5 WATER DIVERTING TOILET
Design of a User-Friendly Toilet that Diverts Water from Human Waste Ergonomic toilet requiring little ushing
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The toilet booths in the Community Sanitation Centres (CSC’s) feature ceramic squat toilets, following Indian customs. A benchmark of existing toilet pans demonstrated the need for improved ergonomics as well as steeper surfaces to better convey feces with less water. The flush (currently less than 1 liter) has been optimized for the removal of feces that drop in front of the toilet outlet. User observations showed that not all position themselves exactly above the outlet, even when applying use cues such as foot rests.
Flus
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Water diverting mechanism
The plastic spiraling hose and the absence of the trigger at its end allows a sturdier and more hygienic design that is less likely to be damaged or stolen in public toilets. Usage is fairly easy. While holding the shower head, the user turns the self-closing faucet up to 90 degrees, depending on the desired amount of water (up to 750 ml per time).
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One of the main innovations of the toilet lies in the separate collection of the fairly unsoiled (anal) cleansing water with the purpose of on-site recycling. The diverting mechanism is located underneath the toilet pan. It consists of two flaps that change position when users activate the handheld shower for the purpose of anal cleansing or cleaning the toilet. In this way, the user does not have to adapt his toilet ritual.
Robust handheld shower for anal cleansing
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Taking into account the loss of flushing water, which goes with human waste, the current prototype has the potential to divert around 70% of all water consumed inside the toilet. For a typical 8-seat Community Sanitation Centre this equals to nearly 1,000 l every day. This significantly reduces the impact on transportation and drying of waste as well as the supply of water at the Community Sanitation Centres. To facilitate higher water pressure for spot cleaning, the user can squeeze the rubber shower head. This creates a spurt of water.
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Flush
Anal cleansing
Clean toilet
water
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Neutral position
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When the toilet is not in use, the waste flap (orange) is closed, avoiding malodors and insects or rodents to leave the toilet.
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Defecating & flushing
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Waste flap (orange) opens freely due to the weight of excrements and/or the power of flushing water, overcoming the flap’s counterweight.
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Water diverting position The diverting mechanism is activated as soon as the user opens the self-closing faucet for the handheld shower. While the waste flap (orange) is pushed down, the water flap (blue) comes up by means of a simple engagement system. In this position, water is directed towards the grey water treatment system. When the shower's faucet has closed itself again, both flaps return to their neutral position.
Self-closing faucet for handheld shower
Hygienic toileting experience The need for cleaning is limited due to the seamless integration of the toilet into the toilet floor, which has rounded edges (similar to a shower tray). When prefabricated as one piece, this can outperform current poor practices of tile laying. Malodors inside the toilet booth are reduced by means of the self-closing waste flap underneath the toilet pan. Besides that, air is sucked out of the cubicle through a stack effect caused by the solar chimney on top of the building.
User testing in emerging economies The design team spent a considerable amount of time in the field to better understand local toilet customs and to validate ideas and concepts. Different research methods have been applied to tackle the complexities of user research inside informal settlements. The sensitivity of toilet usage among both genders as well as the biases towards Western researchers requires a careful approach. TU Delft is compiling their experiences in a scientific paper in order to work towards recommen- dations for designers that operate in similar fields.
Waste Water
Next steps
Optimize the flush to ensure that waste leaves the toilet before the diverting mechanism is activated.
Develop an affordable ceramic toilet pan with integrated divering mechanism for user testing.
Take samples from diverted water for optimization of the grey water treatment system.
www.tudelft.nl/reinventthetoilet
Evaluate the convenience and robustness of the handheld shower concept with potential users.