Science and technology are the essential drivers of sustainable development. The growing global population led to the increase in freshwater scarcity because our water resources get contaminated through hazardous pollutants such as heavy metal ions, pesticides, drugs, and various other inorganic and organic pollutants. Therefore, there is an increase in research to develop sustainable, cost-effective, and efficient technologies for wastewater treatment. The wastewater is treated in such a way that it can be reused for industrial, agricultural, and other domestic activities. The technologies used for wastewater treatment are primary, secondary, and tertiary water treatment technologies. The tertiary treatment based on advanced oxidation process (AOPs), membrane-based technology, and adsorption is the most effective technology for wastewater treatment because the pollutants which are not removed by primary and secondary treatment technology are removed using tertiary water treatment technology. In this chapter, various methods and the materials used for wastewater treatment are discussed. Furthermore, the current status of research on using AOPs (photocatalytic and fenton-based oxidation), membrane-based technology (ultrafiltration, microfiltration, nanofiltration, and reverse osmosis), and adsorption is discussed. The selection of wastewater treatment technology depends upon the cost-effectiveness, selectivity, efficiency, energy consumption, biocompatibility, and types of impurities or pollutants to be treated.