Climate change is predicted to bring more and intense droughts and drier days, which will impact water supply especially in high growth regions with rapid industry and population growth.
A research article by Bauer and others focuses on the high usage of water in Industrial Parks in China and how housing developments are appearing around the edges of these Industrial parks creating ‘edge cities.’
Industries use enormous amounts of water and produce the same amount of wastewater. The additional residential developments would add the demands for water and water availability would be essential to meet increasing demands.
In China, urbanisation increased from 41.8 per cent in 2004 to 53.7 per cent in 2014 with a growth rate of 1.2 per cent every year. This raises water use from 333 billion tons up to 618 billion tons.
To have a sustainable water supply, several concepts of water-reuse and water management emerged.
One of these concepts is the “SEMIZENTRAL” approach which is a “semi-centralized supply and treatment system for fast-growing urban areas” with a focus on re-use that is “fit-for-purpose”.
The SEMIZENTRAL approach is a joint project of Germany and China that aims to tackle the challenges of water supply and disposal for fast-growing megacities because of limited water resources.
It combines water supply, wastewater treatment, and waste treatment into one wholistic integrated approach which contrasts with the conventional systems that strictly separates each function.
The benefit of integrating the functions of water supply and wastewater treatment is a reduction of water demands by 30-40 per cent and energy conservation which will reduce greenhouse gas emissions. Also, biogas can be harvested from wastewater treatment facilities which could supply low-carbon fuels.
The industries or production plants included in the study are grouped according to their main waste components such as carbon, nitrogen, and phosphorus, and other wastes which will determine its type of treatment.
Water from these factories would be used “fit-for-purpose” like toilet flushing, street cleaning, irrigation of city parks and roadside vegetation.
This approach would benefit countries with rapid urban and industrial growth like China where there is a high level of water-stress, water-scarcity exist due to the uneven distribution of natural water resource and intense pollution.
Another advantage from this approach is that it will allow grey infrastructure’s wastewater treatment and green infrastructures to complement each other as treated wastewater will be used to water vegetation and plants around urban areas while these green infrastructures will provide benefits like natural cooling, canopy, absorb runoffs or excess water in case of flooding, and encourage ecosystems.
The study also points out that the energy used in treating water for re-use is more efficient than the production of raw water from natural resources, making treated wastewater a very attractive water source.
However, this does not include industries with already existing wastewater treatments for re-use application in plants or in existing urban structures as these would incur additional cost for extra pipelines but only for “greenfield developments,” or land that has not been used before for various different types of projects.
This is one climate adaptation strategy that countries that have cities with rapid urbanisation should consider undertaking. Of course, it is still wise to integrate this and other climate adaptation strategies in the overall infrastructure management plans of the town or city.
Access the entire study by clicking on the link below:
Bauer, S., Linke, H.J. & Wagne, M. (2020, January 27). Combining industrial and urban water-reuse concepts for increasing the water resources in water-scarce regions. Retrieved from https://onlinelibrary.wiley.com/doi/epdf/10.1002/wer.1298
SEMIZENTRAL concept. (2020). SEMIZENTRAL Germany. Retrieved from http://www.semizentral.de/en/concept/
Greenfield Development. (2020, January 26). Planning Tank. Retrieved from https://planningtank.com/urbanisation/greenfield-development
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