Comparative study of adsorptive removal of Cr(VI) ion from aqueous solution in fixed bed column by peanut shell and almond shell using empirical models and ANN
10 Mar 2017-Environmental Science and Pollution Research (Springer Berlin Heidelberg)-Vol. 24, Iss: 11, pp 10604-10620
TL;DR: These adsorbents have an excellent potential and are useful for water treatment particularly small- and medium-sized industries of third world countries, as breakthrough time and exhaustion time are longer in comparison to peanut shell.
Abstract: Cr(VI) is a toxic water pollutant, which causes cancer and mutation in living organisms. Adsorption has become the most preferred method for removal of Cr(VI) due to its high efficiency and low cost. Peanut and almond shells were used as adsorbents in downflow fixed bed continuous column operation for Cr(VI) removal. The experiments were carried out to scrutinise the adsorptive capacity of the peanut shells and almond shells, as well as to find out the effect of various operating parameters such as column bed depth (5–10 cm), influent flow rate (10–22 ml min−1) and influent Cr(VI) concentration (10–20 mg L−1) on the Cr(VI) removal. The fixed bed column operation for Cr(VI) adsorption the equilibrium was illustrated by Langmuir isotherm. Different well-known mathematical models were applied to the experimental data to identify the best-fitted model to explain the bed dynamics. Prediction of the bed dynamics by Yan et al. model was found to be satisfactory. Applicability of artificial neural network (ANN) modelling is also reported. An ANN modelling of multilayer perceptron with gradient descent and Levenberg-Marquardt algorithms have also been tried to predict the percentage removal of Cr(VI). This study indicates that these adsorbents have an excellent potential and are useful for water treatment particularly small- and medium-sized industries of third world countries. Almond shell represents better adsorptive capacity as breakthrough time and exhaustion time are longer in comparison to peanut shell.
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TL;DR: In this paper, the authors reviewed the research undertaken on the production and application of activated carbon as an adsorbent from olive stones for wastewater treatment, and the future prospects of these materials as adsorbents were discussed.
Abstract: Olive stones have been widely used as a renewable energy biowaste source. As they are rich in elemental carbon (40–45 wt%), much research focussed on effectively converting olive stones, as precursors, into activated carbon adsorbents. However, only a few studies have concentrated on summarising the various techniques used to produce activated carbon from olive stone. This article reviews the research undertaken on the production and application of activated carbon as an adsorbent from olive stones for wastewater treatment. Various physical, chemical and physico-chemical treatments to remove heavy metals, organics and dyes are discussed, and the resultant adsorption capacities are reported. In several cases, very high adsorption capacities are recorded. Finally, the future prospects of these materials as adsorbents are discussed, and after further development work, olive stone-derived activated carbons have great potential especially in the area of organic polluted wastewaters.
263 citations
TL;DR: The results indicated the potential practical application of PANI@AS biocomposite for wastewater treatment as it could be regenerated easily with NaOH solution and efficiently reused for Cr(VI) and OG dye removal from aqueous media.
Abstract: A novel polyaniline@Almond shell (PANI@AS) biocomposite was synthesized via facile in situ chemical polymerization method. The as-synthesized adsorbent was characterized using various analytical techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), and potentiometric titration. A batch adsorption system was applied with the aim of investigating as-synthesized adsorbent ability to remove Cr(VI) ions and Orange G (OG) textile dye from aqueous solutions. Obtained results revealed that adsorption process was strongly depended upon the physicochemical parameters. The adsorption of Cr(VI) and OG dye onto PANI@AS was better described by the pseudo second-order-kinetic model and followed the Freundlich isotherm model. The maximum uptakes were 335.25 for Cr(VI) and 190.98 mg g−1 for OG dye. We further evaluated that PANI@AS biocomposite could be regenerated easily with NaOH solution and efficiently reused for Cr(VI) and OG dye removal from aqueous media. Thus, these results indicated the potential practical application of PANI@AS biocomposite for wastewater treatment.
91 citations
TL;DR: In this paper, a scale-up design for Cr(VI) removal using walnut shell as an adsorbent and its economic feasibility are done to find out its applicability in real life.
90 citations
TL;DR: In this paper, a 3D self-assembled peanut hull/graphene aerogels (3D-PG) was used to prepared three-dimensional self-assembling peanut hull and GOPs in a very simple, green and low-cost way, successfully making use of agricultural waste as well as achieving base-induced one-step synthesis of 3DPG for oil-water separation.
83 citations
TL;DR: In this article, a study was performed in fixed bed downflow columns at multiple flow rates, bed depths, and influent concentrations for Cr(VI) elimination using the above green adsorbents.
39 citations
References
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Book•
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TL;DR: The most widely read reference in the water industry, Water Industry Reference as discussed by the authors, is a comprehensive reference tool for water analysis methods that covers all aspects of USEPA-approved water analysis.
Abstract: Set your standards with these standard methods. This is it: the most widely read publication in the water industry, your all-inclusive reference tool. This comprehensive reference covers all aspects of USEPA-approved water analysis methods. More than 400 methods - all detailed step-by-step; 8 vibrant, full-color pages of aquatic algae illustrations; Never-before-seen figures that will help users with toxicity testing and the identification of apparatus used in the methods; Over 300 superbly illustrated figures; A new analytical tool for a number of inorganic nonmetals; Improved coverage of data evaluation, sample preservation, and reagant water; And much more!
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TL;DR: In this article, the absorption index at the wave length of the band maximum was found to be proportional to the total concentration of metal at shorter wave lengths, however, deviations were observed, the absorption increasing more rapidly with concentration than Beers' law would demand.
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"Comparative study of adsorptive rem..." refers methods in this paper
...The Langmuir isotherm model (Langmuir 1918) is as follows:...
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...The Langmuir isotherm model (Langmuir 1918) is as follows: qexp ¼ qmaxKLCeq 1þ KLCeq ð8Þ where Ceq is defined by the following equation: Ceq ¼ mtotal−qtotalVeff ð9Þ The sorption capacity of Cr(VI) ion onto peanut shell and almond shell in fixed bed column is defined by the following equation. qexp…...
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TL;DR: This review provides an analysis of arsenic, cadmium, chromium, lead, and mercury's environmental occurrence, production and use, potential for human exposure, and molecular mechanisms of toxicity, genotoxicity, and carcinogenicity.
Abstract: Heavy metals are naturally occurring elements that have a high atomic weight and a density at least five times greater than that of water. Their multiple industrial, domestic, agricultural, medical, and technological applications have led to their wide distribution in the environment, raising concerns over their potential effects on human health and the environment. Their toxicity depends on several factors including the dose, route of exposure, and chemical species, as well as the age, gender, genetics, and nutritional status of exposed individuals. Because of their high degree of toxicity, arsenic, cadmium, chromium, lead, and mercury rank among the priority metals that are of public health significance. These metallic elements are considered systemic toxicants that are known to induce multiple organ damage, even at lower levels of exposure. They are also classified as human carcinogens (known or probable) according to the US Environmental Protection Agency and the International Agency for Research on Cancer. This review provides an analysis of their environmental occurrence, production and use, potential for human exposure, and molecular mechanisms of toxicity, genotoxicity, and carcinogenicity.
4,407 citations
"Comparative study of adsorptive rem..." refers background in this paper
...The wastewater discharge from industries like smelting plant, metal plating industries, leather tanning, textile dyeing, batteries, fertilisers, mining, galvanising, paints, pigments, etc. contain different heavy metals (Bhattacharyya et al. 2008; Tchounwou et al. 2012)....
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"Comparative study of adsorptive rem..." refers methods in this paper
...Thomas model (Thomas 1944) is one of the widely used models....
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982 citations
"Comparative study of adsorptive rem..." refers methods in this paper
...Bohart-Adams (Bohart and Adams 1920) model was developed considering the surface reaction theory which assumes that the equilibrium is not instantaneous, and the rate of adsorption is proportional to the adsorption capacity and the concentration of adsorbing metal ion....
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