Climate Adaptation through Industrial and Urban Water-Reuse Concepts

Climate change is predicted to bring more 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 water usage 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 increase the demand 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 yearly. This raised water use from 333 billion tons to 618 billion tons.

Several concepts of water reuse and water management emerged to create a sustainable water supply.

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 holistic, integrated approach, contrasting with conventional systems that strictly separate each function.

Integrating the functions of water supply and wastewater treatment will reduce water demands by 30-40 percent 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, phosphorus, and other wastes, which will determine their type of treatment.

Water from these factories would be used “fit-for-purpose” for things 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 and water scarcity due to the uneven distribution of natural water resources and intense pollution.

Another advantage of this approach is that it will allow grey infrastructure’s wastewater treatment and green infrastructures to complement each other. Treated wastewater will be used to water vegetation and plants around urban areas, while these green infrastructures will provide benefits like natural cooling, canopy, absorption of runoff or excess water in case of flooding, and ecosystems.

The study also points out that the energy used in treating water for reuse 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 costs 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 with cities experiencing rapid urbanisation should consider undertaking. Of course, it is still wise to integrate this and other climate adaptation strategies into the overall infrastructure management plans of the town or city.

Access the entire study by clicking on the link below: