Biosorption of mercury from aqueous solutions by powdered leaves of castor tree (Ricinus communis L.)

Rmalli, Shaban W. Al; Dahmani, Abdella A.; Abuein, M. M.; Gleza, Amar A.

doi:10.1016/j.jhazmat.2007.07.111

Cited by 76 publications

(41 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This could be explained in accordance with the Pearson's soft and hard acid-base (SHAB) concept that Hg(II) is a class B metal ion and preferably complexes covalently with sulfur and nitrogen-containing ligands. The borderline acids Pb(II), Cu(II) and Ni(II) form intermediately strong covalent bonds with sulfur or nitrogen-containing ligands (49). The soft acid-soft base pair has greater probability being stronger.…”

Section: Effect Of Foreign Metal Ions In Binary Systemmentioning

confidence: 99%

Equilibrium, kinetic and thermodynamic biosorption studies of Hg(II) on red algal biomass ofPorphyridium cruentum

Zaib

Athar

Saeed

et al. 2016

Green Chemistry Letters and Reviews

View full text Add to dashboard Cite

Among a variety of microbial materials employed for biosorption, algae have added advantages of non-toxic and autotrophic nature. In this study, biosorption of Hg(II) was studied with red algal biomass of Porphyridium cruentum. The parameters affecting biosorption such as dosage of biosorbent, pH, contact time, initial metal concentration, temperature and effect of foreign metal cations in binary system were evaluated. Kinetic data were described with the help of pseudofirst-order and pseudo-second-order kinetic models. Langmuir, Freundlich, Temkin and DubininRadushkevich isotherm models were applied to adsorption equilibrium data. According to the results, the maximum removal capacity (q max ) was 2.62 mg/g observed at pH 7 with 0.25 g/L of biosorbent dosage for Hg(II) solution containing 10 mg/L of metal ions. The Langmuir isotherm model fits best to the adsorption data while the kinetic data followed the pseudo-second-order model. Thermodynamics studies showed that the biosorption process of Hg(II) on P. cruentum was exothermic in nature.ARTICLE HISTORY

show abstract

Section: Effect Of Foreign Metal Ions In Binary Systemmentioning

confidence: 99%

Equilibrium, kinetic and thermodynamic biosorption studies of Hg(II) on red algal biomass ofPorphyridium cruentum

Zaib

Athar

Saeed

et al. 2016

Green Chemistry Letters and Reviews

View full text Add to dashboard Cite

show abstract

“…This was probably due to the availability of so many adsorptive sites at the beginning of the experiment and as the biosorption proceeds, the free binding sites become rarer causing a slower biosorption rate until approaching the equilibrium due to the saturation of active sites with Hg (II) ions. It was also observed that, the Hg (II) adsorption onto AAS attained equilibrium faster than that onto RAS, which was due to the large surface area of AAS that suggest more adsorptive sites (Al-Rmalli et al, 2008). Figure 7 shows the experimental results obtained from Hg (II) ions removal by RAS and AAS by increasing the temperature from 298 K to 328 K reaching a maximum removal efficiency at 328 K. An increase in the temperature involves increasing the mobility of Hg (II) ions and decreasing the retarding force acting on the diffusing ions, which result in the enhancement in the sorptive capacity of the adsorbent, increasing the chemical interaction between adsorbate-adsorbent and creation of active surface centers or by an enhanced rate of intra-particle diffusion of Hg (II) ions into the pores of the adsorbent at higher temperature (Bouhamed et al, 2012;Kalavathy and Miranda, 2012).…”

Section: Effect Of Contact Time and Temperaturementioning

confidence: 99%

Comparative biosorption study of Hg (II) using raw and chemically activated almond shell

Taha

Moustafa

Abdel-Rahman

et al. 2017

Adsorption Science & Technology

View full text Add to dashboard Cite

This work presents a comparison between the biosorption of Hg (II) by raw almond shell and activated almond shell. Almond shell based activated carbon has been obtained by physicochemical activation. Batch biosorption results confirmed that, activating condition has a strong influence on the final biosorption process. The biosorbent was characterized using scanning electron microscopy and Fourier transform infrared spectroscopy. To optimize the biosorption conditions pH, adsorbent dose, initial concentration, contact time, stirring speed, and temperature on Hg (II) removal were studied. The optimum conditions for maximum Hg (II) was achieved at 20 and 10 min for raw almond shell and activated almond shell, respectively. The equilibrium data were described well by Langmuir, Freundlich, Dubinin-Radushkevich isotherm models and appling a test of model fitness. Best fit of Langmuir and Freundlich models were found for experimental data, which reveal the homogenous surface of raw almond shell and the heterogeneity of activated almond shell surface. The kinetic data had been divided into either pseudo first order or second order on the basis of the best fit obtained from calculations, confirmed by a test of kinetic validity. An industrial application was examined to improve high biosorption capacity of raw and activated almond shells toward Hg (II).

show abstract

“…The solvents were chosen based on previous studies (Kadirvelu et al 2004;Al Rmalli et al 2008;Dias Filho et al 2008). The experiments were carried out at different concentrations of extractants (0.2-2 M), but for brevity, only the results of the highest concentration are presented in Table 5.…”

Section: Mercury Desorption By Sulfurized Activated Carbonsmentioning

confidence: 99%

“…The presence of mercury in aquatic systems above the allowable limits leads to irreparable risks to the living organisms (Eisler 2006). One of the simple and economically attractive ways to reduce mercury in wastewaters and aqueous systems is adsorption by activated carbons or other adsorbents (Krishnan and Anirudhan 2002b; Kadirvelu et al 2004;Al Rmalli et al 2008;Asasian and Kaghazchi 2013a). Though the removal efficiency of AC is primarily linked to its welldeveloped internal pore structure and total surface area, the chemistry of the surface (the nature and amount of functional groups) is of paramount importance in the removal of ionic or polar species such as mercury ions (Edwin 2008).…”

Section: Introductionmentioning

confidence: 99%

Sulfurized activated carbons and their mercury adsorption/desorption behavior in aqueous phase

Asasian

Kaghazchi

2015

Int. J. Environ. Sci. Technol.

View full text Add to dashboard Cite

Sulfurized activated carbons (SACs) are of the most recent forms of modified sorbents with high affinity toward mercury. The adsorption/desorption behavior of SACs has not been studied in detail in liquid phases. The study was carried out with the aim of recognition of similarities and differences in the properties and performances of SACs and activated carbons (ACs) exposing to aqueous-phase mercury. In this study, three different sulfurizing agents including dimethyl disulfide (DMDS), elemental sulfur (S), and sulfur dioxide (SO 2 ) were tested for AC sulfurization (each under the optimal conditions). Sulfurization with DMDS at room temperature led to the formation of elemental sulfur and sulfide/disulfide on the AC surface; however, sulfurization at higher temperatures with SO 2 and powdered S resulted in the formation of more stable organic forms such as thiophene and oxidized sulfur. The equilibrium mercury adsorption capacity of AC-DMDS was so larger than AC and other SACs. On the other hand, the largest surface area drop and consequently the slowest mercury adsorption rate belonged to this sample. However, AC-S and AC-SO 2 led to moderate increase in mercury equilibrium adsorption capacity; they showed several advantages resulted from their extended porosities and more stable sulfur functionalities. The more accelerated adsorption especially at initial stages of contact in batch modes and negligible entry of sulfur compounds into the treating wastewater were of their important advantages. Mercury desorption was also studied and compared using several acidic and potassium halide solvents. The possibility of applicability of SACs in consecutive mercury adsorption/desorption cycles was also investigated.

show abstract

Biosorption of mercury from aqueous solutions by powdered leaves of castor tree (Ricinus communis L.)

Cited by 76 publications

References 20 publications

Equilibrium, kinetic and thermodynamic biosorption studies of Hg(II) on red algal biomass ofPorphyridium cruentum

Equilibrium, kinetic and thermodynamic biosorption studies of Hg(II) on red algal biomass ofPorphyridium cruentum

Comparative biosorption study of Hg (II) using raw and chemically activated almond shell

Sulfurized activated carbons and their mercury adsorption/desorption behavior in aqueous phase

Contact Info

Product

Resources

About