Optimization of Dual-Media Filters for Blue Energy

Fouad Farnisa

Bachelor's thesis

Abstract:

The human population reached 8 billion in 2022 and continued to grow which caused an increased demand on agriculture, infrastructure and of course energy production. The human populations’ need placed a huge strain on the environment in terms of deforestation, habitat disruption, and global climate change from which the effects became evident. To accommodate the needs of a growing population sustainable practices were necessary; the focus being on sustainable energy production. As the climate became less agreeable due to climate change renewable energy sources which depended on natural resources, such as hydroelectric dams and photovaultailc became negatively affected. Energy production through reverse electrodialysis (RED) was a novel form of energy production which gained traction as a promising renewable energy resource somewhat unaffected by climate variability. RED was a form of salinity gradient energy by which energy was captured from an energy potential formed by saline and freshwater on either side of a charged membrane. The main issue with Blue Energy, being membrane fouling, which increased resistance caused by scaling and formation of biofilm on membranes leading to a decrease in net power output. The aim of this thesis was to optimize the pre-treatment, thereby reducing fouling and increasing the amount of energy produced. Two alternate media bed configurations were used for the filtration system, namely activated filter media (AFM) and sand to compare filtration efficiency. Lab analyses were performed on the collected samples to analyze how much organic and inorganic matter made it through the filters; a metric which was used to determine filter efficiency. The primary results from the experiments & analyses were that AFM increased effluent quality for seawater whilst sand media removed more turbidity from freshwater. Sand filtration had an overall higher power density when compared to AFM, which highlighted the importance of high effluent quality of freshwater for RED.

Keywords

Blue Energy, Activated Filter Media, Stacks, Ion Exchange Membranes, Renewable Energy, Salinity Gradient Energy, Reverse Electrodialysis, Fouling, Backwashing

Language used: English

Date on which the thesis was submitted / produced: 3. 4. 2023

Thesis defence

• Date of defence: 23. 5. 2023
• Supervisor: Ing. Roman Juras, Ph.D.
• Reader: Marek Vach, Ph.D.

Czech University of Life Sciences Prague

Faculty of Environmental Sciences

Bachelor programme:
Environmental Engineering