Domestic greywater treatment through the integration of constucted wetlands in Living Wall Systems (LWS)

The main objective of the thesis is to develop a design for a vertical green facade with integrated wastewater treatment. Vertical green systems provide a highly versatile type of facade that upgrades equally the building and it’s surroundings. The lack of quantitative benefits though, limit the motives for installing green facades to aesthetical and ideological reasons. The integration of wastewater treatment would provide a cost-benefit analysis for the green facades through the reduction of water consumption. In the first part of this thesis, the theoretical background, it becomes clear that the treatment of the less polluted streams of domestic wastewater (greywater) is a more acceptable and efficient way of reusing wastewater that can cover the demand for not potable water in the urban environment. Furthermore, through the literature review it is explained how constructed wetlands treat wastewater with the use of saturated soils (a mix of sand and gravel) and plants and why vertical subsurface flow (V-SSF) wetlands are the most efficient constructed wetlands. The V-SSF are selected to become the example for the water treatment procedure that will be followed in this thesis. Their interior structure and the removal mechanisms that take place are analysed and represented in a typical section that will be the starting point of the design development. Furthermore, an overview of the types of vertical green facade systems makes clear that the domestic wastewater treatment is possible through the integration of the V-SSF principles in a living wall system (LWS). This is achieved through the horizontal segmentation of a V-SSF into smaller parts and the creation of a new network with vertical distribution similar to that of a LWS. The demand of the vertical distribution for materials with low weight extended the search for an appropriate substrate to the field of horticulture (more specific: hydroponic cultivations) and green roofing which both focus on the development of lightweight hydraulic systems. The search resulted to the selection of clay aggregate, glass foam gravel, capillary mat and polyethylene drain sheet to replace the sand and gravel of the V-SSF and provide a more lightweight solution. 21 case studies with combinations of types, volumes of substrates and element sizes provided a valuable input for the assessment of the weight and the definition of the final size of the element. In parallel to that the detail design of the planter defined the structural and the hydraulic behaviour of the system.Future Façade Design,Building TechnologyArchitectur