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Low-cost and short time for complete composting with active oxygen treatment from Lake Biwa Tackling the World's Water Hyacinth and Sargassum Breeding Problems WEF Technology Development takes on the challenge

Caribbean Sea Successful high-speed composting of sargassum

WEF技術開発株式会社

Due in part to the effects of global warming, waterweeds and seaweeds have been proliferating in large numbers around the world, threatening the human living environment. One of these is the "blue devil," the water hyacinth, which thrives around the equator, and the other is sargassum (Honda straw), which flows into the Gulf of Mexico and the Caribbean Sea.

(Location: Otsu City, Shiga Prefecture; President: Akira Aoyama) has recently confirmed that sargassum sent from the Dominican Republic can be converted into fully matured compost at low cost and in a short time using active oxygen treatment, the world's most advanced technology, and that it has very excellent fertilizer effects.


Sargassum sent from the Dominican Republic


Finished sargassum compost


Sargassum in the Atlantic Ocean

Sargassum has been breeding in the Atlantic Ocean for a long time, and the sea where a large amount of sargassum accumulates is known as the Sargasso Sea. In recent years, conditions of global warming, eutrophication of the Amazon River, and metal supplies from the Sahara Desert have combined to grow the Sargassum Belt to the point where it crosses the Atlantic Ocean. This has been washed away and washed into the Caribbean Sea and even into the Gulf of Mexico, where it has been launched in large quantities onto the coast.

The large amount of Sargassum washed ashore, which decomposes quickly and produces a strange odor, and is covered with special Vibrio bacteria, etc., is having a major impact on the tourism economy, the environment, and the health sector of the local population, a major industry, and requires an immediate solution.

Universities and companies around the world have been working on this problem for several years, but no effective solution has yet been proven because sargassum has a water content of over 95% and contains heavy metals such as arsenic.

Sargassum in the Atlantic Ocean


Sargassum washed up on the beach


■ Sargassum treatment by active oxygen

Lake Biwa produces nearly 20,000 tons of waterweed every year, of which 5-6,000 tons are harvested by Shiga Prefecture, transported by dump truck to remote areas, and fermented and treated over a period of nearly three years. The amount of CO2 generated during this process is immeasurable. To solve this problem, we have spent nearly 10 years perfecting an activated oxygen compost production system that is a small device, low cost, and has advantages for agricultural use.


1) Activated Oxygen Generator and Its Effects

The active oxygen generator "AOS" is 50w (including air supply fan) and processes 3000L/min (max.) of air.

Active Oxygen Generator "AOS


Active oxygen instantly breaks down strong cell walls.

Cell wall decomposition by active oxygen


2) High-speed composting of sargassum

When sargassum is placed in an agitator and irradiated with active oxygen at room temperature, the cells decompose and the cytoplasm, which is the source of nutrients, is expelled, reducing the volume to 1/5 to 1/10 in 1 to 2 hours. Almost all fungi are sterilized during this time. The discharged water (nutrients) is once absorbed by charcoal, making it very palatable to the microorganisms. This enables fermentation process in a short period of time.


3) Active oxygen composting effect

Sterilization of Vibrio sargassum

Reduction of methane and nitrogen generation by mixing biochar

Crops grow 1.2 to 1.5 times faster on average.

Conversion of arsenic to a less bioavailable form by immobilizing arsenic

Sargassum composting process


The problem of the "blue devil" and the "world's three most harmful grasses," the water hyacinth.

As shown in the figure below, the water hyacinth, which is said to have originated in the Amazon, is now reproducing all over the world and threatening human life. Since the water content of water hyacinth is nearly 95%, it can be used in various ways if dried, but since many regions do not have abundant energy, it is difficult to solve the problem without technology that can dry the water hyacinth with small amounts of energy.


<Problems of water hyacinth

The water hyacinth causes a lack of oxygen in the water and a decrease in water temperature and quality.

It covers the surface of the water and inhibits photosynthesis of other plants.

Interferes with the operation of sluice gates and other facilities

Interferes with vessel and canoe navigation

Increases evapotranspiration and land area.

Becomes a breeding ground for mosquitoes and spread of malaria

Water hyacinth invasion area


One-hour treatment of hotei-aoi by active oxygen


Introduction of new technology originating from Lake Biwa is progressing in various parts of the world

1) Caribbean Sea, Sargassum

Dowa Line (Tokyo), a shipping company operating in the Caribbean Sea and other areas, sent us sargassum from the Dominican Republic to confirm whether activated oxygen treatment can be used in the Caribbean Sea and surrounding areas. Dowa Line, which has been developing its business in the Caribbean for many years, has seen the tourism business, its main industry, severely damaged by sargassum, and the smell of the sargassum affecting the lives of local residents, and has been considering ways to support a solution. The test confirmed that there were no problems with the processing method, fertilizer effect, etc. In the future, the company plans to install the "α-Gaia" processing equipment and expand the composting of sargassum, as well as contribute to the reduction of agricultural fertilizer by composting food waste and agricultural crop residues during the off-season.


2) Water hyacinth in Thailand

Breeding of water hyacinth in rivers and lakes is a major problem in Southeast Asian countries. IEC Corporation, which manufactures coating equipment in Southeast Asia, has been considering the use of recycled water hyacinth, which is also becoming a social problem in Thailand, and six months ago introduced the "α-Gaia" test system (vehicle-mounted type) and has been conducting test demonstrations in various locations with the Thai Ministry of Agriculture.

With the expected increase in demand for rice in Thailand in the future, it is expected to contribute to the problem of fertilizer shortages.



Company Profile

Company name: WEF Technology Development Co.

Representative: Akira Aoyama, Representative Director

Location: 1-19-15 Do, Otsu-shi, Shiga

Establishment : July 2016

Business description: Development and sales of water treatment, waste recycling, and Mg-related technologies

URL : https://aoyama-wefit.com

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