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REVERSE OSMOSIS SYSTEMS
K2 Corporation offers a full series of reverse osmosis systems (ROTEC). Applications vary from drinking water applications and bottling water machines through to industrial processors. Below is a list of K2's general range, please enquire for other available models.
REVERSE OSMOSIS SYSTEM MODELS:
DESIGN & OPERATION:
To design and operate a reverse osmosis system has close relation with the quality of the source water to be treated. It is important to get the detail information of the source water. Source water quality information has the direct effect on the choosing of pretreatment equipments. The followings are the main items to be carried out for the water quality analysis.
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Total Dissolved Solids (TDS)
Total dissolved solids are the total amount of organics and inorganic dissolved in the water. The unit is PPM or mg/l. TDS testing meter converts the amount of conductivity of water to PPM unit. TDS is the fast and easy way to test the quality of the feed water and the product water. TDS is an important water quality factor as it has close effect on the osmotic pressure and the ion intensity.
- Conductivity and Resistively
Conductivity and resistively indicate the amount of conductible materials in the water. The conductivity unit is micro siemens/cm or microomhs/cm. The resistively unit is ohms. cm. Conductivity is the reciprocal of resistivity (1 divided by resistively). Normal water treatment uses conductivity to indicate the quality of the water. Pure water and ultra pure water have very low conductivity. Resistively was used to indicate the quality of the water. There is no clear definition between pure water and ultra pure water. Generally if dissolved matter is less than 1 mg in 1 liter of water, it is pure water. Ultra pure water has resistively over 10M.ohm.cm. Theoretically pure water at 25C has resistively of 18.24mega ohm. cm. It is very sensitive to temperature. Water at 35C and 15C the sensitivities are 11.08 and 31.87mega ohm. cm. Non-conductivity matters dissolved in the water would not affect the conductivity or resistively of the water except the water is very high pure water.
- Alkalinity
The quantitative capacity water to neutralize an acid; that is , the measure of how much acid can be added to a liquid without causing a significant change in pH. Alkalinity is expressed in mg/l of equivalent calcium carbonate. Total alkalinity is the sum of carbonate (CO3), bicarbonate, and hydroxide ( OH- ) alkalinity.
- Hardness
A common quality of water which contains dissolved compounds of calcium and magnesium and, sometimes, other divalent and trivalent metallic elements. The term hardness was originally applied to waters that were hard to wash in, referring to the soap wasting properties of hard water. Hardness prevents soap from lathering by causing the development of an insoluble cruddy precipitate in the water; hardness typically causes the build up of hardness scale (such as seen in cooking pans). Dissolved calcium and magnesium salts are primarily responsible for most scaling in pipes and water heaters and cause numerous problems in laundry, kitchen and bath. Hardness is usually expressed in grains per gallon (or PPM) as calcium carbonate equivalent. Term mg/liter (PPM as CACO3). Soft =<60, moderately hard = 61-120, Hard = 121-180, Very hard = 180 and above. The scaling precipitate on the RO membrane will drop the permeate efficiency of membrane.
- pH Value
A measure of the degree of the acidity or the alkalinity of a solution as measured on a scale (“pH-scale”) of 0 to 14. The midpoint of 7.0 on the pH scale represents neutrality- that is, a neutral solution is neither acid nor alkaline. Numbers below 7.0 indicate acidity, numbers above 7.0 indicate alkalinity. PH valve is very important for water treatment system. Low pH valve water will cause corrosion on the system. High pH valve water will cause scaling on the membrane and lower the efficiency of membrane. The dissolved carbon dioxide in water increases as pH valve of the water increases. RO membrane can not filter out the dissolved CO2 but can eliminate the alkalinity in the water. Therefore the pH valve of the permeate is higher than the feed water and the pH valve of the concentrate is higher.
- Turbidity
The amount of small particles of solid matter suspended in water as measured by the amount of scattering and absorption of light rays caused by the particles. Turbidity blocks light rays and makes the water opaque. Turbidity is measured in nephelometric turbidity units (NTU). Potable water should not exceed 0.5 NTU.
- Silt Density Index (SDI)
A test used to measure the level of suspended solids in feed water for membrane filtration systems. The SDI of feed water to a reverse osmosis membrane should be maintained at less than 5, preferably less than 3.3. SDI can be used to predict the potential of contamination of RO membrane by colloidal fouling.
- Silica
The solubility of the silica in the water depends on temperature and pH valve of the water. Silica is more soluble at pH valve 8 and above. Silica that precipitates on the surface of the membrane could not be washed away. The pH of the concentrate of membrane should not exceed the upper limit of the solubility of silica.
- Iron, Manganese, and Aluminum
Iron was found in soluble form such as ferrous bicarbonate, bound with a soluble organic compound, and as suspended ferric iron particles. Iron above 0.3 mg/l is objectionable in water because of the oxidation and precipitation of ferric hydro-oxide and ferric oxide (ferric iron) into small solid iron particles. Iron can also give a metallic or distorted flavor to water. Iron, manganese and aluminum oxides are the cause of scaling on membrane.
- Sparingly Soluble Salts
The higher the recovery rate of RO membrane system, the larger the density of ion in the concentrate. One must take into account of the saturation and precipitation of sparingly soluble salts.
- Free chlorine and dissolved oxygen
After adding chlorine into the water, it separates into the form of HOCL or OCL. They are called free chlorine. Free chlorine is a strong oxidizer and can destroy the Teflon membrane structure. Dissolved oxygen affected some membrane.
- Total Organic Carbon (TOC)
The amount of carbon covalently bound in organic compounds in a water sample. TOC is measured by the amount of carbon dioxide produced when a water sample is atomized in a combustion chamber. For high purify water, it is very important to eliminate and control TOC.
To discuss the options of RO for your system contact K2 Corporation Pty Ltd
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