Anthroponics is a type of hydroponics system that uses human waste like urine as the source of nutrients for the cultivated plants. In general, the human urine or mixed waste is collected and stored for a period of time, before being applied either directly or passed through a biofilter before reaching the plants. As a form of organic hydroponics, anthroponics combines elements of both hydroponics and aquaponics systems.
While human waste has historically been used as a fertilizer, its use in soilless systems is a recent field of research. The earliest published research on the topic is in 1991 by researcher Guterstam, B., in which the treatment of domestic wastewater by an aquaculture and hydroponic mesocosm is described. [1]
Since then, other researchers have explored both human mixed waste and human urine as nutrient sources for hydroponic cultivation, studying the potential of such waste, [2] comparisons to traditional fertilizers, [3] both in the context of wastewater treatment, [4] [5] agriculture, [6] and even space exploration. [7]
Urine is 91-96% water, with urea constituting the largest amount of solids, and the rest being inorganic salts and organic compounds, including proteins, hormones, and a wide range of metabolites [8]
The urea in urine naturally converts into ammonia through a process known as ammonia volatilization from urea. This process, which can take between 5 weeks to 6 months, increases the pH of the liquid to 9, thus sterilizing it. [9] [10] The time it takes for this process to occur can be drastically reduced to hours or minutes through the addition of the urease enzyme, which can be synthesized or found in watermelon seeds. [11] The sterilized and volatilized liquid is then passed through a biofilter where nitrifying bacteria convert the ammonia to nitrate, a more plant available form of nitrogen.
It has been experimentally shown that on average 0.47mL of human urine can grow 1 gram of lettuce, therefore given that on average an adult human produces around 1.4 litres of urine in just one day, it is estimated that one human adult could produce almost 3 kg of lettuce from the volume of urine excreted in just one day. [9] Wood ash has also been used to supplement urine when cultivating cucumbers, as they require more nutrients than those found in urine. [12]
After the biofilter, the water is transported to the hydroponic component where the plants are located, and where they will absorb the nutrients, cleaning the water before it returns to the biofilter. Almost all techniques used in hydroponics and aquaponics are also applicable to anthroponics. These include: Deep water culture, Nutrient film technique, and Media beds.
Urine based solutions in hydroponics research seem to have been developed out of sustainability concerns with current mineral based hydroponic solutions. Mineral based commercial nutrient solutions are resource intensive and energy demanding, while also producing a lot of waste. The activities involved in its production include: mining, ore treatment, chemical processing, and transportation, which result in the required nutrients for the final solution. The whole process requires fossil fuels, electricity, chemicals, and water, while producing the nutrient solution, but also mining waste, greenhouse gases, and wastewater. By comparison, using urine as the nutrient source requires the collection of urine, electricity, some nutrient salts, and water, while producing no waste, limited greenhouse gases, and the final nutrient solution. [3]
Some disadvantages concerning the use of urine as the nutrient source in an hydroponics system include strict laws concerning the use of human waste in food crops, [13] the unpleasant handling and odors produced by human urine, and the release of persistent organic pollutants [14] and trace metals in human urine. [15]
Hydroponics is a type of horticulture and a subset of hydroculture which involves growing plants, usually crops, without soil, by using water-based mineral nutrient solutions in aqueous solvents. Terrestrial or aquatic plants may grow with their roots exposed to the nutritious liquid or in addition, the roots may be physically supported by an inert medium such as perlite, gravel, or other substrates. Despite inert media, roots can cause changes of the rhizosphere pH and root exudates can affect rhizosphere biology and physiological balance of the nutrient solution by secondary metabolites.
Urea, also known as carbamide, is an organic compound with chemical formula CO(NH2)2. This amide has two –NH2 groups joined by a carbonyl (C=O) functional group.
A fertilizer or fertiliser is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from liming materials or other non-nutrient soil amendments. Many sources of fertilizer exist, both natural and industrially produced. For most modern agricultural practices, fertilization focuses on three main macro nutrients: Nitrogen (N), Phosphorus (P), and Potassium (K) with occasional addition of supplements like rock dust for micronutrients. Farmers applying these fertilizers in a variety of ways: through dry or pelletized or liquid application processes, using large agricultural equipment or hand-tool methods.
Aquaponics is a food production system that couples aquaculture with the hydroponics whereby the nutrient-rich aquaculture water is fed to hydroponically grown plants, where nitrifying bacteria convert ammonia into nitrates.
Biofiltration is a pollution control technique using a bioreactor containing living material to capture and biologically degrade pollutants. Common uses include processing waste water, capturing harmful chemicals or silt from surface runoff, and microbiotic oxidation of contaminants in air. Industrial biofiltration can be classified as the process of utilizing biological oxidation to remove volatile organic compounds, odors, and hydrocarbons.
A constructed wetland (CW) is an artificial wetland to treat sewage, greywater, stormwater runoff or industrial wastewater. It may also be designed for land reclamation after mining, or as a mitigation step for natural areas lost to land development. Constructed wetlands are engineered systems that use the natural functions of vegetation, soil, and organisms to provide secondary treatment to wastewater. The design of the constructed wetland has to be adjusted according to the type of wastewater to be treated. Constructed wetlands have been used in both centralized and decentralized wastewater systems. Primary treatment is recommended when there is a large amount of suspended solids or soluble organic matter.
BioHome was a small facility created by NASA in the late 1980s that could support one person in a fully functional habitat. One of the influences on the project was the results from data obtained on the 1973 Skylab 3 (SL-3), where a total of 107 VOCs were offgassed by synthetic materials that composed the SL-3. However, the study of indoor air quality was not the only focus of the project, as it was a part of research into closed ecological life support systems.
Organic fertilizers are fertilizers that are naturally produced. Fertilizers are materials that can be added to soil or plants, in order to provide nutrients and sustain growth. Typical organic fertilizers include all animal waste including meat processing waste, manure, slurry, and guano; plus plant based fertilizers such as compost; and biosolids. Inorganic "organic fertilizers" include minerals and ash. The organic-ness refers to the Principles of Organic Agriculture, which determines whether a fertilizer can be used for commercial organic agriculture, not whether the fertilizer consists of organic compounds.
Struvite (magnesium ammonium phosphate) is a phosphate mineral with formula: NH4MgPO4·6H2O. Struvite crystallizes in the orthorhombic system as white to yellowish or brownish-white pyramidal crystals or in platy mica-like forms. It is a soft mineral with Mohs hardness of 1.5 to 2 and has a low specific gravity of 1.7. It is sparingly soluble in neutral and alkaline conditions, but readily soluble in acid.
Ecological sanitation, commonly abbreviated as ecosan, is an approach to sanitation provision which aims to safely reuse excreta in agriculture. It is an approach, rather than a technology or a device which is characterized by a desire to "close the loop", mainly for the nutrients and organic matter between sanitation and agriculture in a safe manner. One of the aims is to minimise the use of non-renewable resources. When properly designed and operated, ecosan systems provide a hygienically safe system to convert human excreta into nutrients to be returned to the soil, and water to be returned to the land. Ecosan is also called resource-oriented sanitation.
Vertical farming is the practice of growing crops in vertically stacked layers. It often incorporates controlled-environment agriculture, which aims to optimize plant growth, and soilless farming techniques such as hydroponics, aquaponics, and aeroponics. Some common choices of structures to house vertical farming systems include buildings, shipping containers, tunnels, and abandoned mine shafts. As of 2020, there is the equivalent of about 30 ha of operational vertical farmland in the world.
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra.
Sewage treatment is a type of wastewater treatment which aims to remove contaminants from sewage to produce an effluent that is suitable for discharge to the surrounding environment or an intended reuse application, thereby preventing water pollution from raw sewage discharges. Sewage contains wastewater from households and businesses and possibly pre-treated industrial wastewater. There are a high number of sewage treatment processes to choose from. These can range from decentralized systems to large centralized systems involving a network of pipes and pump stations which convey the sewage to a treatment plant. For cities that have a combined sewer, the sewers will also carry urban runoff (stormwater) to the sewage treatment plant. Sewage treatment often involves two main stages, called primary and secondary treatment, while advanced treatment also incorporates a tertiary treatment stage with polishing processes and nutrient removal. Secondary treatment can reduce organic matter from sewage, using aerobic or anaerobic biological processes.
Sewage is a type of wastewater that is produced by a community of people. It is typically transported through a sewer system. Sewage consists of wastewater discharged from residences and from commercial, institutional and public facilities that exist in the locality. Sub-types of sewage are greywater and blackwater. Sewage also contains soaps and detergents. Food waste may be present from dishwashing, and food quantities may be increased where garbage disposal units are used. In regions where toilet paper is used rather than bidets, that paper is also added to the sewage. Sewage contains macro-pollutants and micro-pollutants, and may also incorporate some municipal solid waste and pollutants from industrial wastewater.
Ammoniacal nitrogen (NH3-N) is a measure for the amount of ammonia, a toxic pollutant often found in landfill leachate and in waste products, such as sewage, liquid manure and other liquid organic waste products. It can also be used as a measure of the health of water in natural bodies such as rivers or lakes, or in man made water reservoirs. The term is used widely in waste treatment and water purification systems.
Organic hydroponics is a hydroponics culture system based on organic agriculture concepts that does not use synthetic inputs such as fertilizers or pesticides. In organic hydroponics, nutrient solutions are derived from organic plant and animal material or naturally mined substances. Most studies on the topic have focused on the use of organic fertilizer.
Reuse of human excreta is the safe, beneficial use of treated human excreta after applying suitable treatment steps and risk management approaches that are customized for the intended reuse application. Beneficial uses of the treated excreta may focus on using the plant-available nutrients that are contained in the treated excreta. They may also make use of the organic matter and energy contained in the excreta. To a lesser extent, reuse of the excreta's water content might also take place, although this is better known as water reclamation from municipal wastewater. The intended reuse applications for the nutrient content may include: soil conditioner or fertilizer in agriculture or horticultural activities. Other reuse applications, which focus more on the organic matter content of the excreta, include use as a fuel source or as an energy source in the form of biogas.
Vermiponics is a soil-less growing technique that combines hydroponics with vermiculture by utilizing diluted wormbin leachate as the nutrient solution as opposed to the use of fish waste or the addition of manufactured chemicals to provide the nutrients.
Recirculating aquaculture systems (RAS) are used in home aquaria and for fish production where water exchange is limited and the use of biofiltration is required to reduce ammonia toxicity. Other types of filtration and environmental control are often also necessary to maintain clean water and provide a suitable habitat for fish. The main benefit of RAS is the ability to reduce the need for fresh, clean water while still maintaining a healthy environment for fish. To be operated economically commercial RAS must have high fish stocking densities, and many researchers are currently conducting studies to determine if RAS is a viable form of intensive aquaculture.
The Sustainable Technology Optimization Research Center (STORC) is a research facility located on the California State University Sacramento campus. There are several players included in operations at the STORC including Sacramento State's Risk Management, the College of Engineering and Computer Science (ECS), and two professors in the Environmental Studies department Brook Murphy and Dudley Burton. The STORC facility is primarily maintained by California State University, Sacramento student interns and volunteers who use applied science and technology to address real world policy, food, health, and energy issues of present-day society. Research at the STORC encompasses engineering and science to test and evaluate new ideas and approaches of sustainable technology to solve environmental problems. Faculty and students address sustainability with an interdisciplinary studies approach. The STORC Vision is to become "an international resource for practical, scalable, and financially viable solutions in the area of sustainable technologies that are suitable for private and/or public sector operations related to the management of energy, food, water, and waste". The STORC Mission is "to demonstrate the operation of innovative commercially viable physical systems that are underpinned by sustainable technologies, and to disseminate the associated plans, public policy discourse, and scientific findings".