Adsorptive potential of modified plant-based adsorbents for sequestration of dyes and heavy metals from wastewater - A review

Currently, sequestration of contaminants like heavy metals and dyes from wastewater has been widely studied by researchers using modified plant-based adsorbents in order to purify water for domestic as well as industrial purposes. Although, there are various promising techniques for the removal of pollutants from wastewater but adsorption technique is considered an ideal alternative to other expensive methods. This review article focuses on the usage of modified plant-based adsorbents for the efficient removal of heavy metals and dyes. Various methods of activation and modification like physical, chemical and composite formation with components such as polymers, carbon nanotube (CNT), graphene, layered double hydroxides (LDHs) and metal oxides are discussed in depth. Generally, these modifications of plant-based adsorbents resulted in significant enhancement of adsorption capacity. Apart from this, the effect of various parameters such as adsorbent dosage, initial contaminant concentration, pH, temperature and contact time on the adsorption efficiency have also been reviewed. The regeneration of used adsorbent prevented the generation of solid waste. The reading of this review will be highly beneficial for researchers working on utilization of modified plant-based adsorbents for wastewater treatment.