Securing Safe Water Resources with Ozone-Based Water Purification System
JGC HOLDINGS CORPORATION
| Publication date | May 09, 2018 (Posted on December 09, 2022) |
|---|---|
| Sector | Water Environment / Water Resources |
Company Overview
Since its establishment in 1928, JGC CORPORATION has been engaged in the construction of a wide range of plants and facilities around the world, mainly in the oil and gas field including oil, natural gas, petrochemical, and LNG plants; extending to the energy infrastructure field including power plants and nonferrous metal plants; the industrial infrastructure field; the social infrastructure field including pharmaceutical plants, hospitals, and environmental facilities. The company is recognized as one of the world's leading engineering contractors.
Adaptation Initiatives
In ponds and lakes where eutrophication progressing, there are cases where the water surface becomes covered with green powder. This phenomenon is called algal bloom, and is particularly observed in summer when the water temperature rises. Algal bloom forms when cyanobacteria start to multiply fast, and when this water is used as raw water for drinking, it can cause odor and damage to the filtration system. There are also some cyanobacteria that produce toxic substances. As climate change progresses, if the water temperature of lakes and marshes rises or the period without rainfall increases, the period of algal bloom occurrence may be prolonged in places where they are presently forming. There is also a concern for algal bloom to occur in lakes and marshes where blooms have not been observed in the past.
In 2008, we conducted a demonstration project for purification using the ozone-based purification system at Lake Taihu in China, where algae bloom had formed. The ozone generated by the purification system decomposes the persistent COD (Chemical Oxygen Demand) into easily degradable COD, and the reacted ozone becomes oxygen. By returning treated water containing a high concentration of oxygen to lakes and marshes in an anoxic condition, the lakes and marshes will become aerobic and recover its natural purification ability, and the microorganisms will purify the degradable COD. In addition, algae bloom containing eutrophic substances are separated from the water and collected as scum. Three weeks after the installation of the system, the lake was successfully purified to a quality that can be used as drinking water.
We propose an ozone-based purification system for areas where there is a risk for long-term algal blooms as climate change progresses, which can contribute to securing safe drinking water sources.
- Water Purification Demonstration Project (China)
