Future work may also involve the addition of sub-models (aeration, gas-liquid mass transfer, aquatic chemistry, etc.), the expansion of the system boundary (coupling with upstream secondary treatment process), or the use of dynamic flow rates and volumes to make the model more flexible to varying environmental and operational conditions. In addition, interactions between microalgae and bacteria may affect the system performance. The inclusion of biological processes for bacteria (heterotrophs, nitrifiers, denitrifiers, etc.) would provide a more comprehensive representation of the mass balance of the system.