An Advanced Review Focusing on the Production of Secondary Plant Biomass-Derived Cellulose Nanocrystal-Activated Char-Based Polyfunctional Bionanoadsorbents for Bulk-Scale Industrial Wastewater Purification: A Fixed-Bed Column Adsorption Study With Mechanism and Modeling

Currently, a massive expanse of wastewater is generated and ejected directly into the environment owing to widespread industrialization, hasty fluctuating technologies, and excess demand of the overgrowing population. This could pollute the ground/surface water, ecosystem, and cause serious damage to public safety/security and ecological balance. Hence, it is critical to develop a more efficient, eco-friendly, and economical technology for the effective purification of crude wastewaters that can be beneficially applied to real-time industrial scale by minimizing the environmental pollution and production cost. In this overview, several advanced fabrication approaches for the production of secondary plant waste biomass-derived cellulose nanocrystal-activated char (CNC-AC)-based biopolymeric nanosorbents are projected. The secondary plants are chosen here to decrease the superfluous pressure on primary plants. Scientists over the world are trying to develop CNC-based bionanocomposites as a replacement for petroleum-based composites for ecological sustainability. But unfortunately, most of the CNC has currently been extracted from primary plants like cotton, jute, hemp, bamboo, etc., which have other industrial applications. Hence, to mitigate these issues and to reduce deforestation, secondary plant’s waste biomass-derived CNC would be very much new, innovative, and advantageous for the production of multifunctional biopolymeric nanosorbents. Additionally, their extraction, modification, in-depth characterization, and application mode have also been proposed. The selected precursors (cellulose and char), considered bionanosorbents, and their application mode would be undoubtedly superior to other approaches because of their greater availability, low cost, high efficiency, eco-friendly nature, impactful involvement, novelty, higher selectivity, and applicability. The bionanosorbents possess outstanding morphological, thermomechanical, physicochemical, and microstructural belongings with higher surface area, mesoporous nature, and substantial receptor sites that must boost the overall adsorption capacity. This study has been devoted to reducing the difficulties that belong to the processing/modification of precursors, production methods, mechanisms, and application modes, and models regarding wastewater treatment to interpret the experimental data/breakthrough curve (BTC).