Enhancement of the Stability of Biosorbents for Metal-Ion Adsorption

Abstract

Biosorbents have demonstrated great potential in the treatment of metal-containing wastewater. However, one of the bottleneck issues of using biosorbents is that amounts of organic carbon release from biosorbents into water. This seriously limits the application of biosorption technology in treating wastewater. In this work, a novel methodology was developed to greatly reduce the organic carbon release and enhance the stability of biosorbents by using barley straw as the model biosorbent material and nickel as the model metal ion. The raw barley straw was first made into cylindrical pellets, which were coated with a sodium alginate (SA) and poly(vinyl alcohol) (PVA) membrane. The coating conditions including the ratio of SA to PVA, glutaraldehyde (GA) dose, concentration of CaCl 2 solution, and cross-linking time were optimized by L 9 (3 4 ) orthogonal array design. The pellets coated at the optimal conditions (1:1 mass ratio of SA to PVA, 1.0 mL of GA, 8% CaCl 2 , and 20 min of crosslinking time) were then applied for nickel adsorption. The effects of the solution pH and ionic strength on the adsorption equilibrium and desorption of adsorbed nickel ions were investigated. Scanning electron microscopy and synchrotron X-ray fluorescence spectroscopy were used to locate the adsorption sites on the coated pellets. The results demonstrated that organic carbon release of the coated pellets was significantly reduced to 3.8−9.7 mg/g of dry barley straw pellets in the nickel adsorption process, while that of the raw barley straw particles was 44 mg/g. The nickel uptake increased to 25.6 mg/g, higher than that of the raw barley straw particles.

Selective Water Removal by Sorption from Butanol–Water Vapor Mixtures: Analyses of Key Operating Parameters and Site Energy Distribution

“…Modeling approach based on the Dubinin−Polanyi model has been employed for water adsorption equilibrium on carbon nanomaterials, 41 modified rice husk, 42 corn meal, 43 and canola meal. 25 This model has been found to give the most reasonable representation of the equilibrium isotherm data in this study.…”

Fabrication and Characterization of Magnetic Hydroxyapatite Entrapped Agarose Composite Beads with High Adsorption Capacity for Heavy Metal Removal

“…Among them, adsorption is generally preferred to address heavy metal ion pollution due to its simple operation and potential recovery and reuse of metals. In this context, a vast variety of adsorbents including activated carbons, clay material, zeolites, and biosorbents have been developed to remove heavy metal ions from various industrial effluents in past years. − …”

Synthetically modified nano‐cellulose for the removal of chromium: a green nanotech perspective

“…Functionalisation of nanobiomaterial was reported by Zhang et al [30] who used layered double hydroxide as a functionalised reagent for the removal of anions. Ou et al [31] reported functionalisation of biomaterial with sodium alginate and poly(vinyl alcohol) for enhancement of the stability of the biosorbent (Barley straw) and explored its sorption efficiency for cationic metals. Similarly, Zargoosh et al [32] reported functionalised nanobiomaterial with thiosalicylhydrazide for the removal of cationic metals.…”