Taisei Construction: Purification of complex contaminated groundwater: use of degrading bacteria N23
January 7, 2020
Taisei Corporation: Groundwater purification:
Taisei Corporation has found a degrading bacterium strain N23 * 1 (hereinafter referred to as N23 strain) that has excellent purification ability.
For the first time in the world, it has been confirmed that “it can be used to decompose multiple pollutants.”
Degradative bacterium N23 strain: excellent purification ability
Confirmed that the decomposing bacterium N23 strain can simultaneously decompose multiple pollutants specified in the groundwater environmental standard * 2.
Under the national groundwater environment standards, 28 pollutants are specified.
Of these, 17 are organic chemicals.
By applying this technology, it is possible to “decompose organic chemicals in complexly contaminated groundwater in a short period of time and at low cost” compared to conventional purification methods.
Also, it can reduce environmental load such as CO2 emission related to purification.
Ministry of the Environment: Groundwater quality measurement survey * 3
There have been many reports of these organic chemicals exceeding environmental standards.
Illegal dumping site: groundwater contamination
Illegal dumping sites / groundwater contains highly water-soluble chemicals such as chloroethylene * 4 and 1,4-dioxane * 4.
Many cases have caused widespread pollution.
Pollution prevention: Pumped water purification * 5
Pumping purification * 5 is usually applied to prevent the spread of pollution.
For groundwater purification, an accelerated oxidation method that purifies with a strong oxidizing agent is effective.
However, issues such as high purification costs and high CO2 emissions have been pointed out.
N23 Purification Performance Test: Validation
We conducted “Microbial purification performance test using N23 strain” for complex polluted groundwater / organic chemical substances.
As a result of confirming the decomposition status, “verification of its effectiveness as a new purification technology that replaces the accelerated oxidation method” was conducted.
N23 Stock Purification Technology: Main Features
The main features of purification technology using N23 strain are as follows.
- Multiple organic chemicals contained in contaminated groundwater can be decomposed simultaneously.
- Decomposes chloroethylene and 1,4-dioxane in a short period of time
- 1 mg / l of each substance: decomposes below groundwater environmental standard within 1 day.
- Compact purification equipment. Efficient purification treatment for load fluctuations of pollutants.
Compared with the advanced oxidation method, purification costs are reduced by up to 50% and CO2 emissions from purification are reduced by up to 84%.
2019 | Taisei Corporation