Carbon Steel Activated Carbon Filter to Remove Deleterious Chemicals

Carbon Water Filters have been used for centuries to filter impurities from drinking water. Carbon is a very powerful absorbant; one pound (half a kilogram) of carbon contains a surface area of 125 acres (0.5 square kilometers). The material has millions tiny pores, usually invisible to eye, and can absorb thousands of water contaminants. Several forms are commonly used in water filtration: Granular Activated Carbon ( GAC ), and Carbon Block. Activated Carbon is a material that has a positive charge, which helps attracting even more impurities. Generally, Carbon Block Filters ( or "charcoal water filters" ) have higher contaminant removal capability than GAC filters, and they usually have a higher cost.
 
Activated Carbon and "Block" Filters a usually rated by size of the particles it can remove. Typical ratings are from 50 micron (least effective) to 0.5 micron (most effective). We generally use 5 micron carbon blocks in our systems, because it gives us very effective absorbtion capabilities in combination with acceptable water flow rates. However, some applications exist where granular carbon is a better fit, such as in removing chloramines (combined chlorine).
 
Although various types of carbon exist, three are generally used for drinking water filtration: bituminous, wood, and coconut shell. Coconut shell variety is most effective for most water filtration.
 
 How Carbon Filters Work?
Carbon filters work so well because of their large surface area. According to the Home Water Purifiers and Filters website, one pound of carbon has a surface area of approximately 125 acres. This allows carbon to physically absorb a large amount of chemicals and substances that pose serious dangers to the normal domestic water supply. Many of these substances can cause cancer, neurological problems and other health risks if ingested in large quantities.

1. Chlorine Removal: Activated carbon may be used to remove chlorine with little degradation or damage to the carbon. Dechlorination occurs rapidly and flow rates are typically high. However, this process requires an extensive amount of surface area, and organics in the water will eventually fill up and block the pores of the carbon. Ultimately, the AC filter will need to be replaced as its ability to dechlorinate the water will slowly decline. Spent carbon can be re-activated; however, re-activated filters should only be used in waste-water treatment applications. One advantage to using AC is its low operating cost and virtual "fail safe" operation once installed. One disadvantage is that as the chlorine is removed from the topmost layer of the media, the AC provides a damp environment ideal for the growth and proliferation of bacteria. Bacteria can cause problems in medical applications, or when using carbon as a pretreatment to reverse osmosis. 
2. Removal of Organic Matter: As water passes through an activated carbon filter, organic particles and chemicals are trapped inside through a process known "adsorption". 
The adsorption process depends upon 5 key factors: 
   a.physical properties of the activated carbon (surface area and pore size distribution); 
   b.the chemical makeup of the carbon source (amount of hydrogen and oxygen);
c.the chemical makeup and concentration of the contaminant;
d.water pH and temperature; 

What Carbon Filters Don't Remove?
Carbon filters are not particularly successful at removing dissolved inorganic contaminants and heavy metals such as minerals, salts, antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, copper, fluoride, mercury, nickel, nitrates, selenium, sulfate, thallium and other contaminants, which may require a reverse osmosis system or distiller instead. Carbon block filters can remove some large, dangerous microorganisms, such as giardia and cryptosporidium, that can cause a number of diseases and epidemics, but nothing less than the size of the carbon itself. Viruses are too small to be removed by carbon, as they usually range between 20 and 400 nanometers in size, according to the University of Oregon.
 
Active carbon filter can be controlled by manual or automatic type to start,wash,backwash,stop and other operations.
 
When pressure difference between water inlet and outlet reach 0.05--0.07 Mpa,backwashing must be started, the replacement period for activated carbon material is every half a year or one year.
 
 
Active carbon material is nutshell carbon,it is light weight,big holes,strong abrasion resistance and strong absorption,the filling height is:
   actived carbon material:    0.6-1.2mm  1100mm, ---top layer
   quartz sand material     0.6-1.2mm   100mm,---middle layer
    quartz sand material   1.2-2.0mm   100mm,----bottom layer
Technical parameters sheet for Mechanical actived carbon filter