High Concentrations Of Heavy Metals Research Articles

Use of Forest Trees in the Treatment of Polluted Soil by Heavy Metals: A Mini Review

Human activities lead to a large accumulation of heavy metals in the soil which comes from industrial activities such as mining smelting refining manufacturing processes and waste resulting from excessive use of chemical fertilizer and vehicle exhausts. So, soil pollutants especially with heavy metals can be treated using different types of plants; such as forest trees and grasses. These plants can tolerate soil pollutants at high concentrations in their biological tissue, and treat pollutants by absorbing and accumulating heavy metals in their living tissues. Therefore, in this article, we reviewed several forest tree species, that showed high resistance in the absorption and accumulation of heavy metals, such as genus Eucalyptus, Acacia, Salix, Populus, Tamarix, Melia, Dalbergia, Leucaena, Acer, Fraxinus, and Thuja. It has been noted that planting forest trees with high biomass that resist high concentrations of heavy metals in soil, works to rid the soil of these pollutants. This is the latest and best technology for treating soil pollution. In particular, it is unique from its counterparts in its environmental friendliness, economic benefits, and other returns resulting from plant cultivation. Therefore, applying phytoremediation techniques that benefit is the best and safest for the environment and living organisms.

Evaluating Technical properties of fired clay Brick production with mosaic sludge: A comprehensive study on heavy metal leachability for sustainable environmental and economic benefits

Mosaic sludge, generated from mosaic industrial activities such as cutting, polishing, and grinding, is often disposed of in landfills or discharged into drainage systems without adequate treatment. This study aims to reuse mosaic sludge from the mosaic industry by incorporating it into fired clay bricks. This approach offers an alternative disposal method, improves brick quality, and minimizes heavy metal leachability, contributing to environmental and economic sustainability. X-Ray Fluorescence (XRF) was conducted to determine the heavy metal concentration from two types of mosaic sludge bodymill mosaic sludge (BS) and polishing mosaic sludge (PS). The result indicates that the highest element concentration in mosaic sludge (BS and PS) shows that barium is the highest with 3253 ppm and 3260 ppm. Meanwhile, the lowest element concentration obtained in BS and PS is cesium with 14 ppm and 17 ppm. SPLP and TCLP also conducted in this study and the result show that, even though the element such as ferum (Fe) and cadmium (Cd) was not detected in XRF but in SPLP and TCLP, it shows that these two elements exist in clay, BS and PS with low concentration. In order to evaluate the compressive strength conducted by incorporating with different proportions 0 %, 1 %, 5 %, 10 %, 20 % and 30 % of BS and PS into fired clay brick. The result shows that compressive strength BS brick was stronger than PS brick. The maximum sludge percentage used in BS brick is 5 % with value of compressive strength is 28.10 MPa. Meanwhile, PS brick had the higher value of compressive strength at 30 % sludge percentage with the value 23.46 MPa. Static Leachate Test (SLT) was performed to evaluate heavy metal leachability from bricks containing different proportions of BS and PS sludge. In the SLT results, Fe exhibits the highest concentration of heavy metals at various proportions of BS and PS: 2.11 mg/L and 2.27 mg/L at 1 %, 1.77 mg/L and 1.88 mg/L at 5 %, 2.34 mg/L and 3.29 mg/L at 20 %, and 2.79 mg/L and 3.64 mg/L at 30 % respectively, among other elements. On the other hand, elements including Cr, Ni, Cu, As, Cd, and Pb demonstrated lower concentrations ranging from 0.00 mg/L - 1.0 mg/L. The result for control brick, BS brick and PS brick shows the same pattern. However, overall results show that the concentration still under limit set by USEPA.

Вміст важких металів у воді, донних відкладах та рибі водних об’єктів різного призначення Дніпропетровської області

Purpose. Assessment of the dynamics of heavy metal accumulation in water, bottom sediments, and fish of water bodies of different purposes in Dnipropetrovsk region. Methodology. The study on heavy metal contents in water, bottom sediments, and hydrobionts (fish) was conducted at various water bodies (Dnipro-Donbas hydraulic canal), fish ponds (ponds of PrJSC “AgroSoyuz”, PrJSC “Petrykivsky Rybhosp” and PE «Agrofirma «Nakhodka»), and multipurpose reservoirs (Dnipro reservoir, Sholokhivske reservoir) in Dnipropetrovsk region from 2015 to 2024. The determination of heavy metal concentrations (Pb, Cd, Mn, Cu, Fe, Ni, Zn) was carried out at the laboratory of the Research Center for Biosafety and Environmental Monitoring of Agricultural Resources of Dnipro State Agricultural and Economic University. The metal content was analyzed using atomic absorption spectrophotometry. The heavy metal contents were measured in four fish species (European perch, roach, Prussian carp, common carp). Sampling, data processing, and statistical analysis were conducted according to standard hydrochemical, hydrobiological, and ichthyological methods. The heavy metal contents were determined in fish muscles. Water quality was assessed according to general requirements and standards for fishery water bodies. Findings. The heavy metal contents in ecosystems of water bodies of different purposes was determined. In the sediment of ponds of PrJSC “AgroSoyuz” and PrJSC “Petrykivsky Rybhosp”, the heavy metal contents were significantly higher than in water or fish body: manganese within 41.24–68.43 mg/kg, cadmium – 0.32 mg/kg, lead 1.50–4.90 mg/kg (for ponds of PrJSC “AgroSoyuz”); manganese – 29.73 mg/kg, cadmium – 0.54 mg/kg, lead 5.72 mg/kg (for recreational pond of PrJSC “Petrykivsky Rybhosp”). For the water of these ponds, which is used for aquaculture, an excess of the content of some heavy metals – Mn, Zn, Cd - was recorded, and for the pond of PrJSC “AgroSoyuz” also Cu. Exceeding the normative heavy metal content for pond water of PE “Agrofirma “Nakhodka” was not noted. The content of some heavy metals in the water of the upper part of the Dnipro reservoir (Cu, Fe) did not meet the fishery norms. At the same time, the heavy metal contents in water and fish of these water bodies does not exceed the fishery standards for water used for fishery purposes. The heavy metal contents in the water of the upper part of the Dniprovske Reservoir (except for the Samara Bay) corresponded to fishery standards. The water in the Dnipro-Donbas hydrotechnical canal was characterized by high levels of heavy metals. Of the 6 investigated heavy metals, the maximum allowable concentrations were not exceeded only for lead (0.40 mg/dm3) The heavy metal contents in C. carpio muscles (juveniles and table fish) in different ponds of PrJSC “Petrykivskyi Rybhosp” (nursery and fattening) corresponded to fishery standards during the three years of the study (2011, 2015, 2016). In the Sholokhivske reservoir, the zinc content in C. gibelio muscles was 46.50 mg/kg, slightly exceeding the maximum allowable concentrations. Exceedances of copper and lead content were not noted. For fish from the Dnipro reservoir, the content of most heavy metals was elevated. In the meat of pelagic roach (R. rutilus), only copper content was within the normal limits (1.56 mg/kg), while all other 6 heavy metals exceeded the maximum allowable concentrations. In the meat of benthophagous Prussian carp (C. gibelio), elevated levels of accumulation of heavy metals were observed for manganese, iron, lead, and nickel, while zinc, copper, and cadmium content were within the standards. In the meat of European perch (P. fluviatilis), the highest content of heavy metals was observed for iron (80.54 mg/kg), with elevated levels observed for manganese, zinc, lead, and nickel. The obtained results indicate that the hydroecosystem of the Dniprovske reservoir, unlike other water bodies in the region, is significantly polluted with heavy metals. This is adequately reflected in the levels of heavy metal accumulation in the organisms of fish from different ecological groups - pelagic herbivores, benthophagous bottom-feeders, and predators. Originality. For the first time, the content of heavy metal accumulation in water, bottom sediments, and fish of water bodies of different purposes in Dnipropetrovsk region has been carried out over several years (2015–2024). Practical Value. The obtained results have theoretical and practical importance for the preparation of scientific-biological justifications for the fishery use of water bodies of various purposes in the region. Continuous monitoring of the heavy metal contents in hydrobionts is necessary to ensure food safety and the quality of raw materials and food fish products. Keywords: Dnipropetrovsk region, heavy metals, Dnipro Reservoir, Dnipro-Donbas Canal, ponds, Sholokhivske Reservoir, water, sediment, fish, accumulation of pollutants.

Deciphering the Environmental Code: SEM-EDX Analysis of Lead and Mercury Distribution in Enhalus Acoroides From Kayeli Bay, Indonesia

Background: Illegal gold mining activities around Kayeli Bay have led to increased heavy metal contamination that has the potential to impair water quality and growth of Enhalus acoroides, an important seaweed species. This study aimed to investigate the distribution and concentration of heavy metals Pb and Hg in Enhalus acoroides organs (roots, rhizomes, and leaves) using SEM-EDX techniques and evaluate the impact of mining activities on the surface microstructure of these organs. Methods: Enhalus acoroides samples were collected from ten sampling points in Kayeli Bay, which were selected based on potential heavy metal contamination. SEM-EDX analysis was performed to assess the surface microstructure and distribution of heavy metals in the seaweed samples. Results: Results showed significant differences in Pb and Hg concentrations among samples from different locations, with Hg content consistently higher than Pb. Surface microstructure analysis showed morphological changes in roots, rhizomes, and leaves exposed to heavy metals, indicating environmental stress in Enhalus acoroides. Conclusion: This study confirmed the negative impact of heavy metal contamination on Enhalus acoroides in Kayeli Bay due to illegal gold mining activities. High concentrations of heavy metals, especially Hg, in seaweed organs indicate potential risks to marine ecosystem health and the sustainability of fisheries resources. These findings emphasize the need for stricter environmental monitoring and management to protect this important marine habitat from heavy metal pollution.

Trifolium repens L. recruits root-associated Microbacterium species to adapt to heavy metal stress in an abandoned Pb-Zn mining area

Root-associated microbiota provide great fitness to hosts under environmental stress. However, the underlying microecological mechanisms controlling the interaction between heavy metal-stressed plants and the microbiota are poorly understood. In this study, we screened and isolated representative amplicon sequence variants (strain M4) from rhizosphere soil samples of Trifolium repens L. growing in areas with high concentrations of heavy metals. To investigate the microecological mechanisms by which T. repens adapts to heavy metal stress in abandoned mining areas, we conducted potting experiments, bacterial growth promotion experiments, biofilm formation experiments, and chemotaxis experiments. The results showed that high concentrations of heavy metals significantly altered the rhizosphere bacterial community structure of T. repens and significantly enriched Microbacterium sp. Strain M4 was demonstrated to significantly increased the biomass and root length of T. repens under heavy metal stress. Additionally, L-proline and stigmasterol could promote bacterial growth and biofilm formation and induce chemotaxis for strain M4, suggesting that they are key rhizosphere secretions of T. repens for Microbacterium sp. recruitment. Our results suggested that T. repens adapted the heavy metal stress by reshaping rhizosphere secretions to modify the rhizosphere microbiota.

Ecotoxicological impact of heavy metals on wild mud crabs (Scylla olivacea) in Malaysia: An integrative approach of omics, molecular docking and human risk assessment

Mud crab, one of the aquatic organisms found in estuary areas, has become a significant economic source of seafood for communities due to its delectable taste. However, they face the threat of heavy metal contamination, which may adversely affect their biological traits. This study explored the comparison of the mud crabs collected from Setiu Wetland as a reference site, while Kuala Sepetang is an area that contains a higher concentration of heavy metals than Setiu Wetlands. Heavy metal levels were quantified using inductively coupled plasma mass spectrometry (ICP-MS), while proteomes were assessed using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and 1H nuclear magnetic resonance (NMR)-based metabolomics, respectively. Heavy metal contamination affects the proteome, metabolome, and putative molecular targets in mud crabs (Scylla olivacea), leading to oxidative stress. Mud crabs collected from the metal-polluted area of Kuala Sepetang in Perak had considerably elevated concentrations of nickel (Ni), copper (Cu), zinc (Zn), lead (Pb), chromium (Cr), and cadmium (Cd) in comparison to the reference site of Setiu Wetlands in Terengganu. The proteome analysis revealed an upregulation of the stress-response protein Hsp70, which triggered superoxide dismutase (SOD) and increased arginine kinase expression (5.47 fold) in the muscle tissue, results in the alteration of metabolite regulation in the mud crab from Kuala Sepetang. Additionally, in the muscle tissues of mud crabs obtained from Kuala Sepetang, uncharacterized myosin-tail 1 domain proteins and sarcoplasmic calcium-binding proteins were downregulated. The metabolomic investigation identified changes in metabolites associated with energy metabolism and osmoregulation. Exploration of docking analysis suggests potential connections between methylarsonic acid and essential proteins in mud crabs. These findings suggest that the presence of heavy metals disrupts physiological processes and highlights potential molecular targets that warrant further investigation.

Spatial distribution and health risk assessment of heavy metals in drinking water in Nikshahr and Iranshahr cities of Iran

ABSTRACT The presence of high concentrations of certain heavy metals (HMs) in drinking water poses a serious threat to the health of consumers. This work was done to investigate the concentration of heavy metals such as Arsenic (As) cadmium (Cd), chromium (Cr), iron (Fe), mercury (Hg), nickel (Ni), lead (Pb) and cobalt (Co) in the water resources of two cities of Iranshahr and Nikshahr in the south of Sistan and Baluchistan province. For this aim, 24 samples of drinking water sources were collected and the concentration of heavy metals was determined by inductively coupled plasma-mass spectrometry (ICP-MS). The results of samples of these networks showed that the average concentration of Pb (11.25 μg/L), Hg (10.33 μg/L), As (10.62 μg/L) and Cd (3.45 μg/L) far exceeds the standard of the World Health Organisation. The average concentration of heavy metals in the drinking water of Iranshahr and Nikshahr is respectively Fe>Pb>As>Hg>Ni>Cr>Co>Cd and Fe>Pb>As> Ni > Cr >Co>Cd> Hg. Potential sources of pollution in this study are attributed to infiltration of industrial effluents and agricultural runoff, which is a significant threat to groundwater quality. The calculated hazard quotients (HQ(values for non-carcinogenic risk show that this value is less than 1 in most metals, but the hazard index)HI) in children is greater than 1, and non-carcinogenic risk is evident. HI was obtained for children 5.4 and adults 2.6. However, the risk of carcinogenics in children and adults is equal to 2.66 E-05 and1.3E–6, respectively, and the increase in the risk of cancer in children is higher due to the consumption of drinking water. Therefore, it is necessary to protect water sources, water treatment and monitor more water distribution networks based on the water safety plan.

A pilot-scale study on the in-situ remediation of acid mine drainage with supplemental of external nutrition: Performance, heavy metal removal and microbial community evolution

Acid mine drainage (AMD), a common environmental problem around the world, is characterized by low pH, high concentrations of heavy metals and sulfate. AMD treatment technology based on stimulating in-situ microorganisms has received widespread attention, but lack of organic matter is a limiting factor that restricts the remediation by heterotrophic microorganisms such as sulfate-reducing bacteria (SRB). In this study, a pilot scale reactor was set up next to an acid reservoir to evaluate the effect of livestock wastes on the in-situ bioremediation of AMD, focusing on performance assessment, heavy metal removal efficacy, and the evolution of the microbial community. Results indicated that the pH of AMD rises rapidly from 3.23 to 4.11, and metals (e.g., Fe, Cu, and Zn) rapidly got removed in Stage I. However, AMD experienced significant stratification in Stage Ⅱ (biogas slurry supplemented). The pH of surface layer (0.5 m below the surface) gradually dropped to 3.67, and the bottom layer (2.3 m below the surface) remained around 4.1, and the metal removal efficiencies further improved. Microbial communities were dominated by Fe-OB and Fe-RB in surface layer, while SRB dominated in bottom layer. The addition of biogas slurry significantly increased the relative abundance of functional microbe in bioremediation. The growth of SRB in the bottom of the reactor made an important contribution to heavy metal removal. Heavy metals were mainly removed through the formation of insoluble hydroxide and sulfide precipitation and co-precipitation. This study innovatively integrates low-cost, locally sourced livestock waste as nutrient supplements into AMD bioremediation processes, and demonstrated the potential for integrating AMD treatment with livestock waste management, addressing both the nutrient needs for AMD processing and the challenge of livestock waste disposal. The findings contribute to the development of cost-effective and eco-friendly strategies for AMD management while advancing the understanding of microbial mechanisms of in-situ bioremediation.

Metagenomic analysis of bacterial communities in heavy metal leachate-contaminated soils at Jalan Lipis Sanitary Landfill, Pahang, Malaysia

A variety of bacterial communities can be found in heavy metal leachate-contaminated soil. These bacteria might have molecular defenses that allow them to endure a high heavy metal concentration. However, there aren't enough datasets on bacterial populations to be exploited for bioremediation, especially the biotreatment of leachate contaminated with heavy metals. This research examined the diversity of the bacterial population in heavy metal leachate-contaminated soil from the Jalan Lipis Sanitary Landfill in Pahang, Malaysia. The soil samples were taken from three (3) different locations. pH analysis showed that the heavy metal leachate-contaminated soil possesses alkaline pH. ICPMS analysis showed high concentration of nickel (112.96 mg/kg) followed by manganase (89.83 mg/kg), arsenic (43.84 mg/kg), and lead (3.62 mg/kg). The three most prevalent bacteria in the heavy metal leachate-contaminated soil from the site were Pseudomonas C (Proteobacteria), Flavobacterium (Bacteroidota), and Proteiniclasticum (Firmicutes), according to metagenomic sequencing of the 16 s rRNA gene. The alpha and beta bacterial diversity analysis indicate that each location with different heavy metal concentration differs significantly on its bacterial diversity providing a valuable information to be applied in heavy metal bioremediation exclusively from landfill leachate.

Environmental Implications of the Soil-to-Groundwater Migration of Heavy Metals in Mining Area Hotspots

Groundwater contamination was studied at several hotspot sites in the Majdanpek copper mining area (Serbia). These sites include a milling facility, a metallurgical wastewater treatment plant, a heavy vehicle service area, and a waste disposal site. In addition to Cu, high concentrations of As and heavy metals (Cd and Pb) were detected in groundwater and soil at the same sampling points. Mining operations and heavy vehicle transport activities have been identified as the main sources of pollution. The migration of metals from soil to groundwater, expressed as a concentration ratio, were the highest for Co and the lowest for Mn. The environmental implications of groundwater pollution were studied using the heavy metal pollution index (HPI), Nemerov pollution index (NPI), hazard index (HI), and incremental lifetime cancer risk (ILCR). HPI and NPI show the high potential of groundwater to have adverse environmental effects. HPI ranges in the following descending order of metals: Cd > Pb > As > Mn > Ni > Cr > Hg > Cu > Zn. NPI exceeds the threshold of 0.7 in 66.7% of the samples. Potential human exposure to the studied groundwater may cause severe health problems in adults, with HI ranging from 0.61 to 5.45 and ILCR from 1.72 × 10−4 to 1.27 × 10−3. Children were more susceptible to non-carcinogenic risk than adults, with HI ranging from 0.95 to 8.27. However, the results indicated that children were less prone to carcinogenic risks, with ILCR ranging from 5.35 × 10−5 to 3.98 × 10−4. Arsenic is the most contributing element to both risks. This research imposes the need for enhanced groundwater monitoring at hotspots in the mining area and the adoption of remediation plans and measures.

Predicting potential pollutant release from waste rock at the abandoned Beck mine (Karelia, Russia) by equilibrium kinetic modeling

The Beck mine, located in the Republic of Karelia, Russia, is an abandoned mining site with significant potential for environmental contamination due to the presence of potential pollutants in its waste rocks. In this study, we investigated the chemical composition of mine waters and waste rocks and developed a theoretical model to understand waterrock interactions and the release of potential pollutants. Water samples collected from various locations on the Beck mine property were analyzed for chemical composition and showed low concentrations of total dissolved solids with pH values ranging from 6.42 to 7.74. The chemical composition of natural waters was determined by ICP-MS, ICP-AES, ion chromatography, potentiometric titration, and spectrophotometry. Equilibrium kinetic modeling was used to simulate water-rock interactions. The model predicted the concentrations of major and trace elements, demonstrating that dissolutionprecipitation and complexation are the primary mechanisms shaping the chemical composition of mine waters. The dynamics of dissolution-precipitation of Fe-containing minerals highlighted the importance of the duration of water-rock interaction, with stagnant mine waters exhibiting higher concentrations of heavy metals. In addition, the presence of dissolved organic matter played a critical role in the accumulation of iron and arsenic in the studied mine waters. Overall, this study highlights the utility of equilibrium kinetic modeling in understanding the behavior of heavy metals during water-rock interactions and provides valuable insights into the potential environmental impacts of abandoned mine sites such as the Beck mine.

Penyisihan Kandungan Perak dalam Limbah Cair Pencucian Film Melalui Proses Biofiltrasi dengan Tanaman Eceng Gondok

Wastewater produced from the film washing process in photo studios generally has very high contents of heavy metals, such as silver (Ag). This situation can cause various health and environmental problems if it is not treated before disposal. Therefore, this research was aimed to reduce the silver content in the wastewater through biological processes. This study was conducted using a biofiltration process using water hyacinth plants. Film washing waste was first acclimatized into concentration of 2.5% and the initial silver content was measured. Afterwards, water hyacinth of 600, 900, 1200, and 1500 g, respectively, was planted into the wastewater. Waste samples were subsequently taken and analyzed every 2 days. The highest removal efficiency of 99.94% was yielded for 1500 g of plant. In this condition, the silver content in wastewater met the environmental quality standards.

Mucor thermorhizoides—A New Species from Post-mining Site in Sudety Mountains (Poland)

Mucor representatives are mostly rapidly growing cosmopolitan soil saprotrophs of early diverged Mucoromycotina subphylum. Although this is the most speciose genus within the group, some lineages are still understudied. In this study, new species of Mucor was isolated from the post-mining area in southwestern Poland, where soil chemical composition analysis revealed high concentration of hydrocarbons and heavy metals. Phylogenetic analysis based on multigene phylogeny showed that the new isolate clusters distinctly from other Mucor species as a sister group to Mucor microsporus. New species Mucor thermorhizoides Abramczyk (Mucorales, Mucoromycota) is characterized by the extensive rhizoid production in elevated temperatures and formation of two layers of sporangiophores. It also significantly differs from M. microsporus in the shape of spores and the size of sporangia. M. thermorhizoides was shown to be able to grow in oligotrophic conditions at low temperatures. Together with M. microsporus they represent understudied and highly variable lineage of the Mucor genus.

Land-Use–Land Cover Changes in the Urban River’s Buffer Zone and Variability of Discharge, Water, and Sediment Quality—A Case of Urban Catchment of the Ngerengere River in Tanzania

The physical integrity of the Ngerengere River and its three tributaries drains within Morogoro Municipality were evaluated by assessing the variations in land-use–land cover (LULC) in the river’s buffer zone, the discharge, and the contamination of river water and sediment from nutrients and heavy metals. Integrated geospatial techniques were used to classify the LULC in the river’s buffer zone. In contrast, the velocity area method and monitoring data from the Wami-Ruvu Basin were used for the discharge measurements. Furthermore, atomic absorption spectrophotometry was used during the laboratory analysis to determine the level of nutrients and heavy metals in the water and river sediment across the 13 sampling locations. The LULC assessment in the river’s buffer during the sampling year of 2023 showed that bare land and built-up areas dominate the river’s buffer, with a coverage of 28% and 38% of the area distribution. The higher discharge across the sampling stations was in the upstream reaches at 3.73 m3/s and 2.36 m3/s at the confluences. The highest concentrations of heavy metals in the water for the dry and wet seasons were 0.09 ± 0.01, 0.25 ± 0.01, 0.03 ± 0.02, 0.73 ± 0.04, 4.07 ± 0.08, and 3.07 ± 0.04 mg/L, respectively, for Pb, Cr, Cd, Cu, Zn, and Ni. The order of magnitude of the heavy metal concentration in the sediments was Zn > Ni > Cr > Cu > Cd > Pb, while the highest NO2−, NO3−, NH3, and PO43− in the water and sediment were 2.05 ± 0.01, 0.394 ± 0.527 0.66 ± 0.05, and 0.63 ± 0.01 mg/L, and 2.64 ± 0.03, 0.63 ± 0.01, 2.36 ± 0.01, and 48.16 ± 0.01 mg/kg, respectively, across all sampling seasons. This study highlights the significant impact of urbanization on river integrity, revealing elevated levels of heavy metal contamination in both water and sediment, the variability of discharge, and alterations in the LULC in the rivers’ buffer. This study recommends the continuous monitoring of the river water quality and quantity of the urban rivers, and the overall land-use plans for conserving river ecosystems.

Remediation of Pb-, Zn-, Cu-, and Cd-Contaminated Soil in a Lead–Zinc Mining Area by Co-Cropping Ilex cornuta and Epipremnum aureum with Illite Application

Phytoremediation is considered an effective strategy for remediation of heavy-metal-contaminated soil in mining areas. However, single-species plants cannot reach the highest potential for uptake of heavy metals due to inhibition of their growth by high concentrations of heavy metals in the soil. Therefore, this study has explored the effects of illite application and two plant species’ co-cropping on soil quality, plant growth, and heavy metal transformation in a soil–plant system. The results reveal that the addition of 1% (mass fraction) of illite significantly enhances soil pH. The co-cropping of Ilex cornuta and Epipremnum aureum is beneficial for improving the organic matter content of the soil. The contents of EDTA-extractable Pb, Zn, and Cu were significantly reduced by 29.8–32.5%, 1.85–5.72%, and 30.0–32.9%, respectively, compared to the control. The co-cropping of Ilex cornuta and Epipremnum aureum promoted enrichment effects of Epipremnum aureum on Pb and Ilex cornuta on Cd (p < 0.05). The co-cropping pattern lowered the biomass of Ilex cornuta and Epipremnum aureum; however, co-cropping of Ilex cornuta and Epipremnum aureum promoted the elimination of Pb, Zn, Cu, and Cd from the soil at 13.0–75.8%, 11.1–38.2%, 8.39–88.4%, and 27.8–72.5%, respectively. It is concluded that illite application combined with co-cropping of Ilex cornuta and Epipremnum aureum is highly effective for the elimination of Pb, Zn, Cu, and Cd from contaminated soil. This study provides a theoretical basis and pathway for the restoration of heavy-metal-contaminated soil in mining with the application of bentonite combined with phytoremediation.

#3096 Exploratory population-based screening of kidney function and heavy metal water source levels in a highly incident CKDu area in Guatemala

Abstract Background and Aims Chronic kidney disease of unknown etiology (CKDu) has exponentially increased in the rural areas of the Pacific Coast in Central America. A multifactorial etiology has been postulated including exposure to environmental nephrotoxins such as heavy metals. The Pacific Coast of Guatemala has a volcanic topography with a high content of heavy metals, and the rural communities use ground water as their regular drinking consumption. Since the highest age group affected by CKDu are young adults, we postulated an exposure during childhood impacting later in life. We aim to identify changes in kidney function in children and adolescent healthy population from a highly incident CKDu area, and the heavy metal levels from water sources as a hypothesis generation exploratory study. Method We performed a population-based cross-sectional study of children and adolescents (below 17 y/o) from La Democracia municipality that were randomly chosen using Epidat software 3.1 from 10 different local schools from March 2019 to March 2020. The study was approved by external ethics board committee external-independent research ethics board committee. Subjects were excluded if they had known diagnosis of CKD, kidney replacement therapy or hypertension. The screening was performed in three different steps including a background assessment questionnaire, clinical assessment, and biochemical testing including creatinine from blood drop using StatSensor XpressTM to calculate estimated glomerular filtration rate (eGFR), urine dipstick, urinary creatinine, and protein. We measured arsenic (33As), cadmium (48Cd), mercury (80Hg), and lead (82Pb) in 21 water wells around the 10 screened schools, while only arsenic (33As), cadmium (48Cd) and mercury (80Hg) were measured in the urine of a small subset of the samples (data not shown in the results). Results A total of 508 randomly selected subjects’ and parents’ consent for screening but only 506 completed assessment. The median age was 14 y/o (IQR 11-17) 50% being female, with a close to 30% of the sample having obesity. The blood pressure was abnormal in 28% of the sample and at least 30% of them had an abnormal urine dipstick. The overall eGFR was 98, being the 25th%tile close to 83 ml/min/1.73 m2 BSA (Tables 1 and 2). Water sources showed higher than recommended levels of all heavy metals tested. Interestingly, the schools “Campiña” showed high levels of Arsenic and Cadmium in water sources, being the subjects tested coincidentally among the lowest eGFR of sample. Conclusion CKDu is an entity devastating low-resourced communities with young adults being the most affected. A likelihood for a link of early exposure needs to be further explored. Addressing the postulated hypothesis are key to implement preventive strategies, including screening earlier in life such as pediatric population.

Development and optimization of a polysilicon-aluminum alkali mineral-enhanced biochar composite for effective heavy metal removal in acidic environments

While traditional biochar demonstrates promising performance in diverse settings, its efficacy may be constrained under specific conditions of high acidity and heavy metal concentrations. In this study, researchers developed a new polysilicon-aluminum alkali mineral-enhanced biochar composite material, GBMSs (green biochar-metakaolin-sodium silicate), by pyrolyzing fibers from dragon fruit peels and blending them with metakaolin and sodium silicate. Using a response surface methodology, this environmentally friendly composite material was optimized for removing copper and zinc contaminants across a range of initial pH levels from 2 to 6. Experimental findings indicated that the adsorption capacity of GBMSs for copper and zinc was significantly enhanced, ranging from 1.5 to 4 times greater compared to pure biochar or biochar mixed solely with a silicon-aluminum mineral. Various analytical techniques including scanning electron microscopy, X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy were utilized to examine the influence of poly-silica-aluminum alkali minerals (GBMSs) on biochar composites. The findings revealed an upsurge in surface binding locations and oxygen-related functional groups because of integrating GBMSs. This augmentation of electronegative features on the biochar surface was credited to the development of stabilizing silica-aluminum connections, ultimately boosting its adsorption effectiveness in acidic surroundings. By applying Langmuir and Freundlich models, it was deduced that the adsorption of GBMSs adheres to a multilayer uniform adsorption mechanism, with surface ion interchange and complexation restricting the adsorption capability. This research highlights the potential of clay mineral-altered biochar in efficiently dealing with intricate environmental contamination.

Artisanal and Small-Scale Gold Mining Impact on Soil and Agriculture: Evidence from Upper Denkyira East Municipality, Ghana

The gold mining industry in Ghana has made a substantial contribution to the country's economic growth by generating diverse employment opportunities, both directly and indirectly, in mining communities. This has the potential to mitigate poverty and improve the quality of life for individuals and households in rural areas, where climate change is having a disproportionate impact on small-scale farmers. Nevertheless, it is crucial to recognize that this sector has also resulted in detrimental environmental impacts. A total 150 key informants in Upper Denkyira East Municipality, comprising representatives from the Environmental Protection Agency, the Forestry Commission, the Mineral Commission, and other stakeholders, were interviewed using standardize questionnaire to ascertain the impact of mining on the soil, agriculture and the environment. The study also employed inductively coupled plasma to assess the concentration of heavy metals in soils at a small-scale mining site. The soil analyses indicated high concentrations of heavy metals, such as mercury, arsenic, nickel, zinc, and iron. The Weighted Average Index, which was used to assess the impact of mining, revealed that communities face challenges such as deforestation, low crop yields, water pollution, land tenure issues, and a high cost of living. The study's analyses of measures to address small scale mining challenges revealed that alternative livelihood, law enforcement, training and support, and access to mining concessions were perceived as suitable for addressing artisanal and small scale mining. The study concluded that stricter mining regulations, promoting sustainable mining practices, and providing comprehensive training to miners on environmental protection and land reclamation can help mitigate the negative impacts of artisanal and small-scale mining. Additionally, supporting alternative means of livelihood for mining communities, such as agriculture or eco-tourism, can reduce reliance on mining and promote sustainable development.

Heavy metals and potential health risk assessment of Lactuca sativa and Daucus carrota from soil treated with organic manures and chemical fertilizer

The large-scale production of food crops with heavy application of chemical fertilizers in the effort to meet the astronomical increase in food demands may be counterproductive to the goal of food security. This study investigated the effect of different soil treatments on the levels of heavy metals (Cr, Cu, Fe, Ni, Pb, and Zn) in two types of vegetables Lactuca sativa (lettuce) and Daucus carrota (carrot). The potential carcinogenic and non-carcinogenic health risks from their consumption were also evaluated. Planting experiment was set up in a randomized block design, with different soil treatments of soil + cow dung (CD), soil + sewage sludge (SS), soil + chemical fertilizer (nitrogen-phosphorus-potassium (NPK)), and untreated soil (UNTRD). The vegetables were harvested at maturity, washed with distilled water, and subjected to an acid digestion process before the levels of heavy metals were measured by inductively coupled plasma spectrometry (ICP-MS). The mean concentrations of the metals in the vegetables across all treatments were below the maximum permissible limits. The pattern of heavy metal accumulation by the vegetables suggested that the lettuce from SS treatment accumulated higher concentrations of heavy metals like Cr (0.20 mg/kg), Cu (3.91 mg/kg), Ni (0.33 mg/kg), and Zn (20.44 mg/kg) than carrot, with highest concentrations of Fe (90.89 mg/kg) and Pb (0.16 mg/kg) recorded in lettuce from NPK treatment. The bioaccumulation factor (BAF) showed that lettuce, a leafy vegetable, has bioaccumulated more heavy metals than carrot, a root vegetable. The BAF was generally below the threshold value of 1 in both vegetables, except in lettuce from NPK and CD treatments and carrot from NPK treatments, with BAF values of 1.6, 1.69, and 1.39, respectively. The cancer risk assessment factors were well below the unacceptable maximum range of 10−4 suggesting that consuming these vegetables might not expose an individual to potential risk of cancer development. The hazard quotient estimations were below the threshold values of 1 for all heavy metals; however, the hazard index (HI) values of 1.27 and 1.58 for lettuce from NPK and SS treatments indicate a potential non-carcinogenic health risk to consumers from intake of all the heavy metals.

Actinomycetes as a Possible Source of Bioremediation of Heavy Metal Cadmium from Contaminated Soil

Annually, a significant volume of chemicals, encompassing fertilizers and pesticides, is administered to agricultural soils. Using pesticides and fertilizers, agricultural practices contribute to heavy metal Cadmium (Cd), Copper (Cu), Lead (Pb) and Zinc (Zn) pollution. Heavy metals and pesticides are high at the peak of ecological contaminants, presence of this has introduced grave risks to the health of the population and agronomics. Among heavy metals, cadmium (Cd) is recognized for its high mobility in various environmental settings. Cd has a deleterious effect on plant phenotypic, cytotoxicity (e.g., lowering chlorophyll concentration and limiting photosynthetic effectiveness), and metabolic activities (e.g., chlorosis and necrosis). Microbial bioremediation by using microorganisms is one of the secure, pure, cost operative and eco-friendly technology for decontaminating polluting sites as compared to physical and chemical techniques. Among microbes, Actinobacteria hold a paramount position, serving as key players in numerous biological processes, utilize toxins as carbon source and turn into high concentrations of pesticides, chemical complexes and heavy metals into commercially viable antibiotics, enzymes, proteins, and plant growth promoting hormones. This study is an effort to explore the potent cadmium resistance actinomycetes to reduce cadmium levels to enhance degradation. For this purpose, 53 actinomycetes strains were tested for heavy metal resistance and tolerance to Cadmium against different concentrations. After secondary screening Four potent isolate have the potential to grow at 1000 mg/L concentration of Cadmium in the medium. When they are able to grow on heavy metal containing media it could be beneficial for reduction and elimination of toxic metals from contaminated environment. When it comes to achieving a suitable level of metal tolerance, this potent powerful actinomycetes strain Streptomyces pactum have been identified to be promising.