Hokkaido University Research Profiles

Japanese

6. Clean Water and Sanitation: 4

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  • 1. No Poverty
  • 2. Zero Hunger
  • 3. Good Health and Well-being
  • 4. Quality Education
  • 5. Gender Equality
  • 6. Clean Water and Sanitation
  • 7. Affordable and Clean Energy
  • 8. Decent Work and Economic Growth
  • 9. Industry, Innovation and Infrastructure
  • 10. Reduced Inequality
  • 11. Sustainable Cities and Communities
  • 12. Responsible Consumption and Production
  • 13. Climate Action
  • 14. Life Below Water
  • 15. Life on Land
  • 16. Peace and Justice Strong Institutions
  • 17. Partnerships to achieve the Goal
  • Catalytic Purification of Nitrate-nitrogen Contaminated Water

    High-performance catalyst for reductive decomposition of nitrate-nitrogen

    Groundwater pollution with nitrate-nitrogen has become a problem. We have developed a high-performance solid catalyst that promotes decomposition of nitrate-nitrogen in water into nitrogen gas through a reaction with hydrogen gas at room temperature. Using a purification system incorporating this catalyst, we have succeeded in purifying contaminated groundwater.

    Research

    Groundwater pollution with nitrate-nitrogen has become a nationwide problem. We have developed a high-performance solid catalyst that promotes decomposition of nitrate-nitrogen in groundwater into nitrogen gas, and have also succeeded in purifying actual contaminated groundwater using a purification system incorporating the developed catalyst.
    The treatment of water containing nitrate-nitrogen is predominantly a biological treatment that involves anaerobic and aerobic treatment. The equipment for that is generally large and its operation is complicated. The catalytic water purification system we have developed is very compact and does not require complicated operations, making it possible to purify contaminated water simply by passing hydrogen gas and contaminated water through a temperature-controlled reactor filled with catalyst.

  • Glowing Plankton

    GFP and luciferase in copepods

    Marine organisms include various bioluminescent creatures. We have identified a green fluorescent protein (GFP) and a secreted luciferase (luminescent enzyme) from copepods, the most dominant plankton species.

    Research

    Zooplankton serves as energy transmitters in marine ecosystems, passing basic production to higher organisms. The dominant zooplankton species in the Arctic Ocean are copepods, most of which have a lifespan of one year or less, but their samples can be preserved semi-permanently with formalin fixation, making them an ideal taxonomic group for assessing the interannual variability in biological production in the region. Some species of copepods are also bioluminescent. It is thought that they emit light when they are about to be predated upon in dark waters, and use it to distract predators. We have identified a fluorescent protein (GFP) and a luciferase (luminescent enzyme) from copepods.

  • Simple Pathogen Measuring Devices

    Pathogens can be measured by simply adding samples to the kit.

    We have developed technology that allows measurement of the concentration of E. coli, coliforms, and enterococci within as early as 1 hour and as late as 12 hours after simply adding 0.1 mL of a sample (sewage, wastewater, food extract, drinking water) to the measurement kit and installing it in the device.

    Research

    Currently, the measurement of pathogenic bacteria requires a much time and labor, including the preparation of agar media, multiple dilutions of a large amount of sample, and 24-hour incubation. We have developed a kit that can measure pathogenic bacteria (fecal contamination indicator bacteria) such as E. coli, coliforms, and enterococci simply by injecting 0.1 mL of liquid sample or food extract. Compared to the current general bacteria measurement technology, this is an extremely simple technology that requires only mixing of the sample with the solution. The bacterial concentration is measured using a fluorescent dye. The fluorescent dye can be used even if the liquid is turbid, so the concentrations of various bacteria, even in turbid samples such as wastewater or food extracts, can be measured directly without any pretreatment.

  • Superomniphobic Aluminum

    Simple production of antifouling surfaces through a wet process

    We have successfully fabricated a micro/nano-hierarchical surface morphology through chemical etching/anodization of aluminum sheets and meshes. By coating the surface with a fluoroalkyl monolayer, we have also succeeded in obtaining a surface that is not wetted by almost any liquids, including oil.

    Research

    It is expected that superomniphobic surfaces, which do not get wet with water or oil, will possess antifouling and self-cleaning properties. In this study, we have realized a superomniphobic surface that does not only repel water but also octane and other liquids with a surface tension as low as 20 mN m-1, by using a simple wet process for aluminum, which is a practical metal material. This process can also be applied to aluminum foil, which can be used as an antifouling surface in various places. It can also be used as a filter to separate oil and water by controlling its wettability using aluminum mesh.