This book first explores the decolourization and biodegradation of three primary dyes employed in the textile industry, namely methyl red, methyl orange and methylene blue. An overview of the developments in membrane bioreactor technology for various types of wastewater treatment is provided, addressing the fundamentals, applications, and strategies from industrial and domestic interests. The authors focus on advances in the development of robust processes for alcoholic fermentation from sugar-sweetened beverage wastewaters. The impact of the preservatives, the initial sugars content and the initial inoculum size of both sugar consumption and ethanol yield are presented. Following this, the applications of nanofiltration in metal and acid recovery are explored, focusing on conventional processes like solvent extraction and ion exchange. The authors go on to elucidate the recent and significant advances in the field of nanomembranes and nanotechnology, addressing their applications in water/wastewater treatment and desalination. The status of global scientific research in the field of arsenic groundwater remediation is reviewed in conjunction with present environmental research. The pollutants contained in industrial wastewater are examined in an effort to research treatment and disposal methods for remediation using agro-food wastes and by-products. This compilation also applies experimental design methodology in the optimization of photocatalytic degradation of dairy industry wastewater. The closing research centers on the degradation of phenol from wastewater using electrocoagulation as pretreatment and using advanced oxidation process. Various parameters such as the initial concentration of phenol and pH of the solution are studied.