Sanitation concerns in Anthroponics systems

As we explore the potential to use human waste for growing food or crops, it is essential to not overlook or underestimate the potential health concerns of such an endeavor.

Let us start with u-anthroponics:

The current proposed methodology for using human urine in a sanitary way for an aquaponics/anthroponics application was documented in the master thesis “Aquaponics and its potential aquaculture wastewater treatment and human urine treatment“. There, the methodology used was based on the methodology used by Pradhan et al, in their 2007 research paper “Use of Human Urine Fertilizer in Cultivation of Cabbage (Brassica oleracea)––Impacts on Chemical, Microbial, and Flavor Quality” (Alternative link).

In both cases, the urine is separated at source from a healthy individual, under no type of medication and without any current disease. While this restriction prevents any large-scale application, it ensures a first layer of protection in terms of potential problems. After the urine is collected, it is kept in a sealed container where the process of urea volatilization will occur. That chemical reaction is described in p.12 of the master thesis and also in the wikipedia page about Ammonia volatilization from urea. The urine is generally stored until its pH reaches a value of 9, which according to Pradhan et al achieves a reduction of the bacterial population and therefore its sterelization. Further research such as conducted by  Hilt et al has shown that fresh urine is not sterile, so a sterelization step such as the one described above is necessary to ensure further sanitation.

However, reaching a pH of at least 9 is a process that can take several weeks up to a month depending on several conditions. There is little information on how to optimize this process, and as such its an essential area that warrants further research for future anthroponic applications.

Moving on to f-anthroponics:

Since there is no record of a feces based aquaponics system ever being constructed, there is little information on how safe this practice would be or if at all possible. However, there exists some base research done which allows us to infer how such a practice could be created and be sanitary, thus protecting its users.

As described in the Types of Anthroponics Systems, the feces would be collected into a recipient where black soldier fly larvae would consume the feces. This process is described by Banks et al 2014 research paper “Growth rates of black soldier fly larvae fed on fresh human faeces and their implication for improving sanitation” (Alternative Link), where it was reported that feeding black soldier fly larvae human feces resulted in significantly larger growth. On the other hand, feeding black soldier fly larvae is a well-known type of fish feed practice in the aquaponics community, having been documented by the master thesis “Integrating Biosystems to foster Sustainable Aquaculture: Using Black Soldier Fly Larvae as Feed in Aquaponic Systems” (Alternative Link).

In order to enable this type of feces-based anthroponics system, some sort of sanitary action must be taken between the harvesting of the black soldier fly larvae and its use for feeding the fish. I proposed a solution in the anthroponics subreddit, which explained:

  • Only use feces from a healthy individual, under no type of medication or without an illness, and without any blood on the feces;
  • freeze the papua before feeding them to the fish;
  • most importantly, keep the handling of the feces/larvae and touching the plants separate, and always wash your harvest thoroughly just in case.

So, basically, the way to ensure the process is sanitary, according to my current understanding of some microbiological processes, is to follow a simple precautionary process to u-anthroponics, and on top of that to wash/clean the harvested black soldier fly larvae, to freeze them and to always keep the handling of the feces/larvae and the growing plants separate.

However, unlike u-anthroponics, f-anthroponics requires a much stricter waste handling since the feces arent sterilized, and overal has more problems that need to be overcome. In theory, f-anthroponics systems (as the one described in this blog) can be sanitary, but only a real world prototype with adequate testing material will be able to compare the final product with, for example, an equivalent product using cow manure as fertilizer.

Anthroponics thesis

I have recently finished my master thesis on the topic of aquaponics and its potential aquaculture wastewater treatment and human urine treatment (aka “peeponics”). While I wasn’t able to mention the term anthroponics (as it wasn’t used widely enough), this thesis can be considered one if not the first academic document on the topic of anthroponics (more specifically, u-anthroponics). The thesis is in english and can be viewed below:

Sanchez 2014

Alternatively, it was uploaded to mediafire and shared with the r/aquaponics and r/anthroponics community. The mediafire file can be viewed here.

A brief comparison of aquaponic home solutions

This past Thursday I had the privilege of being able to pitch the idea of aquaponics in a portuguese university contest, as I was one of the 16 semi-finalists. While I was not selected for the second round, I had prepared alongside with a classmate a brief comparison of all home aquaponic systems currently being marketed that we could find. I believe that information such as this might be valuable for anyone interested in aquaponics and anthroponics, and there was no reason for it to become lost in my computer, so I decided to share it here.

All of the home aquaponic systems I will talk about further on are pioneers, since they are presenting some of the first products that will make it more convenient, simple and practical to have aquaponic systems in urban environments, and sometimes in very small spaces. For that reason, I think they are very important to cover in an anthroponics blog, since these systems are paving the way for future anthroponic systems with easier maintenance and operability. So let’s start!

Home Aquaponics Systems

Name: Home Aquaponics Kit
Price: ~45€
Websitehttps://www.backtotheroots.com/shop/aquafarm

homeaquaponicskit

About: This portable aquaponics system is, I believe, one of the first to show just how small aquaponic systems can be. Some people in reddit and aquaponic forums have expressed concerns over the available water volume for the fish, but nobody can deny that it is a very well designed product from an aesthetic perspective. Despite being highly portable, its size also limits its production capacity, making it suitable for a small amount of salad greens or herbs.


Name: Aquaponicals
Price: ~115€
Websitehttp://aquaponicals.com/
aquaponicals2

About: This other portable aquaponics system seems like a direct response to the previous one. It has been endorsed by Murray Hallam and Sylvia Bernstein, and it is mostly fascinating for me in the way that it uses a very small autosiphon as well as a sump tank. Like the previous one (and in fact, all of the following ones), it is well designed and aesthetically appealing. However, its portability also limits its production, restricting it to growing a small amount of salad greens or herbs.


Name: Aquasprouts
Price: ~90€ (Kickstarter only)
Websitehttp://www.aquasprouts.com/
aquasprouts
About: This system has a different approach to the previous two. Instead of designing a whole system, Aquasprouts is a product that you can install directly in your existing aquarium, thus extending the potential users they can appeal two. It is also bigger in size, thus enabling a slightly bigger production of salad greens and herbs.

Name: AquaDesigner
Price: ~195€ – ~620€
Websitehttp://www.theaquaponicstore.com/Aquaponic-Systems-AquaDesigner-s/477.htm
aquadesigner2
About: AquaDesigner products are a range of aquaponic systems designed for indoor or outdoor systems with a focus on design and ambiance/tranquility, rather than systems with a food production approach. As such, they can be used both to grow some herbs as well as to have ornamental flowers to add more ambiance/tranquility to the location of the system.
 

Name: Aqualibrium
Price: ~490€
Website: http://www.aqualibrium.com/
aqualibrium
About: Aqualibrium is a type of aquaponics/hydroponics product with a significant increase in production capacity compared with most of the previous mentioned systems. However, its design with clear plastic in all system components could prove problematic in the future with algae blooms. It is, once more, a beautifully designed system, with a living room size and enabling the production of salad greens, herbs and also fruit plants. 

Name: Aquabundance
Price: ~1 110€
Websitehttp://www.theaquaponicstore.com/AquaBundance-SpaceSaver-Aquaponics-System-p/tpdas101.htm
aquabundance2
About: The Aquabundance products are big enough to enable a sufficient production of both salad greens, herbs and fruit plants as well as edible fish. However their relatively big size restricts them to a bigger living room or balcony location. 

Name: Farm Tower Renegade
Price: ~2 376€
Websitehttp://store.diyhomeaquaponics.org/

farmtowerrenegage

About: This aquaponics system presents the biggest production potential of all the systems presented here. It also enables different arrangements, allowing for a purely hydroponic set-up, an aquaponic set-up, or an aquaponic set-up where the fish food comes from the vermicomposting level. Its big size might restrict it its application to garages, basements or big rooms.


And there you have it! I’m sure I’ve forgotten some systems, but this list should give you a small idea of what’s already out there and to appreciate the efforts of all the companies and individuals behind these products to spread aquaponic systems to households and urban areas.

Types of Anthroponics Systems

Like aquaponic and hydroponic systems, anthroponic systems can be made of different system components. The most common ones in aquaponics include Media Bed systems, Nutrient Film Technique (NFT) systems, Deep Water Culture(DWC) or Raft systems and hybrids containing two or more of these types. Unlike aquaponic systems however, anthroponic systems can be further broken down into two main systems:

  • urine-based anthroponics systems (u-anthroponics) and 
  • feces-based anthroponics systems (f-anthroponics).

While it may be possible for future anthroponic systems to combine both urine and feces in the same system, currently such system has not been devised.

Current constructed and idealized anthroponic systems are very similar in most of the system components to aquaponic systems, making them easy to understand by those knowledgeable of aquaponic systems.

Let’s start with analyzing a simplified diagram of a u-anthroponics system. Inputs are colored in yellow, the main system with recirculating water in a soilless environment is colored blue, and the output is colored green (click to zoom).

u-anthroponics

U-Anthroponic system overview

Unlike aquaponics, the main nutrient is human urine, which must be placed in a sealed container and aged until it is safe for used. The aged urine is then placed in the water reservoir or sump tank of the system, where the pump is located (remember, there is no fish tank in this system as there are no fish). The urine is diluted and converted into nutrient rich water after passing through the biofilter, where nitrifying bacteria convert the urine to plant fertilizer. The water is then recirculated over and over again, feeding the growing components of the system and allowing for plant growth, coupled with light.

F-anthroponics, to the best of my knowledge, have never been constructed or tested in real life. As I have envisioned them and discussed them in a r/anthroponics thread, they resemble aquaponic systems more since they incorporate fish and a relatively common fish food source: Black Soldier Fly Larvae (BSFL).You can see a f-anthroponics simplified diagram below. Again, inputs are colored in yellow, the main system with recirculating water in a soilless environment is colored blue, and the output is colored green (click to zoom).

 

f-anthroponics

 

F-Anthroponic system overview

Here, the feces are eaten by Black Soldier Fly Larvae which are frozen to kill any potential pathogens and then fed to the fish, with the following cycle resembling the well-known aquaponics nitrogen cycle.

In theory, this type of f-anthroponics should work. One major downside of using feces as a nutrient source is their handling, as they have a very uncomfortable smell and require strict safety measures. I believe the design of a system that minimizes direct human contact with feces and the harvested BSFL will be crucial in turning this type of anthroponics system into a viable and serious alternative.

Why Anthroponics?

Let’s recollect an all too familiar experience for most of us in the so called “developed” world.

You are sitting at your desk, browsing your computer. Suddently, that familiar feeling comes, distracting you from your work or your entertainment. You ignore it, at first, since there are more important things that require your attention. But the urge keeps on increasing, slowly, over time. Suddenly, it’s the only thing on your mind. You head to the bathroom and release a golden stream in your toilet. After you’re done cleaning, you press the magical button and you never have to think about it again.

Most people never bother to think about something as yucky as urine, since we have all been taught to just dispose of it in the appropriate places and ignore it. But the truth is that we are part of an ecosystem, and our outputs are part of an intricate web that connects trophic levels of organisms with soil, water and air resources. For this ecosystem, our urine is valuable and will be processed to feed other organisms in other levels, recycling the nutrients until they reach us again.

But in our cities, we have constructed a slightly different reality. Once we flush our urine down the toilet, we immediately dilute it with freshwater, a precious resource. Our urine will meet other wastewater streams which will contain feces and other fluids until it reaches a wastewater treatment plant. If your city has a combined sewer system (which means the stormwater runoff from rains is mixed with wastewater in the pipes), then your urine will be diluted even further.

Depending on the wastewater treatment plant capacity and technology, the sewage might just suffer a light treatment to meet municipal standards for discharge in a nearby stream, river, lake or ocean. Alternatively, the sewage might suffer further biological degradation and filtration to meet stricter standards. By-products of a wastewater treatment plant include sludge and treated water. The treated water is returned to the ecosystem, whereas sludge may be dried and used for compost and agricultural practices or digested and used for energy production.

Sounds like a good deal overall, right?

Nonetheless, most of us who study wastewater engineering know how expensive and energy intensive these processes can be. On top of that, many of these wastewater treatment plants provide a single point of failure network, making them particularly vulnerable to a sudden power failure, machine malfunction or overwhelming influent. The reason why conventional wastewater treatment is so expensive and energy intensive is due to the fact that some of the main processes’ goal is to separate solids and nutrients from the water, something that could have been easily prevented in the start of our urine journey!

This is why dry/composting toilets or separating toilets have been the topic of research over recent years, since they can supply a solution to the dillution issue, and they keep urine and feces separated for their potential different uses. On the other hand, they are limited in the user benefit they provide, since composting for example takes a considerable amount of time and “only” produces soil as a by-product.

However, most people are not interested in taking care of their waste simply out of the goodness of their hearts or because of environmental awareness, especially considering how unpleasant the smell can be. Even composting might take at best 3 months until you have an useful by-product, and might require too much space to handle daily waste flows.

Anthroponics may be able to provide a more viable alternative since it is a decentralized system which provides the user with a direct benefit: a crop which the user can consume, sell as a fresh produce or process into a product and sell. Anthroponics can be a sustainable way to grow food and fish, without the use of fossil-fuel based industrial fertilizers, while at the same time treating wastewater.

As anthroponic systems are pioneered and explored, their limitations will become clear. But for now, they warrant enough curiosity so that we can think and imagine how we can incorporate them in our apartments and households so we can create more resilient and sustainable agricultural production systems and wastewater treatment systems.