An independent water system with maximized wastewater reuse for non-potable purposes - Model case for future urban development

Abstract

A study was conducted to formulate an optimized plan for upgrading an independent water system in a college campus where the available water source is from 5 groundwater wells with a maximum water supply capacity of 3000 m3/d but the water demand is much beyond this value for both potable and non-potable consumption. By water balance analysis, it was estimated that with the available fresh water consumed only for potable and related miscellaneous uses for 30000 people, the quantity of the reclaimed water could be enough to cover all the non-potable consumption. By material balance analysis, the pollutant loadings of organics, nitrogen and phosphorus were calculated and the requirements for pollutant removal corresponding with reuse purposes were evaluated. Considering the quality criteria of water reuse for lake landscaping, toilet flushing and gardening, and the demand for each water usage in the campus, a dual-quality reclaimed water supply scheme was proposed as (1) supply of lower quality reclaimed water for gardening and road sprinkling by upgrading the existing wastewater treatment facility of 1500 m3/d using conventional process, and (2) supply of higher quality reclaimed water for lake water replenishment and toilet flushing by implementing a new wastewater treatment facility of 2500 m3/d using MBR process. The independent water system thus optimized could sustain a total water consumption of more than 6000 m3/d using the 3000 m3/d source water. This provided a model case for future urban development in the water deficient region.

Global socio-technical regimes

“…One notable example was the city government of Beijing, which introduced a regulation to implement on-site treatment systems in major hotels, schools, government buildings and in the booming residential development zones at the outskirts of the city (Binz et al, 2016b;Mels et al, 2007). Other examples were the cities of Xi'an, which experimented with semicentralized wastewater recycling systems (Wang et al, 2008;Wang et al, 2011;Zhang et al, 2010) and Kunming, which participated in a large international pilot study for no-mix sanitation systems (Medilanski et al, 2006). Throughout the nineties, the relevant Chinese firms, universities and city governments gained high visibility and got embedded in an international network ('global niche') of technology experts and consultants that were trying to establish a more flexible, decentralized and water-sensitive rationality in the urban water sector (Binz et al, 2014;Binz et al, 2016b).…”

The Tianjin Eco-City model in the academic literature on urban sustainability

“…The risks to human health of using reclaimed water are found to be relatively low, provided that rigorous and appropriate treatment processes are implemented for the target usage (Barker-Reid et al, 2010;Sinclair et al, 2010;Wang et al, 2011;Yamagata et al, 2003). Apart from routine issues, which are the object of continuous research, including patterns of indoor water use (Matos et al, 2013), the quality and aesthetics of reclaimed water (Biswas et al 2012), further progress in regulations and incentive strategies also seems to be a key contributor to the use of alternative water sources.…”

Comparative overview of primary sedimentation-based mechanical stage in some Romanian wastewater treatment systems

“…The first component, WW collection, is at least important for WW treatment and disposal, but costs more than 60% of total WW management system budget in centralised systems, particularly in small communities with low population densities, associated with industrial platform site [11][12][13], being kept as minimal as possible in decentralised systems [2].…”