A comprehensive review on vegetable waste biosorbents for sustainable wastewater treatment

Untreated wastewater, including both municipal and industrial wastewater, contaminates soil, surface water, and groundwater, posing a serious environmental risk. Innovative, economical, renewable, and ecologically safe wastewater treatment solutions are currently required. In order to improve wastewater treatment, a number of methods, including ion exchange, co-precipitation, adsorption, membrane separation, oxidation, and biochemical processes, are now being investigated for the production of bioactive components from vegetables. To remove impurities from wastewater, a variety of adsorbents are developed and used among which, bioadsorbents derived from waste biomass stand out for being economical, sustainable, renewable, and environmentally safe. This review examines vegetable-based biomass waste as a low-cost adsorbent for waste water treatment. Vegetable waste has garnered a lot of attention due to its abundance, high biocellulose content (21%), and affordability, with cassava, potato peels, and moringa seeds showing adsorption efficiencies of 85–90% for heavy metals and dyes. The novelty of this review lies in consolidating fragmented findings on vegetable peel based biosorbents into a unified framework linking biomass composition to adsorption performance. Research gap-limited data on regeneration and reusability, absence of standardized protocols related to efficiency-comparison, and insufficient testing in real waste water matrices and at pilot scale. Future work should focus on surface modification techniques, long-term stability assessments, and integration into existing treatment infrastructure. Addressing the above-mentioned gaps is essential to moving vegetable-peel bioadsorbents from laboratory-scale promise to practical, large-scale application in heavy metal and dye removal from wastewater.