Realization of Stable Water Treatment by Underwater Mechanical Aerator and Agitator

HANSHIN ENGINEERING Co., Ltd.

Publication date	September 21, 2023 (Posted on May 10, 2024)
Sector	Water Environment / Water Resources

Company Overview

HANSHIN ENGINEERING Co., Ltd. is a manufacturer and sales company of gear reducers and equipment for waterway facilities, water treatment facilities, and industrial facilities. Our underwater mechanical aeration and agitation technology developed in Japan enables highly efficient and stable water treatment. By introducing this technology in developing countries, where the effects of climate change are particularly severe, we provide support to secure water resources and a stable supply of water to improve the living environment and health/sanitation in local communities.

Climate Change Impacts

The depletion of water resources due to the expansion of desertification and drought caused by the effects of climate change is a serious problem worldwide, and demand for water treatment technology is increasing, especially in developing countries. As a countermeasure against the shortage of water resources, the use of "gray water" (*1), which is recycled water produced by treating sewage, is required in addition to drinking water, and the stability of facilities is important in the treatment of such water.

Adaptation Initiatives

We are actively promoting the international development of the Aquarator® (Fig. 1), a submersible mechanical aeration/agitation system, to ensure stable water treatment.
This product can efficiently and effectively perform aeration/agitation, and has the effect of stimulating the activity of aerobic microorganisms. It can be applied to both aerobic and anaerobic tanks. In aeration, the air supplied from the blower is miniaturized by our original structure, allowing the bubble to reach every corner of the reaction tank (Fig. 2).

The features of this product are as follows

• High oxygen dissolution efficiency and high energy efficiency (energy savings of up to 30% can be realized by replacing the existing diffuser with the Aquarator®).
• Stable treatment because the sludge is well maintained and does not accumulate at the bottom of the tank.
• No need for frequent maintenance and no need to remove sludge from the tank for cleaning.

■The following are some examples of overseas installations of this product.

① Project：Advanced wastewater treatment and resource recycling at a palm oil mill
　Country：Malaysia

This case study was funded by JICA's Overseas Development Support Program for Small and Medium Enterprises - Dissemination and Demonstration Project. One of the local issues was the lack of low-cost technology for stable treatment of wastewater from palm oil mills, one of the major industries in the country, in response to the policy to tighten the effluent discharge standards (upper BOD limit of 20 mg/L). Therefore, we introduced the activated sludge method with Aquarator® as its core, which has a higher treatment capacity than the conventional method, and achieved the effluent discharge standard with the upper BOD limit of 20 mg/L.

② Project：Initiatives at a rubber glove manufacturing plant and aquaculture facilities in Thailand
　Country：Malaysia

This project was funded by the FY 2017 Grant-in-Aid for Carbon Dioxide Emission Reduction Project (Low Carbon Technology Innovation Project for Developing Countries) and the FY 2018 Grant-in-Aid for Carbon Dioxide Emission Reduction Project (Low Carbon Technology Innovation Project for Developing Countries), and is an example of the "development of energy-saving submerged aerator/agitator for wastewater treatment systems in the ASEAN region”. The project examined ways to improve product performance (improvement of oxygen transfer performance (air supply function)), extend the service life of the product (improvement of motor bearings and development of a motor cooling mechanism), and ensure stable use of the product (development of a mechanism to prevent foreign matter entrapment).

Effects / Expected Benefits

Aquarator® enables significant reductions in water treatment costs. The realization of high wastewater treatment capacity and the improvement and development of local equipment performance will enable operation in areas where water resource depletion is a concern.