working principle:
There are a lot of pores inside the activated carbon. There are many capillaries of about 1 Onm~lA in the pores. The internal surface area of ​​1g of activated carbon is about 700-1400m2. These capillaries and pores are the best places for adsorption. .
Main adsorption objects:
1.DOC (Dissolved Organic Carbon) -- DOC with a molecular weight of 60 to 300 Daltons (mainly molecular)
2. Heavy metals
3. Strong non-organic ions such as chlorate ion, hypochlorous acid ion, etc.
The adsorption of activated carbon is a substance that absorbs the appropriate size or polarity by the size and polarity of the pores of the micropores. Therefore, in the case of molecular substances, there is a specific range, and too small and too large are adsorbed. Difficulties. If the molecular weight is small, but the polarity is sufficient, the adsorption will also be enhanced. Therefore, a single atomic ionic state (such as Cl-chloride ion) or a chelate (Chelate) will not be the protagonist of AC adsorption.
Manufacturing method:
Activated carbon is formed by carbonization of wood, fruit core, coconut shell, coal or petroleum bottom slag at a very high temperature. After carbonization, it is still necessary to pass the [activation] process to calculate the activated carbon. The method of activation is physical and chemical; the purpose of activation is mainly to increase pores. Physical activation, for example: introduction of hot air, water vapor; chemical activation, such as: access to phosphoric acid.
Use of activated carbon for marine aquaculture purposes:
Adsorbs DOC, infinite molecules, polar ions, polar molecules, heavy metals in water. Achieve the purpose of removing poison, pigment and odor in water.
Precautions for the use of activated carbon in marine aquaculture:
1. Phosphoric acid release:
Due to the relationship between the raw materials and the processing process, part of the activated carbon releases phosphoric acid after being placed in water. Therefore, we must pay special attention to this for marine aquaculture.
2. Trace elements:
Another part of the controversy is that activated carbon absorbs trace elements together. In this regard, after referring to foreign related websites, books, and monographs on activated carbon, the special summary focuses on the following:
A. Regardless of the use of activated carbon, seawater eco-cylinders have a problem of insufficient trace elements. This means that no matter the use of activated carbon, in order to maintain a healthy tank, it must be supplemented by water or additives.
B. Most of the trace elements are exactly off the peak of the activated carbon adsorption spectrum, meaning that it is not too small (monoatomic ionic state) is too large (chelate).
C. Most experts believe that the benefits of using activated carbon as a whole outweigh the disadvantages. (At least most of the authors I found have this view)
Selection criteria for activated carbon:
Less dust
2. Light texture (loose)
3. When you just put it in the water, it will float on the water and make a buzzing sound.
4. Do not release phosphoric acid
The amount of activated carbon:
Regarding the amount of AC used, the opinions of different authors are much worse, from (one teaspoon/10 liters) to (one kilogram/200 liters). But there are several big principles that are unchanged:
1. Hard Bone Cylinder > Soft Cylinder > FO
2. More algae> Less algae> No algae
The difference between the recommended dosages of the various sects is because each person's breeding organisms and equipment are different. The best way is to find out the most suitable amount of the cylinders by yourself: to observe the biological status of the tank as an indicator, to 1 /2, 1, 3/2, 2... Cup activated carbon corresponds to 100 liters of water to experiment, find the optimum amount.
The period of use of activated carbon:
This point is also a matter of various opinions, some think that it can be effective for half a year, and some think that it must be "hours". Since the validity period is absolutely related to the quality of activated carbon, it is normal for each family to have different validity periods.
For the most standard measurement method, the difference in TOC concentration (or the difference in the number of bacteria) between the influent and the effluent must be determined to determine whether the activated carbon is still effective.
However, activated carbon is not very expensive, and the too old activated carbon tends to release the previously adsorbed substances (but instead become a source of poison), so replacement within 1 to 2 months is a more reasonable approach. Also because of its micro-porosity, where bacteria are implanted, regular small-scale replacement is the ideal way.
For example, if the optimal amount of activated carbon in a cylinder is one kilogram, put activated carbon into 250 grams per pack, put one pack per week until there are four packs in the tank, take out the first pack in the fifth week, and then put in new ones. One pack keeps one kilogram in the tank, but the oldest is no more than one month, and each star is also replaced by a quarter of activated carbon.
The use of activated carbon techniques in marine aquaculture:
# Due to the porous nature of activated carbon, bacteria will be implanted, so it is best to divide the dosage into 3-5 aliquots, sub-package or replace, to avoid sudden changes in the number of bacteria, and thus affect the water quality factor.
For example: I plan to put 500 grams of activated carbon, preferably in packs of 100 grams of five packs, add a pack every week, replace or take out, and also take out (new) one pack a week.
# Place the activated carbon, it is best to place it in a place where there is water pressure, which will force the water to flow, otherwise the effect will be weakened a lot (this is very important, otherwise it will be half the effort)
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