scholarly journals Sherry wine industry by-product as potential biosorbent for the removal of Cr(VI) from aqueous medium

Author(s):  
L. Sánchez-Ponce ◽  
M. D. Granado-Castro ◽  
M. J. Casanueva-Marenco ◽  
M. D. Galindo-Riaño ◽  
M. Díaz-de-Alba

AbstractA low-cost biosorbent obtained from the Palomino Fino grape seed, a Sherry wine industry by-product, has been proposed as a way of valorising this material. The biomass was characterised obtaining values of 0.68 ± 0.05 g mL−1 for bulk density, 1.02 ± 0.09 g mL−1 for apparent density and 33.3% for porosity. The pHpzc was 5.2 and the surface negative charge value was 2.4 ± 0.2 mmol g−1. The analysis of surface morphology showed differences due to the sorption. The results showed a promising potential for chromium(VI) removal from aqueous solutions. The studies were carried out in batch scale and a 23 factorial design was applied for the optimisation of the process. A percentage of 91.7 ± 0.6% was achieved for the biosorption of Cr(VI) under optimal conditions using pH 5.5, 15 g/L of biosorbent and 8 h of contact time. The biosorption capacity showed a remarkable linearity from 0 to 2 mmol L−1 Cr(VI) and a precision of 0.64% for the removal of 1 mmol L−1 of metal. Langmuir, Freundlich and Temkin isotherm equations and the parameters of six kinetic models were used in the equilibrium modelling and identifying the mechanism of the biosorption. The combination of physical and chemical sorption mechanisms was proposed for the chromium removal with a high maximum sorption capacity (qmax = 208.3 mg g−1). Thermodynamic parameters indicated the spontaneous and endothermic nature of the chromium removal. The successful biosorption was based on the special grape seed components with a relevant content in antioxidant and lignocellulosic compounds.

2017 ◽  
Vol 19 (1) ◽  
pp. 107-114 ◽  

<p>In last decades the search for new low cost sorbents that have heavy metal ions binding capabilities is a hot topic in the field of clean-up technologies. In this study,&nbsp; wastes of&nbsp; Romanian silver tree (<em>Abies alba)</em> bark&nbsp; were explored for first time as green and economical sorbent for the removal of Cd(II) ions from aqueous solutions.&nbsp; The effect of various experimental parameters such as initial solution pH, sorbent dose, initial Cd(II) concentration, temperature and contact time has been investigated under batch conditions.&nbsp;</p> <p>The Langmuir and Freundlich models were used to describe the equilibrium isotherms and both models have been fitted very well. According to the evaluation using the Langmuir equation, the maximum sorption capacity of Cd (II) ions on <em>Abies alba</em> bark waste was found to be 11.98<br /> mg g<sup>-1</sup> at 293 K. The thermodynamic parameters showed that the process of Cd(II) sorption on silver fir tree bark was feasible, spontaneous and endothermic. Kinetic data were properly fitted with the pseudo–second order model. The obtained results strongly suggest that Romanian silver tree (<em>Abies alba)</em> bark is eligible as an efficient sorbent for the decontamination of toxic metals from wastewaters.</p>


Foods ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 79
Author(s):  
Berta Baca-Bocanegra ◽  
Julio Nogales-Bueno ◽  
José Miguel Hernández-Hierro ◽  
Francisco José Heredia

After grape processing, large amounts of seeds are produced as a side product. Grape seeds are rich in proteins that could be extracted and revalorized by the wine industry due to their high techno-functional value for modulating quality features of red wines or as an alternative to the use of other stabilizers, which are also proteins but submitted to legal restrictions. Box–Behnken design and response surface methodology were used to optimize the protein extraction from defatted grape seed meal to maximize the protein purity of the isolate under practical operating conditions of pH, temperature, meal/water ratio and extraction time. The most significant factor was pH, both in the linear and quadratic forms. Additionally, the interaction between pH and temperature exhibited a significant effect on protein content. The removal of phenolic compounds from grapeseed meal, before optimizing protein extraction, led to a significant increase of 7.70% in the protein purity of grape seed protein concentrate. Therefore, grape seeds can be used as a sustainable way for protein production in the oenological sector due to the availability of grape seeds, their low cost as a grape-processing by-product, and the protein purity reached thanks to the described procedure for optimization of protein extraction.


Author(s):  
O. V. Rybarchuk ◽  
V. I. Dudarev ◽  
G. N. Dudareva

Chromium is one of the most effective metals used for protection and decorative coating of various products. However, chrome plating typically occurs in a strongly acid medium, thus involving the formation of dangerous and corrosive solutions. In this article, we investigate the possibility of removing chromium from such solutions using carbon adsorbents, which allow for almost complete extraction of the metal from production solutions up to a residual content of no more than 0.05 mg/dm3. A significant advantage of carbon adsorbents is their ability to extract chromium (VI) ions without chromium reduction to the trivalent state. It was established that the sorbent under study exhibits the maximum sorption capacity in a strongly acidic medium at pH = 1.2–2.5. This medium causes the formation of a Cr2O7 2- dimer in the solution, which is an adsorbed ion. A scheme of a production unit for chromium adsorption from solutions of electrochemical production was proposed. The choice of an adsorber with a fluidized bed was determined by the maximal interaction of the flow with the adsorbent in such reactors. The adsorber design in the form of a cylindrical column with tapered upper and lower parts assumes installation of distribution grids inside the apparatus. It is proposed to forward the chromium-containing solution of electrochemical production remained after the averaging tank directly to the adsorber with the loading of the carbon adsorbent. In order to ensure the continuity of the extraction mode, it is necessary to apply two parallel working adsorbers, whose technical parameters were calculated to be as follows: the diameter of 1.2 m; the height of 7.5 m; the loading volume of 5.9 m3; and the loading height of 6 m. The calculated process parameters were determined: the linear flow rate along the walls of the adsorber – 12.75 m/h; the duration of the apparatus operation before coal regeneration – 21 days. The proposed scheme can be recommended for recycling water supply.


2020 ◽  
Vol 16 ◽  
Author(s):  
Vedat Tolga Özdemir ◽  
Himmet Mert Tuğaç ◽  
Özgür Arar

Background: Cellulose is one of the most abundant, non-toxic, and renewable natural biopolymers. The presence of hydroxyl groups in cellulose leads to further modification of it. Preparation and modification of cellulose-based sorbents and their applications on water treatment gained traction in recent years. Objective: A low-cost and eco-friendly biosorbent was designed and fabricated by introducing the acetate functional groups into cellulose for removing Beryllium (Be2+) from an aqueous solution. The so rption of Be2+ on acetate containing cellulose was evaluated for varying sorbent doses and initial solution pH values. Method: The sorbent was prepared by a two-step oxidation process. In the initial step, cellulose reacted with NaIO4 and aldehyde groups were introduced to cellulose. In the second step, newly obtained aldehyde groups were oxidized to create acetate groups. Results: The kinetics of the sorption process showed that Be2+ uptake reached equilibrium in 3 minutes. The sorption isotherm was well fitted in the Langmuir model, and maximum sorption capacity was 4.54 mg/g. Moreover, the thermodynamic studies demonstrated that Be2+ sorption is spontaneous and exothermic. Furthermore, the prepared sorbent can be regenerated by using 0.1 M HCl or H2SO4 solutions. Conclusion: Removal of Be2+ is pH dependent and it is favorable at high solution pH. The kinetics of the prepared sorbent is rapid and equilibrium attained in 3 minutes. The prepared sorbent can be regenerated with 0.1 M acid solution with > 99% efficiency.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Dyan Hatining Ayu Sudarni ◽  
Uyiosa Osagie Aigbe ◽  
Kingsley Eghonghon Ukhurebor ◽  
Robert Birundu Onyancha ◽  
Heri Septya Kusuma ◽  
...  

Although several approaches have been explored for the removal of dyes and other toxic materials from water as well as the entire environment, notwithstanding, researchers/scientists are still pursuing novel, low-cost, and eco-friendly biosorbents for the effective removal of such contaminants. Herein, clove leaves (CL) were utilized as a biosorbent for the sequestration of malachite green (MG) from a water-soluble solution. The CL was subsequently activated using potassium hydroxide (KOH) and characterized using the FTIR and FESEM to determine the functional groups on the activated clove leaves (CL-KOH) and the morphology of the adsorbent. The adsorption of MG was observed to be relatively dependent on the dosage of sorbent utilized, initial MG concentration, and sorption process contact time. The adsorption process of MG to CL was ideally described using the Dubinin–Radushkevich and Elovich models with the determination of maximum sorption capacity of approximately 131.6 mg·g-1. Furthermore, the thermodynamic parameters calculated showed that the adsorption of MG to the adsorbent was exothermic with the process involving physical sorption as well as chemical sorption processes with negligible adsorption energy. In conclusion, the study has revealed that the CL is a cost-effective biosorbent with high adsorption efficiency for the sequestration of MG from a water-soluble solution and can be recycled for further usage.


2014 ◽  
Vol 804 ◽  
pp. 59-62
Author(s):  
Lian Ai ◽  
Xue Gang Luo ◽  
Xiao Yan Lin

Low cost agricultural by-products are potential materials for water pollution treatment such as removal of radionuclide. This paper deals with removal of strontium ions from aqueous solution using sunflower stem (SFS) and leaf (SFL). Batch sorption experiments were performed as a function of initial solution pH, adsorbent dosage and initial strontium (II) concentration. The removal efficiency of strontium (II) increased with initial pH and achieved maximum values at a pH range of 4.0-7.0 both for SFS and SFL. The isotherm adsorption data was modeled best by the nonlinear Langmuir-Freundlich equation. The maximum sorption capacity of SFS and SFL were observed to be 17.87 and 22.31 mg/g under optimal conditions, respectively.


2019 ◽  
Vol 26 (4) ◽  
pp. 743-757
Author(s):  
Michaela Tokarčíková ◽  
Jana Seidlerová ◽  
Oldřich Motyka ◽  
Mirka Šafaříková

Abstract Biochar produced from fermentation residue of maize hybrid was used in untreated form as a sorbent for the removal of Cd(II), Pb(II) and Zn(II) from aqueous solution. The capability of biochar to immobilized ions was investigated by leaching test. Equilibrium between biochar sample and studied elements in solution was reached at a contact time 30 min for Zn(II) and 90 min for Pb(II) and Cd(II). The experimental data were described by pseudofirst-order and pseudo-second-order kinetic model, two- and three-parameter isotherms in non-linear form. The maximum sorption capacity achieved was 30.07 mg·g−1 in the case of Cd(II) ions, 99.44 mg·g−1 in the case of Pb(II) and 40.18 in the case of Zn(II). Biochar developed for this study is comparable to conventional biochar, low cost, non-toxic and experimental results show that is a suitable and efficient sorbent for Cd(II), Pb(II) and Zn(II) removal from aqueous solutions.


2016 ◽  
Vol 81 (11) ◽  
pp. 1321-1333
Author(s):  
Sofia Sarri ◽  
Panagiotis Misaelides ◽  
Dimitrios Zamboulis ◽  
Fotini Noli ◽  
Jolanta Warchoł ◽  
...  

The ability of a synthesized polyethylenimine - epichlorohydrin resin to remove Cr(VI) from aqueous solutions was investigated in absence (initial pH 2 to 7) and presence of background electrolytes (NaNO3 and Na2SO4 solutions of initial pH 3 and 6). The determined Cr-uptake was significantly higher than the one reported for the majority of other sorbents. The photo-metrically determined uptake data were modeled by the Langmuir, Redlich-Peterson, Langmuir-Freundlich, and Toth equations. The modeling results did not point out any preference to one specific model in terms of the goodness-of-fit and the prediction of maximum sorption capacity. The Cr-sorption kinetics was investigated at 15, 25, 35 and 45 oC using 51Cr-labeled solutions and ?-ray spectroscopy. The Cr-sorption was very fast at all studied temperatures and well reproduced by the pseudo-second order kinetics equation. Rate constant and activation energy values were calculated using the experimental data. The Cr-loaded resin was also examined by XRD, XPS, XAFS and SEM/EDS. The XPS and XAFS investigations indicated a partial reduction of Cr(VI) to Cr(III). The environmental compatibility of the Cr-loaded resin was examined using the EPA-TCLP method. The Cr-binding by the resin was very stable and regeneration attempts by HCl solutions of pH 3 were rather unsuccessful.


2016 ◽  
Vol 74 (4) ◽  
pp. 914-926 ◽  
Author(s):  
Gulay Bayramoglu ◽  
Aydin Akbulut ◽  
M. Yakup Arica

Chemical modification of Spirulina platensis biomass was realized by sequential treatment of algal surface with epichlorohydrin and aminopyridine. Adsorptive properties of Cr(VI) ions on native and aminopyridine modified algal biomass were investigated by varying pH, contact time, ionic strength, initial Cr(VI) concentration, and temperature. FTIR and analytical analysis indicated that carboxyl and amino groups were the major functional groups for Cr(VI) ions adsorption. The optimum adsorption was observed at pH 3.0 for native and modified algal biomasses. The adsorption capacity was found to be 79.6 and 158.7 mg g−1, for native and modified algal biomasses, respectively. For continuous system studies, the experiments were conducted to study the effect of important design parameters such as flow rate and initial concentration of metal ions, and the maximum sorption capacity was observed at a flow rate of 50 mL h−1, and Cr(VI) ions concentration 200 mg L−1 with modified biomass. Experimental data fitted a pseudo-second-order equation. The regeneration performance was observed to be 89.6% and 94.3% for native and modified algal biomass, respectively.


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