Soil Pollution Research Articles

Organic substitution contrasting direct fertilizer reduction increases wheat productivity, soil quality, microbial diversity and network complexity

Excessive use of chemical fertilizers negatively impacts crop productivity and farmland ecosystem, impeding sustainable agricultural progress. Consequently, there is an immediate need for a chemical fertilizer reduction strategy that ensures crop productivity and improves soil quality and the ecological environment of farmland. This study implemented a three-year (2018–2020) field experiment with two chemical fertilizer reduction methods (direct fertilizer reduction and organic substitution) to investigate their effects on wheat productivity, soil quality, heavy metal pollution risk and microbial characteristics. The results showed that organic substitution treatments (OF1, OF2 and OF3) improved most wheat plant (nutrient uptake and yield and its components) and soil properties (soil nutrients and carbon and nitrogen fractions), leading to increased crop productivity index (CPI, by 9.18 %-16.39 % and 14.14 %-23.36 %) and soil quality index (SQI, by 84.67 %-138.86 % and 104.11 %-175.91 %) compared to conventional fertilization (CF) and direct fertilizer reduction treatments (RF1, RF2 and RF3) in 2019 and 2020. Additionally, organic substitution enhanced the diversity and network complexity of bacterial community, while raising the soil pollution index (SPI, by 9.30 %-12.84 % and 12.20 %-18.49 %) without causing soil heavy metal pollution. Thus, it is recommended to adopt organic fertilizer substitution as the primary chemical fertilizer reduction strategy for wheat production. This approach will ensure crop yield, and improve soil quality and microbial characteristics, but its long-term application requires monitoring changes in soil heavy metals. Overall, this study provides guidelines for implementing scientific fertilization in agricultural practices, thus contributing to the health and sustainability of farmland ecosystems.

Bioaccumulation and Translocation of Heavy Metals in Solanum elaeagnifolium

Heavy metal pollution is becoming an increasingly common problem. Heavy metals including Chromium, Cadmium, Mercury, Copper, and lead are hazardous environmental pollutants, especially in high anthropogenic activity areas. Heavy metals accretion in soil is a serious concern for agricultural productivity due to its negative influence on food safety, market potential, and the phytotoxicity it causes in crops. Plant ascendancy and metabolic processes affect the geological and biological re-distribution of heavy metals through air, soil, and water pollution. The typical result of heavy metals toxicity is excessive accumulation of reactive methylglyoxal and oxygen species, which lead to lipid peroxidation, enzyme inactivation, nucleic acid damage, and protein oxidation in plants. In this study, bioaccumulation and Translocation of Heavy Metals in Solanum elaeagnifolium was conducted by using standard biological techniques. Twenty-four samples of both shoot and root systems collected ‎from the study sites and Three replications of soil samples from each habitat, including topsoil (0-50 cm depth) were studied.our results showed that the quantitative concentration of heavy metals in the shoots of S. elaeagnifolium for each metal indicated a high enrichment value for (Cr), (Fe), and (Mn), on the other hand, it showed low enrichment values for (Ni) & (Pb). In addition, the concentration of heavy metals in the roots of the plant was differentiated.

Improved mapping of heavy metals in agricultural soils using machine learning augmented with spatial regionalization indices

The accurate spatial mapping of heavy metal levels in agricultural soils is crucial for environmental management and food security. However, the inherent limitations of traditional interpolation methods and emerging machine-learning techniques restrict their spatial prediction accuracy. This study aimed to refine the spatial prediction of heavy metal distributions in Guangxi, China, by integrating machine learning models and spatial regionalization indices (SRIs). The results demonstrated that random forest (RF) models incorporating SRIs outperformed artificial neural network and support vector regression models, achieving R2 values exceeding 0.96 for eight heavy metals on the test data. Hierarchical clustering for feature selection further improved the model performance. The optimized RF models accurately predicted the heavy metal distributions in agricultural soils across the province, revealing higher levels in the central-western regions and lower levels in the north and south. Notably, the models identified that 25.78 % of agricultural soils constitute hotspots with multiple co-occurring heavy metals, and over 6.41 million people are exposed to excessive soil heavy metal levels. Our findings provide valuable insights for the development of targeted strategies for soil pollution control and agricultural soil management to safeguard food security and public health.

Effects of low-molecular-weight organic acids on the transport of polystyrene nanoplastics: An insight at the structure of organic acids

Plastic nanoparticles are extensively used in various products, leading to inevitable pollution in soil. Understanding their transport in soils where various organic substances exist is crucial. This study examined the impact of low-molecular-weight organic acids (LMWOAs) on the transport of polystyrene nanoplastics (PS-NPs) through saturated quartz sand. The experiments involved three dibasic acids—malonic acid (MA1), malic acid (MA2) and tartaric acid (TA) — and four monobasic acids— formic acid (FA), acetic acid (AA), propanoic acid (PA) and glycolic acid (GA) —under different pH levels (4.0, 5.5, 7.0) and in the presence of cations (Na+, Ca2+). The results demonstrated that in the presence of Na+, dibasic acids significantly enhanced PS-NPs transport, with TA being the most effective, followed by MA2 and MA1. This enhancement is attributed to the adsorption of LMWOAs onto the nanoparticles and sand, creating a more negative ζ-potential, which increases the electrostatic repulsion and decreases the PS-NPs deposition, thereby facilitating the transport. Applying the Derjaguin-Landau-Verwey-Overbeek theory, higher pH levels increased the energy barrier and secondary energy minimum, decreasing PS-NPs deposition. Moreover, dibasic acids significantly enhanced the hydrophilicity of PS-NPs. Conversely, monobasic acids, except for GA, slightly reduced the hydrophilicity of PS-NPs, as indicated by a small increase in the water contact angle, hereby minimally affecting PS-NPs transport. As for GA, although it is a monobasic acid, the additional -OH group in its molecular structure promoted PS-NPs transport, similar to dibasic acids. For example, GA also significantly enhanced the hydrophilicity of PS-NPs. In the presence of Ca2+, the enhancement of PS-NPs transport by LMWOAs was comparable to that with Na+, primarily due to the complex-forming and bridging effects of Ca2+ with the organic acids and PS-NPs. These findings provide important insights into predicting and analyzing the transport behaviors of PS-NPs.

Enrichment characteristics of polycyclic aromatic hydrocarbons in coal gangue of the Huaibei Coalfield, China

Coal gangue, a by-product of coal mining, deteriorates and oxidizes, causing environmental pollution. Despite extensive research on polycyclic aromatic hydrocarbon (PAHs) pollution in soil, aerosols, and water, studies on PAHs in coal gangue remain limited. This study aimed to fill this research gap by analyzing gangue samples from three areas in Huaibei. Sixteen priority parent polycyclic aromatic hydrocarbons (16PAHs) and alkyl polycyclic aromatic hydrocarbons (aPAHs) in the samples were analyzed qualitatively and quantitatively via gas chromatography-triple quadrupole mass spectrometry. The results showed that PAHs existed naturally in coal gangue. The aPAHs concentration of multiple samples from the same area (587.88 ng/g, 2972.73 ng/g, and 13528.29 ng/g from Liuqiao, Suntan, and Tongting, respectively) was higher than the 16PAHs concentration (528.79 ng/g, 570.16 ng/g, and 2818.79 ng/g from Liuqiao, Suntan, and Tongting, respectively). Among the 39 samples, the aPAHs concentration after weathering was 7732.78 ng/g, which was higher than the value in the fresh state of 4765.43 ng/g. 16PAHs with low ring number were dominant in the fresh state, but aPAHs with high ring number were dominant after weathering. The diagnostic ratios revealed that traditional diagnostic ratios may confuse sources of PAHs and that gangue should be considered as a single class of source materials. Additionally, there was no significant difference in the ratio between the weathered and fresh state. TEQBaP analysis showed that there was a certain environmental risk in the area and that TEQBaP(weathered) > TEQBaP(fresh). Therefore, the pollution attributable to PAHs in coal gangue, especially weathered gangue, warrants attention.

A study on source identification of contaminated soil with total petroleum hydrocarbons (aromatic and aliphatic) in the Ahvaz oil field.

The oil industry in Khuzestan province (Southwest Iran) is one of the main reasons contributing to the pollution of the environment in this area. TPH, including both aromatic and aliphatic compounds, are important parameters in creating pollution. The present study aimed to investigate the source of soil contamination by TPH in the Ahvaz oil field in 2022. The soil samples were collected from four oil centers (an oil exploitation unit, an oil desalination unit, an oil rig, and a pump oil center). An area outside the oil field was determined as a control area. Ten samples with three replicates were taken from each area according to the standard methods. Aromatic and aliphatic compounds were measured by HPLC and GC methods. The positive matrix factorization (PMF) model and isomeric ratios were used to determine the source apportionment of aromatic compounds in soil samples. The effects range low and effects range median indices were also used to assess the level of ecological risk of petroleum compounds in the soil samples. The results showed that Benzo.b.fluoranthene had the highest concentration with an average of 5667.7 ug/kg in soil samples in the Ahvaz oil field. The highest average was found in samples from the pump oil center area at 7329.48 ug/kg, while the lowest was found in control samples at 1919.4 ug/kg-1. The highest level of aliphatic components was also found in the pump oil center, with a total of 3649 (mg. Kg-1). The results of source apportionment of petroleum compounds in soil samples showed that oil activities accounted for 51.5% of the measured PAHs in soil. 38.3% of other measured compounds had anthropogenic origins, and only 10.1% of these compounds were of biotic origin. The results of the isomeric ratios also indicated the local petroleum and pyrogenic origin of PAH compounds, which is consistent with the PMF results. The analysis of ecological risk indices resulting from the release of PAHs in the environment showed that, except for fluoranthene, other PAHs in the oil exploitation unit area were above the effects range median level (ERM) and at high risk. The results of the study showed that soil pollution by total petroleum hydrocarbons (TPH), both aromatic and aliphatic, is at a high level, and is mainly caused by human activities, particularly oil activities.

Characteristics of different types of nano-biochar and their effects on remediation of cadmium pollution in soil

Characteristics of different types of nano-biochar and their effects on remediation of cadmium pollution in soil

Survival and transfer potential of Salmonella enterica serovar Typhimurium colonising polyethylene microplastics in contaminated agricultural soils

Agricultural environments are becoming increasingly contaminated with plastic pollution. Plastics in the environment can also provide a unique habitat for microbial biofilm, termed the ‘plastisphere’, which can also support the persistence of human pathogens such as Salmonella. Human enteric Salmonella enterica serovar Typhimurium can enter agricultural environments via flooding or from irrigation with contaminated water. Using soil mesocosms we quantified the ability of S. Typhimurium to persist on microplastic beads in two agriculturally relevant soils, under ambient and repeat flood scenarios. S. Typhimurium persisted in the plastisphere for 35 days in both podzol and loamy soils; while during multiple flood events was able to survive in the plastisphere for up to 21 days. S. Typhimurium could dissociate from the plastisphere during flooding events and migrate through soil in leachate, and importantly could colonise new plastic particles in the soil, suggesting that plastic pollution in agricultural soils can aid S. Typhimurium persistence and facilitate further dissemination within the environment. The potential for increased survival of enteric human pathogens in agricultural and food production environments due to plastic contamination poses a significant public health risk, particularly in potato or root vegetable systems where there is the potential for direct contact with crops.

Studying the Effects of Pollutants from Industrial Facilities on Soil and Plant Pollution

Studying the Effects of Pollutants from Industrial Facilities on Soil and Plant Pollution

Insights on leaching, adsorption–desorption of spirotetramat and its four metabolites on “Third Pole” pollution-free area:Qinghai–Tibet Plateau

The use of pesticides has led to increased soil and water pollution, which has even affected the world's third pole, the Tibetan Plateau. In this study, the adsorption and desorption experiments of spirotetramat on three typical soils were conducted to investigate the migration and leaching risk of pesticides in the Qinghai-Tibet Plateau ecosystem. We used batch equilibrium technique for adsorption-desorption experiments and evaluated leaching risk by computational simulation experiments under laboratory conditions. The Freundlich adsorption constants Kf of spirotetramat in the soils of Haidong, Haixi and Haibei were as follows: At 22.26, 15.13 and 6.85, the maximum adsorption capacity Cmax was 434.80, 217.40 and 169.50 mg kg-1, the average adsorption rates were 77.92, 54.27 and 39.13 %, and the desorption constants (Kf) were 43.27, 22.35 and 11.56, respectively. The hysteresis coefficient HI>1.00 in the soil of Haidong and Haixi, and 0.70<HI<1.00 in the soil of Haibei, indicating that with the increase of temperature, the adsorption capacity of the tested soil for spirotetramat decreases, which increases the migration risk of pesticides. The desorption of spirotetramat in the soil of Haidong and Haixi has a lag. The GUS values of spirotetramat in the soils of Haidong, Haixi and Haibei were 1.15, 1.63 and 1.72, respectively, which were all lower than 1.80, indicating that spirotetramat was a non-leaching pesticide, and the leaching risk of spirotetramat in the soils of Qinghai was small, and the potential harm to groundwater was at a low level.

EDUKASI BAHAYA DAN CARA DISPOSAL MINYAK JELANTAH

Used cooking oil has confirmed to be harmful to our health and environtment. In Indonesia, used cooking oil commonly reuse for cooking and dispose directly into the environment. Reusing used cooking oil will increase the risk of cardiovascular disease and cancer and discharging it directly into environment causes water and soil pollution. However, a lack information has been delivered to the community. This article reported community service activity conducted at Desa Pacarkembang Tambaksari Surabaya that has been purposed to increase the community’ knowledge on the dangers and proper disposal of the used cooking oil. A total of 33 participants joined the event. 30 of them had filled the pre and post event questionnaire assessed knowledge in dangers and proper disposal of the used cooking oil. The results showed that there was a rise in number of participants who had positive knowlede on the potential harm and proper disposal method of used cooking oil. A continuous campaign and public education will increase the community knowledge and awareness in maintaining their health and environment.

Water, Sanitation, Waste Management, and Professional Activities in Relation to Diseases with Neighboring Citizens of Congo Rivers in the Brazzaville Agglomeration (Republic of Congo)

Situated on the right bank of the Pool Malébo, in the Congo River basin, the city of Brazzaville is rich in potential water resources. These resources are polluted by human practices that deteriorate the quality of the soil and, consequently, the quality of the water. The aim of this study is therefore to inventory the activities carried out by the population around watercourses, to investigate waste management and to assess the impact on water and soil quality. The survey sample was selected on the basis of impacted zones located between 250 m and 750 m around watercourses. The aim of this study is therefore to inventory the activities carried out by the population around watercourses, to investigate waste management and to assess the impact on water and soil quality. The survey form was drawn up using Sphinx Plus2-Edition Lexica-V5 software. The survey data was entered into the same software, then transferred to Excel to generate the graphical. 880 people were surveyed, the most dominant age group was 25-48 years old, i.e. a rate of 66%. The most dominant gender was female, with a rate of 54%. The average age of the respondents was lower secondary school, and they were generally employed in the private sector. Commercial activities (restaurants/bars, pharmacies, grocery stores/ butchers, markets, etc.) are the most common economic activity, with a rate of around 70%; 59% of these activities are located close to or very close to the watercourse (750-1000 m). The activities that contribute to soil degradation, and consequently water degradation, in the city of Brazzaville are: 59% the dumping of household waste and/or wastewater on the ground and 32% uncontrolled urbanization. The study shows that soil and water pollution in Brazzaville is caused by poor management of household waste and uncontrolled urbanization.

Pan-europski kriteriji i indikatori održivog gospodarenja šumama: Institucionalni aspekti i mogućnost primjene u šumarstvu Federacije Bosne i Hercegovine

Overexploitation of natural resources have caused serious environmental issues, including climate change, biodiversity loss, habitat degradation, and soil and water pollution. The Pan-European criteria and indicators for sustainable forest management offer a tool to monitor progress and report on the sustainability of forest resources at sub-national, national, and regional levels. This paper examines the institutional aspects and possibilities of application of these criteria and indicators in the forestry sector of the Federation of Bosnia and Herzegovina (FBiH), aiming to improve forestry conditions and develop a coherent forest policy. A survey of 360 forestry experts from FBiH revealed that the majority support the positive impact of implementing the Pan-European criteria and indicators in the forestry sector. It was determined that the Ministry of Agriculture, Water Management, and Forestry of FBiH should be responsible for developing and collecting data related to these criteria and indicators. However, the primary barriers to implementation include a lack of financial resources, expertise, and commitment. While the public forest administration is formally prepared to apply these criteria, its current capacities are inadequate for effective implementation. Strengthening the capacity of the public forest administration is crucial to ensure the application of the Pan-European criteria and indicators for sustainable forest management. This would enable consistent and systematic monitoring and improvement of forest resource conditions and the overall state of the forestry sector in FBiH.

Terahertz spectroscopy-based rapid detection of exchangeable heavy metal pollution in soil using Scenedesmus obliquus

This study introduces a novel approach for the rapid detection of exchangeable heavy metal pollution in soil, utilizing Scenedesmus obliquus as a bioadsorbent. Terahertz spectroscopy was used to analyze the cell wall proteins and functional groups of S. obliquus following physical adsorption. This analysis enabled the deduction of the types and concentrations of exchangeable heavy metal ions in soil. We established a prediction model for heavy metal concentrations using partial least squares (PLS) regression, achieving optimal detection times: 10 min for Pb2+, 20 min for Ni2+, and 30 min for Co2+. Validation with real surface soil samples demonstrated excellent accuracy rates: 97.8 % for Pb2+, 91.8 % for Ni2+, and 90 % for Co2+. Notably, our method reduces the detection time to 0.5 hours, requires only 5 ml of sample volume, and enhances detection accuracy to 0.1 μg/L.

Root-soil-microbiome interaction in the rhizosphere of Masson pine (Pinus massoniana) under different levels of heavy metal pollution

Heavy metal pollution of the soil affects the environment and human health. Masson pine is a good candidate for phytoremediation of heavy metal in mining areas. Microorganisms in the rhizosphere can help with the accumulation of heavy metal in host plants. However, studies on its rhizosphere bacterial communities under heavy metal pollution are still limited. Therefore, in this study, the chemical and bacterial characteristics of Masson pine rhizosphere under four different levels of heavy metal pollution were investigated using 16 S rRNA gene sequencing, soil chemistry and analysis of plant enzyme activities. The results showed that soil heavy metal content, plant oxidative stress and microbial diversity damage were lower the farther they were from the mine dump. The co-occurrence network relationship of slightly polluted soils (C1 and C2) was more complicated than that of highly polluted soils (C3 and C4). Relative abundance analysis indicated Sphingomonas and Pseudolabrys were more abundant in slightly polluted soils (C1 and C2), while Gaiella and Haliangium were more abundant in highly polluted soils (C3 and C4). LEfSe analysis indicated Burkholderiaceae, Xanthobacteraceae, Gemmatimonadaceae, Gaiellaceae were significantly enriched in C1 to C4 site, respectively. Mantel analysis showed that available cadmium (Cd) contents of soil was the most important factor influencing the bacterial community assembly. Correlation analysis showed that eight bacterial genus were significantly positively associated with soil available Cd content. To the best of our knowledge, this is the first study to investigate the rhizospheric bacterial community of Masson pine trees under different degrees of heavy metal contamination, which lays the foundation for beneficial bacteria-based phytoremediation using Masson pines in the future.

Unveiling Heavy Metal Pollution in Soils and Rice Crops (Oryza sativa L.) Cultivation

The landscape changes through the increasing built-up areas (settlements and industrial) have a potential impact on reducing the quality of agricultural land. Waste from anthropogenic activities (industrial and domestic) is the main source of heavy metals that can affect rice production in the fields. This study examines the quality changes of paddy fields (Oryza sativa L.) polluted by wastewater in Muara Bakti Village, Bekasi Regency. Wastewater's impact on paddy fields is known through heavy metal contamination analysis in soil and rice plants. Chemical analysis of soil, water and plants was completed by the Balai Penelitian Tanaman Sayuran (Balitsa) Laboratory, West Bandung. The results showed that heavy metal levels such as lead (Pb) and cadmium (Cd) in the paddy soil samples were above the threshold in soil, respectively more than 25 mg/l and 0.01 mg/l. In contrast, the rice plant samples, it was identified as containing heavy metals such as Cd and chromium (Cr). Pb content was not detected in the rice plants. Soil in Muara Bakti Village contained optimal nutrients that are still suitable for agriculture. However, heavy metal content detected in soil samples and rice plants requires special handling to prevent endangering the agroecosystem and human health. Keywords: Agroecosystem, Heavy metals, Paddy fields, Soil pollution, Waste

Development of modified fuzzy FMEA method in environmental risk assessment of earth dams

The investigations have shown that the construction of the dam and its related facilities have significant physical–chemical and ecological effects on the ecosystem. Failure Mode and Effects Analysis (FMEA) is a technique for ranking risks in projects to construct dams, but it has many deficiencies and ambiguities. Therefore, to prevent the shortcomings of the classical method, the modified fuzzy inference system (MFIS-FMEA) method has been used by creating a two-stage model to more accurately assess the risk of Eyvashan Dam. First, all the considered indicators are weighted using the Shannon entropy method, and the environmental risk is prioritized using the Fuzzy OWA method. In this study, two-stage fuzzy reasoning and a Max–Min combination rule are used. When severity (SEV) and occurrence (OCC) variables are combined, the critical risk index (RCI) values are predicted in the first stage. RCI and detection index (DET) input are then used to predict the MFIS-RPN in the second stage. The results of the risk priority number (RPN) in the MFIS-RPN method are much more accurate and serious than the FIS-RPN method due to the two-stage nature and the use of new language terms. The results of the proposed MFIS-RPN technique show that the highest RPN was obtained with immediate action in the dam construction phase for soil erosion and soil pollution and in the dam operation phase for aquatic and water pollution. Therefore, due to the increase in risk score, it is necessary to take immediate and more accurate monitoring during the construction and operation phases.

Upcycling potential of hazardous tannery sludge to value-added products: Process modelling, simulation, and 3E analysis

The sustainability of the tannery sector largely depends on the eco-friendly management of its solid and liquid wastes. Unfortunately, the global tannery sector is strappingly suffering a significant challenge to meet environmental standards towards sustainability due to a lack of tannery sludge (TS) management facilities as well as lacking research on hazardous TS upcycling facilities to value-added products. Hence, TS from leather processing generally undergoes open dumping, responsible for environmental pollution, including water, soil, and air pollution. To ensure the sustainability of tannery sector, pioneeringly, this study attempts to conceptually design gasification based on four novel upcycling potentials of TS-to-value added products such as (i) TS to syngas with steam generation (TS-SS), (ii) TS to hydrogen with power generation (TS-HP), (iii) TS to power generation with carbon capture (TS-PCC), and (iv) TS to methanol production with power production (TS-MPP) using ASPEN Plus® simulator. Further, this research offers a comprehensive techno-economic analysis to evaluate the economic feasibility of the proposed four TS upcycling processes. The TS-PCC and TS-HP processes outperformed for their net energy efficiencies of 72.80 % and 50.22 %, correspondingly, compared to TS-HP (39.13 %) and TS-MPP (40.38 %). Regarding exergy efficiency, the TS upcycling processes coded TS-MPP and TS-HP demonstrated better net exergy efficiencies of 34.34 % and 27.20 %, respectively, compared to TS-SS and TS-PCC upcycling processes. These results confirm that TS-HP is much more efficient in terms of exergy. Furthermore, techno-economic analysis has confirmed that the developed processes, namely TS-SS and TS-PCC, are economically viable at a 70 % plant efficiency, whereas other processes, such as TS-HP and TS-MPP, are financially viable only if a subsidy of $33/ton subsidy is provided. The study findings have a significant impact on the development of circular economy-based industrial-scale TS management facilities in developing countries, which can ensure the sustainability of the leather sector.

Soil amendment-assisted phytoremediation with ryegrass offers a promising approach to mitigate environmental health concerns

This study aimed to examine the potential of soil amendment-assisted phytoremediation using ryegrass in reclaiming abandoned gold mine soil in southwestern Ghana, with a specific focus on the soil contamination hazards associated with metals and metalloids. A pot experiment lasting 60 days was carried out to assess the efficacy of soil amendments, such as compost, iron oxide, and poultry manure, in mitigating environmental hazards. Three soil contamination indices (soil contamination = CF, enrichment factor = ER, and pollution load index = PLI) were used to calculate the extent of soil contamination, enrichment, and pollution of the sites with Co, Hg, Ni, Mo, Se, Sb, and Pb. The findings show that Hg made the greatest contribution (with a maximum soil CF of 18.0) to the overall PLI, with a maximum value of 74.4. The sites were averagely and consequently enriched with toxic elements in the decreasing order: Ni (ER = 33.3) > Mo (20.5) > Sb (14.1) > Pb (11.0) > Hg (7.9) > Se (2.1). The bioaccumulation factor (BCF > 1) suggests that ryegrass has the ability to phytostabilize Co, Hg, Mo, and Ni. This means that the plant may store these elements in its roots, potentially decreasing their negative effects on the environment and human health. Ultimately, the addition of combined manure with iron oxides might have augmented the sequestration of these metals in the root. The elements may have accumulated through sorption on manure or Fe surfaces, dissolution from watering the plants in the pot, or mineralization of organic manure. Thus, ryegrass has shown potential for phytostabilisation of Co, Hg, Mo, and Ni when assisted with a combination of manure and iron oxides; and can consequently mitigate the environmental and human health impacts.

Evaluation of soil pollution effects on maize (Zea mays) at selected Pb-Zn and limestone mine sites in Ebonyi State, Southeastern Nigeria.

This research examined soil contamination and the uptake of potentially toxic elements (PTEs) by maize plants in mining communities. We collected 192 soil samples and 40 maize plant samples from two mining areas and a pristine site. We analyzed the physical properties and element content of the soil, including phosphorus, nitrogen, potassium, Fe, Zn, Co, Pb, Cd, Cr, and Ni. We also measured the elemental concentrations in the maize plants. The study found higher levels of Zn, Cu, and Pb at the mining sites compared to the control areas. The pollution factor (CF) indicated pollution with Cu > Pb > and > Zn at both mine sites. The pollution index (PLI) showed no pollution in the Nkalagu mine and control sites, but heavy and moderate pollution at the Ameka mine and control sites, respectively. The Ameka mine site was enriched with Zn. The bioaccumulation coefficient (BAC) was < 1 except for Zn at the Nkalagu mine and control site. The transfer factor for Fe and Zn from root to shoot was > 1. Pb was > 1 in all study areas except the Ameka mining areas. The results suggest remediation is needed for the two mine sites, especially at Ameka.