SELF
“Self” – an energy and water independent transportable living unit
“Self” is a project carried out in collaboration between Eawag, EMPA and Zurich University of Arts, to build and demonstrate an autonomous living unit, which is independent of external supply of energy and water. It is a living module for two persons, equipped with solar panels and an advanced system of energy storage and management. The water concept is based on rain water collection on the roof and grey water recycling. In both treatment of rainwater and treatment of grey water the GDM (Gravitiy Driven Membrane) technology is applied.
Rain water disinfection
Rainwater is collected in a reservoir on the roof of the living unit and is filtered by gravity through an UF membrane with an area of about 1 m2. The treated rain water is collected in a reservoir and is used for drinking, cooking and in the wash basin of the bathroom. A UV lamp in the reservoir is planned to prevent re-growth of bacteria. The drinking water system is designed to provide around 15 L/day of drinking water for 2 inhabitants, and the storage capacity is sufficient to provide water for up to 20-30 days without rainfall.
Grey-water recycling
The principle of gravity-driven membrane filtration is also implemented in the membrane bioreactor (MBR) used in “self” for grey water treatment, thus no permeate pump is required which saves energy. Additional energy saving is achieved by an intermittent aeration instead of continuous. The MBR is designed for a surface load of < 2 L/m2/h (“conventional” MBR - 20-25 L/m2/h). Similar to the drinking water system the treated grey water is collected in a storage tank (200 L). Treated grey water is reused for the shower, the dishwasher and for toilet flushing (86 L/d and two Persons). A major challenge to guarantee the required water quality is to limit pathogen regrowth in the storage tank. The recycling concept will be tested and evaluated in the coming year.
“Self” - self-sufficient living unit at the Swissbau exhibition in Basel