In a race against scarcity of Earth’s resources, scientists have been looking at possible ways for reducing nutrient depletion. The goal is to reduce and reuse right? As dirty as it sounds, scientists from the University of Hong Kong (and from other parts of the world) have been experimenting with ways to remove nutrients/elements Nitrogen (N), Phosphorous (P) and Potassium (K) from your urine. Yes, that’s right, the goal is to remove these nutrients from your “waste” and reusing them as soil/plant fertilizers to harvest at a more efficient rate. This process of extracting these nutrients from your excretion and used bathing water has been made possible by the process of “Forward Osmosis”. Basically using electrical currents and the ionic properties of these nutrients, they are passed through a membranous sheet that is made out of a cellulose triacetate (CTA). The liquid of your “waste” passes one way and the nutrients of interest stay one side. Although this process does sound simple, they have yet to perfect it. They have found that fresher urine has a more efficient outcome, and the older it is the more energy has to be used to have a successful stripping. Although it has not been perfected, this a process has shown that the benefit beats the cost at a high percent.
Figure 1: Urban nutrients are taken
from households, waste is separated into urine (yellow) / feces (brown) /
bathing water (grey). FO processes the different waste, then extraction is used
as fertilizers.
References:
Zhang, J. et al. 2014. Mining nutrients (N, K, P) from urban source-separated
urine by forward osmosis dewatering. Environmental science technology. DOI:
10.1021/es405266d
No comments:
Post a Comment