Sustainable Adsorbents from Plant-Derived Agricultural Wastes for Anionic Dye Removal: A Review

Abstract

The extensive use of dyes in numerous industries results in massive dye discharge in the wastewater, which is a major cause of water pollution. Globally, the consumption of dyes is near seven hundred thousand tons across different sectors, of which around 10–15% goes into the wastewater. Among the dye kinds, anionic dyes make up the main proportion, having a 32–90% share in the wastewater. Different plant-derived wastes, which are sustainable given their natural abundance, effectiveness, and low cost, are frequently proposed for dye separation. However, these adsorbents are inherently more suitable for cationic dyes than anionic dyes. In recent years, the modification of these wastes has been progressively considered to suit them to anionic dye removal. These modifications involve mechanical, thermal, or chemical treatments, or combinations. These attempts propose two-way benefits, as one abundant waste is being used to cure another severe problem, and eventually both could be diminished. This review has a key focus on the evaluation of plant-derived adsorbents and their modifications, and particularly for anionic dye adsorption. Overall, the mechanism of adsorption and the suitability of the current methods are discussed, and their future potential is explored.

Adsorption of Reactive Red 120 in Decamethyl-Cyclopentasiloxane Non-Aqueous Dyeing System

“…Compared with the pseudo-first-order kinetic model, the the fitting coefficients (R 2 ) of pseudo-second-order kinetic model is suitable for describing the adsorption of dye in D5 dyeing system. Therefore, the adsorption rate of high concentration dye solution on cotton fabric is not proportional to the dye concentration, but it is determined by the square value of the numbers of vacant adsorption spots on the fiber surface [45,46]. It is well known that reactive dye can bind to cotton fiber in the form of covalent bonds.…”

“…D5 dyeing system. Therefore, the adsorption rate of high concentration dye solution on cotton fabric is not proportional to the dye concentration, but it is determined by the square value of the numbers of vacant adsorption spots on the fiber surface [45,46]. It is well known that reactive dye can bind to cotton fiber in the form of covalent bonds.…”

Adsorption of Brilliant Green Dye Using Raw and Activated Adsorbent Prepared from Sesbania Leaves

“…Among of them adsorption has been found to be superior technique due to is cost effective, eco-friendly and easy to operate [18]. Various types of adsorbents such as natural, agricultural, industrial wastes and their prepared activated adsorbent in adsorption process are more attractive due to their easy availability, low-cost or no cost and minimum sludge production [19]. Previously researchers reported different type of low cost adsorbents and activated adsorbents such Assalix alba leaves [20], chemically modified areca nut husk [21], chemically activated date pit carbon [22], activated carbon prepared from waste banana peels [23], activated carbon derived from medlar seeds [24], activated carbon [25], Giombo persimmon seed [26], activated carbon prepared from flamboyant pod, eucalyptus tree, coconut shell and corn cob [27] and nanohydroxyapatite/chitosan composite [28] for removal of brilliant green dye from wastewater.…”

The Effect of Modifying Canadian Goldenrod (Solidago canadensis) Biomass with Ammonia and Epichlorohydrin on the Sorption Efficiency of Anionic Dyes from Water Solutions

“…Plant biomass usually has relatively low sorption capacity with regard to anionic dyes. This is due to the generally acidic or neutral nature of plant biomass and, as a rule, the low content of basic functional groups in its structure [ 19 ]. Appropriate chemical modification of plant biomass can significantly increase its sorption capacity.…”