Strategies for biological treatment of waste water: A critical review

Abstract

Global water demand is continuously growing due to rising population and associated industrial and agricultural activities. However, these factors are also polluting the existing water bodies and therefore, limiting the water supply. Increasing level of contaminants poses risk to human, wildlife and the environment. Widening gap between water demand and supply creates water stress. Therefore, treatment of waste water becomes imperative in order to ensure sustainable development of planet earth. Conventional methods utilizing physical, chemical and biological processes are generally adopted for this purpose. These methods are further modified so as to enhance the efficiency and economy of the treatment process as well as to make them more eco-friendly. None of the conventional or advance technology is individually sufficient for appropriate treatment of wastewater. Therefore, more efficient hybrid methods are required. The development of such hybrid methods needs detailed information about various treatment methods. This paper critically reviews the conventional and advanced biological methods used for waste water treatment. The main objective of this review is to present vital information about various biological treatment methods forming the basis for the development of sustainable hybrid methods for waste water treatment.