April 3, 2017
Kurita Releases Japan's First Continuous One-Step ANAMMOX Process
Broadening the product lineup to provide customers with advantages in extensive markets and fields including biogas power generation
Kurita Water Industries Ltd. (Head Office: Nakano-ku, Tokyo; President: Michiya Kadota, hereinafter "Kurita") today announces its release of Japan's first continuous passing type one-step anaerobic ammonium oxidation (ANAMMOX) process (hereinafter "continuous one-step ANAMMOX process"), which was developed by modifying Kurita's original high efficiency nitrogen removal system for wastewater treatment.
The nitrogen treatment technology based on the ANAMMOX reaction (see 1 in Supplementary Material) is increasingly being applied to the treatment of effluent from semiconductor and chemical factories, wastewater treatment facilities, and dehydration and filtration in wet methane fermentation. The continuous one-step ANAMMOX process has an advantage in that it can be utilized for the treatment of high flow wastewater with low nitrogen concentration.
Kurita developed the ANAMMOX process nitrogen removal system using ANAMMOX bacteria in 2003, and put a full scale system for a large semiconductor factory into operation in 2006. Kurita has been accumulating a track record ever since. In a bid to meet an even higher level of customer requirements, Kurita pressed ahead with technological improvements. To date, it offers the ANAMMOX process in the continuous passing two-step (hereinafter "continuous two-step") method and in the batch one-step method. Kurita has recently developed the new continuous one-step ANAMMOX process that has no track record in Japan to provide technologies to suit a broader range of customer needs.
The one-step ANAMMOX process refers to the ANNAMOX reaction for the partial nitrification of nitrite and nitrogen removal in a single reactor. The introduction of an original granulation technology in which a mixture of ammonia oxidizing bacteria and ANAMMOX bacteria is grown in a biofilm has opened the way for the greater efficiency of the ANAMMOX reactor and for stable nitrogen removal in heavy loading rate.
In addition, the continuous one-step ANAMMOX process utilizes a reactor equipped with a special gas solid separator (GSS) that separates ANAMMOX granules, gas and treated water to carry out the nitrification of nitrous acid and nitrogen removal at the same time. This has made it possible to treat high flow wastewater with low nitrogen concentration, which was traditionally difficult to treat. As a result, the construction expenses and installation space for the continuous one-step ANAMMOX process are each 30% smaller than for the conventional continuous two-step process, and it is easier to maintain and manage.
Kurita has recently released the continuous one-step ANAMMOX process and won the first order for it in Japan. In the future, it will continue its efforts to improve the system structure and the treatment performance of the products in the lineup(*1) and upgrade its after-sales service structure(*2). In addition, Kurita will expand the application of the ANAMMOX process in those areas where future growth is expected, such as wet methane fermentation in biogas power generation, in a bid for further sales expansion.
- *1:Features of products in the lineup
- ・Continuous One-Step ANAMMOX process :
- For treating high flow wastewater with low nitrogen concentration
- ・Batch One-Step ANAMMOX process :
- For treating low flow wastewater with high nitrogen concentration
- ・Continuous Two-Step ANAMMOX process :
- A conventional model that may be added to existing nitrification tanks
- *2:After-sales service structure
The ANAMMOX process is unique in that it employs original ANAMMOX bacteria. On the basis of its extensive introduction track record, Kurita is working to upgrade its after-sales service system to ensure the domestic procurement of ANAMMOX bacteria.
Generally, wastewater containing nitrogen compounds is treated in two steps. The first step is nitrification, in which ammonia as a nitrogen component in wastewater is oxidized into nitrite and then into nitric acid. The second step is denitrification, which decomposes nitrate into nitrogen gas. The nitrification process requires a large amount of electricity to feed in a substantial quantity of air to support growth of nitrifying bacteria. The denitrification process entails a high cost to treat nitrogen, because surplus sludge is generated as waste as a result of the growth of micro-organisms.
The use of ANAMMOX bacteria that decompose ammonia into nitrite and then into nitrogen gas eliminates the necessity to completely oxidize ammonia into nitrate in the nitrification process, and massively reduces power consumption. These bacteria generate a limited amount of surplus sludge, which results in a considerable reduction in the sludge treatment cost.
In addition, they can be utilized for wastewater with a high concentration of nitrogen and with almost no organic substances. This helps slash the cost of chemicals for denitrification.
ANAMMOX bacteria were discovered by researchers at the Delft University of Technology in the Netherlands in 1990. Kurita formed an alliance with Netherlands-based PAQUES, which is a pioneering manufacturer of ANAMMOX bacteria holding a basic patent, to commercialize the denitrification method based on the ANAMMOX reaction in Japan under the name of the ANAMMOX process.
2.Business Expansion in the Biogas Power Generation Market
Since the Feed-in Tariff program came into force, the biomass power generation market has seen its performance grow in Japan. Kurita holds both dry-type and wet-type methane fermentation technologies. It therefore has an advantage in offering fermentation technologies best suited to the characteristics of different biomass materials. When the ANAMMOX process is applied to the dehydration and filtration process, wet methane fermentation exhibits its technical superiority in helping improve the economic efficiency of biogas power generation operations. With its original technologies with distinctive features, Kurita aims to deliver significant advantages in energy creation and waste recycling to customers.