High Concentrations Of Pb Research Articles

Differential growth and metal uptake efficiency of castor bean genotypes on a lead contaminated soil

<p>Present study investigated the unknown responses of five castor bean genotypes to lead (Pb) contaminated soil, focusing on their growth and metal uptake efficiency. A unique aspect is the simultaneous assessment of multiple genotypes, offering a holistic view of their reactions to soil contamination. Five castor genotypes (NIAB Gold, NIAB Spineless, NIAB-2020, DS-30, and C-3) were grown in pots filled with soil spiked with varying concentrations of Pb (0, 100, 200, 400, and 800 mg kg-1). Results have shown that increasing Pb concentrations led to a general decrease in plant biomass and photosynthetic pigments in all castor genotypes, however NIAB-2020 and DS-30 showcased remarkable resilience. Interestingly, the activities of antioxidant enzymes revealed a contrasting pattern. While superoxide dismutase and peroxidase activity declined, catalase and ascorbate peroxidase activity increased with higher Pb levels. Notably, DS-30 and NIAB-2020 exhibited the maximum catalase and ascorbate peroxidase activity at highest Pb concentration. Furthermore, these genotypes displayed impressive Pb uptake, particularly in their roots, exceeding the other tested genotypes. With metal translocation factor less than 1, NIAB-2020 and DS-30 showed promising potential for phytostabilization through efficient Pb accumulation, coupled with strengthened antioxidant defense mechanisms and restricted translocation, making them compelling candidates for eco-friendly remediation strategies.</p>

Assessment of potentially toxic metals in selected local and foreign rice brands from Southwestern Nigeria: Implications for human health

This study evaluated the presence of potentially toxic metals (PTMs) in different local and foreign rice brands from southwestern Nigeria. Eight brands were purchased in four states: Oyo, Osun, Ogun, and Lagos. A total of sixty-four rice samples were analyzed for PTMs (Cd, Pb, Cr, Ni, Cu, Fe, Mn, and Zn) using an atomic absorption spectrophotometer. The data collected were analyzed for descriptive and inferential statistics. Health risk assessments were conducted to evaluate non-carcinogenic risks, including hazard quotient (HQ), hazard index (HI), and cancer risk (CR). The results revealed high concentrations of Pb (7.13±5.40 mg/kg) and Cd (8.71±3.81 mg/kg) in the local brand and a high Cr (5.91±3.71 mg/kg) in the foreign brand, which exceeded the WHO permissible limits of 0.2, 0.3, and 1.0 mg/kg, respectively. The health risk assessment revealed that the HQ values exceeded the permissible limit of 1.0 for Pb, Cd, and Cr in most of the rice brands, indicating adverse health effects. The CR data revealed health concerns for Cd, Cr, and Ni, with values exceeding the limit of 1.0 × 10−4. This suggests a potential risk of cancer development associated with consuming the locally produced and imported rice in the states under study.

Assessment of toxic elements in selected fish species in the marine water at Jamestown, Ghana

Fish is an excellent source of low-fat protein. Fish contains a lot of omega-3 fatty acids, as well as vitamins D and B2 (riboflavin). The daily consumption of contaminated food, especially fish, is among the primary cause of heavy metals pollution to human health. The aim of the research was to determine the concentration of heavy metals in selected species of fish from the Gulf of Guinea at James Town in Ghana. In tandem with the study's objective, samples of different forms of fish, Cassava fish, Flatfish, Redfish, Kingfish, and Silverfish, and sediment were obtained and analyzed for the presence of heavy metals using atomic absorption spectrometer (PerkinElmer®, PinAAcle 900T). The analysis indicated a high concentration of Pb, Cd, and Cr concentrations in fish gills, muscles, and sediment. High lead concentration in Silverfish gills (5.9 mg/kg) and Flatfish gills (2.29 mg/kg) above WHO levels. Cadmium was found in all fish species and sediment except Kingfish. Chromium concentrations were high n Cassava fish (3.10 mg/kg) and Silverfish (4.01 mg/kg) and copper concentrations were absent in the fish species. Arsenic and mercury were also not detected in all fish species and sediment. Manganese concentrations were found in fish and sediment. High cadmium target hazard quotient (0.17–11.60 for adults and 0.24 to 16.24 for children) and cancer risk (0.00–0.04) values in fish samples indicated potential health concerns. The Hazard Index (HI) for the analyzed samples ranged from 0.00 to 12.48 for adults and 0.00 to 17.47 for children. The study suggests that eliminating pollution and other sources of waterbody pollution is crucial to protecting the marine environment and the health of seafood consumers.

Heavy Metals in Surface Waters in A State of The Brazilian Amazon: An Integrative Review

Objective: The aim was to carry out a systematic literature review on studies and research into heavy metals (traces) in rivers in the Amazon region of Pará. Theoretical Framework: To have a chronological understanding of the situation of possible contamination by trace metals, affecting the quality of water in the Amazon, impacting ecosystems and public health. Industrial, agricultural and urban development has had a negative impact on rivers in Pará, contributing to the degradation of water resources. Method: This is a review, with a descriptive, qualitative and quantitative approach, using literature searches (descriptors) of research carried out in the state of Pará, published between 2005 and 2023. Articles with solid evidence were considered, in accordance with the parameters recommended by resolutions 274/2000 and 357/2005 and ordinance 888/2021 of the National Environment Council - CONAMA, expressing the results through descriptive statistics. Results and Discussion: It was possible to demonstrate the main environmental impacts of pollutant and contaminant sources in rivers in the Amazon region of Pará, such as high concentrations of Pb, Cu, As, Cd, Cr and Hg, especially Pb and Hg, which were present in 60% of the studies carried out in different aquatic environments over the last 20 years in the state of Pará. Research Implications: It helps to visualize the little research carried out in the Pará Amazon, as well as providing a better understanding of land use in the region, correlating it with the contamination of surface water by heavy metals. Originality/Value: It is of socio-environmental and scientific importance, as it provides a better understanding of the level of contamination and frequency of heavy metals in the surface waters of the state of Pará.

Chemical constraints and tectonic setting of the Ginebra ophiolite complex

The occurrence and types of ophiolites in the Central Cordillera of the Colombian Andes have not been identified in terms of their tectonic settings and geochemical features. Therefore, the study of the tectonic setting and subduction zones in the ophiolites’ magmatic evolution becomes a significant issue. The Ginebra Ophiolitic Complex (GOC) is located on the western flank of the Central Cordillera in the Valle del Cauca Department, southwest of Colombia, assigned to the Lower Cretaceous period, as indicated by the contact of the GOC with the Buga Batholith. The GOC is formed by three main lithologies: amphibolite, gabbro, and ultramafic rocks (pyroxenite and peridotite), according to Ossa (2007). The rocks in the Puente Piedra section, located in the northeast of Ginebra municipality, are part of the gabbroic cumulates within the ophiolitic sequence. This sequence comprises interspersed layers of gabbroic cumulates, gabbrodiorites, and diorites; interpreted as a result of crystal accumulation and fractional crystallization processes. The mafic rocks of the GOC are sub-alkaline and correspond to the low potassium (K2O wt% 0.03-0.06) tholeiitic series. Geochemically, they have SiO2 wt% ranging from 49 to 61 and an aluminum oxide saturation index of approximately ~0.4 and ~0.8, indicating a metaluminous type. The geochemistry of the studied rocks from Puente Piedra section indicates that the GOC formed through fractional crystallization and accumulation processes from a single magma source. Cluster analysis, used to compare the geochemistry of GOC rocks and the Amaime Complex basalts, suggests a similar magma source, possibly linked to multiple recharge events that underwent fractional crystallization, melt extraction, and accumulation processes. The geochemical parameters are indicative of a suprasubduction zone ophiolite, characterized by a low potassium tholeiitic series affinity, TiO2 values typically <1.2 wt%, Th enrichment typical of subduction zones, high Pb content, and low values of Ti, Y, Yb, Ta, Nb, Zr, and Hf.

1H NMR-metabolomics studies on acute toxicity effect of lead in adult zebrafish (Danio rerio) model

Zebrafish (Danio rerio) is ideal for studying the effects of toxins like lead or plumbum (Pb) which persist in the environment and harm body systems when absorbed. Increasing Pb concentration could result in a higher mortality rate and alteration of behavior and metabolism. The present study evaluates the acute toxicity effect of Pb on metabolome and behavior in adult zebrafish. The zebrafish were exposed to various Pb concentrations ranging from 0 to 30 mg/L for different periods (24, 48, and 72 h) before the fish samples were subjected to Nuclear Magnetic Resonance (NMR)-multivariate data analysis (MVDA) with additional support from behavioral assessment. The behavior of zebrafish was significantly altered after Pb inducement and the differential metabolites increased in low (5 mg/L) while decreased in high (10 mg/L) Pb concentrations. An ideal Pb induction could be achieved by 5 mg/L concentration in 24 h, which induced significant metabolite changes without irreversible damage. Continuing research on the effects of lead toxicity is crucial to develop effective prevention and treatment strategies.

Unveiling the origins and transport processes of radioactive pollutants downstream from a former U-mine site using isotopic tracers and U-238 series disequilibrium

High U concentrations (reaching up to 14,850 mg ⋅ kg−1), were determined in soils and sediments of a wetland downstream of a former U mine in France. This study aims to identify the origin of radioactive contaminants in the wetland by employing Pb isotope fingerprinting, (234U/238U) disequilibrium, SEM, and SIMS observations. Additionally, information about U and 226Ra transport processes was studied using U-238 series disequilibrium. The results of Pb fingerprinting highlighted inherited material inputs of different U-mines with mainly two types of U-ores: i) pitchblende (UO2), and ii) parsonsite (Pb2(UO2)(PO4)2). Moreover, significant disequilibrium of (230Th/238U) and (226Ra/230Th) activity ratios highlighted the mobility of 238U and 226Ra in the wetland, primarily driven by the water table fluctuations. Finally, this work uncovered a limitation of Pb isotope fingerprinting in the case of parsonsite materials, as the high natural Pb content of this mineral may hide the uranogenic Pb signature in the samples.

Biomonitoring potentially toxic elements in atmospheric particulate matter of greater Dhaka region using leaves ofhigher plants.

In this study, four different plant species, namely Artocarpus heterophyllus, Mangifera indica, Psidium guajava, and Swietenia mahagoni, were selected from seven different locations to assess the feasibility of using them as a cost-effective alternative for biomonitoring air quality. Atmospheric coarse particulate matter (PM10), soil samples, and leaf samples were collected from residential, industrial, and traffic-congested sites located in the greater Dhaka region. The heavy metal concentrations (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in the leaves of the different species, PM10, and soil samples were analyzed. The highest Pb (718ng/m3) and Zn (15,956ng/m3) concentrations were found in PM10 of Kodomtoli which is an industrial area. On the other hand, the highest Fe (6,152ng/m3) and Ni (61.1ng/m3) concentrations were recorded in the PM10 of Gabtoli, a heavy-traffic area. A significant positive correlation (r = 0.74; p < 0.01) between Pb content in plant leaves and PM fraction was found which indicated that atmospheric PM-bound Pb may contribute to the uptake of Pb by plant leaves. The analysis of the enrichmentfactor (EF)revealed that soils were contaminated with Cd, Ni, Pb, and Zn. The abaxial leaf surfaces of Psidium guajava growing at the polluted site exhibited up to a 40% decrease in stomatal pores compared to the control site. Saet's summary index (Zc) demonstrated that Mangifera indica had the highest bioaccumulation capacity. The metal accumulation index (MAI) was also evaluated to assess the overall metal accumulation capacity of the selectedplants. Of the four species, Swietenia mahagoni (3.05) exhibited the highest MAI value followed by Mangifera indica (2.97). Mangifera indica and Swietenia mahagoni were also found to accumulate high concentrations of Pb and Cr in their leaves and are deemed to be good candidates to biomonitor Pb and Cr contents in ambient air.

Simultaneous Determination of Ultra-Trace Pt, Pd, Rh, and Ir in Gold Mining Residue by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) with an Antimony-Copper Fire Assay and Microwave Digestion

The evaluation of the flow direction of platinum group elements (PGEs) during gold-copper ore mining is challenging due to the uneven distribution and low content. Therefore, it is vital to accurately and simultaneously determine ultra-trace PGEs Pt, Pd, Rh, and Ir in gold mining residue samples. In this study, a method to simultaneously determine ultra-trace Pt, Pd, Rh, and Ir in gold mining residue is reported using Sb–Cu fire assay, microwave digestion, and inductively coupled plasma-mass spectrometry (ICP-MS). The Sb–Cu fire assay was used to enrich Pt, Pd, Rh, and Ir, obtaining Sb–Cu alloy particles that concentrate these elements. An optimal microwave method was employed to digest the Sb–Cu alloy particles. In ICP-MS, the collision reaction interface was used to eliminate the interferences of other elements and improve the accuracy. Moreover, the matrix-matched multi-external standards combined with internal standard calibration were utilized to reduce the error. High concentrations of Au, Ag, and Pb showed no interferences with Pt, Pd, Rh, or Ir determination. The limits of detection for Pt, Pd, Rh, and Ir were 0.018, 0.052, 0.064, 0.035 ng·g−1, respectively, and the relative standard deviation was 5.18, 4.66, 1.55, and 3.17%. Additionally, the determination of Pt, Pd, Rh, and Ir in standard reference materials showed good agreement with the certified values. In summary, a reliable and efficient method is provided to determine various PGEs which is of great significance for gold-copper ore mining.

Neighborhood-scale lead (Pb) speciation in Akron, Ohio (USA) soils: primary sources, post-deposition diagenesis, and high concentrations of labile Pb

Lead (Pb) poses a significant risk to infants and children through exposure to contaminated soil and dust. However, there is a lack of information on Pb speciation and distribution at the neighborhood-scale. This work aimed to determine: (1) the distribution of acid-extractable (labile) Pb and other metals ([M]AE) in two neighborhoods in Akron, Ohio (USA) (Summit Lake and West Akron; n = 82 samples); and (2) Pb speciation and potential sources. Total metal concentration ([M]T) and [M]AE was strongly correlated for Pb and Zn (R2 of 0.66 and 0.55, respectively), corresponding to 35% and 33% acid-extractability. Lead and Zn exhibited a strong positive correlation with each other (R2 = 0.56 for MT and 0.68 for MAE). Three types of Pb-bearing phases were observed by electron microscopy: (1) galena (PbS)-like (5–10 μm); (2) paint chip residuals (10–20 μm); and (3) Pb-bearing Fe-oxides (20 μm). Isotope ratio values for PbAE were 1.159 to 1.245 for 206Pb/207Pb, and 1.999 to 2.098 for 208Pb/206Pb, and there was a statistically significant difference between the two neighborhoods (p = 0.010 for 206Pb/207Pb and p = 0.009 for 208Pb/206Pb). Paint and petrol are the dominant sources of Pb, with some from coal and fly ash. Lead speciation and distribution is variable and reflects a complex relationship between the input of primary sources and post-deposition transformations. This work highlights the importance of community science collaborations to expand the reach of soil sampling and establish areas most at risk based on neighborhood-dependent Pb speciation and distribution for targeted remediation.

Selection and characterization of lead-tolerant sweetpotato cultivars for phytoremediation

Lead (Pb) is one of the most toxic heavy metals (HMs) for plants and the environment. Sweetpotato [Ipomoea batatas (L.) Lam], the sixth most important food crop in the world, is tolerant to various environmental stresses, owing to its high antioxidant capacity. In this study, we selected sweetpotato cultivars showing high tolerance to lead (Pb) for phytoremediation-related applications. Young seedlings of 20 sweetpotato cultivars were treated with 30 mM Pb. Daeyumi (KO-12) and Dahomi (KO-5) were selected as Pb-tolerant and -sensitive cultivars, respectively, based on their photosynthetic activity and growth inhibition index (I50). In the Pb treatment, hydrogen peroxide and malondialdehyde contents of KO-12 were 1.5-fold less than those of KO-5. In addition, KO-12 showed a higher ability to accumulate Pb in roots and leaves than KO-5. Expression levels of four Pb-responsive genes, including the metallothionein gene IbMT1, were higher in the roots and leaves of KO-12 than in those of KO-5. Interestingly, KO-12 showed greater tolerance to high Pb concentrations than sunflower and rapeseed, which have been well-studied for phytoremediation. Our results suggest that sweetpotato is a suitable biomaterial for the phytoremediation of soils contaminated with HMs, including lead, for sustainable agriculture.

Challenges to Treat Complex Zinc Concentrate and Latest Technical Development

The complex zinc concentrate containing high Pb, Cu, SiO2, Na and K, including the Zn-Pb bulk concentrate, cannot be treated in the fluidized bed roaster. The Imperial Smelting Process (ISP) is the main technology to treat this type of concentrate. However, ISP consumes a large amount of coke, which is not only expensive, but also has high CO2 emission.Several metallurgical processes, which can treat the type of complex zinc concentrate and have low CO2 emission, have been reviewed and compared.Recently, a new technology “Flash Burner Roasting Process” has been tested successfully at the industrial scale suspension roaster, and the tests demonstrate that this technology can treat the complex zinc concentrate containing high contents of Pb, Cu and SiO2. The thermodynamic modelling for this process has been done. The industrial test results, the modelling results and the further development are presented in this paper.

Sublethal Concentrations of Cadmium and Lead: Effects on Hemato-Biochemical Parameters and Tissue Accumulation in Wallagu attu.

The exposure of fish to heavy metals can significantly impact physiological processes and potentially lead to adverse health effects. This study assesses the effects of exposure to Cd and Pb sublethal concentrations in water on Wallagu attu. A total of 48 fish with an average body weight of 145.5 ± 26g were distributed among three groups (control, Cd-treated, and Pb-treated) within 60L fiberglass tanks. They were exposed to30% sublethal concentrations of Cd and Pb for durations of 1, 15, and 30 days. Following this exposure, an assessment was conducted on metal bioaccumulation and hemato-biochemical responses. Results revealed a significantly (P < 0.05) higher concentration of heavy metals in the fish tissues of metals exposed groups than in the control. The concentration of Cd and Pb increases in fish tissues (kidney > gills > intestine) with exposure time. In most cases, the Pb-exposed group exhibited significantly (P < 0.05) higher concentrations of Pb in different tissues than the Cd-treated group. With extended exposure time, the activities of CAT and SOD show a significant decrease in both Cd and Pb-treated groups. However, the reduction in activities was more pronounced in the Cd-exposed group. On 15 and 30 days, the levels of red blood cells (RBC), hemoglobin (HB), hematocrit (HCT), and total protein (TP) decrease in groups exposed to Cd and Pb. The cortisol and glucose levels exhibit a more noticeable (P < 0.05) increase with prolonged exposure to Cd and Pb than the control group. On day 30, the survival rate decreased more in the Pb-exposed group. The findings of this study indicate that exposure to sublethal doses of Cd and Pb induces stress in Wallagu attu, resulting in rapid changes in specific hemato-biochemical parameters.

Monitoring of the Fluctuation of the Pollutant Load of Leachate Rejected in Environment. Study in the Northeast of Algeria

In order to model the environmental impact of leachate produced at the engineered landfill center (ELC) of Bouguerguer, Guelma located in the north east of Algeria. A physico-chemical characterization during 2020, was carried out in order to estimate this impact. For this purpose fourteen parameters have been studied which are, In vivo: pH, conductivity, Salinity. In vitro: Organic element contents (BOD5, COD); Heavy metal contents (Fe, Zn, Pb, Cd and Cr); The contents of nutrient elements (Nitrate, Nitrite, Ammonium and Suspended matter). The results obtained show that the leachates studied, have the following characteristics: A basic pH of 8,85 , Suspended matter a fairly large load with 5397,92 mg/L. The organic load interpreted by a COD that reaches an average 1603, 75 mg O2/L and a BOD5 that reaches an average of 778,54 mg O2/L, which strongly justifies the presence of organic pollution. The mineral pollution is also present, translated by a high electrical conductivity which reaches an average value of 33,38 mS/cm, Nitrates and nitrites average 15,68 and 17,93 mg/l respectively. The leachates are also characterized by a high content of Fr, Zn, Pb, Cd and Cr with an average of (42,70 ; 10,44 ; 8,27 ; 4,37 and 5,97 mg/l) respectively. Noting that the results obtained constitute the first characterization of leachates in this landfill and thus provide a database for future research.

Impact of Varied Lead Concentrations on Lead Accumulation in the Body, Heart and Gill Damage of Milkfish (Chanos chanos)

Milkfish (Chanos chanos) is valued in aquaculture for its affordability and nutritional richness. However, conventional farming techniques frequently result in suboptimal yields due to lead (Pb) contamination. Traditional milkfish ponds are typically situated near coastal areas, river waters, estuaries, ports, and industrial zones, rendering them susceptible to contamination, particularly from heavy metals, like Pb. This study aimed to analyze Pb accumulation in the body of milkfish juvenile, identify liver and gills damage, and examine the growth rate and survival of milkfish exposed to Pb at various concentrations. Juvenile milkfish were exposed to various concentrations of PbNO3, namely 0 mL.L-1, 0.08 mL.L-1, 0.8 mL.L-1, and 8 mL.L-1, including the non-exposed control group. The metal content of the fish bodies was measured using an AA spectrophotometer. Histological analysis of the liver and gills of the fish was performed to evaluate organ damage. The results showed significant Pb accumulation has been observed in milkfish exposed to high Pb concentrations. The control treatments showed a decrease in metal content, whereas treatments with high concentrations showed a significant increase. Exposure to Pb within 30 d can cause organ damage, such as inflammatory cells, secondary lamella fusion, and necrosis that occurs in the gills. In the liver, there is damage such as the accumulation of inflammatory cells, necrosis, and hydrofic degeneration. Pb exposure rapidly damages and disrupts milkfish's biological functions, influencing survival and growth. Pb exposure with doses 8 mL.L-1 significantly affected juvenile milkfish within approximately 60 min.

Potentially Toxic Elements (PTEs) Dispersion in Alluvial Deposits from Abandoned Mining Sites

In the watersheds of abandoned mining districts, it is common to find remains of former facilities and waste dams on stream banks and slopes—a situation that results in the transport and accumulation of metal(loid)s in alluvial deposits. To analyze this problem, an area of the former mining district of Linares–La Carolina (southern Spain) was selected to evaluate the contents and distributions of Ag, As, Ba, Cu, and Pb as potentially toxic elements (PTEs) found in the mineral paragenesis. Specifically, this study focused on the Siles Stream, which runs through a sector where underground mining for the exploitation of galena veins generated abundant mining wastes, mainly waste rock and tailings. Thirty-four sediment samples from the stream bed of the Siles Stream and two sediment samples from the Guadiel River, of which it is a tributary, were analyzed. Floodplain sediments were sampled in the stream banks at the middle and lower reaches (11 samples), as well as the riverine soils developed at the mouth of the Siles Stream (22 samples). The analyzed samples presented high levels of PTEs, in most cases with values much higher than the generic reference levels established by European and regional legislation for PTEs in soils. In the case of Pb, the main metal mined in this district, contents of up to 27,074 mg·kg−1 were observed in the stream bed sediments. Very high concentrations of Pb also appeared in the floodplain sediments, with maximum values in the middle course of the stream, where the concentration reached 43,692 mg·kg−1. With respect to the sediments of the Guadiel river bed, the Pb content was 699 mg·kg−1 before the confluence with the stream and 2537 mg·kg−1 downstream, which clearly reflects the influence of the contributions from the Siles Stream. The enrichment factors (EFs) show that the sediments present a severe to very severe anthropogenic influence for Ag, As, Ba, Cu, and Pb. The geoaccumulation index (Igeo) indicates that the entire basin is extremely polluted by Pb, to which As and Ag are added in the middle course of the stream. The potential ecological risk index (RI) and pollution load index (PLI) based on the contamination factor (CF) suggested that metal loads far exceeded the reference values. Selective chemical extraction methods were used to assess the potential bioavailability of these elements in sediment and soil samples. The results showed high concentrations of Pb in the exchangeable fraction, which poses a significant ecological risk and potential human health risks.

Oyster shell-modified lignite composite in globular shape as a low-cost adsorbent for the removal of Pb2+ and Cd2+ from AMD: Evaluation of adsorption properties and exploration of potential mechanisms

A low-cost composite adsorption material has been synthesized from fishery wastes and natural minerals to address challenges such as ecological balance destruction caused by high concentrations of Pb and Cd in acid mine drainage (AMD), unreasonable use of low-caloric lignite, and environmental pollution caused by idle accumulation of oyster shells. This new adsorbent can effectively treat AMD by improving acidity and adsorbing Pb2+ and Cd2+. In this study, oyster shell-modified lignite composite in globular shape (OSL-G) was synthesized by using pyrolyzed oyster shell and lignite, with the addition of bentonite adhesive. The adsorption properties of OSL-G on AMD were evaluated, and the potential mechanism of OSL-G repairing AMD was explored. The results showed that when the mass ratio of oyster shell to lignite was 1:1, oyster shell-modified lignite composite (OSL) was synthesized at 900 °C for 20 min. When the adhesive content was 15.50 %, the roasting temperature was 640 °C, and the roasting time was 2.35 h, OSL-G was synthesized and the adsorption effect was the best. The OSL-G could effectively treat AMD with pH 4 ∼ 5 and initial Pb2+ and Cd2+ concentrations of 10 mg/L within 600 min at a dosage of 4 g/L. The OSL-G adsorption process followed the quasi-second-order kinetic model and the Freundlich model. The maximum adsorption saturation capacities of Pb2+ and Cd2+ were 107.2821 mg/g and 8.3777 mg/g at 298.15 K, respectively. The adsorption process was a multistep controlled spontaneous endothermic process. The potential mechanism was mainly the adsorption-condensation coexistence results of electrostatic adsorption, neutralization precipitation, ion exchange, and surface complexation. The removal rates of Pb2+ and Cd2+ of the recovered OSL-G (ROSL-G) were still high, reaching 57.26 % and 50.38 % after 5 times of adsorption–desorption, respectively. The applicability of ROSL-G after adsorption–desorption for other heavy metal components in AMD proved its good application potential. This study suggested that OSL-G can be used as a promising environmentally friendly adsorbent for AMD. This study provided a broad picture of the management and reuse possibilities of fishery wastes and natural mineral resources, and addressed established, current, and potential strategic needs, particularly in terms of sustainability challenges and ecological civilization construction.

Pollution Status of Groundwater Resource by Some Heavy Metals Using Index Approach in Some Part of Nasarawa Area, Kano State, Nigeria

Groundwater is the world's most significant natural resource providing water for different purposes, including drinking, domestic, industrial and irrigational. However, polluted groundwater may endanger human survival. This research evaluated the status of groundwater resource pollution caused by some heavy metals in some parts of the Nasarawa local government area of Kano State. 15 groundwater samples were collected from functional boreholes in the area. Heavy metals concentrations evaluated include Zn, Mn, Cr, Mg, Cd, Fe, Cu, and Pb and were compared with the World Health Organization and Nigerian Standard for Drinking Water Quality to establish their suitability for human consumption. Descriptive statistics was employed to summarize the analyzed data. Metal index was used to determine the pollution status of the groundwater. The result revealed that Zn, Fe, Cu, and Mn with the mean value of (0.090, 0.160, 0.191 and 0.11) were found within the stipulated limit set by WHO (3.0, 0.3, 2.0 and 0.5) and NSDWQ (3.0, 0.5-50, 1.0 and 0.2), while Pb, Cd, Cr, and Mg (0.105, 0.127, 0.206 and 0.82) exceeded the permissible limits recommended by WHO (0.01, 0.003, 0.05 and 0.5). A high concentration of Pb, Cd, Cr, and Mg may be attributed to anthropogenic influences possibly deriving from improper municipal and Bampai industrial waste disposal. The values of the metal index (MI) revealed that the water is seriously affected by Pb, Cd and Cr, which can pose serious health damage to consumers. It is recommended that constant and continuous monitoring of Pb, Cd and Cr in groundwater be made in the study area due to its proximity to Bampai and Sharadda industrial sites.

Short communication: Synchrotron-based elemental mapping of single grains to investigate variable infrared-radiofluorescence emissions for luminescence dating

Abstract. During ionizing irradiation, potassium (K)-rich feldspar grains emit infrared (IR) light, which is used for infrared radiofluorescence (IR-RF) dating. The late-saturating IR-RF emission centred at ∼880 nm represents a promising tool to date Quaternary sediments. In the present work, we report the presence of individual grains in the K-feldspar density fraction displaying an aberrant IR-RF signal shape, whose combined intensity contaminates the sum signal of an aliquot composed of dozens of grains. Our experiments were carried out at the National Synchrotron Light Source (NSLS-II) at the submicron-resolution X-ray spectroscopy (SRX) beamline. We analysed coarse (&gt;90 µm) K-feldspar-bearing grains of five samples of different ages and origin in order to characterize the composition of grains yielding the desired or contaminated IR-RF emission. Using micro-X-ray fluorescence (μ-XRF), we successfully acquired element distribution maps of up to 15 elements (&lt;1 µm resolution) of sections of full grains previously used for IR-RF dating. In keeping with current theories of IR-RF signal production, we observed a trend between the relative proportions of Pb and Fe and the shape of the IR-RF signal, namely that most grains with the desired IR-RF signal shape had high Pb and low Fe contents. Interestingly, these grains were also defined by high Ba and low Ca contents. Our study also represents a proof of concept for mapping the oxidation states of Fe using micro-X-ray absorption near-edge structure spectroscopy (μ-XANES) on individual grains. The high spatial resolution enabled by synchrotron X-ray spectroscopy makes it a powerful tool for future experiments to elucidate long-standing issues concerning the nature and type of defect(s) associated with the main dosimetric trap in feldspar.

Spatial distribution characteristics and source apportionment of heavy metal(loid)s in park dust in the Mianyang urban area, China.

Park dust is a carrier of heavy metal pollutants and could potentially harm the health of urban residents. The concentrations of 10 heavy metal(loid)s (HMs) in park dust from the Mianyang urban area were analysed via X-ray fluorescence spectrometry. Based on ArcGIS spatial analysis, Spearman correlation analysis, spatial autocorrelation analysis, and the positive matrix factorization (PMF) model, the spatial distribution and sources of HMs in park dust were studied. The average contents of Zn, Co, Cu, Cr, Pb, and Ba in park dust were 185.0, 33.7, 38.7, 178.7, 51.0, and 662.1mg/kg, respectively, which are higher than the reference values. The 10 HMs exhibited obvious spatial distribution and local spatial agglomeration patterns. High concentrations of As and Pb were primarily concentrated in the eastern part of the Mianyang urban area. High concentrations of Zn, Cr, and Cu were largely distributed in parks near the Changjiang River and Fujiang River. A high concentration of Co was concentrated in the northern region. The high-value areas of Mn, Ba, V, and Ni occurred far from the city centre and were located in the southwestern region. We found that Pb and As primarily originated from mixed traffic and natural sources; Zn, Cr, and Cu mainly originated from industrial activities; Co largely originated from building sources; and Ba, Ni, Mn, and V were mostly derived from natural sources. Mixed, industrial, building, and natural sources accounted for 24.5%, 24.8%, 24.7%, and 26.0%, respectively, of the HM sources. Co, Cu, Cr, and Zn in the Mianyang urban area were obviously influenced by human activities and should receive close attention.