Biopolymers as biofilters and biobarriers

Abstract

The use of biopolymers is a sophisticated method of soil and wastewater treatment as a substitute for using chemicals, which is a public health concern. A number of mechanisms, such as polymer bridging, polymer adsorption, charge neutralization (including electrostatic patch effects), coagulation/flocculation, and adsorption have been suggested to describe the destabilization of colloids and suspensions by

Examining the Effect of a Chitosan Biopolymer on Alkali-Activated Inorganic Material for Aqueous Pb(II) and Zn(II) Sorption

“…A cursory examination of the FTIR of the adsorbents after metal ion adsorption (Figure a) shows no difference between the 0.05% and the other chitosan dose rates. However, the literature suggests that the charge density of a biopolymer (e.g., chitosan) can induce quick destabilization and restabilization of the colloidal system through electrostatic interactions. , The ζ potential of the adsorbents was therefore examined in deionized water and in a metal salt solution, and as shown in Figure b, the adsorbent containing 0.05% chitosan has the lowest ζ potential, indicating a lower dispersion stability. Expectedly, the metal ion adsorption decreases with the decreasing negative ζ potential as a result of the decrease in buoyancy and electrostatic interaction of the negatively charged adsorbent surface with the positively charged aqueous metal ions, hence the observed dip at 0.05% chitosan. − …”

Elucidating the Bulk Morphology of Cellulose‐Based Conducting Aerogels with X‐Ray Microtomography

“…X-Ray Micro-Tomography: X-ray microtomography scans were acquired with a custom laboratory system [57] consisting of a prototype solid anode micro-focus X-ray source (Excillum AB, Sweden) and a photon counting Eiger 2R 500K detector (Dectris Ltd., Switzerland) with a pixel size of 75 μm, placed 0.55 m from the source as depicted in Figure 2A. The X-ray spot was focused to 10 μm at 70 kV acceleration voltage with an emission power of 15 W. Samples were placed 0.2 m from the source, covering their full width, resulting in an effective pixel size of 27.27 μm 2 , and a field-of-view of ≈28 × 14 mm 2 Processing and Reconstruction: For each scan, 1080 projections over 360°were acquired with an exposure time of 2 s per projection. Prior to reconstruction, ring removal was applied using either a normalization or a median filter, [58] and phase retrieval was applied [42] with a delta/beta ratio of 350.…”

“…The most common source of cellulose is wood, in the form of wood pulp [ 1 ] however, cellulose is also produced by bacteria, algae, and fungi. [ 2 ] Materials based on cellulose have been widely used traditionally in paper [ 3 ] and textile [ 4 ] industries. In recent years non‐traditional uses of cellulose have emerged due to the need to reduce the environmental footprint of technological materials by minimizing electronic [ 5 ] and plastic wastes.…”