Chitosan based adsorbents for the removal of phosphate and nitrate: A critical review

• Published in: Carbohydrate polymers Vol. 274; p. 118671
• Main Authors: Eltaweil, Abdelazeem S., Omer, Ahmed M., El-Aqapa, Hisham G., Gaber, Nourhan Mohamed, Attia, Nour F., El-Subruiti, Gehan M., Mohy-Eldin, Mohamed S., Abd El-Monaem, Eman M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.11.2021
• Subjects: adsorbents; Adsorption; biocompatibility; biopolymers; carbon; Chitosan; ecosystems; magnetism; Mechanism; Nitrate; nitrates; Phosphate; phosphates; Reusability; surface area; toxicity; water pollution; water treatment; Nitrate; Reusability; Chitosan; Adsorption; Phosphate; Mechanism
• ISSN: 0144-8617; 1879-1344; 1879-1344
• DOI: 10.1016/j.carbpol.2021.118671

The tremendous development in the industrial sector leads to discharging of the several types of effluents containing detrimental contaminants into water sources. Lately, the proliferation of toxic anions particularly phosphates and nitrates onto aquatic systems certainly depreciates the ecological system and causes a deadly serious problem. Chitosan (Cs) is one of the most auspicious biopolymer adsorbents that are being daily developed for removing of various contaminants from polluted water. This is due to its unparalleled benefits involving biocompatibility, non-toxicity, facile modifications and low-cost production. Nevertheless, chitosan displays considerable drawbacks including low adsorption capacity, low surface area and lack of reusability. Therefore, few findings have been established regarding the aptitude of modified chitosan-based adsorbents towards phosphate and nitrate anions. This review elaborates an overview for the current advances of modified chitosan based-adsorbent for phosphate and nitrate removal, in specific multivalent metals-modified chitosan, clays and zeolite-modified chitosan, magnetic chitosan and carbon materials-modified chitosan. The efforts that have been executed for enriching their adsorption characteristics as well as their possible adsorption mechanisms and reusability were well addressed. Besides, the research conclusions for the optimum adsorption conditions were also discussed, along with emphasizing the foremost research gaps and future potential trends that could motivate further research and innovation to find best solutions for water treatment problems facing the world. [Display omitted] •The adsorption aptitude of chitosan-based adsorbents towards anions was debated.•Parameters affecting the adsorption of phosphate and nitrate anions were discussed.•The hypothesized adsorption mechanisms of phosphate and nitrate were explored.•Gaps of knowledge and future prospects were proposed.