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<br>This system is based on the use of a Biogas Reactor (S.12) to collect, store and treat the Excreta. Additionally, the Biogas Reactor produces Biogas which can be burned for cooking, lighting or electricity generation. [[Sanitation Products | Inputs to the system ]] can include Urine, Faeces, Flushwater, Anal Cleansing Water, Dry Cleansing Materials, Organics (e.g., market or kitchen waste) and, if available, animal waste.
This system supports two different User Interface technologies: a [[Pour Flush Toilet | Pour Flush Toilet]] (U.4) or, if there is a demand for the urine to be used in agriculture, a [[Urine Diverting Dry Toilet | Urine-Diverting Flush Toilet ]] (U.6). A Urinal (U.3) could additionally be used. The User Interface is directly connected to a Biogas Reactor (S.12, also known as an anaerobic digester) for Collection and Storage/Treatment. If a [[Urine Diverting Flush Toilet | Urine-Diverting Flush Toilet ]] is installed (and/or a Urinal), it will be connected to a Storage Tank (S.1) for Urine collection.
Depending on the loading and design of the Biogas Reactor, a thin or thick digestate (Sludge) will be continuously discharged. Because of the high volume and weight of the material generated, the Sludge should be used onsite. In some circumstances, a very thin digestate can be discharged to a sewer (though this is not shown on the system template here). Although the Sludge has undergone anaerobic digestion, it is not pathogen free and should be used with caution, especially if there is no further treatment.
Depending on how it is used, additional treatment (e.g., in [[Planted Drying Beds| Planted Drying Beds]], T.15) may be required before application. It is nutrient-rich and a good fertilizer that can be applied in agriculture (D.5) or transported to a Surface Disposal or Storage site (D.12). The Biogas produced must be constantly used, for example as a clean fuel for cooking or for lighting (D.13). If the gas is not burned, it will accumulate in the tank and, with increasing pressure, will push out the digestate until the Biogas escapes to the atmosphere through the digestate outlet.
A Biogas Reactor can work with or without Urine. The advantage of diverting Urine from the reactor is that it can be used separately as a concentrated nutrient source without pathogen contamination. The Urine collected in the Storage Tank is ideally applied on local fields (D.2). Stored Urine can be transported in [[Jerrycan - tank | Jerrycans ]] or a Tank (C.1), or using a [[Motorized Emptying and Transport | Motorized Emptying and Transport]] technology (C.3).
===Considerations ===
Most types of Dry Cleansing Materials and Organics can be discharged into the Biogas Reactor, although to accelerate digestion and ensure even reactions within the tank, large items should be broken or cut into small pieces. Guidelines for the safe use of Sludge have been published by the World Health Organization (WHO) and are referenced on the relevant technology information sheets.
[[Functional Groups|More on the Functional Groups: U, S, C, T, or D]]<br>
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