Municipal wastewater treatment technologies: Challenges and perspectives

As result of population growth and urbanization, there is an increase in volume of mixed wastewater from households, industrial wastewater and precipitation water commonly known as municipal wastewater (MWW) or sewage. Municipal wastewater comprises water with moderate concentration of dissolved and suspended organic and inorganic solids, heavy metals, microorganism’s pathogens including bacteria, virus, parasitic worms and non-pathogenic microorganisms and consequently, leads to significant environmental and human health effects if not properly discharged. As such, MWW must be treated prior to its release into different environmental compartments. A multitude of technology have been developed and applied for the treatment of municipal wastewater. Traditionally, biological treatment has been used in controlled environment for the treatment of MWW. However, evolution in research and technology has led to the design and application of emerging and green technology such as phytoremediation and constructed wetlands (CWs), membrane bioreactor (MBR) and activated sludge for the treatment of MWW albeit the challenges of sustainability. Herein a detailed chapter on MWW fundamentals, their environmental and human health impacts, existing treatment technologies, new and emerging and future outlooks will be discussed. Their advantages and drawbacks considering future refinements and interventions will be elucidated.