Waste valorization: Physical, chemical, and biological routes

Rapid urbanization, industrial revolution, booming economies, and improvements in standards of living around the globe have tremendously altered the features of various solid, liquid, and gaseous nature wastes. The intermixing of these types of wastes incorporated with harmful and noxious chemicals with water, air, and soil media accelerate the contamination of these mediums, which is responsible for the ecological imbalance and environmental disturbance. In the 20th century, it was understood that both the chemical and allied industries must adopt greener and more sustainable routes to minimize the generation of unwanted wastes for risk management. To obtain this objective, there is a need to reshape the old-style schemes of the process with a variety of newly invented technical routes including physical, chemical, and biological methods. Valorization is a technical route adopted for the recycling of waste into desirable products having economic worth and which are also non-toxic. Recently, waste valorization has attracted scientists and researchers to find out possible alternatives to avoid the dumping of remainders having zero value by transformation of an extensive range of such remainders into desired products as well as to prevent secondary pollution spreading. This chapter will emphasize the valorization of different sectors' generated wastes.