Biosorption of heavy metals from actual electroplating wastewater using encapsulated Moringa oleifera beads in fixed bed column

Eco-friendly treatment of textile dye from aqueous solution using encapsulated biosorbent matrix beads: kinetics and breakthrough analysis

“…It can be explained by the pHzpc of the adsorbent and the nature of the AB-FFS dye (anionic). The pH zpc of the MEA is around 4.9-5.1, which explains that the surface of the adsorbent is positively charged at under pH 5.1 [9]. At lower pH, large amount of H ?…”

“…The peak that appears at 1627 cm -1 may be attributed to the N-H (amine) groups present in the protein portions of the MEA. On the other hand, an FTIR spectrum of MEA after biosorption shows the disappearance of the two peaks, which is due to the mechanism of cross-linking of MEA which could be either by de-protonation or ionic interaction [9]. In addition, the point of zero charge (pH zpc ) was examined for MEA beads, and the results showed that the pH zpc is 4.9-5.1 as shown in Fig.…”

“…After encapsulation, MEA in the calcium chloride solution was incubated at room temperature for 2 h for stability, which led to the complete replacement of sodium ions by calcium ions. Eventually, the beads were dried and washed with 99 % of ethanol for complete sterilization for storage long periods [9]. In addition, the physical appearances and properties of the MEA have been characterized such as BET surface area, porosity, bulk density and stability as shown in Table 1.…”

“…Considering these properties, Moringa oleifera could be used as a good biosorbent when it is encapsulated. Our previous studies have reported that encapsulated Moringa oleifera beads are effectively used for the removal of heavy metals [9]. Hence, this present study is focused on the performance of encapsulated Moringa oleifera seed powder by cross-linking with polymer Ca-alginate, to obtain stable beads and used for its biosorption efficiency for AB-FFS solution.…”

“…Therefore, there is a need to investigate the fixed bed column study to obtain engineering data for scaling up from laboratory-scale to pilot-scale level. Recently, a variety of natural adsorbents such as pistachio hull waste [8], dried Moringa oleifera seeds [9], orange peel cellulose [10] and Artocarpus heterophyllus [11] have been reported for the removal of heavy metals and dyes.…”