Natural resources - activated carbon

Natural materials for water filters

Natural materials for water filters

Activated carbon is a natural material

The natural product is refined activated carbon from CARBONIT by a unique and internationally patented process. All data processed by CARBONIT commodities are residue controlled and monitored LGA. They comply with stringent European standards for water filters. Most modern technology for unparalleled performance. The CARBONIT - water filters combine exceptional Filtration down to 0.45 microns with the high adsorption of activated carbon. As spring water from the tap. No carrying heavy crates of water.
Activated carbon is a work based on natural raw materials, which binds through its porous structure and therefore extremely large internal surface chemical compounds and molecules. Traditional applies charcoal in many processes in the chemical industry. The high adsorptive capacity, it is mainly used in the purification of exhaust air, drinking water and sewage as well as in the food industry, pharmaceuticals and chemicals used.
The starting materials for the production of activated carbon are carbonaceous raw materials such as wood, peat, lignite, coal, fruit stones or coconut shells. However, other carbonaceous materials, such as plastic waste or petroleum products can be processed into activated carbon due to the high carbon content. These carbonaceous materials are similarly obtained the production of charcoal and then, as the name suggests, activated. This activation process increases the adsorptive property of the coal and leading to an improvement in cleaning performance as compared to conventional charcoal.
Activated carbon consists of an irregularly arranged crystal lattice of carbon atoms. These randomly shifted
Lattice planes lead to a very porous structure and thus a large internal surface area. You may be at commercial activated carbon in the range of 500 to 1500 square meters per gram.
For comparison: 4 to 5 grams of activated carbon include the area of ​​a football field complete. The inner surface of the activated carbon is characterized on the basis of the pore system, a distinction is simplified pores of various sizes or diameters. So is differentiated between macropores (the feed pores in the grain interior) and adsorption pores (that is, the pores in which the actual addition of the molecules takes place at the inner surface).
The structure of the pore system influences the transport of the sorptive from the grain boundary in the grain interior as well as the adsorption property of the substance on the surface.

Surface properties of activated carbon

In addition to the pore structure of the chemical property of the surface has a further decisive influence on the adsorption capacity of activated carbon. Given the large amount of impurities, such as can occur in the water or in the air, in practice, the cleaning performance of activated carbon to specific groups of substances is aligned. A selection of hazardous substances, as may occur using the example of drinking water purification is, hereinafter referred to as:
• odors and flavors,
•To dye,
• petroleum hydrocarbons,
• halogenated organic hydrocarbons,
• organic hydrocarbons,
• chlorine, chlorine dioxide, ozone, permanganate,
• Heavy metals,
• ammonia, nitrate,
• active pharmaceutical ingredients.
 
 
 

Since each of these compounds has a different Adsoptionsverhalten and binding capacity due to their chemical composition, the physical properties such as grain and pore size with the chemical properties of the surface are combined. This ultimately leads to an optimum cleaning performance in the particular application.
 

Adsorption

As adsorption is called a process in which substances on a surface anneal (Fig. B). There are known two types of adsorption. On the one hand we speak of the physical adsorption, this is mainly caused by the van der Waals forces. The van der Waals force is quite weak attraction, but sufficient, molecules or atoms adhere to a surface due to their charge (adsorb). This force is reversible, that is, enters a stronger force to, for example, Brownian motion when the temperature increases, the adsorbed substance can be reset released again. The situation is different in the chemical adsorption, or also known as chemisorption. Here is overcome as with all chemical reactions, activation energy for the interfering substance (adsorbate) forms a chemical bond with the surface of activated carbon (adsorbent). The chemisorption is stronger than the physical adsorption in their binding. Basically, it can lead to desorption (redissolution) of substances but also when bonding forces of other substance groups are more pronounced. If the capacity (capacity for pollutants) an activated carbon filter is exhausted, speaks in this case of a loaded filter. However laden filters need not be necessarily disposed. Often, the activated carbon contained in the filter can be regenerated by the adsorbed substances are removed from the surface of the activated carbon again. This desorption process (ie the reverse adsorption process) may, for. Example, be effected by a pressure reduction or temperature increase. After repeated desorption or in the adsorption hard Desorbable substances the loaded activated carbon, however, must be fully reactivated .. Here, the loaded activated carbon passes through a renewed - albeit shorter - activation process with the aim to raise the inner surface back to the original level. Another way to regenerate loaded activated carbon, is the extraction. The adsorbed substances are removed by means of an organic solvent from the surface of coal. But even microorganisms (macroporous) activated carbon regeneration by decomposing organic easily desorb compounds biologically. Particularly in industrial applications regenerated activated carbons are used, such as in printing, in food technology, drinking water treatment and wastewater treatment. In this case valuable substances can be prepared by the desorption often be recovered, as it demonstrates the adsorptive recovery of toluene in printing, wherein the toluene from the exhaust air recovered is recycled in the printing process.

manufacturing process

Activated carbon can be produced from almost any carbonaceous material. These raw materials can be present both in unverkohlter form and in the form of coals and cokes. The basic principle of activation is to selectively reduce a portion of the carbon under appropriate conditions. The selective degradation with the result that numerous pores, fissures and cracks caused by the escape of volatile substances, can take place in which the adsorption of substances. In the manufacture of activated carbon, a distinction is two methods: the chemical activation and the activation gas. In chemical activation unverkohlte raw materials such as peat or sawdust are having a dehydrating effect (hygroscopic) acting agents, e.g. Zinc chloride or phosphoric acid, and subsequently mixed at temperatures of 400 - 600 ° C activates. Here mainly arise macroporous activated carbon, which can be used due to their properties, for example, for bleaching liquids.

The second variant is the gas activation. If you are generally already charred natural products such as Charcoal,

Peat coke, Kokosnussschalenkoks, coal or lignite used. These have already before activating a few small pores and thus a first, but little pronounced adsorption through the activation process, the number of pores and therefore the size of the surface increased significantly. The activation is conducted at temperatures of 700 - 1000 ° C and carried out using water vapor and carbon dioxide. The water vapor and carbon dioxide lead to partial oxidation in particular the non-crystalline carbon. Here are tar-like products that clog the fine pores, expelled and the carbon skeleton largely exposed. Inside the raw material, the desired pores of a fine-pored activated carbon now be formed. Since it is necessary for the activation of a high temperature, the use of Drehroh-, stack or shaft has established itself in the industry. Here activated carbons and their pore distribution for the various applications can be tailored.

Activated carbon is sold as a powder or granular carbon or carbon mold. In the manufacture of molded carbon e.g. for water filters (activated carbon block filter), the carbonized semi-finished product is pulverized, activated and then mixed with a binder and extruded or sintered as required. The few millimeter large granulocarbon there as broken particles or as a rod-shaped compacts. Granulocarbon used in adsorber vessels through which the to-clean gas or liquid stream is passed through it. The broken, sharp charcoal is preferred for the water purification

used. Its compact design replaced an activated carbon block filter voluminous loose beds of powder coal. Also the capacity for accumulation of undesirable substances is significantly increased and the tendency to submit once annealed substances (so-called chromatography effect) lower. In microporous block filters of high filtration fineness is in addition to the chemical-physical adsorption and also good mechanical filtration property to particulates and microorganisms.

 

drinking water treatment

Drinking water is mostly from aquifers, but also in ground water poor regions, for example from the bank filtrate of rivers. A large proportion of the compounds and impurities, which dismisses the man in nature, is biodegraded by bacteria in the soil in the infiltration. Yet repeatedly occur exceeded the legal limits, which cause the water obtained must be treated before being fed into the drinking water network. The filters used for this purpose is called monolayer or multilayer filter.
The Einschichtfilter made entirely of one filter material, whereas the multilayer filters are composed of a combination of various filter materials. The multilayer filters usually consist of a layer (for example, sand) for the retention of coarse particles and a layer of activated carbon. Since utilities guarantee the quality of drinking water according to the law only to the house connection, are also in the private sector are increasingly drinking water filters for use.
These filters have the task may be eliminated through the pipeline network registered particles, bacteria, odors and flavors as well as heavy metals. It may also happen that pollutants are not completely contained in the waterworks. This may be pesticides, drug residues or even hormonal substances that pass through the diffuse contamination of groundwater and pass the waterworks unhindered. Unsuitable or outdated household can deliver heavy metals in the drinking water. If in the selection of pipe materials the locally different composition of drinking water only considered insufficient, heavy metal ions can be solved. These are ions of the elements copper, nickel, zinc and lead. In all these cases it is advisable to install an activated carbon filter in front of the discharge point of the drinking water, which can remove heavy metals, drug residues and pesticides from drinking water (Fig. F). The essential for the human organism minerals, salts and trace elements are not affected. They happen because of their small size and agility to filter and are therefore even after filtering available.