The potential of reusing fruit bio-adsorbents for water purification: A minireview

Abstract

Fruit peels, cortexes or rinds are sourced from a wide range of fruits including watermelon, banana, orange, mango, pineapple and lemon among others. They are readily available materials that can be used as bio-sorbents for various pollutants found in contaminated water. This study reviews reported works on the usability of different fruit bio-peels as adsorbents for water pollutants. The findings show that fruit peels must undergo various physicochemical modifications to be used as bio-sorbents. The peels have functionalized moieties such as –OH, –COOH and –NH2 groups that can attract cations of pollutants in aqueous solutions facilitating adsorption. Furthermore, the bio-adsorbents can be regenerated for reuse in several adsorption cycles. Most of the reviewed studies showed that bio-peels are effective in decontaminating various dyes and heavy metals in polluted waters. The decontamination efficacy differs based on the pollutant targeted, quantity and volume of adsorbate, concentration of adsorbent, pH, temperature and surface area. To enhance the effectiveness of fruit bio-sorbents in water purification, there is need to extend research to optimize biosorption processes, combine it with other water purification processes, control the parameters influencing the process and effectively processes resultant waste for environmental conservation.