scholarly journals Use of Porous no Metallic Minerals to Remove Heavy Metals, Precious Metals and Rare Earths, by Cationic Exchange

2021 ◽  
Author(s):  
Juan Hernandez-Avila ◽  
Edgar Omar Serrano-Mejía ◽  
Eleazar Salinas-Rodríguez ◽  
Eduardo Cerecedo-Sáenz ◽  
María Isabel Reyes-Valderrama ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Rare Earths ◽  
Precious Metals ◽  
Exchange Capacity ◽  
Metals Removal ◽  
Preliminary Study ◽  
Cationic Exchange ◽  
Materials Used

This chapter is related with the preliminary study of some non-metallic minerals to evaluate their cationic exchange capacity, to remove heavy and precious metals, as well as rare earths elements. The minerals and materials used to execute the ion metals removal were bentonite, phosphorite, and diatomite. The chapter shows the physicochemical behavior of all these minerals, which were used to remove the mentioned elements from solutions coming from ore leaching. It was found that in all cases, the removal of heavy and precious metals, as well as rare earths elements reached over 90%. Although, there were minimal differences in efficiency for all minerals used (bentonite, phosphorite, and diatomite), it could be pointed that the phosphorite has the best results going from 99.43% of removal of Gd, to 99.95–100% for the case of Ce, Nd, La, Yb, Eu, Er, Sm, Tb, Ge, Pd, Pt, and Au.

Heavy Metals Removal from Wastewater by Using Activated Peat

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2309-2312 ◽  
Author(s):  
J. S. D'Avila ◽  
C. M. Matos ◽  
M. R. Cavalcanti
Keyword(s):  
Heavy Metals ◽  
Cation Exchange ◽  
Metal Ion ◽  
Fixed Bed ◽  
Exchange Capacity ◽  
Ion Concentration ◽  
Fixed Bed Reactor ◽  
Stirred Tank Reactors ◽  
Metals Removal ◽  
Low Efficiency

The processes used to remove heavy metals from inorganic wastewater have in general low efficiency. The use of activated peat obtained by using a process similar to a cation exchange reaction increases the removal efficiency up to five times when compared with peat “in natura”. The main objective of this work is to show the fundamental mathematical model, governed by diffusion process and the algorithms utilized to design the batch and the continuous feed stirred tank reactors or in some cases a fixed bed reactor. The principal dimensions of these equipments are obtained from the knowledge of the activated peat's cation exchange capacity used in the process, and the main chemical characteristics of the heavy metal ion contained in the wastewater. Besides, two important parameters are also included: the ion concentration and the efficiency of the process obtained from laboratory kinetics experiments. For example Pb+2 is removed l:rom a wastewater at a concentration of 50g/m3 in five minutes or less, with an efficiency of 98%.

Treatment of metals-contaminated wastewaters by use of natural zeolites

1999 ◽  
Vol 39 (10-11) ◽  
pp. 115-122 ◽  
Author(s):  
S. K. Ouki ◽  
M. Kavannagh
Keyword(s):  
Heavy Metals ◽  
Metal Removal ◽  
Low Cost ◽  
Exchange Capacity ◽  
Natural Zeolites ◽  
Al Substitution ◽  
Metals Removal ◽  
Exchange Material ◽  
Na Ions ◽  
Competing Ions

This paper assesses the potential of natural zeolite utilization as a low-cost in exchange material for heavy metals removal. Two natural zeolites, clinoptilolite and chabazite, have been evaluated with respect to their selectivity and removal performance for the treatment of effluents contaminated with mixed heavy metals (Pb, Cd, Cu, Zn, Cr, Ni and Co). The effects of relevant parameters such as chemical treatment, metals concentration, pH, and presence of competing ions were examined. The results showed that the received zeolites contained exchangeable K, Ca and Na ions, but exposing them to concentrated NaCl solutions converted them to a homoionic state in the Na form which improved their exchange capacity. Clinoptilolite and chabazite exhibited different selectivity profiles for all metals studied except for Pb for which both zeolites performed exceptionally well. The results also showed that chabazite exchange capacity is superior to that of clinoptilolite mainly due to the higher Al substitution of Si which provides chabazite with a negative framework favourable to higher exchange capability. The pH was found to have an effect on metal removal as it can influence both the character of the exchanging ions and the zeolite itself. Overall, the removal mechanism was controlled by ion exchange and precipitation was proven negligible.

scholarly journals Mono and Poly-Cationic Adsorption of Heavy Metals Using Natural Glauconite

Minerals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 470 ◽  
Author(s):  
Franus ◽  
Bandura ◽  
Madej
Keyword(s):  
Heavy Metals ◽  
Flow Rate ◽  
Inductively Coupled Plasma ◽  
Environmental Concern ◽  
Nitrogen Adsorption ◽  
Exchange Capacity ◽  
Point Of Zero Charge ◽  
Batch System ◽  
Metals Removal ◽  
The Impact

The issue of heavy metal pollution of industrial wastewaters is a major environmental concern nowadays. The aim of this study was to investigate the effectiveness of heavy metals removal from aqueous solutions by natural glauconite, in batch and dynamic systems. Glauconite was characterized by X-ray diffraction, nitrogen adsorption–desorption isotherm, scanning electron microscope, differential thermal analysis, and inductively coupled plasma spectroscopy. Cation exchange capacity, bulk density and point of zero charge were also determined. In the batch system, the impact of initial concentration, contact time, and pH of metal solutions on sorption efficiency was analysed, whereas for the dynamic system, the influence of flow rate was studied. The adsorption capacity in the batch system followed the order: Pb > Cd > Zn > Cu. The highest adsorption rate was achieved in the pH range 7–9. In the column experiments, the selectivity order in the case of mono-cationic system was the same as that of batch system, whereas in the case of poly-cationic system it was: Pb > Zn > Cd > Cu. With the increase of the flow rate, the total capacity at the exhaustion point increased.

scholarly journals Removal of Heavy Metals from Wastewaters: A Challenge from Current Treatment Methods to Nanotechnology Applications

Toxics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 101
Author(s):  
Ruxandra Vidu ◽  
Ecaterina Matei ◽  
Andra Mihaela Predescu ◽  
Badriyah Alhalaili ◽  
Cristian Pantilimon ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Water Treatment ◽  
Current Treatment ◽  
Constant Attention ◽  
Metals Removal ◽  
Removal Of Heavy Metals ◽  
Alternative Water ◽  
Materials Used ◽  
Water Treatments

Removing heavy metals from wastewaters is a challenging process that requires constant attention and monitoring, as heavy metals are major wastewater pollutants that are not biodegradable and thus accumulate in the ecosystem. In addition, the persistent nature, toxicity and accumulation of heavy metal ions in the human body have become the driving force for searching new and more efficient water treatment technologies to reduce the concentration of heavy metal in waters. Because the conventional techniques will not be able to keep up with the growing demand for lower heavy metals levels in drinking water and wastewaters, it is becoming increasingly challenging to implement technologically advanced alternative water treatments. Nanotechnology offers a number of advantages compared to other methods. Nanomaterials are more efficient in terms of cost and volume, and many process mechanisms are better and faster at nanoscale. Although nanomaterials have already proved themselves in water technology, there are specific challenges related to their stability, toxicity and recovery, which led to innovations to counteract them. Taking into account the multidisciplinary research of water treatment for the removal of heavy metals, the present review provides an updated report on the main technologies and materials used for the removal of heavy metals with an emphasis on nanoscale materials and processes involved in the heavy metals removal and detection.

scholarly journals Diatoms and Their Capability for Heavy Metals Removal by Cationic Exchange

2017 ◽  
Author(s):  
Juan Hernández-Ávila ◽  
Eleazar Salinas-Rodríguez ◽  
Eduardo Cerecedo-Sáenz ◽  
Ma. Isabel Reyes-Valderrama ◽  
Alberto Arenas-Flores ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Chemical Composition ◽  
The Other ◽  
Mineralogical Characterization ◽  
Heavy Metals Removal ◽  
Chromium Vi ◽  
Other Hand ◽  
Metals Removal ◽  
Cationic Exchange

This work shows the physicochemical and mineralogical characterization of diatomites form the Hidalgo and Jalisco States, Mexico. In the case of the mineral from Hidalgo State, this has the following chemical composition; 70.0 % wt. SiO2, 11.63 wt. % Al2O3, 1.95 wt. % FeO, 1.79 wt. % MgO, 2.41 wt. % K2O, 0.85 wt. % CaO and 6.10 wt. % Na2O. On the other hand, the mineral from Jalisco has the following chemical composition; 93.58 wt. % SiO2, 3.03 wt. % Al2O3, 1.81 wt. % FeO, 0.40 wt. % MgO, 0.92 wt. % K2O, 0.11 wt. % CaO and 0.24 wt. % Na2O. For recovery of metals, both minerals got arsenic, silver, lead and nickel recoveries upper to 95 % and lower to 10 % for chromium. According to efficiency of interchange, the mineral from Hidalgo is slightly higher in the case of arsenic, lead and silver; while for nickel and particularly chromium (VI) the efficiency is higher for the mineral from Jalisco.

scholarly journals Prediction and Verification of the Conditions Governing the Synthesis of Tailored Zeolite a for Heavy Metals Removal

2016 ◽  
Vol 11 (2) ◽  
pp. 83
Author(s):  
Heba A. Hani ◽  
Shadia R. Tewfik ◽  
Mohamed H. Sorour ◽  
Nabil Abdel Monem
Keyword(s):  
Heavy Metals ◽  
Initial Conditions ◽  
Exchange Capacity ◽  
Optimization Techniques ◽  
Zeolite A ◽  
Synthesis Conditions ◽  
Testing Procedures ◽  
Optimum Synthesis ◽  
Metals Removal ◽  
Experimental Trials

Numerous experimental trials, exhaustive analytical and testing procedures are usually undertaken, to reach the appropriate conditions for synthesis of “Zeolite A”. However, it is possible to come-up with a semi quantitative approach, through modeling and optimization techniques, to define the approximate range of initial conditions governing the preparation of a tailored zeolite with specific characteristics including silica to alumina ratio, particle size, and cation exchange capacity to be used for the removal of heavy metals. This paper is an attempt to adopt an engineering approach essentially comprising the formulation of a mathematical model relating the characteristics of zeolite A to the synthesis conditions based on numerous experimental published results, optimization to define the synthesis conditions required to produce specific zeolite A , verification of this proposed approach with experimental results for preparation of tailored zeolite A conducted at our laboratories and the assessment of its efficiency for separation of chromium (III). The composition of the synthesized zeolite A has been as anticipated and the removal of chromium (III) has been in agreement with the developed model. These results indicate that is possible to adopt this approach in a generic manner to select the optimum synthesis conditions for the preparation of zeolites having specific performance characteristics.

Metals Related to Radionuclides and Heavy Metals Removal Using Photosynthetic Bacteria Immobilized Recovery Type Porous Ceramic

2010 ◽  
Vol 46 (3) ◽  
pp. 119-127 ◽  
Author(s):  
KEN SASAKI ◽  
CHIHIRO HARA ◽  
KENJI TAKENO ◽  
HIROSHI OKUHATA ◽  
HITOSHI MIYASAKA
Keyword(s):  
Heavy Metals ◽  
Photosynthetic Bacteria ◽  
Porous Ceramic ◽  
Heavy Metals Removal ◽  
Metals Removal

Metals Removal and Recovery by Arthrobacter sp. Biomass

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2149-2152 ◽  
Author(s):  
A. Grappelli ◽  
L. Campanella ◽  
E. Cardarelli ◽  
F. Mazzei ◽  
M. Cordatore ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Industrial Wastes ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Real Possibility ◽  
Metals Removal ◽  
Metal Capture ◽  
Accumulation Of Metals ◽  
Removal And Recovery

Experiments on the real possibility of employing microorganisms to capture inorganic polluting substances, mainly heavy metals from urban and industrial wastes, are running using bacteria biomass. Many strains of Arthrobacter spp., gram-negative bacteria, diffused in the soil also inacondition of environmental stresses, have been proved to be particulary effective in heavy metal capture (Cd, Cr, Pb, Cu, Zn). The active and passive processes in accumulation of metals by bacteria were studied. Our experiments have been done on fluid biomass and on a membrane both for practical use and for an easy recovery.

scholarly journals Technologies Developing in Heavy Metals’ Removal from Water

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 860
Author(s):  
Konstantinos Simeonidis ◽  
Manassis Mitrakas
Keyword(s):  
Heavy Metals ◽  
Drinking Water ◽  
Water Resources ◽  
Human Health ◽  
Urban Wastewater ◽  
Heavy Metals Removal ◽  
Metals Removal ◽  
Drinking Water Resources

Elevated concentrations of heavy metals in drinking water resources and industrial or urban wastewater pose a serious threat to human health and the equilibrium of ecosystems [...]

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