Quartz sand filter
Quartz sand filter can effectively remove suspended solids in the water by assorption,it can also effectively remove colloids, iron, organics, pesticides, manganese, bacteria, viruses and other pollutants ,the main advantage is with small filtration resistance. large specific surface area, strong resistance to acid and alkali , resistance to oxidation,.appicapable PH with 2 to 13 and strong pollution-resistance. As a unique advantages of the quartz sand filter, the filter is able to realize self-adaptively rworking by optmizing design on the filter media and filter, therefore the filter material has a strong adaptivity to raw water concentration, operating conditions and pretreatment process. i.e. that is,loose upper layer and density bottom layer status will be on the filter bed automatically during filtration, which ensures the good water output under a variety of operating conditions,the filter material will spread out during backwashing to achieve good cleaning effect.
The sand filter has some advantages,such as fast filtering speed, high filtration rating and large interception capacity on pollutant, etc. it is used in the industrial water, domestic water and municipal water systems which requires water output should be below 5mg/I in turbidity ,it is also applicapable to remove suspended solid sand solids in industrial or residential wastewater to complys with drinking water quality standards. it can be used in ion-exchange ,pretreatment for softening desalination system,coarse filtration for ordinary quality industrial supplying water, swimming pool circulating water treatment system and cooling tower circulating water purification system.
Activated carbon filter
Activated carbon filter is used for the remove color, taste, residual chlorine and organics mainly by adsorption. activated carbon is an artificial sorbent. Its cell-hole structure and huge superficial area, which has a strong adsorption capacity for the dissolved organics in the water, such as benzene and phenolic compounds.besides,
It shows strong removal efficiency for organic pollutants which is hard to be removed by biological and chemical methods, such as chroma, stench, surfactants, synthetic detergents and dyes, etc.Granular activated carbon material is able to remove 85% of Ag + , Cr2 + and Cr04-2 in the water .after the raw water flows through the activated carbon filter bed, the suspended solid in the water will be less than 0.1 mg/L, COD removal rate is generally 40% to 50% and free chlorine is less than 0.1mg/I. It can be used as pretreatment of ion exchange, electrodialysis and reverse osmosis in pure water technology so as to remove organics, colloids and residual chlorine; it can be also used as an advanced treatment method after the secondary treatment section to ensure the quality of reuse water.
Iron and manganese removal filter
Iron and manganese removal filter, filled with refined manganese sand and quartz sand, is used to remove iron and manganese in the water. It is applicable for the iron and manganese treatment of groundwater with iron content of less than 10mg/l and the maximum of no exceeding 15 mg/I and pH value below 5.5.A fter treatment by this filter, the iron content in the water could be below 0.3mg/I and the manganese content could be below 0.1mg/I, which meets the standards for drinking water, it is only used in the pretreatment section of raw water which contains iron and manganese content.
Sizing of sand filter vessels:
Sizing for multi-media/sand filters is based on several properties of the water stream the client needs to treat.
Concentration of solids: Higher concentrations of solids will require lower loading rates through the filter vessels and as a result, larger diameter vessels.
Application of discharge water and discharge limits: The required effluent concentrations in the process stream helps determine the size of the vessels. The diameter of the vessels will increase as the restrictions get tighter for discharge allowances.
Size of particles you wish to filter: The loading rate required to adequately filter solids from the process stream needs to be lower for smaller sized solids. As a result, the diameter of the vessels will increase as the size of the particles that need to be filtered decreases.
Source of backwash water: Backwash water is used to clean the filters and flush out the suspended solids that have been trapped in the media bed. Water for backwashing can come either from the filters themselves (Self Source) or from an external source of clean water (Outside Source, such as a domestic water line or a storage tank).
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.
The Benefits of Multimedia Filtration over Conventional Sand Filters
Unlike traditional sand filters, multi-media water filters are composed of three filtration media, ordered in decreasing porosity. Because of their multi-layer design, multi-media water filters are able to trap and retain a far larger number of particles than traditional sand filters before backwashing becomes necessary. Trapping sediment and particulates throughout the entire depth of the filter bed, allows multi-media water filters to operate for much longer periods of time than conventional sand filters. The process of multimedia filtration produces high quality, filtered water at much faster flow rates than traditional sand filtration.
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