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Recycling Waste Water
Water Reuse
Water reuse is one of the key future technologies required to make sustainable water management possible. Water reuse has emerged as an important method of efficiently consuming limited water resources to cope with the growing imbalance between water demand and supply due to exacerbating climate change.
Text by Editorial Team
Source by Industrial Water Management Dept., K-water
Turn Waste Water into Resources
Using waste for purposes other than originally intended or reusing it after processing is referred to as recycling. It has been one of the solutions mankind have used to survive since ancient times. Since all natural resources are finite, recycling waste including plastic and paper is essential to achieve sustainability.
What about water? Water is also a limited resource and is becoming continuingly less available for different reasons. There have been growing concerns for many years over water shortages, highlighting the importance of sustainable water management. Global water consumption has increased 6.7 times in the 20th century as a result of the growing global population, industrialization and increased farming. As a result, natural water resources alone can no longer meet the demand sustainably. Water demand will only steeply rise and projected to increase over 35% by 2050. At the same time, the water supply is adversely affected by climate change resulting from accelerating global warming, unstable precipitation and rising water temperature. Given this, it has become even more imperative to reuse water. Water reuse involves reclaiming water from various sources by treating and reusing it. Rainwater, sewage, wastewater and thermal effluents are treated at water treatment facilities and used for various purposes. Water reuse is not only a key strategy for effectively conserving natural water resources and promoting sustainable water management but also an effective tool to respond to climate change.
Water Reuse as Global Agenda
Water and sanitation are elements of the United Nations Sustainable Development Goals (SDGs). The goal is to raise the level of water use efficiency in all facets, ensure sustainable consumption and the water supply to address water shortages, and reduce the number of people suffering from water shortages. Water reuse is viewed as one of the key instruments to achieve the SDGs.
What actions are being taken to reuse water around the world? Water reuse, including sewage recycling, is being actively encouraged and implemented in the Middle East in absolute water shortages, in addition to the U.S. Singapore and Europe. Municipal wastewater is treated and reused for agricultural purposes in the state of California that endures chronic droughts. Similarly, Australia has instituted a system to reclaim and treat household wastewater for its use in gardening and bathroom flushing, while European countries plan to increase the amount of sewage recycling six times to 6.6 billion ㎥/year by 2025.
Water is an essential resource for individuals and industries as well. Therefore, water shortages can result in massive industrial damages. Global IT companies such as Google and Microsoft are attempting to improve water efficiency throughout their entire supply chains and strengthen the reuse of rainwater and sewage in order to secure a stable water supply. South Korea has ample annual rainfall but still deals with water shortages because a considerable portion of rainfall flows into rivers and the ocean. Average daily water use is 295L per person, the third largest after the U.S. and Japan. On the other hand, annual water resources per person is 1,453 ton, 129th out of 153 countries. With the river water consumption at 36%, Korea is classified as a water stress country. In response, the Korean government is exploring more alternatives to reuse water. Guri City municipality in Gyeonggi-do Province treats sewage to replenish the river crossing Jangja Lake Park and clean the roads. In Paju, Gyeonggi-do Province, and Gumi and Pohang, Gyeongbuk Province, water discharged from sewage treatment facilities is processed and used for industrial purposes.
Water Reuse by K-water
K-water has started to treat and reuse sewage firstly in Chilgok County in 2007, followed by Asan and Pohang, where K-water treats and supplies 137,000 tons of treated sewage to steel and display factories. Also, K-water has plans to retreat pre-treated sewage of Yeosu City discharged into the South Sea and provide it for the Yeosu National Industrial Complex by 2025.
In addition, K-water is seeking solutions to reuse thermal effluents and secure more industrial water. Thermal effluents entail the discharge of water used for cooling at power plants into the ocean. Since the water travels solely through a pipeline until it is discharged into the ocean, it is not contaminated.
The water used in this process remains uncontaminated by external substances as it flows through a completely sealed conduit until it is discharged into the sea. How can we repurpose wastewater as industrial water? The answer to this can be found in the separate Q&A below.
K-water aims to address any shortages of industrial water by increasing water reuse, as well as support the government’s low-carbon, green growth policies by reducing pollution associated with wastewater discharge into rivers and ocean. Water reuse is not an option but a necessity.
