Mechancial filter
Multi-media filter to make one or several filter media makes water of high turbidity flow through agranular or non-granular material of a certain thickness under a certain pressure, thereby effectively removing suspended impurities in the water and clarifying the water. The commonly used filter materials including quartz sand, anthracite and manganese sand, etc. they are mainly used for turbidity removal of water treatment, water softening and pretreatment of pure water in preceding stages and the outflow turbidity can be below 3 NTU. The filter is mainly used for reverse osmosis. electrodialysis, ion exchange as well as softening and demineralization system pretreatment and can also be used as coarse filtration of industry water supplying with undemanding water quality, circulating cooling water, reuse water treatment of wastewater and recycled water, etc.
Actived carbon filter
Activated carbon filters are typically used to remove organic compounds and/or free chlorine from water to make water suitable for use in manufacturing or discharge. Removing organics like fulvic and humic acid from potable water prevents these acids from chemically reacting with chlorine to form a class of carcinogens known as trihalomethanes.
As with any water treatment method, activated carbon (AC) filtration is not suitable for removing every type of contaminant. AC filtration is not able to remove sodium, fluoride, microbes, or nitrates. AC filters also do not soften water. Only a specific type of activated carbon water treatment is able to remove heavy metals, such as lead, and this AC filter is typically only utilized in household point of-use filters.
Organic sources of activated carbon include coal (bituminous or anthracite) and coconut shells. Carbon is formed when the organic source is burned in an environment absent of oxygen, driving off heavy organic molecules and leaving about 30%of the original mass intact.. Next, the carbon must be "activated" for use in water treatment. The activation process further drives off unwanted molecules, as well as opens up the carbon's huge number of pores. These pores are what allow for contaminant absorption. The absorption rate of a surface area of just one pound of AC is equivalent to 60 to 150 acres!
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;
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
Self-Source Auto-Backwash is achieved by using the filtered raw water from two (2) or three (3) of the filtered cells and diverting over to the remaining cell. All cells are backwashed in sequence. The filtration process will continue while in the backwash cycle so the system is not "down" while backwashing. An independent backwash water supply is not required. Self-source system typically three or four filters to allow enough flow to reach 12-15 gpm/ft2 of filter bed surface back wash flow rate. During these periods (which typically last for several minutes per filter), the amount of filtered effluent flowing downstream of the filter is reduced or stopped completely by the amount of water required for backwashing, although the process flow into the system continues to while backwashing. It is easy to operate and maintain and a pressure sensor, timer or manual initiation can be used to initiate the backwash cycle.
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