Mathematical Modeling of Energy Balance in the Photobiological Treatment Plants

The paper deals with photobiological treatment facilities integrated with building's architectural shell. Using such a kind of systems solves the following tasks: receiving third-generation biofuels, disposing carbon dioxide, cleaning and disinfecting the wastewater, recycling phosphorus compounds, using solar radiation for heating. Our study implements the idea of creating a partially closed cycle for flows of matter and energy within a wastewater treatment process. We focus on the use of natural light when photoreactors with algae are placed on a building architectural shell. However, in this case there is a need to ensure proper temperature conditions for the stable growing of algae. The problem can be solved by control of energy flow within the system. To do this, we apply methods of numerical simulations based on ordinary differential equations. The model takes into account seasonal variations of the day length and the outside air temperature. The engineering basis for energy flow control is the trigeneration system (combined heat, power and cooling) working in conjunction with photobioreactors installed on the facade, which can be considered as solar collectors.