How Words Can Constrain Creative Solutions
As an area where biomimicry, or “learning from nature” is a valid approach, sewage seems a good choice: isn’t the process of a cow pat, slowly becoming cow food (grass) again, a more elegant option than a noisy smelly sewage plant?
Current sewage treatment offers lots of scope for improvement: it uses bacteria, but also a lot of energy, and disposes of the output. Not much in line with Nature’s circular, low-energy world where waste has no place.
The incentive is there too: 30% of global farm land degraded and with poor moisture retention, water shortages, climate change, cities struggling with effluent: plenty of greenery nearby could do with a boost.
Sewage in Today’s Context
Over 80 per cent of wastewater goes into the environment without treatment, in some countries over 95%. But also in the treated sewage, the euphemistically named “emerging pollutants” are growing in amount and number: pharmaceuticals (including antibiotics), personal care products, pesticides, herbicides, surfactants, some 40,000. I prefer the old term “persistent organic compounds”: they’re certainly persistent. Health effects are concerning, yet often unknown.
The usual approach to today’s sewage issues consists of regulating and then letting the sewage industry do its job. As an established industry, they are bound (by shareholders) to do “more of the same”: big infrastructure with a large carbon footprint and high running costs, each “improvement” adding complexity and maintenance cost to a simple basic process. Meanwhile the persistent contaminants keep on going into the environment, the carbon emissions into the atmosphere, and tax money to new constructions.
There exist proven, practical, affordable, and relatively “simple” solutions, with a zero or negative carbon footprint, yet we fail to apply them.
Not simply sewage: it’s the words “simple” and “sewage”.
The word “sewage” implies waste, something we need to get rid of. It implies stench, disease, and vermin; it is horrible, and says: “let’s get rid of that (problematic) sewage”.
The word “simple” implies we can understand exactly how it works, so the solutions can be engineered, built and then just switched on.
Both words block creativity and focus the industrial mind‑set firmly on reducing the problem quickly to a disposable size. Which is precisely what we do, and it’s not helpful when we really need to think freely about this huge steam of nutrients, and what great good it might bring.
A Weakness of Biomimicry
When I mentioned earlier that there are proven practical, affordable, and relatively “simple” solutions, I was referring to “Natural Sewage Treatment”, effectively biomimicry. Proven over decades, yet with little mainstream acceptance; not just “constructed wetlands”.
Looking attentively at nature, two things stand out – Nature knows no waste, and “natural processes” may look simple but are often both complex and complicated. That last part is great for researchers, who can keep on discovering. It’s less great for engineers with a desire to “biomimic”, because they want to fully explain each function in detail.
Strength of Biomimicry
In pursuit of “natural solutions”, we need to accept these two features of nature: “no waste” and “the detail could be complicated”.
If we become blind to the “waste” concept of sewage and focus on the value side, can we turn what we have into what nature (including humans) would like to have?
Nature breaks sewage -a mix of excrement, water and other mostly biological matter- down into smaller components and uses this to grow stuff. The “sewage to fertilizer” process, evolved over millions of years, works well. The big question is: how does nature break down these components? And the answer to that question is the engineer’s nightmare: with bacteria, thousands, maybe millions of different types.
The dismal “state of the art” solution
The engineer’s nightmare is not that it’s bacteria, but that it’s “thousands or millions of types”, so solutions “must be” simplified down to these two options:
Option 1: A machine which uses a limited number of different bacteria, with predetermined outcomes, and optimizes the environment for these few bacteria - a modern, noisy, energy consuming sewage treatment plant.
Option 2: A machine which uses a different range of bacteria, and produces biogas to sell, usually with reduced cleanliness for disposal – a modern biogas unit.
This is the state of the industry, with ever bigger compressors, stirrers, now adding things like high pressure microfiltration, to improve the outflow (waste) specification.
A mind-set lesson from a Chip…
Several decades ago I looked to design usable electronics from basic components, and struggled. When a co-student said: “there’s a chip that does roughly that, buy that and make it work”, I realised: there’s no need to understand what the chip does inside its black box: just connect the pins, test, and adjust. It was a mind-set issue; to be effective, not scientific.
…taken to natural sewage treatment.
In natural sewage treatment this same black box idea can work. There are people who know how to get a good number of the right bacteria to do their job in decomposing sewage to harmless effluent, including most persistent compounds. While they may not know each bacteria strain, they know what works overall.
Once commissioned, the installations work away quietly, and few people take notice. That compounds the problem: they look like parks or gardens, and few realise they’re coupled anaerobic/aerobic sewage systems, with flowers and plants selected for root structure, nutrient need, and resilience, and a size footprint no greater than an industrial installation. Variable residence times vastly improve results, yet little maintenance is needed. Their effectiveness restricts their fame – nice peaceful spaces rarely make the news.
Changing the frame
Now here’s a project which will change the common frame of reference in many ways, simultaneously. It’s a sexy (circular farm) system, from a proven design, with animal manure to start with. Effectiveness and resilience will be rigorously analysed under a range of parametric changes.
Results will be published to allow replication elsewhere, anywhere. By open-sourcing outcomes and data standards, expect accelerated learning from other locations and situations, turning around today’s inefficient and wasteful sewage treatment practices.
There’s more information in a short (16 min.) film produced for the ThinkDif circular innovation conference, [here]. Or link to it from www.circular-canary.com.
The unasked question: “what can we grow with this stream of nutrients”, is also part of the project: the complete project covers disassembly and reassembly, which are very much connected.
As you’d expect from nature.