Preparation and characterization of calcium treated bentonite clay and its application for the removal of lead and cadmium ions: Adsorption and thermodynamic modeling

2017 ◽  
Vol 111 ◽  
pp. 244-252 ◽  
Author(s):  
Joziane G. Meneguin ◽  
Murilo P. Moisés ◽  
Thirugnanasambandham Karchiyappan ◽  
Sergio Henrique Bernardo Faria ◽  
Marcelino L. Gimenes ◽  
...  
2010 ◽  
Vol 26-28 ◽  
pp. 682-685 ◽  
Author(s):  
Dong Zhang ◽  
Chun Li Zhang

Nanometer barium-stroutium titanate immobilized on aluminum oxide (ABST) was prepared by the citric acid sol–gel method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrophotometry (FTIR). Its Pb2+ and Cd2+ adsorption properties from water were studied. Adsorption and elution were investigated under different conditions. The results showed that the nanometer barium-strontium titanate was immobilized on aluminum oxide firmly, becoming a composite adsorbent. The lead and cadmium ions were quantitatively retained at pH 5-8; their adsorption capacities of ABST were 70.28 mg•g-1 and 8.12 mg•g-1, respectively. The adsorbent of adsorped lead and cadmium ions were regenerated completely by elution with 1 mol•L-1 HNO3. The adsorbent had a promising prospect in analyticl chemistry and water treatment.


Author(s):  
L. L. Sutter ◽  
G. R. Dewey ◽  
J. F. Sandell

Municipal waste combustion typically involves both energy recovery as well as volume reduction of municipal solid waste prior to landfilling. However, due to environmental concerns, municipal waste combustion (MWC) has not been a widely accepted practice. A primary concern is the leaching behavior of MWC ash when it is stored in a landfill. The ash consists of a finely divided fly ash fraction (10% by volume) and a coarser bottom ash (90% by volume). Typically, MWC fly ash fails tests used to evaluate leaching behavior due to high amounts of soluble lead and cadmium species. The focus of this study was to identify specific lead bearing phases in MWC fly ash. Detailed information regarding lead speciation is necessary to completely understand the leaching behavior of MWC ash.


2020 ◽  
Author(s):  
Awinash Kumar ◽  
Pradip Lingfa ◽  
Nabam Hina Papu ◽  
Moiching Sajit Ahamed

Author(s):  
N. I. Hradovych ◽  
R. P. Paranyak ◽  
Yu. M. Zabytivskyi

Information about the influence of zeolite used as adsorbent to reduce the concentration of Lead and Cadmium in separate links of trophic chain of hydroecosystem namelyn in water, phytoplankton and muscular tissue of Silver carp is given in the article. As a sorbent we used zeolite of Sokirnitsa deposit (village Sokirnitsa, Khust district Transcarpathian region) of fraction 1.0 – 4.0 mm. Investigations were made at the Lviv research station of Institute of fisheries NAAS (Lviv oblast, Horodok region, Velykyi Lyubin). The sorption properties of natural Transcarpathian clinoptilolite towards Lead and Cadmium at dynamic conditions have been studied. The paper represents research results aimed at estimating effectiveness of removing of Lead and Cadmium ions from hydroecosystems using natural mineral–zeolite. The dynamics of heavy metals content at phytoplankton and muscular tissue of silver carp (Hypophthalmichthys molitrix Valenciennes, 1844) was studied. Measurements were perfomed in pond № 24 (12) area 0.14 hectares which is fed by waters of the river Vereshchytsia. The pond depth is 1 – 1.5 meters.  Results of investigations worked out statistically combining the groups. Considerable lowering of ions content of both metals in water was determined. The lowering of cadmium content in muscular tissue of Silver carp was much noticeable than the content of Lead. Results of such investigations are rather actual and perspective and will help to reduce the content of some toxicants in water medium. Improvement of water ecosystems after use of natural sorbents will guarantee ecologically safe products of fish culture and will increase the efficiency of the branch.


Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 406 ◽  
Author(s):  
Abdulaziz N. Amro ◽  
Mohammad K. Abhary ◽  
Muhammad Mansoor Shaikh ◽  
Samah Ali

In recent years, the interest in waste water treatment increased to preserve the environment. The objective of this study is the removal of lead and cadmium ions from aqueous solution by treated Phragmites biomass (TPB). TPB was characterized by using Fourier transform infrared spectroscopy (FTIR) and energy dispersive X-ray analysis (EDS) which indicates the presence of functional groups that may be responsible of metal adsorption such as hydroxyl, carbonyl, sulfonate and carboxylate. Characterization by scanning electron microscopy (SEM) and surface area analysis using the Brunauer–Emmett–Teller method (BET) illustrated that TPB is nonporous with a small surface area. The influences of various experimental factors were investigated; the proposed method recommended the extraction of Pb+2 and Cd+2 metal ions by TPB at pH 5.0. A contact time of 60 and 45 min was required for the adsorption 50 mL (50 ppm) Pb+2 and Cd+2 respectively to reach equilibrium when 0.10 g TPB was used. The optimum TPB dosage was 0.20 g for adsorption both metal ions when adsorbate solution was 50 mL (50 ppm). Particle sizes of 0.125–0.212 mm showed the best metal ion removal of both metal ions. Thermodynamic study illustrated that both metal ions correlate more with Langmuir isotherm. Furthermore, chemisorption of Pb+2 and Cd+2 on TPB was more likely according to kinetic study data.


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