**4. Conclusion**

In this chapter, we have reviewed the use of the MT, Microalgae and MFC technology, particularly focusing on their strengths and limitations in treating wastewater while producing bioenergy and other viable products. In the case of membrane distillation, continuous studies are needed to adequately understand the concept of temperature polarization and, accordingly, a suitable membrane should be developed to make the process viable for large scale application. Microalgal WWT achieves a dual purpose of reducing wastewater of their pollutants and producing biomass of value. It also adds the benefit of mitigating global warming as microalgae biofix anthropogenic carbon dioxide. Microalgal WWT by the airlift bioreactor technology application has advantages over other available reactor technologies as it maximizes carbon dioxide and oxygen gas mass transfer with high remediation potentials. Presently, MFC technology is at research stage hence more research and practical attempts are a necessity for its commercial viability and applications practically at large scale. Although some of the basic knowledge has been gained in MFC research, there is still a lot to be learned in the scale-up of MFC for real plant application and commercialization.
