Removal of Cr(VI) and Cu(II) ions from aqueous solution by rice husk ash—column studies
TL;DR: In this paper, the technical feasibility of rice husk ash for adsorptive removal of Cr(VI) and Cu(II) is examined in packed bed from aqueous solutions.
Abstract: In this present study, the technical feasibility of rice husk ash for adsorptive removal of Cr(VI) and Cu(II) is examined in packed bed from aqueous solutions. The effects of different operating parameters such as height of the packed bed column (5–15 cm), flow rate of aqueous metal ion solution (10–30 ml min−1), and initial metal ion concentration (10–30 mg L−1) were studied. Capacity of the bed to absorb metal ions was found to increase with an increase in bed height, decrease in flow rate, and metal ion concentration. Adams–Bohart, Yoon–Nelson, and Thomas models were applied to the experimental data for the prediction of breakthrough point and also to determine the model parameters to characterize the column. The Yoon–Nelson model and Thomas model were applicable for Cr(VI) removal, and for Cu(II), Thomas model was suited.
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TL;DR: In this paper, the effect of various mineral additives on the mechanical, durability and microstructure properties of concrete and geopolymer mixtures was summarized and the results advocate that mixtures with desired properties can be designed for ambient temperature curing condition with minerals additives which may further promote them as an environmentally friendly construction material.
125 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: 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.
41 citations
Cites background from "Removal of Cr(VI) and Cu(II) ions f..."
...Higher incoming flow rate gives the lower removal efficiency (Han et al. 2009b; Chen et al. 2012; Sarkar and Das 2015) Effect of influent concentration of Cr(VI) The effects of influent concentration of Cr(VI) on the breakthrough curves for peanut and almond shell are shown in Fig....
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...…transfer coefficient or diffusion coefficient and hence the breakthrough curves became sharper which indicates that the adsorption process controlled by the smaller mass transfer zone and also intra-particle diffusion (Uddin et al. 2009, Baral et al. 2009; Chen et al. 2011, Sarkar and Das 2015)....
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...The intake of Cr(VI) increased with the increase of bed depth due to an increase in contact time for Cr(VI) adsorption as well as adsorbent surface area increased (Suksabye et al. 2008; Sarkar and Das 2015)....
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...Higher incoming flow rate gives the lower removal efficiency (Han et al. 2009b; Chen et al. 2012; Sarkar and Das 2015) Effect of influent concentration of Cr(VI)...
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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
TL;DR: In this article , the performance and applicability of several adsorptive materials for hexavalent chromium (Cr(VI) removal from aqueous media are discussed, along with a detailed analysis of the mechanisms involved.
38 citations
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TL;DR: Different active functional groups were identified by FTIR studies which were responsible for Cu(II) ion adsorbent process and it was observed that the adsorption process was spontaneous and endothermic.
193 citations
01 Jan 2012
TL;DR: In this article, the adsorption performance of packed bed column using activated carbon prepared from oil palm fibre (OPF) for the removal of lead (11) from aqueous solution was investigated.
Abstract: The adsorption performance of packed bed column using activated carbon prepared from oil palm fibre (OPF) for the removal of lead (11) from aqueous solution was investigated. The influence of important parameters like inlet ion concentration, flow rate and bed height on the breakthrough curves and adsorption performance was studied. The result indicated that adsorption efficiency increased with increase in the inlet ion concentration and bed height and decreased with increase in flow rate. Increasing the flow rate resulted to a shorter time for saturation. The result revealed that the throughput volume of the aqueous solution increased with increase in bed height, due to the availability of more number of sorption sites. The adsorption kinetics was analyzed using Thomas and Yoon and Nelson kinetic models. The kinetic data were well described by both models. The maximum adsorption capacity, calculated from both models, increased with increase in flow rate and initial ion concentration but decreased with increase in bed height. For Yoon and Nelson model, the rate constant increased with increase in flow rate, initial ion concentration and bed height. The time required for 50% breakthrough decreased with increase in flow rate, bed height and initial ion concentration. The kinetic data correlated well with both models. The comparison of the experimental breakthrough curve to the breakthrough profile obtained from Yoon and Nelson method showed a satisfactory fit for activated carbon derived from oil palm empty fruit bunch.
86 citations
TL;DR: In this article, the biosorption capacities and adsorption rates of Cr(VI) and Cu(II) ions onto live and dried tea fungal biomass were evaluated.
83 citations
TL;DR: In this paper, the adsorption of copper (II) from aqueous solution by kenaf (Hibiscus cannabinus, L) fibres was investigated in fixed-bed column.
74 citations
Journal Article•
TL;DR: In this article, a batch and continuous sorption studies to remove copper (II) from aqueous solution was tested using marine alga, Sargassum tenerrimum.
Abstract: Batch and continuous sorption studies to remove copper (II) from aqueous solution was tested using marine alga, Sargassum tenerrimum. Maximum copper uptake of 174.23 mg/g was observed according to the Langmuir model at an initial pH of 6. The copper loaded biomass was eluted using 0.1 M HCl and no damage to the biosorbent was caused. Effects of operating parameters such as bed height and flow rate were studied in a packed column and the metal uptake decreased with increase in flow rate. The Bed Depth Service Time and Thomas models were used to analyze the experimental data and the model parameters were estimated. During regeneration experiments, a loss of sorption performance was observed during seven cycles of sorption-desorption indicated by a shortened breakthrough time and a broadened mass transfer zone.
30 citations