At the present practice of urban wastewater treatment in the world, secondary treatment (removal of organics, pathogens, TN to nitrate), tertiary treatment (plus removal of TN, TP), and advanced treatment are applied to reclaim water for safe reuse or recharging groundwater sources. Secondary treatment is a conventional approach which originated since early 1900s from Europe and America, and Vietnam is now applying this approach with some improvement. However, this kind of treatment consumes a lot of energy (the world average consumption is 4% of total electricity produced, and it will reach 8% by 2040), and waste renewable resources in wastewater. On the other side, the amount of municipal solid wastes (MSW) constantly increases along with the growth of population and living; in Vietnam, the large cities have to spend about 3-3.5% of their budget just for MSW (containing ~60% organics) collection, transportation and treatment for landfilling. During the last 20 years, a lot of researches have been conducted in the direction of new approaches in the field of waste treatment, this is the concepts of sustainable development - circular economy. This mean energy and materials including wastewater are recovered and reused. Urban wastewater, industrial rich organic wastewaters, animal breeding wastewater, organic fraction of MSW can be the input into this treatment system, outputs such as renewable energies, reclaimed water and fertilizers, and other useful materials can also be produced. This paper reviews real developments in this promising field, a sustainable development opportunity that Vietnam should pursue.