**3. Emerging trends in wastewater treatment technologies**

One of the primary reasons that has driven the inception of new or improved wastewater treatment technologies is the legislation and hefty fines that are attracted when the disposal of wastewater does not meet the set discharge limits. This impact on the financial wellbeing of factories and industries has fueled the emergence of new or improved treatment technologies.

Anaerobic and aerobic technologies have been popular lately in the treatment of organic wastewater because of their friendliness to the environment and costeffectiveness. Anaerobic technologies are, however, a cut above other technologies because of the low energy consumption.

The nature of the wastewater primarily dictates the choice of technology to be adopted, and thus it is crucial to characterize streams to determine key wastewater characteristics, such as COD, TS, VS, and salt content, among others. The main thrust of this chapter is premised on three emerging technologies, that is,

membrane, microalgal, and microbial fuel cell (MFC) technologies. These technologies can be employed independently or in series as a treatment mechanism.
