Rhizosphere Microbial Communities and Heavy Metals

The rhizosphere is a microhabitat where there is an intense chemical dialogue between plants and microorganisms. The two coexist and develop synergistic actions, which can promote plants’ functions and productivity, but also their capacity to respond to stress conditions, including heavy metal (HM) contamination. If HMs are present in soils used for agriculture, there is a risk of metal uptake by edible plants with subsequent bioaccumulation in humans and animals and detrimental consequences for their health. Plant productivity can also be negatively affected. Many bacteria have defensive mechanisms for resisting heavy metals and, through various complex processes, can improve plant response to HM stress. Bacteria-plant synergic interactions in the rhizosphere, as a homeostatic ecosystem response to HM disturbance, are common in soil. However, this is hard to achieve in agroecosystems managed with traditional practices, because concentrating on maximizing crop yield does not make it possible to establish rhizosphere interactions. Improving knowledge of the complex interactions mediated by plant exudates and secondary metabolites can lead to nature-based solutions for plant health in HM contaminated soils. This paper reports the main ecotoxicological effects of HMs and the various compounds (including several secondary metabolites) produced by plant-microorganism holobionts for removing, immobilizing and containing toxic elements.

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Evaluation of Phytoremediation Potential of Castor Cultivars for Heavy Metals from Soil

Planta Daninha ◽

10.1590/s0100-83582019370100134 ◽

2019 ◽

Vol 37 ◽

Author(s):

M.J. KHAN ◽

N. AHMED ◽

W. HASSAN ◽

T. SABA ◽

S. KHAN ◽

...

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Contaminated Soils ◽

Metal Uptake ◽

Plant Biomass ◽

Ricinus Communis ◽

Contaminated Sites ◽

Heavy Metal Uptake ◽

Randomized Design ◽

Completely Randomized Design

ABSTRACT: Phytoremediation is a useful tool to restore heavy metals contaminated soils. This study was carried out to test two castor (Ricinus communis) cultivars [Local and DS-30] for phytoextraction of heavy metals from the soil spiked by known concentrations of seven metals (Cu, Cr, Fe, Mn, Ni, Pb and Zn). A pot experiment was laid out by using a completely randomized design. Soil and plant samples were analyzed at 100 days after planting. The data on heavy metal uptake by plant tissues (roots, leaves and shoots) of the two castor cultivars suggested that a considerable amount of metals (Fe = 27.18 mg L-1; Cu = 5.06 mg L-1; Cr = 2.95 mg L-1; Mn = 0.22 mg L-1; Ni = 4.66 mg L-1; Pb = 3.33 mg L-1; Zn = 15.04 mg L-1) was accumulated in the plant biomass. The soil heavy metal content at the end of experiment significantly decreased with both cultivars, resulting in improved soil quality. Therefore, it is concluded that both castor cultivars, Local and DS-30, can be used for phytoremediation of heavy metal-contaminated sites.

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Uptake of Heavy Metals from Urban Wastewater Contaminated Soils by Using Selected Crop Species of Mysuru City, India

IRA-International Journal of Applied Sciences (ISSN 2455-4499) ◽

10.21013/jas.v4.n3.p18 ◽

2016 ◽

Vol 4 (3) ◽

pp. 553

Author(s):

Abhilash M.R ◽

Srikantaswamy S ◽

Shiva Kumar D

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Contaminated Soils ◽

Metal Uptake ◽

Field Experiments ◽

Ecological Factors ◽

Field Studies ◽

Contaminated Sites ◽

Urban Wastewater ◽

Crop Species

<div><p><em>Heavy metals are among the most important sorts of pollutant in the environment. Numerous methods already used to clean up the environment from these kinds of contaminants, but most of them are costly and difficult to get optimum results. F</em><em>actors influencing heavy metal uptake by Crops were studied by pot and field experiments in Mysuru City, India. Results concern with soils is contaminated with Urban Wastewater. In this paper demonstrated effects on the heavy metal content of eight cultivated crop species, in three wastewater contaminated sites of Mysuru City. Interaction between ecological factors and crop characters was demonstrated, as well as results of pot and field studies were compared. Tested plant species were grouped on the basis of their accumulation capability and susceptibility of heavy metals.</em></p></div>

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Amelioration of Heavy Metals from Contaminated Soils of Hazaribagh and Tejgaon Areas from Bangladesh Using Red Mud

Bangladesh Journal of Scientific and Industrial Research ◽

10.3329/bjsir.v44i4.4602 ◽

1970 ◽

Vol 44 (4) ◽

pp. 479-484 ◽

Cited By ~ 1

Author(s):

AS Chamon ◽

MN Mondol ◽

SM Ullah

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Red Mud ◽

Contaminated Soils ◽

Metal Uptake ◽

Tomato Fruit ◽

Wheat Variety ◽

Dry Weight ◽

Wheat Grain ◽

Heavy Metal Uptake

Pot experiments with soil from two heavy metals contaminated sites were conducted. The objective of the experiment was to test red mud as an inorganic soil amendment to reduce heavy metal uptake and to alleviate toxicity in tomato (variety- Ratan) and wheat (variety- Agrani) crops. Iron (Fe) oxides contained in red mud, a byproduct of the aluminum industry, reduced soil to plant transfer of zinc (Zn), nickel (Ni), cadmium (Cd), and chromium (Cr). In Hazaribagh soil, tomato fruit yield (dry weight) increased by 72%. Shoot length and biomass production were positively influenced by red mud containing high amounts of Fe2O3. Heavy metal uptake into tomato plants was significantly ameliorated in both soil. On Tejgaon soil the effect of red mud on wheat grain yield production was not significantly different but the ameliorative effect of red mud application was clearly observed in the wheat grain samples for Tejgaon soil. Key words: Red Mud; Wheat; Tomato; Remediation; Heavy metals DOI: 10.3329/bjsir.v44i4.4602 Bangladesh J. Sci. Ind. Res. 44(4), 479-484, 2009

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ANTHROPOGENIC EFFECTS ON HEAVY METALS AND MACRONUTRIENTS ACCUMULATION IN SOIL AND WOOD OF PINUS SYLVESTRIS L. / ANTROPOGENINIO POVEIKIO ĮTAKA SUNKIŲJŲ METALŲ IR MAKROELEMENTŲ KAUPIMUISI DIRVOŽEMYJE IR PUŠIES (PINUS SYLVESTRIS L.) MEDIENOJE / ВЛИЯНИЕ АНТРОПОГЕННОГО ЗАГРЯЗНЕНИЯ ТЯЖЕЛЫМИ МЕТАЛЛАМИ И МАКРОЭЛЕМЕНТАМИНА ПОЧВУ И СОСНУ ОБЫКНОВЕННУЮ (PINUS SYLVESTRIS L.)

Journal of Environmental Engineering and Landscape Management ◽

10.3846/16486897.2011.557473 ◽

2011 ◽

Vol 19 (1) ◽

pp. 34-43 ◽

Cited By ~ 34

Author(s):

Neringa Pundytė ◽

Edita Baltrėnaitė ◽

Paulo Pereira ◽

Dainius Paliulis

Keyword(s):

Heavy Metals ◽

Organic Carbon ◽

Pinus Sylvestris ◽

Contaminated Soils ◽

Metal Uptake ◽

Control Site ◽

Control Plot ◽

Anthropogenic Effects ◽

Significant Difference ◽

And Control

The investigation is focused on the uptake of heavy metals and macronutrients fluxes in Pinus sylvestris L. wood and soil under the sampled trees from contaminated and control sites. Soil pH, total organic carbon (TOC) and total and bioavailable heavy metals lead (Pb), cadmium (Cd), copper (Cu) and zinc (Zn) and macronutrients, potassium (K) and magnesium (Mg) were compared on contaminated and control sites. Also, metal uptake of contaminated and control pine woods was determined. Concentrations of soil bioavailable Cd (0.009 mg kg−1), Pb (0.11 mg kg−1), Cu (0.076 mg kg−1), Zn (0.51 mg kg−1) and K (24.42 mg kg−1), Mg (8.44 mg kg−1) on the contaminated plot were significantly higher (p < 0.001) than on the control plot 0.00004 mg kg−1for Cd, 0.007 mg kg−1 for Pb, 0.002 mg kg−1 for Cu, 0.22 mg kg−1 for Zn and 7.81 mg kg−1 for K, 2.40 mg kg−1for Mg. In addition, the percentage of bioavailable metals in contaminated soils was higher. Pb (34.49 mg kg−1), Cu (0.258 mg kg−1), Zn (1.36 mg kg−1) and K, Mg concentrations in wood were statistically higher than on the control site Pb (0.01 mg kg−1), Cu (0.172 mg kg−1), Zn (0.93 mg kg−1), at p < 0.05 and p < 0.001, respectively. Cd did not show any significant difference in concentration on the contaminated plot in comparison to the control site. Santrauka Pagrindinis tiriamojo darbo tikslas – nustatyti sunkiųjų metalų kiekį paprastosios pušies (Pinus sylvestris L.), augusios šalia buvusios Ekrano gamyklos Panevėžyje, medienoje bei palyginti su augusios kontrolinėje teritorijoje. Įvertinta ir palyginta abiejų teritorijų dirvožemis, nustatyta dirvožemio pH, bendrosios anglies kiekis (TOC), įvertintos suminė ir judriosios fazės sunkiųjų metalų – švino (Pb), kadmio (Cd), vario (Cu), cinko (Zn) bei makroelementų – kalio (K) ir magnio(Mg) koncentracijos. Nustatyta į pušų medieną užterštoje ir kontrolinėje teritorijose patekusių metalų kiekiai. Akivaizdu, kad judriosios fazės metalų koncentracijos užterštoje teritorijoje (Cd – 0,009 mg·kg–1, Pb – 0,11 mg·kg–1, Cu – 0,076 mg·kg–1, Zn – 0,51 mg·kg–1 ir K – 24,42 mg·kg–1, Mg – 8,44 mg·kg–1) yra didesnės (p < 0,001) nei kontrolinėje(Cd – 0,000 04 mg·kg–1, Pb – 0,007 mg·kg–1, Cu – 0,000 2 mg·kg–1, Zn – 0,22 mg·kg–1 ir K – 7,81 mg·kg–1, Mg – 2,40 mg·kg–1). Pb (34,5 mg·kg–1), Cu (0,258 mg·kg–1), Zn (1,36 mg·kg–1) ir K bei Mg koncentracijos buvo statistiškaididesnės užterštoje teritorijoje (p < 0,05) augusios pušies medienoje nei kontrolinės (p < 0,001) – Pb – 0,01 mg kg–1, Cu – 0,172 mg·kg–1, Zn – 0,93 mg kg–1. Cd koncentracija užterštoje teritorijoje augusios pušies medienoje nedaug skyrėsi nuo kontrolinės. Резюме Главной целью научноисследовательской работы было определить количество тяжелых металлов в древесинесосны обыкновенной (Pinus sylvestris L.) на территории бывшего завода «Экранас» в Паневежисе и сравнить его сданными контрольной территории. В исследовательской работе оценены и сравнены почвы обеих территорий,определен показатель рН почвы, общее количество углерода (ОКУ), оценены общие и растворимые концентрации тяжелых металлов свинца (Pb), кадмия (Cd), меди (Cu), цинка (Zn), концентрации макроэлементов калия (K) имагния (Mg). Также оценено попадание металлов в древесину сосны в загрязненной и контрольной зонах. Замечена тенденция: концентрация растворимых металлов Cd (0,009 мг·кг–1), Pb (0,11 мг·кг–1), Cu (0,076 мг·кг–1), Zn (0,51 мг·кг–1) и K (24,42 мг·кг–1), Mg (8,44 мг·кг–1) в загрязненной зоне выше (p < 0.001), чем в контрольной, соответственно Cd (0,00004 мг·кг–1), Pb (0,007 мг·кг–1), Cu (0,002 мг·кг–1), Zn (0,22 мг·кг–1) ir K (7,81 мг·кг–1), Mg (2,40 мг·кг–1). Концентрации Pb (34,49 мг·кг–1), Cu (0,258 мг·кг–1), Zn (1,36 мг·кг–1), K и Mg в древесине были статистически выше на загрязненной территории (p < 0,05), чем на контрольной (p < 0,001) – Pb (0,01 мг·кг–1), Cu (0,172 мг·кг–1), Zn (0,93 мг·кг–1). Концентрация Cd на загрязненной территории существенно не отличалась отконцентрации на контрольной территории.

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Synergistic Effect of Rhamnolipid and Saponin Biosurfactants on Removal of Heavy Metals from Oil Contaminated Soils

Tenside Surfactants Detergents ◽

10.3139/113.110672 ◽

2020 ◽

Vol 57 (2) ◽

pp. 109-114

Author(s):

Amirhossein Dolatzadeh khiyavi ◽

Reza Hajimohammadi ◽

Hossein Amani ◽

Hadi Soltani

Keyword(s):

Heavy Metals ◽

Synergistic Effect ◽

Contaminated Soils ◽

Removal Of Heavy Metals

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Enhanced heavy metal uptake by activated sludge cultures grown in the presence of biopolymer stimulators

Water Science & Technology ◽

10.2166/wst.1996.0559 ◽

1996 ◽

Vol 34 (5-6) ◽

pp. 267-272 ◽

Cited By ~ 10

Author(s):

Ken Fukushi ◽

Duk Chang ◽

Sam Ghosh

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Activated Sludge ◽

G Protein ◽

Metal Uptake ◽

Heavy Metal Uptake ◽

Culture Viability ◽

Grown Culture

The objective of this research was to investigate the feasibility of developing improved activated sludge cultures capable of removing heavy metals. Cystine, peptone, and β-glycerophosphate (BGP) stimulated metal uptake without the significant reduction of culture viability otherwise experienced in the absence of these chemicals. The cystine-peptone-BGP-grown culture exhibited the highest removal of copper and cadmium of 5.67 and 2.53 mM/g protein, respectively.

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Chemical Properties of Heavy Metal-Contaminated Soils from a Korean Military Shooting Range: Evaluation of Pb Sources Using Pb Isotope Ratios

Applied Sciences ◽

10.3390/app11157099 ◽

2021 ◽

Vol 11 (15) ◽

pp. 7099

Author(s):

Inkyeong Moon ◽

Honghyun Kim ◽

Sangjo Jeong ◽

Hyungjin Choi ◽

Jungtae Park ◽

...

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Contaminated Soils ◽

Management Strategies ◽

Chemical Properties ◽

Heavy Metal Concentration ◽

Soil Samples ◽

Shooting Range ◽

Geochemical Properties ◽

Mineral Phases

In this study, the geochemical properties of heavy metal-contaminated soils from a Korean military shooting range were analyzed. The chemical behavior of heavy metals was determined by analyzing the soil pH, heavy metal concentration, mineral composition, and Pb isotopes. In total, 24 soil samples were collected from a Korean military shooting range. The soil samples consist of quartz, albite, microcline, muscovite/illite, kaolinite, chlorite, and calcite. Lead minerals, such as hydrocerussite and anglesite, which are indicative of a transformation into secondary mineral phases, were not observed. All soils were strongly contaminated with Pb with minor concentrations of Cu, Ni, Cd, and Zn. Arsenic was rarely detected. The obtained results are indicated that the soils from the shooting range are contaminated with heavy metals and have evidences of different degree of anthropogenic Pb sources. This study is crucial for the evaluation of heavy metal-contaminated soils in shooting ranges and their environmental effect as well as for the establishment of management strategies for the mitigation of environmental risks.

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Fractionation of Heavy Metals in Multi-Contaminated Soil Treated with Biochar Using the Sequential Extraction Procedure

Biomolecules ◽

10.3390/biom11030448 ◽

2021 ◽

Vol 11 (3) ◽

pp. 448

Author(s):

Mahrous Awad ◽

Zhongzhen Liu ◽

Milan Skalicky ◽

Eldessoky S. Dessoky ◽

Marian Brestic ◽

...

Keyword(s):

Heavy Metals ◽

Organic Matter ◽

Soil Organic Matter ◽

Soil Ph ◽

Contaminated Soil ◽

Contaminated Soils ◽

Extraction Procedure ◽

Sequential Fractionation ◽

Relationship Of ◽

The Relationship

Heavy metals (HMs) toxicity represents a global problem depending on the soil environment’s geochemical forms. Biochar addition safely reduces HMs mobile forms, thus, reducing their toxicity to plants. While several studies have shown that biochar could significantly stabilize HMs in contaminated soils, the study of the relationship of soil properties to potential mechanisms still needs further clarification; hence the importance of assessing a naturally contaminated soil amended, in this case with Paulownia biochar (PB) and Bamboo biochar (BB) to fractionate Pb, Cd, Zn, and Cu using short sequential fractionation plans. The relationship of soil pH and organic matter and its effect on the redistribution of these metals were estimated. The results indicated that the acid-soluble metals decreased while the fraction bound to organic matter increased compared to untreated pots. The increase in the organic matter metal-bound was mostly at the expense of the decrease in the acid extractable and Fe/Mn bound ones. The highest application of PB increased the organically bound fraction of Pb, Cd, Zn, and Cu (62, 61, 34, and 61%, respectively), while the BB increased them (61, 49, 42, and 22%, respectively) over the control. Meanwhile, Fe/Mn oxides bound represents the large portion associated with zinc and copper. Concerning soil organic matter (SOM) and soil pH, as potential tools to reduce the risk of the target metals, a significant positive correlation was observed with acid-soluble extractable metal, while a negative correlation was obtained with organic matter-bound metal. The principal component analysis (PCA) shows that the total variance represents 89.7% for the TCPL-extractable and HMs forms and their relation to pH and SOM, which confirms the positive effect of the pH and SOM under PB and BB treatments on reducing the risk of the studied metals. The mobility and bioavailability of these metals and their geochemical forms widely varied according to pH, soil organic matter, biochar types, and application rates. As an environmentally friendly and economical material, biochar emphasizes its importance as a tool that makes the soil more suitable for safe cultivation in the short term and its long-term sustainability. This study proves that it reduces the mobility of HMs, their environmental risks and contributes to food safety. It also confirms that performing more controlled experiments, such as a pot, is a disciplined and effective way to assess the suitability of different types of biochar as soil modifications to restore HMs contaminated soil via controlling the mobilization of these minerals.

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Enhanced Electrokinetic Remediation for the Removal of Heavy Metals from Contaminated Soils

Applied Sciences ◽

10.3390/app11041799 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1799

Author(s):

Claudio Cameselle ◽

Susana Gouveia ◽

Adrian Cabo

Keyword(s):

Heavy Metals ◽

Citric Acid ◽

Organic Acids ◽

Contaminated Soils ◽

Electrokinetic Remediation ◽

Deionized Water ◽

Soil Specimen ◽

Removal Of Heavy Metals ◽

Ph Conditions ◽

Neutral Metal

The electrokinetic remediation of an agricultural soil contaminated with heavy metals was studied using organic acids as facilitating agents. The unenhanced electrokinetic treatment using deionized water as processing fluid did not show any significant mobilization and removal of heavy metals due to the low solubilization of metals and precipitation at high pH conditions close to the cathode. EDTA and citric acid 0.1 M were used as facilitating agents to favor the dissolution and transportation of metals. The organic acids were added to the catholyte and penetrated into the soil specimen by electromigration. EDTA formed negatively charged complexes. Citric acid formed neutral metal complexes in the soil pH conditions (pH = 2–4). Citric acid was much more effective in the dissolution and transportation out of the soil specimen of complexed metals. In order to enhance the removal of metals, the concentration of citric acid was increased up to 0.5 M, resulting in the removal of 78.7% of Cd, 78.6% of Co, 72.5% of Cu, 73.3% of Zn, 11.8% of Cr and 9.8% of Pb.

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