scholarly journals Heavy Metal Immobilization Studies and Enhancement in Geotechnical Properties of Cohesive Soils by EICP Technique

2020 ◽  
Vol 10 (21) ◽  
pp. 7568
Author(s):  
Arif Ali Baig Moghal ◽  
Mohammed Abdul Lateef ◽  
Syed Abu Sayeed Mohammed ◽  
Munir Ahmad ◽  
Adel R.A. Usman ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Cohesive Soils ◽  
Retention Capacity ◽  
Reliable Technique ◽  
Landfill Liner ◽  
Permeability Characteristics ◽  
In Situ Conditions ◽  
Contaminant Remediation ◽  
Multiple Heavy Metals

Soil treatment methods to cope with ever-growing demands of construction industry and environmental aspects are always explored for their suitability in different in-situ conditions. Of late, enzyme induced calcite precipitation (EICP) is gaining importance as a reliable technique to improve soil properties and for contaminant remediation scenarios. In the present work, swelling and permeability characteristics of two native Indian cohesive soils (Black and Red) are explored. Experiments on the sorption and desorption of multiple heavy metals (Cd, Ni and Pb) onto these soils were conducted to understand the sorptive response of the heavy metals. To improve the heavy metal retention capacity and enhance swelling and permeability characteristics, the selected soils were treated with different enzyme solutions. The results revealed that EICP technique could immobilize the heavy metals in selected soils to a significant level and reduce the swelling and permeability. This technique is contaminant selective and performance varies with the nature and type of heavy metal used. Citric acid (C6H8O7) and ethylene diamine tetra-acetic acid (EDTA) were used as extractants in the present study to study the desorption response of heavy metals for different EICP conditions. The results indicate that calcium carbonate (CaCO3) precipitate deposited in the voids of soil has the innate potential in reducing the permeability of soil up to 47-fold and swelling pressure by 4-fold at the end of 21 days of curing period. Reduction in permeability and swell, following EICP treatment can be maintained with one time rinsing of the treated soil in water to avoid dissolution of precipitated CaCO3. Outcomes of this study have revealed that EICP technique can be adopted on selected native soils to reduce swelling and permeability characteristics followed by enhanced contaminant remediation enabling their potential as excellent landfill liner materials.

Heavy metal and essential elements in beers from turkey market: A risk assessment study

2021 ◽  
pp. 096032712199321
Author(s):  
M Charehsaz ◽  
S Helvacıoğlu ◽  
S Çetinkaya ◽  
R Demir ◽  
O Erdem ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Inductively Coupled Plasma ◽  
Hazard Quotient ◽  
Daily Intake ◽  
Hazard Index ◽  
Carcinogenic Risk ◽  
Essential Elements ◽  
Inductively Coupled ◽  
Multiple Heavy Metals

In this study, the level of arsenic (As), lead (Pb) and cadmium (Cd) and also essential elements in beer samples consumed in Turkey were investigated using the inductively coupled plasma mass spectrometry (ICP-MS) method. The heavy metal-induced non-carcinogenic and carcinogenic risks were calculated. For essential elements, the calculated estimated daily intake of iron (Fe), copper (Cu), selenium (Se) and cobalt (Co) from beer consumption were compared with their toxicity reference values. Tukey post-hoc test showed that As was found at a significantly higher level when compared to Pb. Also, a significant correlation was found between As level and alcohol by volume percent. All samples had a hazard quotient and hazard index <1, indicating no non-carcinogenic risk from exposure to single or multiple heavy metals. Some samples exceeded the threshold limit of acceptable cancer risk for As in the high beer consumer group. This assessment showed that in addition to health implications based on the alcohol content of beer, there might be a carcinogenic risk associated with the heavy metals content of these beverages.

scholarly journals Effect of heavy metal contamination on the plasticity of kaolin-bentonite clay mixtures and an illite-smectite rich natural clay

2019 ◽  
Vol 92 ◽  
pp. 10005 ◽  
Author(s):  
Abdulla Muththalib ◽  
Béatrice A. Baudet
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Contamination ◽  
Bentonite Clay ◽  
Liquid Limit ◽  
Plasticity Index ◽  
Lead Ion ◽  
Inorganic Contaminants ◽  
Zinc Cations ◽  
Multiple Heavy Metals

The behaviour of soil is complex in a natural environment. Contamination of soil with organic and inorganic contaminants may change the properties of soil. Recent studies have shown that the heavy metal contaminants affect the plasticity and consolidation behaviours. However, little is known about the effects of heavy metals on the behaviour of different types of clay, especially how clay behaves when multiple heavy metals are present in clay. The paper will present results from tests on the effect of three different heavy metal ions used separately, and mixed together in combinations, on the liquid limit (wL), plastic limit (wP) and plasticity index (PI) of kaolin, bentonite, mixtures of kaolin and bentonite and reconstituted Lucera clay. It is found that plasticity index of bentonite is reduced significantly with the addition of heavy metals while PI increases slightly in kaolin. A 1:1 clay mixture of kaolin and bentonite showed significant reduction, while reconstituted Lucera clay has shown small reduction with the addition of heavy metals. It is found that at higher concentrations of copper and zinc cations, the effect takes reverse trend on the liquid limit of kaolin and similar behaviour was observed on the bentonite at higher concentrations of lead ion. Interestingly, lead ion exhibited a significant effect on the plasticity of bentonite when tested with NaCl solution as pore fluid.

scholarly journals Impact of Multi-metal Mixture Administration Through Drinking Water on the Gut Bacterial Microflora and Oxidative Stress Parameters in Male and Female Mice

2022 ◽  
Vol 16 (1) ◽  
pp. 1-8
Author(s):  
Priyanka Bist ◽  
◽  
Sangeeta Choudhary ◽  
Keyword(s):  
Oxidative Stress ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Drinking Water ◽  
Bacterial Count ◽  
High Dose ◽  
Male And Female ◽  
Metal Mixture ◽  
Female Mice ◽  
Multiple Heavy Metals

Background: Heavy metal containing wastes reaches to the food chain either directly or indirectly. These ingested toxic elements manifest direct impact on the gut ecosystem and its overall functioning. The present study explores the alteration in mice gut bacteria on exposure to mixture of toxic heavy metals through drinking water. Methods: Twelve experimental groups of Swiss albino male and female mice were exposed to the metal mixture of varying concentrations. Profiling of gut bacterial flora was done by periodical collection of fecal samples via culture-based technique. Redox status of all experimental animals was analyzed in blood samples collected on the day 30. Results: In comparison to the controls, nearly a 10-fold decline in colony forming units/ml was observed at higher modal concentrations (50× & 100×) at the end of 15 days, but 100-fold reduced bacterial count was recorded following 30 days of dosing. Sex specific significant alteration in the bacteria count and diversity was also observed. Overall experimental results showed a heavy metal dose-dependent decline in bacterial count and loss in diversity. Disturbance in the oxidative stress markers was recorded in response to high dose of metal mixture. In group receiving 100× dose, malondialdehyde levels were increased in the erythrocytes (P<0.05), and all of the other antioxidant parameters were decreased (P<0.05), except for reduced glutathione in both male and female mice. Conclusion: The present work is the first report on the multiple heavy metals induced gut microbiota alterations and its correlation to oxidative stress.

scholarly journals pH-Regulated Carbon Dots Fluorescence Sensor Array Detection of Multiple Heavy Metal Ions Under Stepwise Prediction

2022 ◽  
Author(s):  
Zijun Xu ◽  
Yuying Liu ◽  
Jiao Chen ◽  
Xiyuan Wang ◽  
Hao Liu ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ions ◽  
Metal Ion ◽  
Heavy Metal Ions ◽  
Sensor Array ◽  
Chelating Agent ◽  
Fluorescence Sensor ◽  
Array Detection ◽  
Multiple Heavy Metals

Abstract As a large amount of heavy metals leaches into water sources from industrial effluents, heavy metal pollution has become an important factor affecting water quality. To enable the detection of multiple heavy metals, we constructed a pH-regulation fluorescence sensor array. Firstly, by adding a metal chelating agent as receptor, metal ions and carbon quantum dots (CDs) were connected to distinguish between Cr6+, Fe3+, Fe2+, and Hg2+ ions. Thus, the lack of affinity between the indicator functional groups and the analyte was solved. Secondly, by adjusting the pH environment of the solution system, an economical and simple array sensing platform is established, which effectively simplified the array construction. In this study, the SX-model was used in the field of fluorescence sensor array detection for metal ion recognition. Based on the strategy of stepwise prediction, combined with the classification and concentration models, the bottleneck of the unified model in previous studies was broken. This sensor array demonstrated sensitive detection of four heavy metal ions within a concentration range from 1 to 50 µM, with an accuracy of 95.45%. Moreover, it displayed the ability to efficiently identify binary mixed samples with an accuracy of 95.45%. Furthermore, metal ions in 15 real samples (lake water) were effectively discriminated with 100% accuracy. A chelating agent was used to improve the sensitivity of heavy metal ion detection and eventually led to high-precision prediction using the SX-model.

The use of volcanic soil as mineral landfill liner - III. Heavy metals retention capacity

2005 ◽  
Vol 23 (3) ◽  
pp. 260-269 ◽  
Author(s):  
Rodrigo Navia ◽  
Bárbara Fuentes ◽  
María C. Diez ◽  
Karl E. Lorber
Keyword(s):  
Heavy Metals ◽  
Volcanic Soil ◽  
Retention Capacity ◽  
Landfill Liner

IN-SITU DETECTION OF HEAVY METAL POLLUTION IN SEAWATER WITH DIAMOND COATED ELECTRODES

2019 ◽  
Vol 26 (04) ◽  
pp. 1850179
Author(s):  
BIN ZHAO ◽  
JIA LI ◽  
XIANG YU ◽  
JING ZHANG ◽  
YI REN
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Mercury Electrode ◽  
In Situ Monitoring ◽  
National Standard ◽  
Electrochemical Window ◽  
Multiple Heavy Metals

Heavy metal pollution endangers seawater and there is urgent need for the development of effective detectors that can provide warning of heavy metal pollution. Anodic stripping voltammetry is applicable for the detection of heavy metal pollution in sea water, but it suffers from two problems that are associated with the mercury electrode used: one is insufficient sensitivity and the other is secondary pollution caused by toxic mercury. In this work, we employed boron-doped diamond electrode as an alternative to mercury electrode for the detection of heavy metals. The BDD electrode was fabricated and its electrochemical properties were ascertained. The results of this work showed that: (1) the electrode prepared has a wide electrochemical window (4.2 V) and low background current ([Formula: see text]A). (2) multiple heavy metals (Pb[Formula: see text], Cd[Formula: see text], Zn[Formula: see text] and Cu[Formula: see text]) in seawater samples are detected simultaneously with the optimized electrode, with high sensitivity and good repeatability. (3) the repeatability of the detection meets the values stipulated in the national standard. The detection period is less than 15[Formula: see text]min, and in situ monitoring of heavy metals in seawater can be achieved by automatic sampling and wireless data transmission.

Hydroxyapatite Nanoparticles for Acidic Mine Waters Remediation

2019 ◽  
Vol 70 (9) ◽  
pp. 3167-3175
Author(s):  
Claudia Maria Simonescu ◽  
Daniela Cristina Culita ◽  
Virgil Marinescu ◽  
Christu Tardei ◽  
Dorinel Talpeanu
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ions ◽  
Specific Surface ◽  
Metal Ion ◽  
Heavy Metal Ions ◽  
Mining Activities ◽  
Retention Capacity ◽  
Synthesis Conditions ◽  
Mining Wastewater

Mining activities have a high negative impact on the environment and on human health. Environmental impacts can result in contamination of surface water, groundwater, soil and air. Large volumes of wastewater produced by mining activities have to be remediated before being discharged into the environment. Due to the complex composition of wastewater coming from the mining industry and because their negative impacts, numerous remediation techniques have been applied. Adsorption is one of the most extensively used ways to remediate mining wastewater as a consequence of its low cost, easiness to be performed, and also due to the wide variety of materials (natural and synthetic) that can be use as adsorbents. Hydroxyapatite (HAP, Ca10(PO4)6(OH)2), a naturally occurring form of calcium phosphate has a good capacity to remove heavy metal ions from aqueous solutions due to its excellent properties. By preparing hydroxyapatite using different synthesis methods, its properties can be manipulated in order to increase the adsorption properties and reactivity. Herein, we reported synthesis of hydroxyapatite (HAP) samples using different synthesis conditions to establish the effect of synthesis conditions onto HAP properties. The HAP samples prepared have been characterized by the use of X-ray diffraction, FT-IR spectroscopy, specific surface measurements, Scanning Electron Microscopy (SEM). The stoichiometric compounds with high degree of crystallinity, low average particle diameter values, and low specific surface have been prepared by the solid state reaction and high calcination temepratures. The addition of surfactant (dispersant) has resulted in an increase in the specific surface area, which will result in an increase in the retention capacity of heavy metal ions in wastewater. The adsorbents prepared were used to remediate mine water. Results showed that non-calcinated HAP samples have a higher heavy metals adsorption capacity compared to HAP samples calcinated at 600 �C and 900 �C. The HAP samples prepared in presence of surfactant exhibit a higher heavy metals adsorption capacity than samples prepared in absence of surfactant. The values of the retention capacity differ depending on the nature of the metal ion: QMn(II) ] QFe(III) ] QZn(II) ] QPb(II) ] QNi(II). A change in the pH of mine water from 2.6 to 5.5 has occur that means that the metal ion retention mechanism goes through chemical reactions. The metal ions retention capacity suggests application of hydroxyapatite for remediation of mining wastewater.

Study on Tdsorption of Heavy Metalion in Metallurgical Wastewater by Montmorillonite

2012 ◽  
Vol 461 ◽  
pp. 601-605
Author(s):  
Xiu Yan Zhou ◽  
Xiang Xin Xue ◽  
Yu Hua Zhao ◽  
Ou Liu
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Adsorption Capacity ◽  
Removal Rate ◽  
Adsorption Time ◽  
Adsorbent Dosage ◽  
Temperature Conditions ◽  
Multiple Heavy Metals

In this study, the sorption of single heavy metal (Cu2+, Pb2+ and Zn2+) and multiple heavy metals in simulated metallurgical wastewater by montmorillonite was investigated. The effect of adsorption time and temperature conditions, etc. on the adsorption was also studied. The results showed that in the same concentration of adsorbent dosage, removal rate of single heavy metal is the highest (99.9%, 88.1% and 98.3%) when the concentration of Cu2+, Pb2+ and Zn2+ is 50 mg/L, 20mg/L and 100mg/L, respectively. The adsorption of multiple heavy metals in simulated metallurgical wastewater is the highest in 4 hours at 20°C. The adsorption capacity is in order of Pb2+≈Zn2+>Cu2+>Cd2+ and removal rate is 90.8%, 87.3%, 70.0% and 51.6%, respectively.

The effect of multiple heavy metals on ascorbate, glutathione and related enzymes in two mangrove plant seedlings (Kandelia candel and Bruguiera gymnorrhiza)

2010 ◽  
Vol 39 (1) ◽  
Author(s):  
Guo-Yong Huang ◽  
You-Shao Wang ◽  
Cui-Ci Sun ◽  
Jun-De Dong ◽  
Zong-Xun Sun
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Stress ◽  
Metal Stress ◽  
Kandelia Candel ◽  
Bruguiera Gymnorrhiza ◽  
Mangrove Plant ◽  
Multiple Heavy Metals ◽  
Plant Seedlings

The effect of multiple heavy metals on ascorbate, glutathione and related enzymes in two mangrove plant seedlings (In this study, the effect of multiple heavy metal stress on ascorbate (AsA), glutathione (GSH) and related enzymes was investigated in the leaves, stems and roots of

scholarly journals Strippable Polymeric Nanocomposites Comprising “Green” Chelates, for the Removal of Heavy Metals and Radionuclides

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4194
Author(s):  
Gabriela Toader ◽  
Daniela Pulpea ◽  
Traian Rotariu ◽  
Aurel Diacon ◽  
Edina Rusen ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Complexing Agents ◽  
Mechanical And Thermal Properties ◽  
Polymeric Nanocomposites ◽  
Retention Capacity ◽  
Metal Retention ◽  
Removal Of Heavy Metals ◽  
Iminodisuccinic Acid ◽  
Minimal Environmental Impact

The issue of heavy metal and radionuclide contamination is still causing a great deal of concern worldwide for environmental protection and industrial sites remediation. Various techniques have been developed for surface decontamination aiming for high decontamination factors (DF) and minimal environmental impact, but strippable polymeric nanocomposite coatings are some of the best candidates in this area. In this study, novel strippable coatings for heavy metal and radionuclides decontamination were developed based on the film-forming ability of polyvinyl alcohol, with the remarkable metal retention capacity of bentonite nanoclay, together with the chelating ability of sodium alginate and with “new-generation” “green” complexing agents: iminodisuccinic acid (IDS) and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC). These environmentally friendly water-based decontamination solutions are capable of generating strippable polymeric films with optimized mechanical and thermal properties while exhibiting high decontamination efficiency (DF ≈ 95–98% for heavy metals tested on glass surface and DF ≈ 91–97% for radionuclides 241Am, 90Sr-Y and 137Cs on metal, painted metal, plastic, and glass surfaces).

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