scispace - formally typeset
Search or ask a question
Journal ArticleDOI

A breakthrough biosorbent in removing heavy metals: Equilibrium, kinetic, thermodynamic and mechanism analyses in a lab-scale study

TL;DR: This novel MMBB can effectively be utilized as an adsorbent to remove heavy metal ions from aqueous solutions and calculated thermodynamic parameters indicated feasible, spontaneous and exothermic biosorption process.
About: This article is published in Science of The Total Environment.The article was published on 2016-01-15 and is currently open access. It has received 125 citations till now. The article focuses on the topics: Biosorption & Adsorption.

Summary (4 min read)

1. Introduction

  • Heavy metals are discharged to aquatic environments from various industries such as paper, textile, plastic, ceramic and cement manufacturing, mining and electronics plating.
  • The significant difference between previous studies and current work is gaining the advantages and also using the biosorptive potentials of various biosorbents in a combination.
  • In addition, thermodynamic parameters were determined for the sorption of all metal ions to explain the process feasibility.

2.1. Preparation of adsorbents and heavy metal-containing effluent

  • All the reagents used for analysis were of analytical reagent grade from Scharlau and Chem-Supply Pty Ltd. .
  • The metal concentration was analyzed by Microwave Plasma-Atomic Emission Spectrometer, MP-AES, (Agilent Technologies, USA).
  • The biosorbents were applied in metal removal process for selecting the best ones in term of biosorption capacity sawdust (SD), sugarcane (SC), corncob (CC), tea waste (TW), apple peel (AP), grape stalk (GS), palm tree skin (PS), eucalyptus leaves (EU), mandarin peel (MP), maple leaves (ML) and garden grass (GG).
  • After using or removing their useable parts, they were washed by tap and distilled water to remove any dirt, color or impurity and then dried in the oven (Labec Laboratory Equipment Pty Ltd., Australia) at 105 °C overnight.

2.2. Biosorption studies in batch system

  • The tests were performed with synthetic multi-metal stock solution with concentration of 3000 mg/L for each metal, prepared by dilution in Milli-Q water.
  • Solution pH was adjusted with 1 M HCl and NaOH solutions.
  • After equilibration, to separate the biomasses from solutions, the solutions were filtered by Whatman™ GF/C-47 mm/circle (GE Healthcare, Buckinghamshire, UK) filter paper and final concentration of metal was measured using MPAES.
  • All the experiments were carried out in duplicates.
  • The statistical analysis was performed by analysis of variance .

2.3. Characterization of adsorbents by FTIR and SEM

  • To determine the functional groups involved in biosorption of Cd(II), Cu(II), Pb(II) and Zn(II) onto MMBB, a comparison between the Fourier Transform Infrared Spectroscopy (FTIR) before and after meal loading was done using Shimadzu FTIR 8400S (Kyoto, Japan).
  • Metal-loaded biosorbent were filtered and dried in the oven.
  • The small amount of samples was placed in the FTIR chamber on the KBr plates for analyzing the functional groups involving in biosorbent process by comparing with unused multi-metal biosorbent.

3.1. Selection of adsorbents

  • Eleven different natural biosorbents, namely sawdust, sugarcane, corncob, tea waste, apple peel, grape stalk, palm tree skin, eucalyptus leaves, mandarin peel, maple leaves and garden grass, individually were compared in regard to the biosorption capacities for Cd(II), Cu(II), Pb(II) and Zn(II) uptake in Fig.
  • The results indicate TW, ML and MP showed satisfying biosorptive capacity for all heavy metal ions (cadmiu , copper, lead and zinc).
  • TW:ML:MP combination was selected to apply for further batch experiments.
  • Apparently, there are no significant differences between the equal proportions of 1:1:1 and the others, especially for lead and copper.
  • This wadespite the fact that ANOVA results for each metal indicated the rejection of the null hypothesis due to P value was less than 0.05.

3.2. Characterization of adsorbents by FTIR

  • The FTIR spectrum of MMBB exhibited a large number of absorption peaks, indicating the complexity in nature of this adsorbent.
  • The shift of some functional groups bands and their intensity significantly changed after heavy metal biosorption (Table 1).
  • These shifts may be attributed to carboxylic (C O) and hydroxylic (O–H) groups on the MMBB's surface.

3.3. SEM analysis

  • From Table 1, SEM depicts the morphology changes of unloaded and loaded biosorbent.
  • After biosorption of heavy metal ions, the surface became smoother with less porosity with probable metal entrapping and adsorbing on biosorbent.
  • The SEM/EDS was reported in previous study (Abdolali et al., 2015).

3.4.1. Influence of pH

  • The initial pH values above 5.5 are not preferable du to the observed presence of metal hydroxide precipitation, so as the experiments were not conducted beyond pH 5.5.
  • The results indicated that the optimum pH value was 5.5 for all metals.

3.4.2. Influence of contact time

  • It is evident from Fig. 3(b) that the rate of metal uptake was very fast within first 30 min as a result of the exuberant number of available active sit s on adsorbent surfaces and then decreased until equilibrium was reached.
  • Biosorption capacity leveled off at equilibrium state within 180 min.
  • Therefore, the biosorption time was set to 180 min in each experiment.

3.4.3. Influence of adsorbent dose

  • Biosorption capacity was also affected by biosorptin dose and amount of available active sites and this effect is shown in Fig. 3(c).
  • The experimental results indicate that the percentage removal of all metal ions on MMBB represents an equilibrium pattern for biosorbent amounts of 5 g/L and more.
  • Furthermore, the removal efficien y decreased by increasing initial metal ion solution with similar trends.

3.4.4. Effect of biosorbent particle size

  • The effect of particle size of biosorbent was conducted for 5 g/L adsorbent dose and an initial concentration of 50 mg/L.
  • It was found that biosorpti n capacity did not significantly change by varying particle sizes.
  • The reason was that these particle size distributions were very small (less than 300 µm).
  • The smaller biosorbent size exhibits better performance in regard with metal removal due to a higher surface area for metal adsorption; however the mechanical stability reduces particularly in column (Liu et al., 2012).

3.5. Adsorption kinetics

  • A kinetic investigation was carried out to quantify the adsorption rate controlling steps in Cd(II), Cu(II), Pb(II) and Zn(II) uptake on MMBB.
  • The pseudo-first-order kinetic model known as the Lagergren equation and takes the form as: (2) where, qt and qe are the metal adsorbed at time t and equilibrium, respectively, and K1 (min− 1) is the first-order reaction rate equilibrium constant.
  • The experimental data and obtained parameters of these models were measured by MATLAB® and summarized in Table 2.
  • As shown in Table 2, with comparison between adsorption rate constants, the estimated q and the coefficients of correlation associated with the Lagergren pseudo-first-order and the pseudo-secnd-order kinetic models at room temperature for MMBB, it is obvious that both kinetic models well described all metal biosorption.
  • The coefficients of correlation (R2) of pseudo-second-order kinetic model were slightly larger than those of pseudo-first-order kinetic model for Cu in all initial concentrations.

3.6. Adsorption isotherm

  • The correlation between the adsorbed and the aqueous metal concentrations at equilibrium has been described by the Langmuir, Freundlich, Dubinin–Radushkevich, Sips, Redlich– Peterson and Khan adsorption isotherm models.
  • Furthermore, residual root mean square error (RMSE), error sum of square (SSE) and correlation of determination (R2) were used to measure the exactness of fitting.
  • Among three-parameter isotherm models, for Cu(II) and Zn(II), Khan isotherm describes biosorption conditions moderately better than Sips and Redlich–Peterson models, while for Cd(II) and Pb(II), the Sips model was found to provide the best correlation of the biosorption equilibrium data.
  • Various kinds of agro-industrial wastes and by-products were studied for heavy metal removal.
  • A comparison between maximum adsorptive capa ities of MMBB and some other adsorbents is shown in Table 4.

3.7. Biosorption mechanism

  • The main mechanisms known for metal sorption on ligocellulosic biosorbents are chelating, ion exchanging and making complexion with functional groups and releasing [H3O] + into aqueous solution.
  • Ionic exchange is known as a mechanism which involves electrostatic interaction between positive metallic cations and the negatively charged groups in the cell walls.
  • On the other hand, many characterization studies confirmed that ion exchange mechanism was included in heavy metal biosorption process rather than complexation with functional groups on the biosorbent surface and also showed the role of sodium, potassium, calcium and magnesium present in the adsorbent in ion exchange mechanism (Ding et al., 2012 and Akar et al., 2012).
  • In addition, the mean free energy of adsorption calcul ted from Dubinin– Radushkevich isotherm can evaluate sorption properties and main mechanism.
  • With respect to kinetic modeling, it also established that metal uptake by the micro-organisms takes place in two consecutive stages: a passive and quick uptake that follows by an active and very slow uptake.

3.8. Adsorption thermodynamics

  • The experimental results indicated dependency of adsorption on the temperature and are listed in Table 5.
  • The Gibbs free energy indicates the degree of spontaneity of sorption process, and the higher negative value reflects a more energetically favorable sorption.
  • ∆H° and ∆S° were obtained from the slop and intercept of the Van't Hoff plots (Fig. 5).
  • I addition, the low value of ∆S° may imply that no remarkable change in entropy occurred during the sorption of Cd, Cu, Pb and Zn ions on MMBB.

4. Conclusions

  • The present work explores a new economical and selective lignocellulosic biosorbent containing tea waste, maple leaves and mandarin peels as an alternative to costly adsorbents for the removal of Cd(II), Cu(II), Pb(II) and Zn(II) ions.
  • The low cost, rapid attainment of phase equilibrium (within 3 h) and high sorption capacity values may be cited among the main advantages.
  • Adsorption kinetics follows a pseudo-second-order kinetic model and negative values of ∆H° and ∆G° prove the exothermic and spontaneous nature of the biosorption phenomenon.
  • Hence, this novel MMBB can be a promising adsorbent to eliminate heavy metal ions from aqueous solutions.

Did you find this useful? Give us your feedback

Citations
More filters
Journal ArticleDOI
TL;DR: In this article, the development and exploration of low-cost, promising adsorbents to remove contaminants in water bodies cause potential health risks for humans and great environmental threats, and therefore, the research and development of low cost, promising adorbents is needed.
Abstract: Contaminants in water bodies cause potential health risks for humans and great environmental threats. Therefore, the development and exploration of low-cost, promising adsorbents to remove ...

67 citations


Cites background from "A breakthrough biosorbent in removi..."

  • ...In addition, Ngah and Hanafiah (2008) proposed that ion exchange is primarily responsible for Cu(II) biosorption onto NaOHtreated rubber leaves because (1) the E value was 8.8 kJ/mol and (2) the ratio of adsorbed cations (Cu2þ) to cations (Hþ, Naþ, Ca2þ, and Mg2þ) released from the leaves was almost unity....

    [...]

  • ...In general, if electrostatic attraction is mainly responsible for the adsorption of cationic adsorbates (i.e., Cu2þ), the adsorption process is highly reversible when pure water at a low pH value (often pH 2.0) is used as the desorbing agent....

    [...]

  • ...…> Cd(II) (Chojnacka et al., 2005), Cu(II) > Zn(II) > Cd(II) (Yu et al., 2015), Cu(II) > Ni(II) > Pb(II) (Salehi, Asghari, & Mohammadi, 2008), Cu(II) > Zn(II) > Pb(II) > Cd(II) (Abdolali et al., 2016), and Cu(II) > Co(II) > Ni(II) > Cr(III) > Zn(II) > Cd(II) > Pb(II) (Batool, Iqbal, & Akbar, 2017)....

    [...]

  • ...Furthermore, for the multi-adsorbate system (Pb2þ, Cd2þ, Ni2þ, and Cu2þ), Abdolali et al. (2016) reported that the total amounts of adsorbed heavy metal ions (1.43mmol/L) and exchanged alkali ions (1.51mmol/L) were approximately equal....

    [...]

  • ...Conversely, Lin, Zhan, and Zhu (2011) examined the removal behavior of Cu2þ ions by humic acid-immobilized surfactant-modified zeolite, concluding that the adsorption process was chemisorption (Ea ¼ 63....

    [...]

Journal ArticleDOI
TL;DR: In this article, a low-cost anion adsorbent for Cr(VI) effectively removing was synthesized by hyperbranched polyamide modified corncob (HPMC).

63 citations

Journal ArticleDOI
TL;DR: The preparation of hierarchically nanostructured shuriken like bismuth vanadate (BiVO4) as a bifunctional catalyst for photocatalytic degradation and electrochemical detection of highly toxic hexavalent chromium (Cr(VI) using the green deep eutectic solvent reline, which allows morphology control in one of the less energy-intensive routes.

57 citations

Journal ArticleDOI
TL;DR: In this article, a review compiles different adsorption kinetics and isotherms models and also presents their origins, modified versions, and their applicability in the liquid adaption situation.
Abstract: Cadmium (Cd) and lead (Pb) contaminations are disturbing environmental issues, which causes serious harm to aqueous systems and human health. Therefore, removing them from aqueous solution is essential to prevent its damage to the environment. Environmental adsorption research as one solution has seen a boom over the past decade. Using modified biochar has proved to be more suitable for the adsorption of cadmium and lead. Most of the studies apply a routine method such as kinetic and isotherm modelling to demonstrate the macroscopic trend of adsorption, often without elaborative evaluation of the effectiveness and characteristics of the models. This review compiles different adsorption kinetics and isotherms models and also presents their origins, modified versions, and their applicability in the liquid adsorption situation. The effect of experimental parameters and adsorption mechanisms are discussed to study the adsorption performances of modified biochar. The adsorption mechanism was majorly by surface precipitation, ion exchange, electrostatic attraction, complexation and physical adsorption. The adsorption was majorly endothermic and spontaneous. Additionally, preparation and regeneration of modified biochar are also presented to provide a direction for sustainable improvement. This paper summarizes with a note on challenges, prospects and future perspectives of adsorption of cadmium and lead pollutions.

54 citations

Journal ArticleDOI
TL;DR: In this article, three low-cost adsorbents (purified raw attapulgite (A-ATP), high-temperature-calcined ATP, and hydrothermal loading of MgO) were prepared as adsorbent for the removal of Cd(II) and Pb(II), by evaluating the effect of the initial solution pH, contact time, initial solution concentration, temperature and coexistence of metal ions.

53 citations

References
More filters
Journal ArticleDOI
TL;DR: It is evident from the literature survey articles that ion-exchange, adsorption and membrane filtration are the most frequently studied for the treatment of heavy metal wastewater.

6,844 citations


"A breakthrough biosorbent in removi..." refers background in this paper

  • ...chemical precipitation, extraction, ion exchange, filtration, reverse osmosis, membrane bioreactor and electrochemical techniques) (Santos et al., 2015; Abdolali et al., 2014a; Montazer-Rahmati et al., 2011; Fu and Wang, 2011)....

    [...]

  • ...…a wide range of treatment technologies are employed in industry (e.g. chemical precipitation, extraction, ion exchange, filtration, reverse osmosis, membrane bioreactor and electrochemical techniques) (Santos et al., 2015; Abdolali et al., 2014a; Montazer-Rahmati et al., 2011; Fu and Wang, 2011)....

    [...]

Journal ArticleDOI
TL;DR: Distinctive adsorption equilibria and kinetic models are of extensive use in explaining the biosorption of heavy metals, denoting the need to highlight and summarize their essential issues, which is the main purpose of this paper.

1,471 citations

Journal ArticleDOI
TL;DR: In this article, the authors provided the scattered available information on various aspects of utilization of the agricultural waste materials for heavy metal removal, which can be exploited for high efficiency and multiple reuse to enhance their applicability at industrial scale.

1,322 citations

01 Jan 2008
TL;DR: Biosorption is emerging as a potential alternative to the existing conventional technologies for the removal and/or recovery of metal ions from aqueous solutions for heavy metal remediation.
Abstract: Heavy metal remediation of aqueous streams is of special concern due to recalcitrant and persistency of heavy metals in environment. Conventional treatment technologies for the removal of these toxic heavy metals are not economical and further generate huge quantity of toxic chemical sludge. Biosorption is emerging as a potential alternative to the existing conventional technologies for the removal and/or recovery of metal ions from aqueous solutions. The major advantages of biosorption over conventional treatment methods include: low cost, high efficiency, minimization of chemical or biological sludge, regeneration of biosorbents and possibility of metal recovery. Cellulosic agricultural waste materials are an abundant source for significant metal biosorption. The functional groups present in agricultural waste biomass viz. acetamido, alcoholic, carbonyl, phenolic, amido, amino, sulphydryl groups etc. have affinity for heavy metal ions to form metal complexes or chelates. The mechanism of biosorption process includes chemisorption, complexation, adsorption on surface, diffusion through pores and ion exchange etc. The purpose of this review article is to provide the scattered available information on various aspects of utilization of the agricultural waste materials for heavy metal removal. Agricultural waste material being highly efficient, low cost and renewable source of biomass can be exploited for heavy metal remediation. Further these biosorbents can be modified for better efficiency and multiple reuses to enhance their applicability at industrial scale.

1,245 citations


"A breakthrough biosorbent in removi..." refers background in this paper

  • ...Nonetheless, these methods are not effective enough in low concentrations and might be very expensive as a result of high chemical reagent and energy requirements, aswell as the disposal problem of toxic secondary sludge (Bulut and Tez, 2007; Sud et al., 2008)....

    [...]

Journal ArticleDOI
TL;DR: Biosorption is a physico-chemical process and includes such mechanisms as absorption, adsorption, ion exchange, surface complexation and precipitation as discussed by the authors, which has been heralded as a promising biotechnology for pollutant removal from solution, and/or pollutant recovery.
Abstract: Biosorption may be simply defined as the removal of substances from solution by biological material. Such substances can be organic and inorganic, and in gaseous, soluble or insoluble forms. Biosorption is a physico-chemical process and includes such mechanisms as absorption, adsorption, ion exchange, surface complexation and precipitation. Biosorption is a property of both living and dead organisms (and their components) and has been heralded as a promising biotechnology for pollutant removal from solution, and/or pollutant recovery, for a number of years, because of its efficiency, simplicity, analogous operation to conventional ion exchange technology, and availability of biomass. Most biosorption studies have carried out on microbial systems, chiefly bacteria, microalgae and fungi, and with toxic metals and radionuclides, including actinides like uranium and thorium. However, practically all biological material has an affinity for metal species and a considerable amount of other research exists with macroalgae (seaweeds) as well as plant and animal biomass, waste organic sludges, and many other wastes or derived bio-products. While most biosorption research concerns metals and related substances, including radionuclides, the term is now applied to particulates and all manner of organic substances as well. However, despite continuing dramatic increases in published research on biosorption, there has been little or no exploitation in an industrial context. This article critically reviews aspects of biosorption research regarding the benefits, disadvantages, and future potential of biosorption as an industrial process, the rationale, scope and scientific value of biosorption research, and the significance of biosorption in other waste treatment processes and in the environment. Copyright © 2008 Society of Chemical Industry

1,063 citations


"A breakthrough biosorbent in removi..." refers background in this paper

  • ...…many researchers into this matter in recent decades (Abdolali et al., 2014b; Tang et al., 2013; Fu et al., 2013; Kumar et al., 2012; Hossain et al., 2012; Witek-Krowiak et al., 2011; Gadd, 2009; Volesky, 2007; Šćiban et al., 2007) to use cheap agro-industrial wastes and by-products as biosorbents....

    [...]

  • ...Therefore, introducing a properly eco-friendly and cost effective technology for wastewater treatment has provoked many researchers into this matter in recent decades (Abdolali et al., 2014b; Tang et al., 2013; Fu et al., 2013; Kumar et al., 2012; Hossain et al., 2012; Witek-Krowiak et al., 2011; Gadd, 2009; Volesky, 2007; Šćiban et al., 2007) to use cheap agro-industrial wastes and by-products as biosorbents....

    [...]

Frequently Asked Questions (1)
Q1. What have the authors contributed in "A breakthrough biosorbent in removing heavy metals: equilibrium, kinetic, thermodynamic and mechanism analyses in a lab-scale study" ?

For Cu ( II ) and Zn ( II ), the Khan isotherm describes better biosorption conditions while for Cd ( II ) and Pb ( II ), the Sips model was found to provide the best correlation of the biosorption equilibrium data.