Sustainability evaluation of shared greywater recycling in urban mixed-use regeneration areas

[摘要] Greywater (GW) recycling for non-potable uses (e.g. urinal and toilet flushing) provides an urban water management strategy to help alleviate this risk by reducing mains water demands. The research described in this thesis proposes scenarios for an innovative cross-connected system that collects GW from residential buildings and recycles it for toilet/urinal flushing in both residential and office buildings. The capital cost (CAPEX), operational cost (OPEX), the carbon costs (embodied and operational), and water saving potential are calculated for individual block of residential and office buildings and shared GW recycling system between both building blocks in an urban mixed-use regeneration area in the UK assuming two different treatment processes; a membrane bioreactor (MBR) and a vertical flow constructed wetland (VFCW). The Net Present Value (NPV) method was used to compare the financial performance of each considered scenario from where it was found that over a 15 year period a shared GW recycling system (MBR) was the most economically viable option with an NPV of £213.11k and potable water savings of almost 27% (compared with mains water only system); 12% (compared with individual block GW recycling system). However, over the same time period it was shown that shared CW treatment had the lowest carbon emissions, saving up to 11% (compared to conventional mains supply), whereas a shared MBR increased carbon emissions by up to 27%. The sensitivity of this financial and emission model was assessed considering six parameters (i.e. water supply and sewerage charges, discount rate(s), electricity charges, service life, building description, user behaviour and improved technological efficiency).

[发布机构] University:University of Birmingham;Department:School of Engineering, Department of Civil Engineering

[关键词] T Technology;TA Engineering (General). Civil engineering (General)