Difference between revisions of "Pour Flush Pit System without Sludge Production"

Revision as of 00:03, 11 October 2014

This is a water-based system utilizing the Pour Flush Toilet (pedestal or squat pan) to produce a partially digested, humus-like Product, which can be used as a soil amendment. If water is not available, please refer to Systems 1, 2 and 4. Greywater can be used in system and does not require separate treatment.

The inputs to the system can include Faeces, Urine, Flushwater, Anal Cleansing Water, Dry Cleansing Materials and Greywater.

The User Interface Technology for this system is a Pour Flush Toilet. A Urinal should only be used in addition to, and not instead of, the Pour Flush Toilet. Twin Pits for Pour Flush is one of the technologies used for the Collection and Storage/Treatment of the Black water output from the User Interface. The Twin Pits are lined with a porous material that allows the Effluent to infiltrate into the ground while solids accumulate and degrade at the bottom of the pit. While one pit is filling with Blackwater, the other pit remains out of service. When the first pit is full, it is covered and temporarily taken out of service. It should take a minimum of two (2) years to fill a pit. When the second pit is full, the first pit is re-opened and the contents are removed. The Treated Sludge that is generated in the pit after two (2) years is removed and transported for Use and/ or Disposal manually using a Human Powered E&T Conveyance Technology. Since it has undergone significant degradation, it is not as pathogenic as raw, undigested sludge. There is no need to transport the treated sludge to a (Semi-) Centralized Treatment facility as treatment of the Blackwater takes place onsite.

Dry Cleansing Materials may clog the pit and prevent water from infiltrating into the soil and so it should be collected separately and transferred for Surface Disposal.

Alternatively, the blackwater can be directed towards an Anaerobic Biogas Reactor. The reactor will function better if animal manure and organic waste are also added; liquid inputs like Greywater should be kept to a minimum. The Biogas that is generated (not shown) can be used for cooking, and the Treated Sludge can be used as a soil amendment.

For the Use and/or Disposal component of the System Template, the Application of Sludge Technology is utilized. Effluent from the Twin Pits for Pour Flush is directly infiltrated into the soil onsite from each pit. Therefore, this system should only be installed where there is a low groundwater table that is not at risk of contamination from these pits.

Considerations

Depending on the Collection and Storage/Treatment technology chosen, the system will depend on different criteria. In the case of the double pits, the system will depend on soil which can continually and adequately absorb moisture; clayey or densely packed soils are not appropriate. The material that is removed should be in a safe, useable form, although the task of removing, transporting and using it may not be favourable in some circumstances. The use of a household biogas digester is best suited to peri-urban or rural areas where there is a source of organic and/or animal waste material and a need for the digested sludge. The piping system for the gas must be well maintained to prevent leaks and potential explosions.

This system is wellsuited for anal cleansing with water. Dry cleansing materials should be disposed of separately because they could easily clog the pit or the reactor, see Surface Disposal.

References

• Elizabeth Tilley et.al (2008). Compendium of Sanitation Systems and Technologies (low res version). Department of Water and Sanitation in Development Countries (Sandec) at the Swiss Federal Institute of Aquatic Science and Technology (Eawag). (Provides a full overview of sanitation systems.)