate (PbCO3), lead acetetrahydrate (PbC2H6) and lead chloride (PbCl2) separately in three replicate using aqueous standard solutions. Tillers of Eleusine Indica were placed in the metal - polluted soil immediately and the experiment was allowed to stay for 15 weeks. The result showed that the uptake efficiency for Eleusine indica in both shoots and roots for lead nitrate was 0.016% and 0.8%, lead sulphate 0.016 % and 0.352 %, lead carbonate 0.064% and 0.496 %, lead acetetrahydrate 0.032 % and 0.688 %, and lead chloride 0.08 % and 0.72 % respectively, indicating that the plant might have sequestered the metal in the soil rather than accumulating it in the leaves. This was evident in the presentation of the metal sequestration factor of over 70 % irrespective of the nature of the metal. Microbial count of soil before and after contamination with lead nitrate was 1.9×104 and 0.4×104 cfu/g indicating a reduction. The study therefore revealed that Eleusine indica is a high efficient plant in sequestering lead in polluted soil. [ABSTRACT FROM AUTHOR]

For the purpose of the nondestructive measurements of hazardous heavy-element-containing substances in soil samples, the emerging technique, triple-exposure X-ray computed tomography (CT), is proposed. The use of triple exposure (i.e. three different acceleration voltages for the X-ray tube) improves the accuracy of the identification of the atomic number of a heavy element. With lead as the target element, virtual X-ray microtomography simulations utilizing a polychromatic X-ray source accelerated at 70, 100, and 140 kV were performed. CT images for the three voltages were reconstructed on a computer for clayey soil samples with heavy-element-containing natural minerals, namely galena (PbS), witherite (BaCO3), stibnite (Sb2S3), sphalerite (ZnS), and magnetite (Fe3O4). Quantitative analysis of the reconstructed CT images was performed to obtain the following results. (i) Galena can be distinguished from other heavy minerals (i.e. witherite, stibnite, sphalerite, and magnetite). (ii) The lead content in the clayey soil can be estimated with reasonable accuracy. These successful results demonstrate that the triple-exposure CT technique is promising for the nondestructive characterization of soil samples contaminated with hazardous heavy elements such as lead. [ABSTRACT FROM AUTHOR]

Cow manure derived biochar (CMBC) can serve as a promising functional material, and CMBC can be regarded as an ecofriendly approach compared to conventional ones. CM bioadsorbent can be employed for heavy metal immobilization (such as for lead) as well as an amendment to increase soil fertility (e.g., phosphorus). Few studies have examined the surface interactions between pollutants and bioadsorbents when inherent nutrient release is present. In this work, CMBC was prepared and applied for Pb(II) removal, and the vital roles of released phosphorus from CMBC were comprehensively disclosed. Furthermore, CMBC could immobilize part of the Pb(II) in soil and promote plant growth. CM400 was an effective adsorbent whose calculated Qe reached 691.34 mg·g−1, and it rapidly adsorbed 98.36 mg·g−1 of Pb(II) within 1 min. The adsorption mechanisms of Pb(II) by CMBC include ion exchange, physical adsorption, electrostatic attraction, chemical precipitation, surface complexation, and cation–π bond interaction. Based on the residual phosphorus content and adsorption effect, complexation rather than the chemical precipitation had a greater contribution toward adsorption. Besides, as the concentration of Pb(II) increased, the main adsorption mechanisms likely transformed from chemical precipitation to ion exchange and complexation. CMBC not only had a good effect on Pb(II) removal in the solution, but also immobilized the Pb(II) in soil to restrain plant uptake as well as promote plant growth. The main novelty of this work is providing more insights to the cow manure bio adsorbent on Pb immobilization and phosphorus release. This study is expected to serve as a basis and reference for analyzing the release effects of inherent nutrients and the interfacial behaviors with heavy metals when using CMBC and other nutrient–rich carbon–based fertilizers for pollution control.

Tall fescue (Festuca arundinacea Schreb.) shows huge potential for lead (Pb) phytoremediation, while little is known on the molecular mechanisms involved in Pb tolerance and accumulation. Here, genetic engineering strategy was firstly used to investigate Pb tolerance and accumulation in tall fescue. The transgenic tall fescue overexpressing a class II (CII) sHSP gene FaHSP17.8-CII was generated. After exposure to 1000 mg/L Pb(NO3)2, two FaHSP17.8-CII overexpressing lines, OE#3 and OE#7, showed higher tolerance to Pb as illustrated by the reduced levels of electrolyte leakage (EL) and malondialdehyde (MDA) as compared to the wild-type (WT) plants under Pb stress. Moreover, the FaHSP17.8-CII overexpression lines, OE#3 and OE#7, exhibited 36.3% and 46.6% higher shoot Pb accumulation relative to the WT grasses. When the grasses were exposed to Pb stress, the two OE lines had higher CAT, POD and SOD activities as compared to WT. Additionally, overexpression of FaHSP17.8-CII improved the synthesis of chlorophyll and transcript abundance of FapsbC, FapsbD and FapsbE, and alleviated the photoinhibition of PSII in tall fescue under Pb stress. This study provides an initial genetic engineering strategy to improve Pb phytoremediation efficiency in tall fescue by FaHSP17.8-CII overexpression.

Lead (Pb) is one of the most common metal pollutants in soil, and phytoextraction is a sustainable and cost-effective way to remove it. The purpose of this work was to develop a phytoextraction strategy able to efficiently remove Pb from the soil of a decommissioned fuel depot located in Italy by the combined use of EDTA and endophytic bacteria isolated from indigenous plants. A total of 12 endophytic strains from three native species (Lotus cornicolatus, Sonchus tenerrimus, Bromus sterilis) were isolated and selected to prepare a microbial consortium used to inoculate microcosms of Brassica juncea and Helianthus annuus. As for B. juncea, experimental data showed that treatment with microbial inoculum alone was the most effective in improving Pb phytoextraction in shoots (up to 25 times more than the control). In H. annuus, on the other hand, the most effective treatment was the combined treatment (EDTA and inoculum) with up to three times more Pb uptake values. These results, also validated by the metagenomic analysis, confirm that plant-microbe interaction is a crucial key point in phytoremediation. [ABSTRACT FROM AUTHOR]

• The growth, biosynthesis of pigments and other macromolecules appeared to be strong predictors in appraisal of Pb tolerance/susceptibility in durum wheat. • Germplasm of CBD59, CBD63 and CBD66 can be exploited for future selection and breeding programs. • The bioaccumulation of metal in grains of some cultivars of durum wheat much below than permissible limits set by FAO/WHO is of great significance owing to its implications for food safety. Lead (Pb) pollution emerged as an international issue particularly during second and third industrial revolution and is of serious global concern. Cereal crops have shown different capabilities, innate variability and mechanisms to cope with heavy metals present in their environment. Keeping in view the perspectives of food security and safety with increasing demand for Triticum durum L. it becomes imperative to appraise sustainability potential of the crop for Pb contaminated soils. The current study was conducted to test the hypothesis that T. durum germplasm holds genetic variability to evolve under Pb contamination through modulations of morpho-biochemical parameters of selective advantage. The performance of nine T. durum L. cultivars (CBD25, CBD46, CBD58, CBD59, CBD63, CBD66, CBD68, CBD69 and CBD82) was evaluated following exposure to varying Pb levels (control, 10, 20 and 40 mg kg−1) in soil. Growth, biosynthesis of macromolecules and metal distribution in plant parts were assessed using valid procedures and protocols. The cultivars exhibited a differential degree of tolerance to Pb and among the tested germplasm, CBD59 performed better followed by CBD63 and CBD66 for their primary productivity traits, biosynthesis of pigments and other macromolecules (amino acids, proteins and sugar) along with resilience for Pb uptake and its consequent bioaccumulation in grains. The traits used in the study served as strong predictors to provide superior/selective ability to survive under contaminated environment. The study signified that metal tolerance/sensitivity in the cultivars is independent of magnitude of metal stress, growth responses and Pb accumulation in plant parts hence varied in space and time. The existence of genetic variability, which is a pre-requisite for selection can definitely be of great advantage for future breeding projects to develop high yielding varieties/ cultivars of durum wheat with Pb free grains to assure food security and safety. [ABSTRACT FROM AUTHOR]

• A facile one-pot method for synthesizing 3D honeycomb-like LDHs/chitosan beads. • The oriented aggregation and growth of the LDHs induced the unique structure. • The MgFe-LDH/chitosan beads exhibited well removal performance to Pb2+ in spirit. Presence of toxic lead (Pb2+) in alcoholic beverages in trace concentrations has been documented in literature. However, only a handful of facile and inexpensive treatments can effectively remove Pb2+ from alcoholic beverages. Herein, a convenient approach for the synthesis of hydride beads is presented that is composed of chitosan and layered double hydroxides (LDHs), in which the LDH nanosheets were grown on the chitosan skeletons and resulted in a hierarchical structure with interconnected network of LDH nanosheets. In particular, the as-synthesized MgFe-LDH/chitosan beads were used as a model to evaluate their capacity to remove trace Pb2+ from spirit. The as-synthesized MgFe-LDH/chitosan beads exhibited good stability, and excellent removal capacity for Pb2+ that could decrease the concentration of Pb2+ from 2 to 0.005 mg/L, which is well below the acceptable limits in alcoholic beverages in China (0.5 mg/L). The results from X-ray photoelectron spectroscopy (XPS) and structural characterizations confirmed the presence of strong interactions between Mg sites and Pb2+. Furthermore, the experiments with laboratory-scale column system demonstrated the potential feasibility of the proposed method in practical applications. It is envisioned that the work can provide a convenient, efficient, safe and cost-effective strategy to address the issue of treating alcoholic beverages contaminated by heavy metals. Additionally, a series of LDH-based beads were also synthesized using the proposed method, offering a platform to address the challenges faced when LDHs are used in powdered forms. [ABSTRACT FROM AUTHOR]