Chromium (VI) Adsorption Characteristics of Bentonite Under Different Modification Patterns

Li, Wenbin; Meng, Zhaofu; Liu, Ze; Chen, Huayun; Wu, Qiong; Xu, Shaoe

doi:10.15244/pjoes/61626

Cited by 18 publications

(3 citation statements)

References 19 publications

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“…The result showed that the amount of fluoride adsorbed on fired clay pot was significantly affected when the concentration increases from 0 to 1000 mg/L KNO 3 . The same effect of ionic strength was also observed for the adsorption of Cr(VI) on bentonite [40]. Studying the influence of ionic strength is a simple approach to distinguish between inner sphere and outer sphere surface complexes when direct evidence from microscopic data is absent.…”

Section: Effect Of Ionic Strengthsupporting

confidence: 55%

Removal of Fluoride from Water by Adsorption onto Fired Clay Pots: Kinetics and Equilibrium Studies

Kofa

Gomdje

Telegang

et al. 2017

Journal of Applied Chemistry

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Excessive fluoride in potable water is a serious health problem in rural areas of many developing countries. Hence, there is a need to find a simple and cost-effective method for water defluoridation in such areas. In the northern part of Cameroon, clay pots are used for cooking food and water storage. The firing of these pots consists of intensive burning using fire wood. They were tested as a potential adsorbent for removing excess fluoride from water. Experiments were carried out in a jar test at room temperature (25 ± 2 ∘ C). Effects of contact time (0-90 min), pH (4, 5, 7, 8, and 9), stirring speed (60, 90, 120, and 200 rpm), and ionic strength (0-1000 mg/L) were investigated. Results showed that equilibrium was attained in 10 min whatever the pH. Pseudo-second-order and pore diffusion models described well the adsorption process. The highest amount of fluoride adsorbed (1.6 mg/g) was obtained at pH 4-5 and the optimum stirring speed is 120 rpm. Ionic strength has a significant effect on fluoride adsorption.

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Section: Effect Of Ionic Strengthsupporting

confidence: 55%

Removal of Fluoride from Water by Adsorption onto Fired Clay Pots: Kinetics and Equilibrium Studies

Kofa

Gomdje

Telegang

et al. 2017

Journal of Applied Chemistry

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“…Liu [ 41 , 42 ] found that modified bentonite with amphoteric surfactants was effective at adsorbing bisphenol A, Pb 2+ , and Cd 2+ . This was probably due to the carboxyl groups (−COO−) and positively charged groups (−N + ) that were present in the amphoteric surfactants, which make it simpler to adsorb metal ions and organic contaminants [ 43 , 44 , 45 ].…”

Section: Introductionmentioning

confidence: 99%

A Study on the Impermeability of Nanodispersible Modified Bentonite Based on Colloidal Osmotic Pressure Mechanisms and the Adsorption of Harmful Substances

Zhang

Gong

et al. 2023

Nanomaterials

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With the growing demands of human beings, sanitary landfill, along with the increase in landfill depth and leachate water pressure, has put forward new and higher requirements for the impermeable layer. In particular, it is required to have a certain adsorption capacity of harmful substances from the perspective of environmental protection. Hence, the impermeability of polymer bentonite–sand mixtures (PBTS) at different water pressure and the adsorption properties of polymer bentonite (PBT) on contaminants were investigated through the modification of PBT using betaine compounded with sodium polyacrylate (SPA). It was found that the composite modification of betaine and SPA could reduce the average particle size of PBT dispersed in water (reduced to 106 nm from 201 nm) and enhance the swelling properties. As the content of SPA increased, the hydraulic conductivity of PBTS system decreases and the permeability resistance improves, while the resistance to external water pressure increases. It is proposed a concept of the potential of osmotic pressure in a constrained space to explain the impermeability mechanism of PBTS. The potential of osmotic pressure obtained by linear extrapolation of the trendline of colloidal osmotic pressure versus mass content of PBT could represent the external water pressure that the PBT resist. Additionally, the PBT also has a high adsorption capacity for both organic pollutants and heavy metal ions. The adsorption rate of PBT was up to 99.36% for phenol; up to 99.9% for methylene blue; and 99.89%, 99.9%, and 95.7% for low concentrations of Pb2+, Cd2+, and Hg+, respectively. This work is expected to provide strong technical support for the future development in the field of impermeability and removal of hazardous substances (organic and heavy metals).

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“…Among the numerous physical, chemical and biological methods for the removal of Cr(VI) compounds from aqueous solutions, the adsorption method is the applicable method based on its simplicity and costeffectiveness. Various numbers of different materials such as natural clays (Zachara et al, 1988;Ajouyed et al, 2011;Li et al, 2016;Algamal et al, 2018), natural zeolites (Faghihian & Bowman, 2005;Jorfi et al, 2017), agricultural and industrial waste material (Šćiban & Klašnja, 2002), different carbon materials, activated carbon (Mohan & Pittman, 2006) etc. were tested as an adsorbent for Cr(VI) compounds from aqueous medium.…”

Section: Introductionmentioning

confidence: 99%

Kinetics of Cr(VI) adsorption from aqueous medium onto bentonite

Petrović

2020

GHTERS

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Because of its abundance and toxicity, heavy metals have become a seriousenvironmental problem. The presence of heavy metals, such as Cr(VI), in thewatercourses leads to numerous health problems in humans and animals. Cr(VI) ishighly toxic, even in low concentrations. Because of its carcinogenic, mutagenic andteratogenic effects on human beings, Cr(VI) is considered one of the most criticalpollutants. Due to this, it is necessary to remove Cr(VI) from wastewater prior to itsdischarge into the recipient.This paper studied the possibility for application of bentonite as an adsorbent forCr(VI) from aqueous medium. The characterization of bentonite was determined withchemical composition, specific surface, XRD method and FTIR. Optimal parameterssuch as pH of solution, adsorbent weight, time of adsorption and temperaturewere examined. Values of those parameters were: initial pH value of solution pH=2,adsorbent weight 2 g, time of adsorption 60 min, temperature 308 K. Experimentaldata were obtained by Freundlich and Langmuir isotherm adsorption models as wellas pseudo-first and pseudo-second order kinetics. Results were best described withFreundlich isotherm adsorption model and pseudo-second order kinetics.

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Chromium (VI) Adsorption Characteristics of Bentonite Under Different Modification Patterns

Cited by 18 publications

References 19 publications

Removal of Fluoride from Water by Adsorption onto Fired Clay Pots: Kinetics and Equilibrium Studies

Removal of Fluoride from Water by Adsorption onto Fired Clay Pots: Kinetics and Equilibrium Studies

A Study on the Impermeability of Nanodispersible Modified Bentonite Based on Colloidal Osmotic Pressure Mechanisms and the Adsorption of Harmful Substances

Kinetics of Cr(VI) adsorption from aqueous medium onto bentonite

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