Environmental Engineering [Prof Jaeweon Cho] at South Korea’s Ulsan National Institute of Science and Technology specializes in water and waste management. He has developed an energy-generating toilet called BeeVi (pronounced beevee) that recycles your waste in three ways. Liquid waste is processed in a microbial reaction tank to make a liquid fertilizer. Solid waste is pumped into an anaerobic digestion tank, which results in methane gas used to power a silicone oxide fuel cell to make electricity. The remaining solids are composted to make fertilizer. The daily waste from one person is about 500 g, which can generate about 50 L of methane.
The BeeVi toilets, located on the UNIST campus, pay students in a digital currently called Ggools, or Honey Money in English. Each deposit earns 10 Ggools, which can be used to purchase coffee, instant noodles, and other items (one Ggool is equivalent to about $3.00 value). The output from this pilot project is used to partially power the building on campus, and to fertilize gardens on the grounds. If you want to learn more, here is a video lecture by [Prof Cho] (in English).
Waste management is an area of research around the world. The Gates Foundation has been funding research into this field for ten years, and has held a number of expos over the years highlighting innovative solutions, most recently being the 2018 Reinvent the Toilet Expo in Beijing. We wrote a piece about the future of toilets last year as well.
Continue reading “Modern Toilet Generates Energy”
We’ve seen countless automated plant care systems over the years, but for some reason they almost never involve the secret sauce of gardening — fertilizer. But [xythobuz] knows what’s up. When they moved into their new flat by themselves, it was time to spread out and start growing some plants on the balcony. Before long, the garden was big enough to warrant an automated system for watering and fertilizing.
This clever DIY system is based around a 5L gravity-fed water tank with solenoid control and three [jugs] of liquid fertilizer that is added to the water via peristaltic pump. Don’t worry, the water tank has float switches, and [xythobuz] is there to switch it off manually every time so it doesn’t flood the flat.
On the UI side, an Arduino Nano clone is running the show, providing the LCD output and handling the keypad input. The machine itself is controlled with an ESP32 and a pair of four-channel relay boards that control the inlet valve, the four outlet valves, and the three peristaltic pumps that squirt out the fertilizer. The ESP also serves up a web interface that mimics the control panel and adds in the debug logs. These two boards communicate using I²C over DB-9, because that’s probably what [xythobuz] had lying around. Check out the demo video after the break, and then go check on your own plants. They miss you!
Don’t want to buy just any old peristaltic pumps? Maybe you could print your own.
Continue reading “Automated Watering Machine Has What Plants Crave: Fertilizer”
For all but the most experienced gardeners and botanists, taking care of the soil around one’s plants can seem like an unsolvable mystery. Not only does soil need the correct amount of nutrients for plants to thrive, but it also needs a certain amount of moisture, correct pH, proper temperature, and a whole host of other qualities. And, since you can’t manage what you can’t measure, [Jan] created a unique setup for maintaining his plants, complete with custom nutrient pumps.
While it might seem like standard plant care on the surface, [Jan]’s project uses a peristaltic pump for the nutrient solution that is completely 3D printed with the exception of the rollers and the screws that hold the assembly together. With that out of the way, it was possible to begin adding this nutrient solution to the plants. The entire setup from the pump itself to the monitoring of the plants’ soil through an array of sensors is handled by an ESP32 running with help from ESPHome.
For anyone struggling with growing plants indoors, this project could be a great first step to improving vegetable yields or even just helping along a decorative houseplant. The real gem is the 3D printed pump, though, which may have wider applications for anyone with a 3D printer and who also needs something like an automatic coffee refilling machine.
If you are using live plants in your aquarium you must remember to fertilize them at regular intervals. Being a bit forgetful, [Deven] automated the process by building this auto-doser.
There are three different chemicals which are dispensed by the system. They are stored in the drink bottles seen above. Each has a plastic tube which runs up to the dosing motors mounted on the black box. [Deven] sourced the motors from eBay. They are designed for this type of application.
Inside the black box is the Arduino that handles timing and switches the motors. The control circuitry is protected using one MOSFET for each. To keep the fish safe the outflow is directed right into the aquarium pump so that the concentrated chemicals are quickly dispersed through the entire tank.
Now that he’s made it this far he might as well add the ability to feed the fish and control the lighting.
Continue reading “Automated Aquarium Fertilizer Doser”
Keeping live plants in an aquarium happy can be quite a chore. One of the frequent rituals is adding fertilizer, which is called dosing. [Majstor76] came up with a creative way to automatically dose using an air freshener. He got rid of the canister that holds the scent and re-purposed a hand soap pump to move the nutrient-rich liquid. After the break you can see that there’s no shortage of power to actuate the pump and the powered air freshener base has a delay circuit, allowing for a few different time-release options. As long as the volumetric output is fairly consistent we figure you can dilute your fertilizer to fine-tune the dose.
Continue reading “Fertilizing A Planted Aquarium Using Air Freshener Hardware”