Face CASE28 Face

Honda Engineering Co., Ltd.Business Administration Division, Facilities Management Department

Masuhiro Sakurai, Senior Staff Engineer, Environmental Administrator, Facilities Department, Business Administration Division, Honda Engineering Co., Ltd.

Masuhiro Sakurai, Senior Staff Engineer, Environmental Administrator, Facilities Department, Business Administration Division, Honda Engineering Co., Ltd.

'Looking at our new water recycling system, we realized we could close the loop entirely.'

 Having achieved the purification of discharged water by constructing an advanced wastewater treatment system in the 1990s, Honda Engineering next embarked on a campaign to recycle its domestic wastewater. Water use was starting to grow as a result of business and workforce expansion. The company decided to take the concept of clean effluent one step further. It set forth a policy to effectively utilize water resources through purification and reuse. The idea was to recycle some of the water used in the restrooms, showers, and kitchens for use in toilets and other non-potable systems.
  Shortly after completing a recycling system for some of the domestic wastewater, Senior Staff Engineer Masuhiro Sakurai was transferred to the same Business Administration Division as Ishida.
 “I came here in 2004, just around the time when the recycling system was completed. After looking at the system, I approached the team and suggested that we expand the scale of the project. A new project got underway in 2005, the following year."
 At the start of project construction in 2005, Honda Engineering was purchasing 59,000 tons of potable water and 48,000 tons of industrial water per year, while discharging 62,000 tons of domestic wastewater and 24,000 tons of industrial wastewater. Sakurai said that the initial objective was to somehow reduce the discharge quantity of this domestic wastewater.
 In 2007, two years after the project was started, a new domestic water recycling system was completed as the first step toward a closed-loop system. The flow of water in the system is as follows. First, wastewater from kitchens, restrooms, and showers is sent to the No. 1 and No. 2 Domestic Wastewater Treatment Facilities and purified to a standard whereby it can be discharged. Next, the water is purified further, to a quality at which it can be used in the plant. This recycled water is reused as toilet water, coolant, and industrial water, and water from the toilets is returned once again to the treatment facilities.
 With the completion of this recycling system, the 62,000 tons of discharged domestic wastewater was reduced to 25,000 tons, some of which was also made available for use as industrial water, contributing to a reduction in the volume of water purchased for industrial use. Despite an increase in the number of associates at a rate of several hundred people per year for business expansion, the amount of water used has not changed since then, indicating a considerable economization of water resources.
●Recycling system for domestic wastewater (as of 2007)
Recycling system for domestic wastewater (as of 2007)

Special innovations led to the completion of the first closed-loop water recycling system at a Honda company.

 Next, an initiative to recycle industrial water began in 2008. As with domestic wastewater, Honda Engineering constructed a system to recycle industrial wastewater produced at the plant. Since industrial wastewater contains various chemicals used for research and development, the treatment method differs from that of domestic wastewater. One of the innovations applied by Honda Engineering was a biological carrier medium called Fabios. Fabios creates a comfortable living space for the microbes that are cultivated inside a water tank for processing sludge. Using this technology allows microbes to live long enough to process impurities such as nitrogen and phosphorus.
 Another innovation was an advanced filter called a reverse osmosis (RO) membrane. Some research and development processes, such as the cleaning of precision instruments, require water of a higher quality than tap water (i.e. pure water). RO membrane was thus used to filter treated industrial wastewater and remove fine particles and ionic material in order to create pure water.
 The recycling system for industrial wastewater was built on these special innovations and research. This consequently led to Honda Engineering’s terminating its purchase agreement for industrial water. The basic rate for industrial water is expensive to begin with and becomes more so as the amount used decreases. Thus, by making it possible to meet the plant’s industrial water needs by recycling domestic wastewater and reusing industrial wastewater, the company was able to stop purchasing industrial water, which in turn led to the elimination of industrial wastewater discharge (with the exception of concentrated water (see note)), creating substantial cost benefits over the course of a year.
 In this way, recycling was achieved for both domestic and industrial wastewater and the closed-loop water recycling system was finally completed in 2009.
 Note: Water that contains the salt content of the wastewater and cannot be reused

A screen installed in the monitoring room shows the status of water throughout the system in real-time.

A screen installed in the monitoring room shows the status of water throughout the system in real-time.
 Hayashida spoke on the difficulties the team faced when constructing the system.
  “To stop purchasing industrial water means to use recycled water in its place. The most difficult thing was figuring out how much each facility uses and allocating water appropriately to prevent shortages. The plant needs water, and a shortage even has the potential to bring work to a halt. However, potable water is used in kitchens and the like, and so kitchen water will run out if too much is used as industrial water. We have to coordinate the flow of both kinds of water to ensure there is no deficiency in either. Moreover, there are three tanks that store the water to be sent to the plant, with each having a different capacity. If too much water is stored in one tank, another will run short. In fact, there have been cases where there were difficulties in water management that caused shortages and trouble for the plant. In order to become better at controlling water, we have steadily accumulated know-how by collecting past data and conducting simulations.”
 Kenichi Tasaki, who has managed the system since 2009, went on to speak about the difficulties of maintaining a closed-loop water recycling system. “The quality of the water coming out of the plant varies according to the type of research being conducted, which means we constantly have to change our treatment methods. Sometimes, depending on the types of chemicals used in research, we can’t treat the water here, because passing the water with these chemicals through our treatment facilities could break the equipment. For this reason, we’ve installed monitoring equipment and now try to prepare for changes in research activities by constantly checking the quality and quantity of the water at all treatment sites and asking about upcoming research.”

Page Top

Honda Worldwide site

Home | Site Map | Site Index | About this Site

Copyright, Honda Motor Co., Ltd. and its subsidiaries and affiliates. All Rights Reserved.