Water Treatment Plant

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Water treatment plant

Ultrafiltration Systems (UF Systems)

Ultrafiltration is a separation process using membranes with pore sizes in the range of 0.1 to 0.001 micron. Typically, ultrafiltration will remove high molecular-weight substances, colloidal materials, and organic and inorganic polymeric molecules. Low molecular-weight organics and ions such as sodium, calcium, magnesium chloride, and sulfate are not removed. Because only high-molecular weight species are removed, the osmotic pressure differential across the membrane surface is negligible. Low applied pressures are therefore sufficient to achieve high flux rates from an ultrafiltration membrane. Flux of a membrane is defined as the amount of permeate produced per unit area of membrane surface per unit time. Generally flux is expressed as gallons per square foot per day (GFD) or as cubic meters per square meters per day.

Ultrafiltration membranes can have extremely high fluxes but in most practical applications the flux varies between 50 and 200 GFD at an operating pressure of about 50 psig in contrast, reverse osmosis membranes only produce between 10 to 30 GFD at 200 to 400 psig.

Recovery

Recovery of an ultrafiltration system is defined as the percentage of the feed water that is converted into the permeate, or:

Where:

 R = Recovery
P = Volume of permeate
F = Volume of Feed
Performance of Ultrafiltration Systems

In high purity water systems, ultrafiltration is slowly replacing the traditional 0.2-micron cartridge filters. In Japan, practically all of the semiconductor industry follows this practice. An ultrafiltration membrane with a molecular-weight cutoff of 10,000 has a nominal pore size of 0.003 micron. When an ultrafiltration membrane is used instead of a 0.2-micron cartridge filter, particle removal efficiency is greatly improved. In addition, ultrafiltration membranes are not susceptible to the problem of bacteria growing through them, as is the case with 0.2-micron filters.

In a recent study (1), the performance of an ultrafilter was compared with that of a 0.2-micron cartridge filter. Some of these results are given in Table A.

The Ultrafilter used in the study had a molecular-weight cutoff of 100,000- (pore size 0.006 micron). As the requirements for the quality of high purity water become more stringent, we can expect to see an increasing use of ultrafiltration as a final filter.

Table A

Effectiveness of Ultrafiltration Particle Counts on Waters
Test Location 0.2 Micron Filtered
DI Rinse Water		 Unfiltered
DI Rinse Water
1 200-300 20-30*
2 175-200 0-25
3 120 5
4 275 125*

*Plumbing after UF not upgraded

R.O.System

Reverse osmosis (RO), also known as hyper filtration, is used by our Commercial & Industrial Brackish Water & Seawater Reverse Osmosis Systems to purify water by removing salts and other impurities. It is also capable of rejecting bacteria, sugars, proteins, particles, dyes, and other constituents that have a molecular weight of greater than 150-250 daltons. SAI-TREAT manufactures a full line of seawater desalination systems designed for heavy or continuous duty service in the marine applications where quality and dependable performance are keys. Our standard Brackish Water Reverse Osmosis systems are available with capacities ranging from 250 GPD to 500,000 GPD, and our standard Seawater Reverse Osmosis systems or water makers or RO desalination systems are available with capacities ranging from 200 lit/hr to 20000 lit.hr. SAI-TREAT is also capable of manufacturing custom built Reverse Osmosis plants.

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Municipalities and industrial facilities are able to use RO permeate as a consistently pure drinking water supply and to transform drinking water to high purity water for industrial use at microelectronics, food and beverage, power, marine and pharmaceutical facilities.

Unique source for your water purification needs:

Reverse Osmosis systems from SAI-TREAT deliver high performance at the lowest life-cycle costs. Our pre-engineered systems are built with high-quality components designed specifically for water purification. They arrive at your facility ready to run with all filters, membranes, pumps, piping, controls and operating manuals.

We supply membrane elements, valves, filters, pumps, nanofiltration and ultrafiltration equipment and other components. SAI-TREAT is also unique in design and operation of these units. We build the complete machine, but SAI-TREAT stock all major RO systems components, such as membrane elements, controls, filters and high pressure pumps.

With expertise of SAI-TREAT , you will receive economical solution that creates value for you while reducing your operating costs for reverse osmosis systems.

Sand & Carbon Filter

Dual Media FIlters work on the principal of depth filtration. The principal media in these filters is quartz grade sand and anthracite. Other supporting media include pebbles of various sizes, crushed gravel and silex.

Features of Dual Media FIlters:

  • 1.The major advantage of this kind of filters is that anthracite which provides for coarse filtration is lighter than filtering sand.

  • 2.Due to which one stage of coarse filtration takes place on the anthracite bed & the next stage takes place on the sand bed. Thus, depth filtration is achieved.

  • 3.Both media (viz sand & anthracite) are employed their capacities, the dirt loading capacity of these filters is twice that of pressure & sand filters.

  • 4.These type of filters are are more capable & gave high performance.

    • The principal media in these filters is Activated Carbon Filters. Other supporting media include pebbles of various sizes, crushed gravel and silex.

    Features of Activated Carbon Filters:

    1.The activated carbon is a highly porous media. This property of carbon allows it to absorb the free chlorine in raw water.

    2.Organic matter present in colloidal form is absorbed in these pores. Thus odour emanating from raw water on account of these colloids is reduced.

    3.The activated carbon present in the standard range has an iodine value of 450. This carbon is also available in iodine values of 900 and 1200.

    Softener

    Water Softeners

    A water softener system is a unit that is used to soften water, by removing the minerals that cause the water to be hard.

    Water softening is an important process, because the hardness of water in different applications is reduced during this process.

    When water is hard, it can clog pipes, damage boilers, heat exchangers, and many other devices. Water softening can prevent these negative effects.

    Hard water causes a higher risk of lime scale deposits in industrial, commercial and household water systems. Due to this lime scale build-up, pipes are blocked and the efficiency of hot boilers and tanks is reduced. This increases the cost of domestic water heating by about fifteen to twenty percent.

    Another negative effect of lime scale is that it has damaging effects on household machinery, such as laundry machines.

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    Water softening using SAI TREAT water softener system expands the life span of each household machine, such as laundry machines, and the life span of pipelines. It also contributes to the improved working, and longer lifespan of solar heating systems, air conditioning units and many other water-based applications.

    What do water softeners do?

    Industrial water softeners are specific ion exchangers that are designed to remove ions, which are positively charged.

    Softeners mainly remove calcium (Ca2+) and magnesium (Mg2+) ions. Calcium and magnesium are often referred to as 'hardness minerals'.

    Softeners are sometimes even applied to remove iron. The softening devices are able to remove up to five milligrams per liter (5 mg/L) of dissolved iron.

    Softeners can operate automatic, semi-automatic, or manual. Each type is rated on the amount of hardness it can remove before regeneration is necessary.

    Commercial water softeners collect hardness minerals within its conditioning tank and from time to time flushes them away to drain.

    Ion exchangers are often used for water softening. When an ion exchanger is applied for water softening, it will replace the calcium and magnesium ions in the water with other ions, for instance sodium or potassium. The exchanger ions are added to the ion exchanger reservoir as sodium and potassium salts (NaCl and KCl).

    Softening salts

    For water softening, three types of salt are generally sold:
    - Rock salt
    - Solar salt
    - Evaporated salt

    How often should one add salt to a softener?

    Salt is usually added to the reservoir during regeneration of the softener. The more often a softener is regenerated, the more often salt needs to be added.
    Usually water softeners are checked twice a month. To guarantee a satisfactory production of soft water, the salt level should be kept at least half-full at all times.
    With expertise of SAI TREAT ’s water softener systems you will receive economical solution that creates value for you while reducing your costs.

    Deionzer

    SAI TREAT is a leading provider of deionization solutions. Our water deionizers are rugged, pre-engineered, pre-assembled, standardized units that minimize expensive installation and start-up costs. We have designed our Deionization systems to maximize the efficiency and repeatability of the unit during the service and regeneration modes.

    The Process of Deionization or Ion-exchange

    In the context of water purification, ion-exchange is a rapid and reversible process in which impurity ions present in the water are replaced by ions released by an ion-exchange resin. The impurity ions are taken up by the resin, which must be periodically regenerated to restore it to the original ionic form. (An ion is an atom or group of atoms with an electric charge. Positively-charged ions are called cations and are usually metals; negatively-charged ions are called anions and are usually non-metals).

    The following ions are widely found in raw waters:
    Cations Anions
    Calcium (Ca2+) Chloride (Cl-)
    Magnesium (Mg2+) Bicarbonate (HCO3-)
    Sodium (Na+) Nitrate (NO3-)
    Potassium (K+) Carbonate (CO32-)
    Iron (Fe2+) Sulfate (SO42-)





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    Ion Exchange Resins

    There are two basic types of resin - cation-exchange and anion-exchange resins. Cation exchange resins will release Hydrogen (H+) ions or other positively charged ions in exchange for impurity cations present in the water. Anion exchange resins will release hydroxyl (OH-) ions or other negatively charged ions in exchange for impurity anions present in the water.

    The application of ion-exchange to water treatment and purification

    There are three ways in which ion-exchange technology can be used in water treatment and purification: first, cation-exchange resins alone can be employed to soften water by base exchange; secondly, anion-exchange resins alone can be used for organic scavenging or nitrate removal; and thirdly, combinations of cation-exchange and anion-exchange resins can be used to remove virtually all the ionic impurities present in the feedwater, a process known as deionization. Water deionizers purification process results in water of exceptionally high quality.

    Deionization

    For many laboratory and industrial applications, high-purity water which is essentially free from ionic contaminants is required. Water of this quality can be produced by deionization.The two most common types of deionization are:

    • 1.Two-bed deionization
    • 2.Mixed-bed deionization

    Two-bed deionization:-

    The two-bed deionizer consists of two vessels - one containing a cation-exchange resin in the hydrogen (H+) form and the other containing an anion resin in the hydroxyl (OH-) form. Water flows through the cation column, whereupon all the cations are exchanged for hydrogen ions.To keep the water electrically balanced, for every monovalent cation, e.g. Na+, one hydrogen ion is exchanged and for every divalent cation, e.g. Ca2+, or Mg2+, two hydrogen ions are exchanged. The same principle applies when considering anion-exchange. The decationised water then flows through the anion column. This time, all the negatively charged ions are exchanged for hydroxide ions which then combine with the hydrogen ions to form water (H2O).

    Mixed-bed deionization:-

    In mixed-bed deionizers the cation-exchange and anion-exchange resins are intimately mixed and contained in a single pressure vessel. The thorough mixture of cation-exchangers and anion-exchangers in a single column makes a mixed-bed deionizer equivalent to a lengthy series of two-bed plants. As a result, the water quality obtained from a mixed-bed deionizer is appreciably higher than that produced by a two-bed plant. Although more efficient in purifying the incoming feedwater, mixed-bed plants are more sensitive to impurities in the water supply and involve a more complicated regeneration process. Mixed-bed deionizers are normally used to ‘polish’ the water to higher levels of purity after it has been initially treated by either a two-bed deionizer or a reverse osmosis unit.

    Electrodeionization

    EDI Electrodeionization Systems remove ions from aqueous streams, typically in conjunction with reverse osmosis (RO) and other purification devices. Our high-quality deionization modules continually produce ultrapure water up to 18.2MW/cm. EDI may be run continuously or intermittently.

    Ozonation

    SAI-TREAT designs and assemble complete ozone generators and ozone water treatment systems for commercial, residential and industrial water treatment purposes. Applications range from treating swimming pool water to food processing water and bottling applications.

    Ozonation

    Ozone is a strong oxidizer and can be particularly effective for water and waste water treatment with less than 1% organic content. It is sometimes used as a pretreatment method, or to disinfect wastewater after biological treatment. It oxidizes a wide range of organics, can destroy cyanide wastes and phenolic compounds, and is faster acting than alkaline chlorination. And, unlike chlorine, ozone doesn't generate toxic ions in the oxidation process.

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    Ozone is the triatomic form of oxygen formed naturally during lightning strikes and anytime an electric arc is formed. It is a very unstable compound and must be produced at the same time it is needed, usually by ultraviolet excitation and corona discharge. It isn't effective in treating slurries, sludges, solids, organic solvents, or tars. Before use, consider the possibility that ozone will oxidize other stream components that didn't need treatment. Excess ozone, (that is, ozone not consumed in the reaction) must be catalytically decomposed since release isn't permitted.

    Ozone Water Treatment Systems

    Ozonation is an established and proven disinfection alternative as well as a peroxidant for the control of THM precursors. It also has the benefits of:

    Oxidation and volatilization of organics
    Control of algae and associated compounds
    Destabilization (microflocculation) of certain types of turbidity
    Removal of color-causing compounds
    Oxidation of iron and manganese
    Very short disinfection times
    Partial oxidation of organics for subsequent removal by microorganisms.

    Ozone Generator Selection

    Ozone is generated by passing a high voltage alternating current (6-20 kV) across a dielectric discharge gap through which oxygen gas is injected. Setting aside the sales pitches from manufacturers, most practical generators are either low (50-60 Hz) or medium (200-1000 Hz) frequency. Medium frequency generators are generally considered better performers. It is often helpful to contact SAI TREAT in similar applications to finalize the selection of an ozone generator.

    Electro Deionzation

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    ELECTROPURE EXL-600 modules are specifically Designed as direct replacement for E-cell MK-2 and MK-2E modules , LX-24 and LX-30 modules. They are configured to easily retrofit existing Systems with added electropure technology benfits, so the old troublesome E-cell CONCENTRATE RECIRULATION IS ELIMMANATED. The new ELECTROPURE EXL-600 Modules have the same physical profiles as E-cell MK abd IONPURE lX modules but have Electropure EDI technology inside. This includes Electropure’s Patented Excellion Membranes, New “ never-leak” permanent O-ring Seals, Our unique Non-scaling electrode system, our efficient thin cell technology, and Our GF union connectors.
    With Electropure EDI thin Concentrate technology, There is no there is no need for the troublesome E-coli or Emexell recirculation system, so it can be estimated from the system. With the mass-transfer built into electropure EDI thin-concentrate technology, you don’t need either salt injector of feed-and-bleed systems. You also don’t need the IONPURE “all-filled” design.