xxix

Preface

Zero waste should be a sustainable approach to minimize or nullify the waste and

making the world better. This concept is being adopted in various sectors like min-

ing, urbanization, manufacturing, agriculture, etc. Though zero waste manufactur-

ing is believed to be the best and futuristic approach, most of the zero waste drives are

currently focused on optimum recycling, reuse, and resource recovery. Manufactur-

ing scrap, e-waste, discarded constructional materials, plastics, domestic, agri-food

waste, and sewage have been haunting because their disposal affects the environ-

ment. Different physical and chemical methods to tackle these wastes by recycling

and resource recovery in turn generate hazardous chemicals, emissions, and acces-

sory wastes which are not eco-friendly.

Biotechnological approaches for reaching zero waste are more eco-friendly and

sustainable. Research has been conducted on the recovery of energy and biofuels

from agricultural, urban, and food wastes since long, and it has been practiced quite

well, though enzyme-based technology was developed recently for the recovery

ethanol from lignocellulosic waste. Bio-H2 was produced by dark fermentation

process, and recycling of used cooking oil as fuel is gaining momentum. Zero waste

approach should look wastes as salvageable resources, which contain valuable

nutrients, bioactives, industrial chemicals, and precious metals. Bioconversion

technologies like bioleaching, biosorption, and bioremediation were used to obtain

above valuable products from different wastes, and these technologies use different

organisms and enzymes. However, composting has been used for converting

agro-food waste into biofertilizers since long time. Submerged and solid-state

fermentation technologies were used for the biotransformation of agro-food

wastes into useful biochemicals and biopolymers which can be used for making

biodegradable packaging materials. Plastic waste is one among the major current

threatening problems to environment. Recently, Microbes and their enzymes were

explored for the degradation of plastics, and microbes were used for the production

of biodegradable plastics, though it was not economical. Microbes were also used

in the bioremediation of pesticides which originate as accessory contaminants of

agricultural practices. Biopulping and biofiltration were also applied for processing

agro wastes. In this book, biotechnological approaches for reaching zero waste will

be discussed in detail.