Fixed-bed column studies for the removal of hazardous malachite green dye from aqueous solution using novel nano zerovalent iron algal biocomposite

Abstract

Sargassum swartzii, a marine alga was used as precursor for the synthesis of novel nano zerovalent iron S. swartzii (nZVI-SS) biocomposite for the removal of malachite green (MG) from simulated wastewater in a fixed-bed column. The performance of the biocomposite was evaluated in the fixed-bed column at various operating conditions such as bed height (3-9 cm), flow rate (5-15 mL/min) and initial MG concentration (5-15 mg/L). The lowest bed height (3 cm), lowest flow rate (5 mL/min) and highest inlet MG concentration (15 mg/L) resulted in highest MG uptake of 0.56 mg/g, compared to other experimental conditions. The column experimental data obtained at different conditions were analyzed using three different models, viz., Adam-Bohart model, Thomas model and Yoon-Nelson model. All three models provided a good breakthrough curve prediction; however, the results obtained from Thomas model and Yoon-Nelson model were more satisfactory. The well-recognized BDST model was also used for describing the effect of bed height on the breakthrough curve. The various characteristics of the biocomposite were studied using SEM, DLS, XRD, XRF and XANES. The nZVI-SS biocomposite fixed-bed column proved to be the potential biosorbent for the removal of MG from aqueous phase.

Strategically dewaxed honeycomb powder is a promising and eco-friendly alternative for the removal of malachite green through fixed bed column

“…The chief driving force for adsorption includes vander waals forces, electrostatic attraction and hydrogen bonding forces which holded the dye molecules on the solid surface of the material. In addition to this since the dye and the adsorbent both have several aromatic organic moieties, pi-pi stacking also supports the adherence of the dye on the surface of the adsorbent [12] .…”

“…Besides, we have shown the excellent removal capacity of dewaxed honeycomb for dye removal from water by batch techniques. [10][11][12][13][14]25] The batch e ciency of dewaxed honeycomb powder for the removal of malachite green dye was investigated and optimized at various experimental conditions [12] . A detailed cost-bene t analysis has also been presented.…”

Modeling of the dynamics adsorption of some hazardous elements from aqueous solution onto bentonite-calcium-alginate beads

“…Feed flow rate is one of an important parameters that could affect retention capacity in fixed-bed experiments, especially for a continuous process at a manufacture scale [33].The influence of flow-rate on retention for component (Cs + , Sr 2+ , UO2 2+ and Co 2+ ) onto bentonite-Ca-alginate composite adsorbents in a column from multicomponent solution was investigated about various flow rates from 0.5 to 2.0 mL/min with a bed depth 3.0 cm, Co of 50 mg/L of each ion and pH of 5.5. Fig.…”