Removal of Ni2+ ions from Contaminated Water by New Exopolysaccharide Extracted from K. oxytoca J7 as Biosorbent

Abstract

Nowadays, exopolysaccharides (EPS) produced from bacterial cells are manufactured for their use in different industries in the world, mainly in the food, pharmaceutical, and wastewater industries. The characteristics of EPS, such as being biodegradable, safe, high adsorption capacity, and reusable, make them signi cant and potential applications in the puri cation of contaminated water of heavy metals. In this study, the possible application in biosorption Ni 2+ ions from contaminated water was assessed using this exopolysaccharide as a biosorbent. The new exopolysaccharide from the bacterial strain K. oxytoca J7 was extracted, isolated, and characterized using SEM, FTIR, XRD, TGA/DTG, and MALDI-TOF MS analysis. Likewise, the cytotoxic activity was performed for EPS from K. oxytoca J7 strain. The aim of this study was to investigate the possible application of non-toxic exopolysaccharide in the puri cation of contaminated water by removing Ni 2+ ions. The results obtained from the biosorption study showed that the Langmuir model is well suited to describe the adsorption process of Ni 2+ ions by EPS from K. oxytoca J7, with a maximum adsorption capacity of 269.97 mg g -1 . The importance of this study is the possible use of natural nontoxic exopolysaccharide extracted from the pathogen microorganism, K. oxytoca J7, for the removal of Ni 2+ ions from the contaminated water.

Efficient and Rapid Removal of Nickel Ions from Electroplating Wastewater Using Micro-/Nanostructured Biogenic Manganese Oxide Composite

“…The peak at 1021.23 cm −1 represents the bending vibration of Mn-OH on the surface of the BMO, in addition to the characteristic vibration peaks of relatively weak Mn-O bonds in the range of 500-700 cm −1 , thereby proving that Mn-O bonds exist in the BMO [33]. It is noteworthy that the BMO composite also includes Mn(II)-oxidizing cells and extracellular polymeric substances and thus has abundant anionic carboxyl and hydroxyl functional groups that might participate in Ni ion removal [34]. Moreover, the BMO composite is structurally layered and generally contains varying amounts of Mn(III) and vacant sites in the Mn layers [35], and the significant variation in the Mn-O bond wavenumbers before and after Ni 2+ removal indicates that the Mn-O bond also plays a specific role in the Ni 2+ removal process of the BMO composite.…”