|
|
Carbon Fiber
Water quality purification using carbon fiber is economical and effective
method. And it is low environmental impact. Active biofilm are formed by
high bioaffinity of carbon fiber, and its microorganisms decompose contaminants.
On the other hand, biosonic radiates from carbon fiber activate microorganisms
and gather fishes. Carbon fiber exercises seaweed bed function.
What is Carbon Fiber ?
- Carbon fiber is a “fibrous carbon substance having a fine graphite crystal structure” which is manufactured by carbonizing acryl fibers by a special heat treatment process.
(Polyacrylonitrile (PAN) type)
- Carbon fiber is generally said to be a “light, strong, corrosion-resistant” advanced functional material.
It is widely used in diverse applications, taking advantage of its combination of properties as a lightweight materials with excellent mechanical properties, and its excellent properties as a carbon material.
○ Specific strength (tensile strength/specific weight): 10x that of steel.
○ Specific modulus (tensile modulus of elasticity/specific weight):7x that of steel.
○ Applications: Aircraft, automobiles, reinforcing material
for concrete structures, fishing rods, golf clubs, etc.
- Carbon fibers for use as a water purification materials are given a special surface treatment to cause the fibers to expand in water.
- Carbon fibers for water purification consist of clusters (bundles) of 12,000 ultra-fine, 7μm filaments.
Functions of Carbon Fiber
| ■ Function of Water Purification |
- Pollutants in water are adsorbed on the large surface area of the carbon fibers.
- At the same time, microorganisms in the water are attracted and fixed.
- Due to their high biocompatibility, the carbon fibers form an active microorganism film and become a habitat for the microorganisms.
- The microbial film sways in the water, capturing and decomposing pollutants.
→ Water purification.
- The microorganisms are activated, attracting fish and creating a habitat for egg-laying and the growth of young fish. → Formation of seaweed bed.
- Effects include water purification, preservation of the ecosystem, and securing biodiversity.
 |
 |
When immersed in water, a water-soluble sizing agent dissolves, and the filaments unravel and spread.
|
Pollutants are adsorbed and microorganisms are fixed on the large surface area of the carbon fiber.
|
 |
 |
Bio film
( radical sludge) |
Microorganism
(microscope photo) |
page top
| ■ Mechanism of Water Purification |
 |
Swaying of the carbon fibers causes movement
of the water and decomposition of pollutants. |
Main nutrients and metabolism products
of microorganisms in microbial film. |
page top
Water Purification Effects
Water quality purification using carbon fiber is effective in improvement of transparency in a short time, decrease COD and BOD, and purification of TN and TP.
Removal rate of water quality purification using carbon fiber items（％）
| items |
river |
lake |
sewage |
| biological oxygen demand (BOD) |
50～70 |
20～90 |
90～95 |
| suspended solid (SS) |
50～70 |
20～90 |
90～95 |
| total nitrogen (TN) |
10～30 |
10～30 |
30～70 |
| total phosphorus (TP) |
10～50 |
30～90 |
30～50 |
| ■ Possible Fields of Application of Carbon Fiber |
- Environmental water (rivers, lakes and marshes, ponds, sea water)
- City sewage (human excreta purification tanks, advanced wastewater treatment tanks)
- Factory organic wastewater (food, brewing, chemical industries)
- Livestock organic wastewater (excreta, milking)
- Residential wastewater, kitchen wastewater
| ■ Features of Water Purification by Carbon Fiber |
● Advantages of Water Purification by Carbon Fiber
・Fast organic matter decomposition treatment rate by activation of microorganisms.
・Minimal generation of excess sludge, and minimal peeling off of attached matter.
・Large denitrification and dephosphorization effects.
・High suspended particle capture effect.
・Low installation cost, easy maintenance control, and no running costs.
● Points Requiring Consideration in Water Purification by Carbon Fiber
・Difficult to produce effects in environments with few microorganisms, and time is required.
→ Countermeasure： Seed microorganisms
・Effect is reduced by deposits of excess sludge, e.g., skeletons of microorganisms, etc.
→ Countermeasure： Maintenance control
・Aerobic bacteria are not activated in oxygen-poor environments.
→ Countermeasure： Aeration equipment
・When no water flow exists, purification is not possible because pollutants do not come into contact
with microorganisms.
→ Countermeasure： Circulating water flow
・When a large amount of pollutants is adsorbed, time is required for decomposition.
→ Countermeasure： Maintenance control
”Large effects are achieved by activation of microorganisms
with appropriate oxygen and water flow.”
| ■ Features of Microorganism Groups Fixed on Carbon Fiber |
- Microorganism fixing rate is fast, and the amount fixed is large.
- Deposited microorganisms resist peeling off, and at the same time,their activity is high.
- Within the groups of microorganisms deposited on the fibers, the aerobic microorganism phase and anaerobic microorganism phase exist in a well-dispersed state.
- Microorganisms with high bulk are deposited on the carbon fiber bundles.A type of pump motion in the moving water and swaying of the carbon fiber bundles causes mass transfer and accelerates the decomposition of pollutants.
- The range of effect is expanded by the coexistence of a microorganism multiplication action, which is due to sound waves emitted by carbon in an early stage in the initial phase of deposition of aerobic bacteria, with groups of microorganisms.
| ■ Amount of Carbon Fiber Installed |
The amount installed is calculated based on various conditions, including
the shape of the water area, water depth, water quality, flow velocity,
residence time, etc.
| Location of installation |
Purpose |
Amount of carbon fiber g/m³ |
| Pond, lake/marsh, sea |
Water purification |
10～100 |
| River |
Water purification |
100～200 |
| Sewage/factory wastewater |
Water purification |
200～600 |
| Pond, lake/marsh, sea |
Seaweed bed formation |
10～200 |
page top
Carbon Fiber Water Purification Method
With carbon fiber, a large water purification effect can be obtained simply by installing the carbon fibers in water.
However, the manner in which this effect appears differs greatly, depending on site conditions such as the water area, water depth, amount of water, water flows, water quality, etc.
and the method of installation and amount of carbon fiber installed.
In cases where higher cost-effectiveness is required in water purification, the optimum installation plan is necessary.
■ Classification of Direct Environmental Water Purification Methods
Using Carbon Fiber |
page top
■ Standard Carbon Fiber Installation Methods
(Water Purification/Seaweed Bed Formation) |
It is important for miracarbon to swing in water. The way of using is decided by the purpose, the pollution extent,and the site situation,･･･etc.
1．HANGING in the water.
2．FIXING in the water.
3．FLOATING in the water.
4．BOTTOM-LAYING in the water.
| Purpose |
Method |
Type |
Attachment method |
Water purification
Seaweed bed formation |
HANGING |
Rope |
･Hanging with Rope type U, I
|
| Rope-Float |
･Hanging with Rope and Floats |
| Raft |
･Hanging with the Raft,
(PVC made, Wood made) |
| Floating island |
･Hanging with the Float-Island,
(Foam material made, Wood made) |
| FIXING |
Frame |
･Fixing with the steel-Frame in the water |
| FLOATING |
Float |
･Floating with floats in the water |
| Bottom sediment decomposition |
BOTTOM-LAYING |
Frame |
･Fixing with the steel-Frame in the water |
| Pile |
･Fixing with the steel-Piles/weights in the water |
Water purification
Seaweed bed formation
Bottom sediment decomposition |
FIXING & BOTTOM-LAYING |
Frame |
･Fixing with the steel-Frame in the water
･Bottom-Laying in the water |
| FLOATING & BOTTOM-LAYING |
Float |
･Floating with floats in the water
･Bottom-Laying in the water |
|
*If only BOTTOM-LAYING is used, water purification is not achieved and the effect will be small; therefore, a combination of FLOATING + BOTTOM-LAYING or HANGING + BOTTOM-LAYING is effective.
page top
● Direct Purification Methods for Rivers
|
 |
Main stream installation method
|
 |
| Contact pond installation method |
|
page top
● Influx Water Purification Facility
page top
● Separation Method
● Considerations in separation type purification facilities
∙ Aeration by drop or mechanical method
∙ Microorganism maintenance control, activated sludge
∙ Adjustment of intake flow rate and holding time
|
 |
River Separation Method – Direct Purification Facility |
|
 |
|
|
 |
|
|
page top
● Direct Purification Methods for Lakes and Marshes
● Considerations in case of closed water bodies
∙ Cause motion of the carbon fiber by water flows.
∙ Place polluted water in contact with microbial film on carbon fibers.
∙ Installation of aeration equipment in case of oxygen-poor conditions.
∙ In cases where there is no water flow oxygen, time is required.
|
 |
Intake water method |
|
|
 |
In-pond circulation method |
|
 |
In-pond individual device method |
page top
● Direct Purification Methods for Sea Water Areas
|
 |
|
|
|
 |
|
|
 |
”Recovering a Beautiful Water Environment with Carbon Fiber !” |
page top
|
