Estate Living Magazine Design for living - Issue 42 June 2019 | Page 44

I N V E S T
&
D E V E L O P
There are also logistics to be considered: urine collection and
transport to a resource recovery. Randall has discussed these
opportunities in a recent review paper on urine. Another of his
master’s students is investigating the transport logistics of urine
collection and treatment with some very promising results.
Social acceptance is another consideration
‘At the moment we’re only dealing with urine collection from male
urinals because that’s socially accepted. But what about the other
half of the population?’
In the run-up to unveiling the bio-brick, both students expressed
optimism about the potential of innovation in the sustainability
space.
Chemically speaking, urine is liquid gold, according to Randall. It
accounts for less than 1% of domestic waste water (by volume) but
contains 80% of the nitrogen, 56% of the phosphorus and 63% of the
potassium of this waste water.
Some 97% of the phosphorus present in the urine can be converted
into calcium phosphate, the key ingredient in fertilisers that underpin
commercial farming worldwide. This is significant because the
world’s natural phosphate reserves are running dry.
Zero waste
The fertilisers are produced as part of the phased process used to
produce the bio-bricks.
First, urine is collected in novel fertiliser-producing urinals and used
to make a solid fertiliser. The remaining liquid is then used in the
biological process to grow the bio-brick.
‘This project has been a huge part of my life for the past year and a
half, and I see so much potential for the process’s application in the
real world. I can’t wait for when the world is ready for it,’ Lambert
said.
‘Working on this project has been an eye-opening experience.
Given the progress made in the research here at UCT, creating a
truly sustainable construction material is now a possibility,’ Mukhari
added.
Randall said the work is creating paradigm shifts with respect to how
society views waste and the upcycling of that waste.
‘In this example you take something that is considered a waste and
make multiple products from it. You can use the same process for
any waste stream. It’s about rethinking things,’ he said.
‘But in that process, we’re only after two components: carbonate
ions and the calcium. What we do last is take the remaining liquid
product from the bio-brick process and make a second fertiliser,’ he
explained.
The overall scheme would effectively result in zero waste, with the
urine completely converted into three useful products.
‘No-one’s looked at it in terms of that entire cycle and the potential
to recover multiple valuable products. The next question is how to
do that in an optimised way so that profit can be created from urine.’
Helen Swingler, photos by Robyn Walker
This article first appeared in new.uct.ac.za