Reducing Water Use and Carbon Footprint: Working toward a circular economy tackles some of today's most pressing environmental, economic, and social challenges. Aligned with the principles of the Circular Economy, the 2030 Agenda for Sustainable Development, and the European Green Deal, it showcases groundbreaking technologies that reduce carbon and water footprints, improve air quality, and promote smarter, more sustainable water and waste management. Designed for scientists, graduate students, industry professionals, policymakers, and environmentally conscious readers, this publication provides both the scientific foundation for and practical insights into efficient, cost-effective methods for exhaust gas purification and post-process waste utilization, framed within the Circular Economy's 6R concept - refuse, reduce, reuse, repair, recycle, rethink. Particular attention is given to novel carbon capture techniques using water-soluble sorbents and ferriferrohydrosol (FFH)-an innovative, affordable, and environmentally friendly reagent with catalytic and coagulating properties. The first part of the book provides an overview of modern CO2 capture technologies, comparative analyses of removal costs in solid fuel conversion processes, and the evolving regulatory framework for greenhouse gas emissions in small and medium-sized enterprises. The second part turns to innovative solutions for industrial waste and water management, including steam plasma processing of biomass and organic waste to generate hydrogen-enriched syngas and biochar, and the incorporation of fine granite waste into ceramic tile production to boost durability and reduce water absorption. Blending cutting-edge technologies and sustainable strategies, this book offers practical pathways toward lower CO2 emissions and water use, supporting the global transition to a low-carbon circular economy and resource-efficient future.