Production of Biosorbents from Citrus Wastes for Adsorption of Pollutants and Salt from Wastewaters

One of the most important environmental issues in the world, and especially in Iran, is the accumulation of solid waste because its amount in the gross domestic product and national income is worrying. Solid wastes such as citrus wastes have no economic value and are considered useless. Therefore, it is necessary to use these wastes by providing a suitable method to valorize them. On the other hand, the wastewater of many industries contains a wide range of organic and mineral pollutants. Its cost-effective treatment is necessary to solve the water crisis. The adsorption method using cheap and available biosorbents is one of the most efficient methods for removing pollutants from industrial wastewater. Thus, using citrus wastes and improving their adsorption properties with the physical and chemical treatments, carbonization, and a combination of these methods simultaneously solves the problem of citrus wastes and industrial wastewater. In this review study, different adsorbents obtained from citrus wastes along with their production methods are investigated, and their adsorption behavior is expressed based on isotherm, kinetic, and thermodynamic models. Also, adsorbent regeneration, economic evaluation, and suggestions for the development of this approach are provided.