Urine to Fertilzer DIY Kit. Derive houseplant fertilizer and ocean-safe water from your pee!
We all think of human pee as gross and something that ought to be vigorously “cleaned up” or sanitized. However, human urine is actually sterile (unlike faeces, urine is bacteria-free). This liquid by product of our daily lives can be a rich food source if it gets into the RIGHT part of the right ecosystem. Now, most human urine travels untreated into the waterways and is a significant cause of eutrophication, a toxic condition caused by harmful algae blooms, in the oceans. The excess Nitrogen and Phosphorus in our urine overfeeds algae (like Red Tide) and effectively suffocates fish. However, a pioneering biological waste treament process being used in Switzerland can extract this phosphorus & nitrogen for use as a fertilizer, leaving the rest of urine almost harmless to aquatic life. This kit gives users the opportunity to replicate the new technique at home and fertilize their plants with their own pee.
Users will test their urine before the reaction. Then, they will add an enzyme, wait for their urine to hydrolyse, and then add Magnesium Chloride. A sediment will build up at the bottom of the jar. Using a filter, they will pour off and flush the liquid, leaving the fertilzer in the jar. They can add water and the seeds included in the kit to grow their own watercress in the glass container used for the reaction.
Materials Included in the DIY Kits:
1. Prep and observe: Urinate into the bowl included in the kit. For best results, use your first pee of the day. Pour off excess so that urine level reaches the 200 ml mark on the bowl. Note the smell and color as they are likely to change throughout the reaction. Measure the pH of the urine using one of the pH test strips and the color chart. Record pH here: ____.
2. Create urease solution: Drop distilled water from the included dropper bottle into the vial that contains the Urease (smallest vial with tiny amount of white powder) until full. Cap the small Urease vial and swirl the container around until the urease appears to dissolve in the water.
3. Hydrolyse urea: Use the dropper to extract as much of the Urease solution as possible from the bottle and gently squirt it into the urine. Stir the urine and urease solution with the stirring rod provided. Use the plastic wrap to loosely cover the mixture. Note the time here: _____________. Place in fridge for 1.5 hours. Thoroughly rinse stir rod in running water.
4. Observe: After 1.5 hours, you may notice that the mixture now smells less like urine and more like ammonia. Use another dip stick to test the pH. Write the pH reading here: ____. The pH should have risen. Ideally, the pH should read 9 or above. If it does, proceed to the next step. If the pH reads less than 9, let the mixture sit for a couple more hours before proceeding. Test the pH again and write the result here: ____. Proceed to the next step.
5. Precipitate Struvite: Move to a well-ventilated area if you have not done so already. Slowly begin to add the magnesium chloride powder into the urine while gently stirring with the rod provided. Add only a fraction of a teaspoon at a time. The solution will get warm and may fizz slightly. Continue to stir for 30 seconds after adding all of the magnesium chloride provided. After 5 minutes, you will begin to notice a white sediment, called struvite, accumulating at the bottom of the glass. Allow the struvite to continue to accumulate for several hours- even overnight- or until you do not see any more building up. Thoroughly rinse stir rod with water only.
6. Observe: Test the pH and write your result here: ____. The pH should have decreased again. As the sediment accumulates the pH of the remaining liquid may go as low as 6. At this point, the benign portion of the urine will be in liquid form, with most of the pollutants trapped in the small amount of struvite sediment at the bottom of your container.
7. Filter liquid: Secure the lab filter to the top of your glass bowl with the rubberband. Slowly turn the container over and allow the liquid to gradually drain through the filter into your sink, toilet, or an intermediary container.
After all of the liquid has all passed through and the struvite is beginning to dry, remove the rubberband and push the filter into the bowl. Fill the bowl with tap water and swirl to release the struvite from the filter. Pull the filter out and put in your paper recycling or compost bin.
8. Dilute struvite fertilizer: Leave approximately 1 teaspoon of the struvite-water mixture in the glass bowl, but pour the rest into a watering can or other large container. Add approximately 1 gallon of water. Use this nutrient-rich water to feed your houseplants.
9. Grow edible watercress: Fill the glass bowl with tap water to further dilute the remaining struvite that will nourish your new watercress seeds as they germinate. Sprinkle watercress seeds from the included vial and place in indirect sunlight. They should start to sprout within a few days.
The DrinkPeeDrinkPeeDrinkPee Urine to Fertilizer DIY Kit probes the exchanges between our bodies and the environment. As sentient ecosystems, how do we direct the flow of our biological by-products into the larger ecosystems that sustain us in turn?
You will be prompting ocean-derived magnesium to bond with the nitrogen, phosphorus, pharmacological micropollutants, and other metabolites in your urine. As a result, you will produce a solid fertilizer called struvite and a liquid by-product. You can use the struvite solid as a fertilizer for your houseplants. Its nitrogen and phosphorus content will nourish them and promote root growth. The liquid by-product of the reaction is less likely than your raw urine to create conditions of eutrophication and pharmacological micropollution in the waterways beyond your toilet.
Urine is an aqueous solution of unused electrolytes and metabolites our kidneys produce to maintain homeostasis within our bodies. Every batch of pee is different, but on average, human urine consists of 59% urea.
Urea is an organic compound with the formula (NH2)2CO.
The nitrogen in urea cannot bond with magnesium until hydrolysis frees it from the urea in the form of ammonia. Hydrolysis occurs automatically in nature and in sewage pipes over longer periods of time when sterile urea meets environmental bacteria. You will be accelerating this process by adding an enzyme, a concentrated urease derived from jack beans.
Urease catalyzes the hydrolysis of urea into released carbon dioxide gas and liquid ammonia:
The magnesium chloride (MgCl2) bonds with the nitrogen in ammonia and the phosphorus in the urine to create struvite. Researchers have found that this chemical process is also highly effective in removing some pharmacological micropollutants from the remaining liquid by-product that you will be flushing down the toilet.
Struvite, or ammonium magnesium phosphate, (NH4)MgPO4·6(H2O) has been used as a fertilizer for centuries. The small amount left in the glass bowl will nourish your new watercress seeds as they germinate and allow them to grow hydroponically until maturity.