Skyscraper Competition 2021
Nuclear-contaminated water sources have caused environmental problems since Japan’s Fukushima nuclear power plant was destroyed by an earthquake-triggered tsunami in March 2011, and radioactive wastewater is produced during the process of cooling of disused nuclear power plants. Under the influence of the earthquake and the tsunami, the operating equipment and the cooling system of the nuclear power plant were completely destroyed. In order to avoid the collapse of this nuclear power plant, the workers have been continuously pouring water into it to cool the core for ten years. Indeed, the water used for cooling will fix a large quantity of radionuclide after having been injected into the core; therefore, these waters cannot be reused. After preliminary purification of nuclides, the radioactive wastewater that has been essentially purified will be stored in water tanks, but the element tritium in it is still difficult to remove. In 2020, the amount of wastewater in all water reservoirs exceeded 1 million tons, and this figure continues to increase dramatically. Nowadays, a large amount of waste water containing tritium elements needs to be treated urgently.
Challenge and Opportunity
In 2020, the team of Japanese experts proposes to discharge wastewater containing tritium into the ocean. Experts point out that the ocean can dilute sewage containing tritium. However, the impacts of tritium elements on all creatures have yet to be tested. Once sewage discharged into the ocean, these tritium elements could accumulate in marine organisms and eventually reach the human body through the food chain. Worse still, these tritium elements could spread to all parts of the world with ocean currents. In my opinion, there should be a better solution to treat wastewater in an environmentally friendly way. Therefore, the tritium removal skyscraper is designed to purify waste water and recycle tritium elements for industrial purposes. Meanwhile, the skyscraper can be quickly built and implemented to purify sewage.
The skyscraper is designed to use a diffusion-based method to remove tritium from water by converting the tritium in the water into a stream of elemental hydrogen, which then passes through membrane diffusion for separation and tritium enrichment. Then the tritium flux will be enriched by the thermal diffusion parts. This process combines the high flux capability of membrane diffusion at low tritium concentrations and the simplicity of thermal diffusion for final tritium enrichment. In the membrane diffusion step, a metal membrane permeable to hydrogen is used to effectively enrich the element tritium, and this method can be used safely at low pressure and temperature. Finally, the element tritium can be completely removed from the water, and clean water can be poured into the ocean.