PROJECT DESCRIPTION
BACKGROUND
If the goal of sustainable development is to be achieved a critical approach towards current resource use patterns and waste and water generation is necessary. Only a small proportion of the drinkable water used by households is used for drinking and cooking (ca. 4 percent). The rest is used for other purposes. Demand for drinkable water is increasing worldwide and more rational use of this resource can make a key contribution to finding a solution to this critical problem.
OBJECTIVES
The project aimed to use different water saving and recycling technologies in order to achieve a target of a 50 percent reduction of potable water consumption. This would be done in a residential complex and thus at a significant scale. In addition, through better environmental accounting, a reduction of energy, land and environmental resources consumption was sought. Methodology: The project set out to design and implement a separated system of water distribution and discharge for rainwater, potable and grey water in a residential complex of eight flats. The plant maximizes reuse by a) a grey water use system, which collects, treats (through filtration and disinfection) and sends grey water (coming from showers, bathtubs, and washbasins located in bathrooms) to toilet flushing; b) a rainwater use system, which collects, treats (through filtration and disinfection) and sends rainwater (coming from 200 square meters roof surface) to dishwashers and cloth washing machines. The plant minimizes waste production by installation of low water consumption components in the flats.
RESULTS
The project was accompanied by a data collection campaign enabling evaluation of the results, of management implications and of environmental and economic aspects. The project demonstrated that a potential reduction of around 50 percent in consumption of drinkable water can be achieved, through implementation of new techniques compared with traditional systems. Of this 50 percent, around 30 percent is due to the use of low water consumption appliances, around 15 percent to the re-use of ‘grey water’ and the remaining 5 percent to the use of rainwater. Grey water from personal washing (33 percent of total household consumption) can be used for up to 23 percent of water flushes. Rainwater can provide a household water saving of up to 8 percent. Up to 66 percent of the total consumption of washing machines (both clothes and dishwashers) can be covered by rainwater. The project was analysed using LCA methods, and compared with the drinkable water production cycle and with the wastewater management system in Bologna. The analysis revealed that there are no counter-indications for the adoption of the proposed methodology. Continuation of experimentation will make it possible to obtain more data about sustainable development.The project was accompanied by a data collection campaign enabling evaluation of the results, of management implications and of environmental and economic aspects. The project demonstrated that a potential reduction of around 50 percent in consumption of drinkable water can be achieved, through implementation of new techniques compared with traditional systems. Of this 50 percent, around 30 percent is due to the use of low water consumption appliances, around 15 percent to the re-use of ‘grey water’ and the remaining 5 percent to the use of rainwater. Grey water from personal washing (33 percent of total household consumption) can be used for up to 23 percent of water flushes. Rainwater can provide a household water saving of up to 8 percent. Up to 66 percent of the total consumption of washing machines (both clothes and dishwashers) can be covered by rainwater. The project was analysed using LCA methods, and compared with the drinkable water production cycle and with the wastewater management system in Bologna. The analysis revealed that there are no counter-indications for the adoption of the proposed methodology. Continuation of experimentation will make it possible to obtain more data about sustainable development.
