ABSTRACT
Zero-waste technologies are very important for a sustainable environment. Biotechnological methods are more viable zero-waste technologies since they are environmentally friendly. Agricultural and food wastes have long been converted into biofuels, and recently enzymes have been used for converting lignocellulosic waste into bioethanol, which is eco-friendly. Biotechnological methods are also used for converting agri-food waste into valuable chemicals, biopolymers, bioadsorbents, biosurfactants, etc., which will significantly contribute towards a circular economy. Dark fermentation and microbial fuel cells are also used for producing bio-hydrogen and electricity from municipal sludge. Biomaterials were integrated with nanomaterials in order to remediate the environment. Some of these biotechnological approaches were discussed, which will lead to zero waste and a circular economy.
