In recent years, numerous investigations have explored the use of biochar for the removal of organic and inorganic pollutants in single component systems. Biochar is a carbonaceous material produced from waste biomass, mainly by thermochemical conversion methods. This material was used as a biosorbent in various removal processes of pollutants, and its efficiency was strongly influenced by the characteristics of the biomass feedstock. This review integrates the recent works of literature to understand the biosorption behaviour of dyes onto biochar-based biosorbents. The factors influencing the biosorption process and the mechanisms describing the biosorption behaviours of the biochar have been broadly reviewed. Furthermore, the biosorption models can be used to comprehend the competence of the biochar as biosorbent for dye removal techniques. Graphical Abstract

Every year, the global food industry produces a significant number of wastes and by-products from a variety of sources. By-products from the food-processing sector are produced in large quantities, and because of their undesirable qualities, they are frequently wasted, losing important resources. In order to pursue a circular economy that refers to waste reduction and effective waste management, by-products valorization recently received increased interest. By-products are rich in bioactive compounds and can be used in various industrial applications for health promotion and nutritional benefits. A novel step in its sustainable application is the use of these inexpensive waste agri-food by-products to create the value-added products. The present review intended to summarize the different types of agro-industrial by-products and their properties and highlight their nutritional composition and potential health benefits. Applications of agri-food by-products in foods as well as the potential health and sustainability implications of by-products in food products were also covered. According to research, agri-food by-products can be added to a variety of food to increase their bioactive profile, fiber content, and antioxidant capacity while maintaining good sensory acceptability. Overall, the sustainability of the agri-food chain and consumer health can both benefit from the use of agri-food by-products in food formulation.