Recovery of Phosphate(V) Ions from Water and Wastewater Using Chitosan-Based Sorbents Modified—A Literature Review

Abstract

Over the past two decades, there has been increasing interest in the use of low-cost and effective sorbents in water treatment. Hybrid chitosan sorbents are potential materials for the adsorptive removal of phosphorus, which occurs in natural waters mainly in the form of orthophosphate(V). Even though there are numerous publications on this topic, the use of such sorbents in industrial water treatment and purification is limited and controversial. However, due to the explosive human population growth, the ever-increasing global demand for food has contributed to the consumption of phosphorus compounds and other biogenic elements (such as nitrogen, potassium, or sodium) in plant cultivation and animal husbandry. Therefore, the recovery and reuse of phosphorus compounds is an important issue to investigate for the development and maintenance of a circular economy. This paper characterizes the problem of the presence of excess phosphorus in water reservoirs and presents methods for the adsorptive removal of phosphate(V) from water matrices using chitosan composites. Additionally, we compare the impact of modifications, structure, and form of chitosan composites on the efficiency of phosphate ion removal and adsorption capacity. The state of knowledge regarding the mechanism of adsorption is detailed, and the results of research on the desorption of phosphates are described.

Chitosan: Structural and Chemical Modification, Properties, and Application

“…A significant advantage of using chitosan hydrogels as adsorbents in the natural environment problems is their non-toxicity and biodegradability. An example is the adsorption removal of phosphates from water and wastewater [ 49 , 50 ]. Different surface modifications can be employed by adding active fillings like metal oxides and hydroxides, carbons and biochars, zeolites and minerals, magnetic nanoparticles, and others to the chitosan matrix to enhance the capability of chitosan towards phosphate anions or other ions [ 51 , 52 ].…”