Wastewater treatment: A short assessment on available techniques

Over the past few decades, there has been a significant increase in population and unsustainable urbanization, resulting in the exploitation of water and energy resources on a large scale. This has led to a rise in the demand for freshwater, which, in turn, has caused water pollution due to the improper disposal of wastewater from various sources such as industries, agriculture, and households. The wastewater from industries often contains toxic heavy metals and harmful emerging contaminants (ECs), which can harm living beings and cannot biodegrade. Hence, it is a severe issue that needs to be addressed. To combat this problem, wastewater treatments are necessary for two main reasons: firstly, to recycle and reuse wastewater to meet future human demand and reduce water scarcity, and secondly, to ensure compliance with wastewater discharge standards for environmental sustainability while minimizing groundwater and soil contamination. In this review, several wastewater treatment technologies comprising physical, chemical, and biological methods have been discussed critically. The state-of-the-art discussion on different existing wastewater treatment techniques and their limitations has been deliberated. Finally, the limitations of the various existing wastewater treatment techniques and contemporary trends in wastewater treatment have been highlighted.