Sustainable Removal of Contaminants by Biopolymers: A Novel Approach for Wastewater Treatment. Current State and Future Perspectives

Abstract

Naturally occurring substances or polymeric biomolecules synthesized by living organisms during their entire life cycle are commonly defined as biopolymers. Different classifications of biopolymers have been proposed, focusing on their monomeric units, thus allowing them to be distinguished into three different classes with a huge diversity of secondary structures. Due to their ability to be easily manipulated and modified, their versatility, and their sustainability, biopolymers have been proposed in different fields of interest, starting from food, pharmaceutical, and biomedical industries, (i.e., as excipients, gelling agents, stabilizers, or thickeners). Furthermore, due to their sustainable and renewable features, their biodegradability, and their non-toxicity, biopolymers have also been proposed in wastewater treatment, in combination with different reinforcing materials (natural fibers, inorganic micro- or nano-sized fillers, antioxidants, and pigments) toward the development of novel composites with improved properties. On the other hand, the improper or illegal emission of untreated industrial, agricultural, and household wastewater containing a variety of organic and inorganic pollutants represents a great risk to aquatic systems, with a negative impact due to their high toxicity. Among the remediation techniques, adsorption is widely used and documented for its efficiency, intrinsic simplicity, and low cost. Biopolymers represent promising and challenging adsorbents for aquatic environments’ decontamination from organic and inorganic pollutants, allowing for protection of the environment and living organisms. This review summarizes the results obtained in recent years from the sustainable removal of contaminants by biopolymers, trying to identify open questions and future perspectives to overcome the present gaps and limitations.

Natural Fiber-Reinforced Thermoplastic ENR/PVC Composites as Potential Membrane Technology in Industrial Wastewater Treatment: A Review

“…Various treatment methods, including physical, chemical, biological, or a combination thereof, have been used to treat wastewater from this industry [116][117][118][119][120][121][122][123]. However, these methods are still seen to be less effective and less efficient because the resulting wastewater has various compositions and is difficult to classify in general [124,125].…”

Extremophilic Exopolysaccharides: Biotechnologies and Wastewater Remediation

“…Apart from its application in drug delivery, biosensors, vaccine development, and genetic engineering, the potential role of nano-biotechnology in wastewater treatment is emerging. Biogenic nanoparticles appear to be promising candidates for wastewater bioremediation, among which biopolymeric metallic nanomaterials are of great scientific interest (Sarkar et al, 2020;Russo et al, 2021). The high surface area to volume ratio of nanoscale adsorbent materials bestows increased catalytic activity, due to which nano-adsorbents are presently capturing the spotlight in the field of wastewater treatment (Pereira et al, 2015).…”

Recent Advances in Biopolymeric Membranes towards the Removal of Emerging Organic Pollutants from Water

“…On the other hand, natural biopolymers are sourced from natural sources [5,6]. These naturally sourced biopolymers include cellulose, starch, chitosan [5][6][7], collagen, fibrinogen [5,6], chitin, alginate, and carrageenan, among others [7]. Among these, chitosan and cellulose are the most readily available biopolymers in nature.…”

“…Carrageenan, which is a seaweed, is divided into three derivatives, i.e., kappa-carrageenan, iota-carrageenan, and lambda-carrageenan, which is determined by the degree of sulfation. Starch is mostly obtained from stalks, roots, and crop seeds [7]. Similarly, cellulose is sourced from plants, fungi, bacteria, and algae [8].…”