Review of metal (hydr)oxide and other adsorptive materials for phosphate removal from water

Abstract

Abstract Eutrophication, a worldwide problem, threatens the ecology of freshwater bodies and marine environments. However, the control of nutrients, especially phosphate in water bodies and contaminated sediments, poses major technical and economic challenges. Today, various attempts have been made to investigate a cost-effective way to have phosphate control. Among the various techniques applied to remove phosphate, the process of adsorption has drawn great attention due to its low cost, ease of operation, and simplicity of design. Another attractive feature of adsorption is the usage of nutrient-loaded adsorbents, which can be used as a phosphate fertilizer and a soil conditioner in agriculture. In this regard, many different types of chemicals with various structures have been synthesized and applied for the capture of phosphate from water. This review summaries contemporary development of adsorbents for phosphate removal, most specifically, the adsorption by metal-based materials, mesoporous materials, organic and metal-organic hybrid materials, carbon-supported materials, minerals, and modified wastes. The effects of operational parameters on phosphate adsorption and fitting of adsorption process, as well as regeneration of used adsorbents are also examined. Metal (hydr)oxides loaded adsorbents have been widely researched. Additional modifying of material characteristics such as improving porosity and surface area, the stability and potential risks of adsorbents in complex condition, and their efficient separation and regeneration should be taken into consideration in further studies.