The huge development of the industrial sector has resulted in the release of large quantities of phosphate anions which adversely affect the environment, human health, and aquatic ecosystems. Naturally occurring biopolymers have attracted considerable attention as efficient adsorbents for phosphate anions due to their biocompatibility, biodegradability, environmentally-friendly nature, low-cost production, availability in nature, and ease of modification. Amongst them, alginate-based adsorbents are considered one of the most effective adsorbents for removing various types of pollutants from industrial wastewater. The presence of active COOH and OH− groups along the alginate backbone facilitate its physical and chemical modifications and participate in various possible adsorption mechanisms of phosphate anions. Herein, we focus our attention on presenting a comprehensive overview of recent advances in phosphate removal by alginate-based adsorbents. Modification of alginate by various materials, including clays, magnetic materials, layered double hydroxides, carbon materials, and multivalent metals, is addressed. The adsorption potentials of these modified forms for removing phosphate anions, in addition to their adsorption mechanisms are clearly discussed. It is concluded that ion exchange, complexation, precipitation, Lewis acid–base interaction and electrostatic interaction are the most common adsorption mechanisms of phosphate removal by alginate-based adsorbents. Pseudo-2nd order and Freundlich isotherms were figured out to be the major kinetic and isotherm models for the removal process of phosphate. The research findings revealed that some issues, including the high cost of production, leaching, and low efficiency of recyclability of alginate-based adsorbents still need to be resolved. Future trends that could inspire further studies to find the best solutions for removing phosphate anions from aquatic systems are also elaborated, such as the synthesis of magnetic-based alginate and various-shaped alginate nanocomposites that are capable of preventing the leaching of the active materials.

https://pubs.rsc.org/en/content/articlepdf/2022/ra/d1ra09193j

Recent developments in alginate-based adsorbents for removing phosphate ions from wastewater: a review

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Concurrent removal of phosphate and ammonium from wastewater for utilization using Mg-doped biochar/bentonite composite beads

Flexible reduced graphene oxide/V2O5 composite battery-type cathode and MXene capacitor-type anode for aqueous zinc ion hybrid supercapacitors with high energy density

MXene/CoS heterostructures self-assembled through electrostatic interaction as superior microwave absorber

Highly selective adsorption of phosphate from high-salinity water environment using MgO-loaded and sodium alginate-immobilized bentonite beads

Pizza-like heterostructured Ti3C2Tx/Bi2S3@N-C with ultra-high specific capacitance as a potential electrode material for aqueous zinc-ion hybrid supercapacitors

A novel “butter-sandwich” Ti3C2Tx/PANI/PPY electrode with enhanced adsorption capacity and recyclability toward asymmetric capacitive deionization

Although supercapacitors have attracted more and more attention owing to their fast charging speed and high power density, their wide applications have still been limited by their low energy density. In this study, a new CuS-nanoparticle-decorated Ti3C2Txelectrode material is fabricated via a facilein situsynthesis strategy at room temperature. CuS nanoparticles, generated from thein situreaction of Cu (NO3)2·3H2O with Na2S·9H2O, are anchored between the Ti3C2Txinterlayers through electrostatic interaction. This type of structural construction is found capable of not only reducing the surface oxidation of Ti3C2Tx, but also preventing the accumulation of CuS nanoparticles by the template effect of Ti3C2Txnanoplates. As a result, the CuS/Ti3C2Txnanohybrid delivers a maximum specific capacitance of 911 F g-1at 1 A g-1and a good cycling stability. A symmetric supercapacitor fabricated using the CuS/Ti3C2Txnanohybrid as the electrode material exhibits an energy density of 43.56 W h kg-1with a power density of 475 W kg-1. Consequently, this work provides a new perspective of microstructural design for the preparation of electrode materials with superhigh specific capacitance through an easy and low-costin situ-reaction method at room temperature.

Facile decoration of two-dimensional Ti3C2Tx nanoplates with CuS nanoparticles via a facile in-situ synthesis strategy at room temperature for superhigh specific capacitance of supercapacitors

Haoli Jiang

Papers

Highly selective adsorption of phosphate from high-salinity water environment using MgO-loaded and sodium alginate-immobilized bentonite beads

Pizza-like heterostructured Ti3C2Tx/Bi2S3@N-C with ultra-high specific capacitance as a potential electrode material for aqueous zinc-ion hybrid supercapacitors

A novel “butter-sandwich” Ti3C2Tx/PANI/PPY electrode with enhanced adsorption capacity and recyclability toward asymmetric capacitive deionization

Facile decoration of two-dimensional Ti3C2Tx nanoplates with CuS nanoparticles via a facile in-situ synthesis strategy at room temperature for superhigh specific capacitance of supercapacitors