(71b) Ecosystem Services As Unit Operations: Integrated Design of Constructed Wastewater Treatment Wetlands By Simulation Software

The development of simulation software packages has enriched the area of process design because they are easy to use in the evaluation of different process designs, without investing any resources. Although these process simulators are commonly used in academia and industry, they are limited to the technological modules in their library. With the advances in other disciplines such as ecological and environmental sciences, some alternatives represented in ecosystem services emerged as strong candidates to replace some technological solutions.

Ecosystems have attracted substantial interest in recent years for valuing and accounting for the goods and services provided. The variety of the ecosystem service around us in everyday life brings up the good question of can we utilize them on a larger scale. Models of ecosystem service are available in the literature but not that many are implemented in process design.

This work aims to evaluate these ecosystem services as alternatives in process design by including some services as a unit operation in simulation software. This implementation of the available models will enable researchers and designers to assess the benefits and drawbacks of including these services. It will also allow them to come up with different designs without any expertise in a specific discipline and complicated models.

The developed module of constructed wetlands is used as a wastewater treatment unit in a biodiesel manufacturing process, implemented in the simulation software CHEMCAD. This work includes an environmental evaluation of water reuse, economic assessment and possible energy savings of using wetlands in different designs compared with current practices, as well as an integrated design where both technology and wetlands are used at the same time. The tool also allows us to test different topologies and design setups and gain insight into important process design parameters. This case study will also show some of the possible improved designs and the cost saving associated with each by incorporating wetlands in an integrated design, as well as the tradeoffs associated with that.