Synthesis of cost-effective and sustainable pathways to wastewater treatment

Water is one of the most essential resources to sustain all forms of life. The upsurge in global demand at a rate of about 1% per year is due to the rise in population growth, economic development, climate change, among other factors. Unlike energy, water has no ancillary alternatives. There is, therefore, the need to treat and re-use wastewater to meet this increasing global demand. There are various treatment technologies that have been developed over the years – like, sedimentation, filtration, advanced oxidation processes, ultrasonic, among others. One of the main problems associated with the treatment process is that there are different combinations of technologies that inadvertently give rise to different pathways. Furthermore, the cost of treatment is always a major deciding factor in choosing a particular pathway. It is, therefore, imperative to develop wastewater treatment pathways that are capable of meeting the standards for a specific kind of task with a lower cost association. In order to meet these demands, we formulated an optimization problem to find the different pathways that satisfy our functional models, and as well, give the cost of each pathway in a ranking order, from the least to the greatest. These problems were formulated as a mixed integer programming (MIP) optimization problem. They were solved using the integer programming solver, advanced branch-and-bound (ABB) in P-Graph software. A life cycle analysis was carried out for each ranked order using the SPI index methodology.