Polysaccharides derived from Enteromorpha prolifera for the removal of silver nanoparticle-humic acid contaminants by a coagulation-ultrafiltration process

Abstract

Applying Ep as a coagulant aid in C-UF process could simultaneously remove AgNPs and reduce membrane fouling.

A Review of Natural Polysaccharides-Based Flocculants Derived from Waste: Application Efficiency, Function Mechanism, and Development Prospects

“…44,45 EP, which is one of the main components of E. prolifera, is an acidic or neutral polysaccharide mainly composed of galactose, xylose, and rhamnose in a linear polymer structure, with a molecular weight distribution of 30−500 kDa. 46,47 sugar ring (1 → 4), (1 → 2, 4) and (1 → 3, 4) structural sites, in addition, glucuronic acid and xylose are connected to the (1 → 4) site, which composes a complete structural unit (shown in Figure 1). 46,47 It has been reported that E. prolifera extract can be used as a flocculant aid of traditional flocculants (Al-, Fe-), and polysaccharide component is the main contributors to the flocculation aid effects.…”

“…Because of global climate change and eutrophication of water bodies, large-scale green tides of the seaweed Enteromorpha prolifera ( E. prolifera ) frequently erupt in various sea areas worldwide . Many E. prolifera float, accumulate on the shore, and decompose and emit a foul odor that impacts the marine ecosystem. , EP, which is one of the main components of E. prolifera , is an acidic or neutral polysaccharide mainly composed of galactose, xylose, and rhamnose in a linear polymer structure, with a molecular weight distribution of 30–500 kDa. , −OH, −COOH, −NH 2 , and −SO 3 – were the main active groups in the linear structure of EP . The C-2 and C-5 are the binding sites for hydroxyl and carboxyl groups; the C-3 site binds sulfonic acid, amino, and hydroxyl groups.…”

“…Rhamnose is connected to the sugar ring (1 → 4), (1 → 2, 4) and (1 → 3, 4) structural sites, in addition, glucuronic acid and xylose are connected to the (1 → 4) site, which composes a complete structural unit (shown in Figure ). , It has been reported that E. prolifera extract can be used as a flocculant aid of traditional flocculants (Al-, Fe-), and polysaccharide component is the main contributors to the flocculation aid effects. , …”

“…Unlike the charge neutralization mechanisms generated after the hydrolysis of metal saltwater, adsorption bridging, net trapping, and sweeping are the main manifestations of the flocculation-aided effect. 47 WPs participate in the flocculation process, preferentially selecting the metal cation sites exposed on the surface of the adsorption flocs and combining the active site in the pollutant structure through hydrogen bonds and intermolecular forces. Similar to the adsorption bridging effect of the flocculant aid, −C−N/−C−O/−C�O/−COOH/− OH and other groups in the pollutants are also important participants in the binding effect.…”

“…Molecular structure of polysaccharides derived from (a) Enteromorpha prolifera ; (b) Laminaria ; (c) Panax ; (d) Lentinus ; (e) Auricularia auricula ; (f) Ulva ; (g) Bletilla striata ; (h) Dioscorea ; (i) Fucoidan ; (j) Ficus pandurata H. ; (k) Angelica sinensis ; (l) Holothuria (m) Sea cucumbers ; (n) Poria coco ; (o) Carrageenan ; and (p) Cucurbita …”