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

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.

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Phosphorus and Metals Leaching from Green Roof Substrates and Aggregates Used in Their Composition

Minerals ◽

10.3390/min10020112 ◽

2020 ◽

Vol 10 (2) ◽

pp. 112 ◽

Cited By ~ 1

Author(s):

Agnieszka Karczmarczyk ◽

Anna Baryła ◽

Joanna Fronczyk ◽

Agnieszka Bus ◽

Józef Mosiej

Keyword(s):

Heavy Metals ◽

Green Roof ◽

Green Roofs ◽

Point Of View ◽

Water Retention Capacity ◽

Retention Capacity ◽

Batch Tests ◽

Quality Literature ◽

Materials Used ◽

Runoff Quality

Green roofs are constructions made of different layers, each serving a dedicated function. Substrates and materials used in their composition are essential from the point of view of rainwater retention and plant development, but they may have an adverse effect on runoff quality. Literature studies show that phosphorus and heavy metals are of main importance. The total roofs area covered with green increased in the last years in cities as they are efficient in retention of rainwater and delaying of the runoff, therefore, protecting the cities against floods. As green roofs filtrate a significant amount of rainwater, materials used in substrates composition should be carefully selected to protect urban receivers against pollution. The aim of this study was to assess phosphorus and heavy metals leaching from different green roof substrates and their components with the focus on green roof runoff quality. Both commercially made green roof substrates and often used compounds (construction aggregates) were tested in laboratory batch tests for P, Cu, Ni, Cd, and Zn content in extracts. Based on the results of this study, it could be emphasized that a large part of commonly used construction aggregates can be a source of phosphorus, some also can release elevated values of nickel. Therefore, the materials should be carefully tested before use in the green roof substrate composition, not only for their physical properties reflecting water retention capacity, but also for chemical composition.

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The Research of Biochar Adsorption on Soil

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.448-453.417 ◽

2013 ◽

Vol 448-453 ◽

pp. 417-424

Author(s):

Jie Chen ◽

You Yang Wang ◽

Jun Hui Wu ◽

Hui Ping Si ◽

Kai Yan Lin

Keyword(s):

Heavy Metals ◽

Functional Groups ◽

Organic Pollutants ◽

Contaminated Soils ◽

Sustainable Use ◽

Organic Pollution ◽

Water Retention Capacity ◽

Retention Capacity ◽

Research Directions ◽

Organic Mulch

This article discusses biochar adsorption and its effects on soil and discusses the future trends in this area. The large surface area, and many oxygen-containing functional groups of biochar determined by the feedstocks and the condition in pyrolysis affect the capacity of biochar to adsorb fertilizer, water, heavy metals and organic pollution. With enriched porous structures, biachar can increase the porosity and water retention capacity of soils. With the functional groups and the composition, biochar have a high adsorption capacity for fertilizer, heavy metals, organic pollutants. This paper provides an overview on the biochar sorption in fertilizer, heavy metals and organic pollutants in soil and its implication for soil to keep soil fertilizer as a controlled-released carrier and to improve soil environments as landscaping organic mulch, as well as for remediation of contaminated soils. Further research directions are identified to ensure a safe and sustainable use of biochar as a soil amendment.

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Landscape geochemical conditions and patterns of inter-element redistribution of heavy metals in landscapes of Kivertsi National Nature Park “Tsumanska Pushcha”

Journal of Geology Geography and Geoecology ◽

10.15421/112115 ◽

2021 ◽

Vol 30 (1) ◽

pp. 165-178

Author(s):

Anastasiia O. Splodytel ◽

Liudmyla Yu. Sorokina ◽

Oksana V. Lunova

Keyword(s):

Heavy Metals ◽

Chemical Elements ◽

Water Retention Capacity ◽

Moisture Regime ◽

Geochemical Background ◽

High Accumulation ◽

Retention Capacity ◽

Geochemical Conditions ◽

Geochemical Parameters ◽

Nature Park

nalysis of landscape geochemical conditions of the territory of Kivertsi National Nature Park “Tsumanska Pushcha” was carried out also the levels of pollution of landscapes within the park and adjacent territories were established. Features of the accumulation and distribution of pollutants in the landscapes of the territory under conditions of natural and Technogenic geochemical anomalies are considered. The landscapes of the studied migration classes (calcium, calcium carbonate, carbonate clayey, acidic calcium) are characterized by a relatively high coefficient of migration intensity due to relatively weak buffering capacity, low water retention capacity and contrasting moisture regime. However, strong gleyed horizons are able to fix contaminants during their surface movement. Using the methods of landscape geochemical research, analytical methods, data on the gross and mobile content of heavy metals were obtained and analyzed. The highest concentrations of manganese and chromium are found in soils differentiated on loess sediments, nickel and copper on glacial sediments. Most of the studied heavy metals exceed the regional geochemical background. In terms of the gross content in soils, trace elements form the following geochemical series: Zn>Cu>Pb>Ni>Mn>Cr. The accumulation of lead up to 2-3 MPC in forest litters is clearly traced. Dependences of the stability of landscapes to Technogenic pollution on the level of conservation of natural geochemical parameters of soils, the degree of their anthropogenic transformation and the level of heavy metals incomings have been established. All studied plants maximally accumulated Mn, Cu, Cr and minimally Zn and Ti which is consistent with the patterns of migration of these elements in the soil. The high accumulation of heavy metals in the aboveground part of the studied plants indicates a significant removal of elements from the soil, which, in turn, makes it possible to consider certain plant species as potential phytoremediators. According to the average values of the concentration of macro elements in plants, the following geochemical series is established: CaO>K2O>MgO>P2O5>SiO2>SO3> Al2O3> Fe2O3>Na2O>TiO2. On the basis of the data obtained, 4 types of biogeochemical bonds between chemical elements in the soil – plant system for the territory of the NPP were identified: V, Ti - soil> plant; Ni - soil <plant; Cr - soil> plant; Mn, Cu - soil <plant.

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Hydroxyapatite Nanoparticles for Acidic Mine Waters Remediation

Revista de Chimie ◽

10.37358/rc.19.9.7509 ◽

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.

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Effective reuse of waste material as an amendment in composite landfill liner: Assessment of geotechnical properties and pollutant retention capacity

Waste Management & Research ◽

10.1177/0734242x19886920 ◽

2019 ◽

Vol 38 (2) ◽

pp. 134-141

Author(s):

Namitha Nambiar ◽

Neelancherry Remya ◽

George K Varghese

Keyword(s):

Silica Fume ◽

Manufacturing Industry ◽

Pollution Abatement ◽

Exchange Capacity ◽

Dry Density ◽

Maximum Dry Density ◽

Retention Capacity ◽

Liner Material ◽

Landfill Liner ◽

Swell Index

The effective reuse silica fume (S), a by-product from the silicon manufacturing industry, as an amendment in the composite landfill liner along with natural clay (C) and bentonite (B) was investigated in the present study. Experiments were conducted with various proportions of silica fume (10%–50%) to clay and bentonite to get mixtures C–B–S1 to C–B–S5. The study indicated significant improvement in the geotechnical and pollutant retention capacity by silica fume addition. The maximum dry density of the mixtures ranged from 1.568 to 1.732 g cm-3. Permeability was in the order of C–B<C–B–S1 to C–B–S5<clay. Unconfined compressive strength of the C–B mix increased with the addition of silica fume from 10% to 25%, with a maximum value of 241.31 kPa. The free swell index decreased to 3.6 and the cation exchange capacity increased to 83 meq/100 g with the addition of 50% silica fume. The percentage removal of copper with C–B–S1 to C–B–S5 was 91.2%, 92%, 93.5%, and 95.2%, respectively, when the initial copper concentration was about 30 mg L-1. Based on the assessment of geotechnical and pollution abatement capacity C–B–S3 with 25% silica fume addition was proposed as the composite liner material for the naturally available clay at the landfill site.

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

Polymers ◽

10.3390/polym13234194 ◽

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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Adsorption of heavy metal by natural clayey soil

Journal of Applied Geology ◽

10.22146/jag.7183 ◽

2015 ◽

Vol 3 (1) ◽

Author(s):

Wawan Budianta

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Soil Sample ◽

Waste Disposal ◽

Clayey Soil ◽

Batch Experiment ◽

Concentrated Solutions ◽

Retention Capacity ◽

Metal Retention ◽

Soil Batch

This study focused on the capability of Clayey soil to retain and release heavy metals. Batch experiment for sample of clayey soil was conducted with several concentrated solutions of heavy metals. The results show that the clayey soil sample may have a relatively high heavy metal retention capacity. This is particularly positive in the context of municipal waste disposal (landfills) in Indonesia Keywords: Adsorption, heavy metal, clayey soil, batch experiment

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