Performance assessment and life cycle analysis of potable water production from harvested rainwater by a decentralized system

Abstract

a b s t r a c tDecentralized rainwater harvesting (RWH) from roof runoff can complement the centralized supply of mains (drinking) water for a range of contexts, to assist in alleviating issues of water security. However, treatment to potable standard of harvested rainwater is not widespread. Consequently a comparative life cycle analysis (LCA) of decentralized and centralized potable water supply has not previously been undertaken. In this paper we describe a novel point-of-use (POU) treatment device, which was used to treat harvested rainwater to potable standard. We then provide a performance assessment for this system and an LCA with a comparison to centralized supply. Results of the performance assessment indicate a water saving efficiency (E T ) of between 0.6 and 100%, depending on rainfall (0.6 from April when rainfall was significantly below average). This highlights that the POU device was able to deal with the scale of roof runoff supply originating from a RWH system at a commercial building scale. The LCA results suggest that potable water produced from this decentralized RWH POU system currently performs more poorly than centralized water from an environmental perspective. Its impacts in most categories would be significantly reduced if the electricity consumed by the system were supplied from a renewable source such as solar PV or wind turbines instead of the UK grid. Priority should be given to optimizing the energy efficiency and exploring opportunities for combined use with renewable energy technologies in order to improve the environmental performance of POU treatment devices.

Policy and legislative barriers to close water-related loops in innovative small water and wastewater systems in Europe: A critical analysis

“…The authors further confirmed their findings' compliance with the national (German) requirements for treated effluent reuse. In another study, Yan et al (2018) set up a rainwater harvesting system in an office building on the University of Exeter's Streatham campus with around 300 occupants. Although the rainwater harvesting system aimed to reduce water consumption in the toilet flushing, the system enabled to get water with a quality met with the criteria for the potable water in the UK which can also be used for washing the building and drinking.…”

Embedding social inclusiveness and appropriateness in engineering assessment of green infrastructure to enhance urban resilience

“…Recently this has changed and perhaps the most well known and applied addition to represent environmental aspects within urban water infrastructure engineering assessment currently is life-cycle assessment or analysis (LCA) or life-cycle impact assessment (as according to ISO 14040:2006 and14044:2006). Traditionally used to assess environmental impacts associated with product design, manufacture and decommissioning, LCA has more recently been applied to wastewater, drinking water, stormwater and integrated urban water systems (Byrne et al 2017) and to compare decentralised and centralised water systems for potable water production from harvested rainwater (Yan et al 2017).…”

Economic and Environmental Assessment of Two Different Rain Water Harvesting Systems for Agriculture

“…The present water scarcity leads to a new paradigm in water resource management, and the application of sustainable water supply solutions is essential [6,7]. Some studies [8,9] have catalyzed interest in alternative approaches to ensure water security by applying, for example, rainwater harvesting systems.…”