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Water treatment (waste water): Eco-friendly Non-Electric Sand Filtration Device

Water treatment (waste water): Eco-friendly Non-Electric Sand Filtration Device

Nihon Genryo Co., Ltd.

Eco-Friendly Non-Electric Sand  
Filtration Device


Produced by Nihon Genryo Co., Ltd, the Non-Electric SIPHON TANK (NEST) has the ability to consistently produce high-quality filtered water without the need to replace filter media. As such, this water could be utilized for drinking, industrial use and emergency situations. Through the company’s patented technology called “Siphon Washing Technology,” the creation of twin vertical and horizontal vortices is possible, prompting sand particles to be agitated in a three-dimensional washing activity. This is designed to remove the hard sludge layer on particle surfaces.

The best part is, NEST can operate without the use of electricity, making access to safe water possible -- even in areas where electricity is not possible.

NEST is utilized as a backup unit in emergencies such as natural disasters. For example, if a power failure occurs that compromises water purification facilities, the disaster ceases all operation. This does not have to happen with NEST.

In addition, NEST offers non-polluting and zero-emission equipment development due to the fact that no electrical resources are required in order for it to operate.

Major Features and Advantages

I. Portability

In the event this equipment needs to be used in emergency and disaster areas, the Non-Electric SIPHON TANK can easily be transported, with easy operation. Thus, it can be installed wherever clean water needs to be used, at any time. This makes it easy to use in areas struck by disaster, small villages with no potable water, and other similar situations.

II. No filter media replacement

Filter media can be used on a semi-permanent basis with no need for replacement thanks to Siphon Washing Technology. Disposal of filter media as industrial waste is no longer a concern, as a result. SIPHON TANK is "earth-friendly" filtration device that significantly contributes to a response to ISO14000.

III. Reduce backwashed water

The need for backwashing water is drastically reduced, thanks to Siphon Washing Technology that efficiently takes away suspended substances. This means backwashing is only needed for rinsing off those suspended substances. This is a drastic reduction when compared with traditional sand filtration devices, which all require frequent backwashing and therefore create waste.

IV. No fixation of filter media

With the use of NEST, there is no fixation and thus the filter media stays clean. When sewage water containing lots of organic matter is treated by conventional filter tanks, filter media can’t filter properly. With this equipment, this is no longer a concern. Media is therefore always kept clean thanks to Siphon Washing Technology, which washes for just one minute each day.

From compact design and easy operation to low cost of operation and maintenance, the Non-Electric SIPHON TANK (NEST) by Nihon Genryo Co., Ltd. carries many benefit in today’s society.

Technology Data

Conceivable applications

Non-Electric SIPHON TANK (NEST) can consistently produce high quality filtered water without replacing filter media. High quality filtered water would be available for drinking, industrial use and emergency.

This is achieved by our patented technology, so-called ‘Siphon Washing Technology’. This technology creates twin vertical and horizontal vortices that cause sand particles to be kneaded each other in a three-dimensional washing action to remove hard sludge layer on the surface of particles.
In addition, NEST can operate without use of electricity. This equipment will enable to access to safe water even in areas where electricity is not supplied.

Competitive advantages

1. Movable for emergency and disaster areas
Non-Electric SIPHON TANK is easy to transport and is simple to operate. Since it is portable unit, it can be installed anywhere and anytime to provide clean water.

2. No need for filter media replacement
Filter media can be used semi-permanently without replacement, because of Siphon Washing Technology. Therefore, there is no need to dispose used filter media as industrial waste. SHIPON TANK is “earth-friendly” filtration device that significantly contributes to a response to ISO14000.

3. Amount of backwashing water can be dramatically reduced
Since MST efficiently removes suspended substances by Siphon Washing Technology and conducts backwashing only for rinsing away the suspended substances, the amount of backwashing water can be significantly reduced, compared with the conventional sand filtration devices.

4. Prevention of fixation of filter media
When sewage and water with high content of organic matters are treated by the conventional filter tanks, filter media usually cannot filter and may stop functioning properly. However, MOBILE SIPHON TANK can prevent the fixation and keep media always in a clean condition by our Siphon Washing Technology (washing is conducted for only 1 minute in every single day.


NEST can be used as a backup unit in emergency (i.e. natural disaster) during a power failure when water purification facilities are damaged and the operation is stopped by the disaster.
Also, NEST has made a huge contribution to non-polluting and zero-emission equipment development, because it does not need any electrical resources to operate.

Technical maturity / Past record of introduction

Nihon Genryo conducted a formulation survey to explore the possibility of sustainable drinking water supply in Niassa of the northern part of Mozambique in 2013. With Next, this project conducted hearing investigations in 3 provinces and also conducted pilot demonstrations in 4 places. Result of the demonstrations shows that NEST can significantly reduce turbidity of raw water. The quantitative results are as shown below;

Lake water             From 10.9 NTU to 0.58 NTU
River water             From 11.0 NTU to 0.91 NTU
Spring water           From 7.25 NTU to 0.80 NTU
Shallow well water  From 297 NTU to 0.43 NTU

Conceivable risk

The following materials have to be removed in advance, because surface water is preferable as raw water for the device, such as river, spring and lake water;

– Agricultural chemicals
– Heavy Metals
– Fluorine
– Sea water

Information on patent related to this technology

“Siphon Washing Technology” has patents in 33 countries.
(Ex: Japanese patent No. 3020452, 3020464, 3919098 and so on)

Company Data

Name Nihon Genryo Co., Ltd.
Address NKF Kawasaki Bldg 1-2 Higashida-cho,
Kawasaki-ku Kawasaki-shi Kanagawa 210-0005
Capital 95 million JPY
Contact person Overseas Division: Mr. Hiroshi EJIMA
Tel +81-44-222-5555
Fax +81-44-222-5556
Number of employees 69 (including 4 staff of Overseas Management Division)
Date of company foundation December 19th, 1939
The type of business 
  1. Designing, developing and manufacturing of ECO-friendly water treatment products.
  2. Designing, developing and manufacturing of filter media (More than 80% of purification plants in Japan are using our filter media).
  3. Equipment works for water treatment facilities, such as new construction and recycling work.
Overseas Offices
Gyeonggi-do, Korea Hoimyung Corp.

Modality of business transaction

We are looking for business partners which specializes in the field of water treatment and/or assembly.

Export of product
We would like to sell our products directly or through distributors.


1. Introduction of Non-Electric Siphon Tank


2. Water Turbidity Treated by Non-Electric Siphon Tank


Contact Person(s)

Mr. Hiroshi EJIMAE-mail:
Mr. Hiroshi EJIMAE-mail:

*Please mention that you saw UNIDO's website when making the first contact with the company.

Registered Category

  • Environmental Technologies : Pollution Prevention and Control