كيفية تقليل كمية الاملاح المذابة للماء(اولا/جودة المياه والمشكلات المؤثرة بها)

Water Quality
Water Quality and Common Problems

If we think back to our school days, most of us can remember studying the "hydrological cycle".

You remember the process of how water vapor condenses in the atmosphere and falls to earth as precipitation

. Once on the surface of the earth, most of the water evaporates back into the atmosphere, where it will again condense and fall back to earth as precipitation. About 30% of the precipitation, however, does not evaporate

. Instead, it seeps into the ground or runs off into streams, rivers, or lakes. As the water seeps into the ground or as it flows over the surface, it dissolves minerals and other substances contained in the ground. Under the surface, the water tends to collect in porous portions called 'aquifers.' These aquifers are the source of our well water.

Points To Keep In Mind
• Water as found in nature, will always have some substances dissolved in it.
• It will always have the potential to have particles suspended in it.

• It will always have the potential to be a suitable home to disease causing organisms.

This is true of "fresh" mountain streams, well water, and even municipally treated water systems. To achieve "pure water", or anything close to that goal, water must be filtered or treated in some way.

As you begin to see, the problem for us to solve will depend upon what the water has had contact with. These conditions can vary greatly, not only from one region of the country to another, but also within the same general location. Water drawn from wells in the same area may not be exactly the same. The quality of water from a municipality owned treatment facility will depend upon the age and condition of the equipment. Even though the water may be classified as safe to drink, the aesthetic quality may be less than desirable.

Fortunately, our knowledge of the nature of water has increased steadily over the years.

The most frequently occurring problems have been studied very closely. We now know the symptoms, the cause of the symptoms, and how to cure the problem itself.
Sometimes the symptoms are easy to read and easy to cure. Other times, several problems exist in the water at the same time.

Then it gets more complicated, and usually more costly to correct.

Let's examine these water problems as they will be reported to you by your customers ...

the symptoms they see, taste, smell or fear. Along with the symptoms we will provide the cause of the condition, so you will be able to explain to our customer exactly what is going on with their water supply.

Common Water Problems

HARDNESS (Calcium and Magnesium)

The term hardness refers to the quantity of dissolved calcium and magnesium in water.

These minerals, which come primarily from limestone type rock formations, are found to some degree in almost all natural waters. Calcium and magnesium cause problems for two principal reasons:

• When the water is warmed, they precipitate out of solution and form a hard, rock-like scale. This scale accelerates corrosion, restricts flow, and reduces heat transfer in water heaters and boilers.

• When they combine with soap, they react to form a curd, which interferes with cleaning, dries out skin, and leaves deposits on plumbing and clothes (bathtub ring; ring around the collar).

Waters which naturally contain very little hardness can also be problematic because they may be corrosive in some applications (such as acidity).

For some applications, sequestering agents (Siliphos) are good for hardness conditions under 15 gpg.

The only practical method for hardness removal above 15 gpg in residential applications is through cation exchange process employed by water softeners (also called conditioners).

Acidity (pH)

Water which contains excess acidity tends to act aggressively towards plumbing and fixtures, causing corrosion and staining (i.e.-blue green stains on fixtures from copper pipes).

Relative acidity/alkalinity is measured on the pH scale, ranging from 0- 1 4, where 7 is neutral, numbers lower than 7 are progressively more acidic, and numbers higher than seven are increasingly alkaline (basic).

The pH value refers not to the quantity of acidity, but rather to the relative acidity/alkalinity of a particular sample.

Alkalinity acts as a buffer to deactivate the acidity, a process called neutralization. For example, limestone (calcium carbonate) is often applied to soil to offset the acidity which comes from acid rain and decaying organic material.
The acceptable range for water is 6.5-8.5.

Acidity cannot be removed from water. However, it can be neutralized by raising the pH with alkalinity.

This can be done by injecting a highly basic (alkaline) solution with a feed pump or by passing the water through a bed of processed limestone or similar material.

Iron (Fe)

The presence of Iron is a very common water quality problem, particularly in water from deep wells.

Water containing even a significant quantity of iron may appear clear when drawn, but will rapidly turn red upon exposure to air.

This process is called oxidation, and involves the conversion of ferrous (dissolved) iron, which is highly soluble, to ferric (precipitated) iron, which is largely insoluble.

The ferric iron then causes red/brown staining on clothes, fixtures, etc.

Iron concentration is measured in ppm or mg/l (milligrams per liter, where 1 ppm = 1 mg/l).

Staining usually becomes a problem at concentrations greater than 0.3 ppm. Removal is through ion exchange (water softener) or oxidation/filtration (APIR).

Manganese (Mn)

Manganese is a metal similar to iron which causes a grey/black stain.

It can cause staining in concentrations as low as 0.05 ppm.

Manganese is removed in a manner similar to iron, although oxidation is more difficult, requiring a pH of at least 8.5.

Hydrogen Sulphide (H2S)

Hydrogen Sulphide is a gas which smells strongly like rotten eggs.

It results from the decay of organic matter with organic sulphur and the presence of certain types of bacteria.

Even very low concentrations are offensive as well as highly corrosive (silver tarnishes almost immediately upon contact with H2S).

Because it is in a gaseous form, H2S cannot be collected in a sample bottle for laboratory analysis.

Therefore, its presence must be reported when a sample is submitted for a treatment recommendation.

It can be removed by oxidation/filtration, aeration, or well sanitization.

Turbidity

Turbidity is a measure of suspended particles in water and can range from large particles which settle out of solution rapidly (such as sand), to extremely fine sediment which may stay suspended in solution even after standing for hours. Treatment depends upon size, which is measured in microns.

Tastes and Odors

Most tastes and odours are caused by the presence of organic matter and chlorine.
The vast majority of these can be removed with activated carbon.

Organic Chemical Contaminants

The presence of toxic chemicals at various concentrations has been widely documented in many water supplies.

Detection can be difficult as these contaminants often have no taste or odour. Treatment depends on type and concentration.

These chemicals may be industrial solvents or agricultural pesticides and herbicides.

One of the most common is Trihalomethane (THM) which is formed when chlorine in the water reacts with natural organic matter.

Total Dissolved Solids (TDS)

TDS is the sum of the mineral salts in water and if too high can result in objectionable taste, cloudy ice, interference with the flavor of foods and beverages and scale left behind in cookware.

Generally speaking, the lower the TDS the more acceptable the drinking water. TDS of 1,000 ppm or more is unacceptable for drinking water.

Reverse Osmosis (R0) process has proven itself as the most practical and cost effective method of correcting problems caused by high TDS.

Nitrates (NO3)

Nitrates are inorganic chemicals dissolved in some water supplies as a result of feedlot and agricultural activities.

Nitrate levels over 45 mg/L as actual NO3 (or 10 mg/L as Nitrogen, N) can be a serious health risk to infants and children.

Reverse Osmosis has proven itself as an effective method of reducing Nitrates to safe levels.

Heavy Metals

-Lead (Pb);Cadmium (Cd);Mercury (Hg);Arsenic (As);Selenium (Se);Chromium (Cr)

The so-called heavy metals are toxic elemental metals such as Lead, Cadmium, Mercury, and Arsenic that find their way into water supplies from natural and industrial sources as well as home plumbing.

These metals, especially Lead, can seriously affect the mental and neurological development of infants and children.

Reverse Osmosis (R0) is recognized as the most practical method of reducing Lead to insignificant levels in drinking water.

Carbon Block technology that incorporates ceramic ion exchange media is also an effective method of reducing lead.

Radium 226/228 (Ra)

Radium occurs in ground water due to the radioactive decay of Uranium in geologic formation.

There is a health risk if the Radium level exceeds 20 pecocuries per liter (pCi/L). Cation exchange water softeners using proper regeneration procedures are effective in reducing Radium for POE applications.

Reverse Osmosis systems are effective for reducing Radium for POU applications.

Total Dissolved Solids (TDS)
•
Water classification
Water can be classified by the amount of TDS per litre:[8]
• fresh water < 1500 mg/L TDS
• brackish water 1500 to 5000 mg/L TDS
• saline water > 5000 mg/L TDS

Total Dissolved Solids (TDS)

An aesthetic objective of ≤500 mg/L has been established for total dissolved solids (TDS) in drinking water.

At higher levels, excessive hardness, unpalatability, mineral deposition and corrosion may occur.

At low levels, however, TDS contributes to the palatability of water.
Definition
Total dissolved solids (TDS) comprise inorganic salts and small amounts of organic matter that are dissolved in water.

The principal constituents are usually the cations calcium, magnesium, sodium and potassium and the anions carbonate, bicarbonate, chloride, sulphate and, particularly in groundwater, nitrate (from agricultural use).

Occurrence

Total dissolved solids in water supplies originate from natural sources, sewage, urban and agricultural runoff and industrial wastewater.

the salts used for road deicing can contribute significantly to the TDS loading of water supplies.

Concentrations of TDS in water vary owing to different mineral solubilities in different geological regions.

The concentration of TDS in water in contact with granite, siliceous sand, well-leached soil or other relatively insoluble materials is usually below 30 mg/L.

In areas of Precambrian rock, TDS concentrations in water are generally less than 65 mg/L.

Levels are higher in regions of Palaeozoic and Mesozoic sedimentary rock, ranging from 195 to 1100 mg/L because of the presence of carbonates, chlorides, calcium, magnesium and sulphates.

Concentrations of TDS in some streams and small lakes regions are often as high as 15 000 mg/L .

Concentrations of TDS, expressed as the sum of its constituents, were below 500 mg/L in rivers.

Concentrations of TDS in drinking water are generally below 500 mg/L but are considerably higher in some locations.

\Analytical Methods and Treatment Technology

The method most commonly used for the analysis of TDS in water supplies is the measurement of specific conductivity with a conductivity probe that detects the presence of ions in water.

Conductivity measurements are converted to TDS values by a factor that varies with the type of water.

The practical quantitation limit for TDS in water by this method is 10 mg/L.

High TDS concentrations can also be measured gravimetrically, although this method excludes volatile organics.

The constituents of TDS can also be measured individually.

Total dissolved solids are not appreciably removed using conventional water treatment processes.

In fact, the addition of chemicals during conventional water treatment generally increases the TDS concentration.

Certain treatment processes, such as lime-soda ash softening and sodium exchange zeolite softening, may slightly decrease or increase the TDS concentration, respectively.

Demineralization processes are required for significant TDS removal.

Although the technology is available to reduce TDS levels significantly, the economic cost may be a major constraint.

Reverse osmosis and electrodialysis would probably be the most economical processes for removing TDS from public water supplies.

concentration of dry residue in each district, and no attempt was made to take into account possible confounding factors.

Other Considerations
The presence of dissolved solids in water may affect its taste.

The palatability of drinking water has been rated, by panels of tasters, according to TDS level as follows:

excellent, less than 300 mg/L;
good, between 300 and 600 mg/L;
fair, between 600 and 900 mg/L;
poor, between 900 and 1200 mg/L;
and unacceptable, greater than 1200 mg/L.

What Are Total Dissolved Solids - TDS?

1. "Dissolved solids" refer to any minerals, salts, metals, cations or anions dissolved in water.

This includes anything present in water other than the pure water (H20) molecule and suspended solids.

(Suspended solids are any particles/substances that are neither dissolved nor settled in the water, such as wood pulp.)

2. In general, the total dissolved solids concentration is the sum of the cations (positively charged) and anions (negatively charged) ions in the water.

3. Parts per Million (ppm) is the weight-to-weight ratio of any ion to water.

4. Conductivity is usually about 100 times the total cations or anions expressed as equivalents.

Total dissolved solids (TDS) in ppm usually ranges from 0.5 to 1.0 times the electrical conductivity.

Where do Dissolved Solids come from?

1. Some dissolved solids come from organic sources such as leaves, silt, plankton, and industrial waste and sewage.

Other sources come from runoff from urban areas, road salts used on street during the winter, and fertilizers and pesticides used on lawns and farms.

2. Dissolved solids also come from inorganic materials such as rocks and air that may contain calcium bicarbonate, nitrogen, iron phosphorous, sulfur, and other minerals.

Many of these materials form salts, which are compounds that contain both a metal and a nonmetal.

Salts usually dissolve in water forming ions. Ions are particles that have a positive or negative charge.

3. Water may also pick up metals such as lead or copper as they travel through pipes used to distribute water to consumers.

Why Should You Measure the TDS level in your Water?

The EPA Secondary Regulations advise a maximum contamination level (MCL) of 500mg/liter (500 parts per million (ppm)) for TDS.

Numerous water supplies exceed this level.

When TDS levels exceed 1000mg/L it is generally considered unfit for human consumption.

A high level of TDS is an indicator of potential concerns, and warrants further investigation.

Most often, high levels of TDS are caused by the presence of potassium, chlorides and sodium.

These ions have little or no short-term effects, but toxic ions (lead arsenic, cadmium, nitrate and others) may also be dissolved in the water.

The following are reasons why it is helpful to constantly test for TDS:

Taste/Health

High TDS results in undesirable taste which could be salty, bitter, or metallic. It could also indicate the presence of toxic minerals. The EPA's recommended maximum of TDS in water is 500mg/L (500ppm).

Filter performance

Test your water to make sure the filter system has a high rejection rate and know when to change your filter (or membrane) cartridges.

Hardness

High TDS indicates Hard water, which causes scale buildup in pipes and valves, inhibiting performance.

Aquaculture

A constant level of minerals is necessary for aquatic life. The water in an aquarium should have the same levels of TDS and pH as the fish and reef's original habitat.

Hydroponics

TDS is the best measurement of the nutrient concentration in a hydroponics' solution.

Pools and Spas

TDS levels must be monitored to prevent maintenance problems.

Commercial/Industrial

High TDS levels could impede the functions of certain applications.


Ideal Drinking water from reverse osmosis, distillation, deionization, microfiltration, etc..

0-50 PPM

Often considered acceptable range for carbon filtration, mountain springs or aquifers.

50-140 PPM

Average tap water.

140-400 PPM

Hard water.

170 PPM or above

Less desirable
200-300 PPM

Unpleasant levels from tap water, aquifers or mountain springs.

300-500 PPM

The EPA's maximum contamination level.

500 PPM

Total Dissolved Solids

Sources of Total Dissolved Solids (Minerals)
in Drinking Water
Water is a good solvent and picks up impurities easily.

Pure water -- tasteless, colorless, and odorless -- is often called the universal solvent.

Dissolved solids" refer to any minerals, salts, metals, cations or anions dissolved in water.

Total dissolved solids (TDS) comprise inorganic salts (principally calcium, magnesium, potassium, sodium, bicarbonates, chlorides and sulfates) and some small amounts of organic matter that are dissolved in water.

TDS in drinking-water originate from natural sources, sewage, urban run-off, industrial wastewater, and chemicals used in the water treatment process, and the nature of the piping or hardware used to convey the water, i.e., the plumbing..

the elevated TDS has been due to natural environmental features such as:

mineral springs, carbonate deposits, salt deposits, and sea water intrusion, but

other sources may include:

salts used for road de-icing, anti-skid materials, drinking water treatment chemicals, stormwater and agricultural runoff, and point/non-point wastewater discharges.
In general, the total dissolved solids concentration is the sum of the cations (positively charged) and anions (negatively charged) ions in the water.

Therefore, the total dissolved solids test provides an qualitative measure of the amount of dissolved ions, but does not tell us the nature or ion relationships.

In addition, the test does not provide us insight into the specific water quality issues, such as: Elevated Hardness, Salty Taste, or Corrosiveness.

Therefore, the total dissolved solids test is used as an indicator test to determine the general quality of the water.

The sources of total dissolved solids can include all of the dissolved cations and anions, but the following table can be used as a generalization of the relationship of TDS to water quality problems.

Cations combined with Carbonates
CaCO3, MgCO3 etc Associated with hardness, scale formation, bitter taste
Cations combined with Chloride
NaCl, KCl Salty or brackish taste, increase corrosivity

Potential Health Effects

An elevated total dissolved solids (TDS) concentration is not a health hazard.

The TDS concentration is a secondary drinking water standard and therefore is regulated because it is more of an aesthetic rather than a health hazard.

An elevated TDS indicates the following:

1)The concentration of the dissolved ions may cause the water to be corrosive, salty or brackish taste, result in scale formation, and interfere and decrease efficiency of hot water heaters.

2)Many contain elevated levels of ions that are above the Primary or Secondary Drinking Water Standards, such as: an elevated level of nitrate, arsenic, aluminum, copper, lead, etc.

Testing

Total Dissolved Solids (TDS): In a laboratory setting, the total dissolved solids is determined by filtering a measured volume of sample through a standard glass fiber filter.
The filtrate (i.e., filtered liquid) is then added to a preweighed ceramic dish that is placed in a drying oven at a temperature of 103 C.

After the sample dries, the temperature is increase to 180 C to remove an occluded water, i.e., water molecules trapped in mineral matrix.

Total dissolved solids means the total dissolved (filterable) solids .

High total dissolved solids may effect the aesthetic quality of the water, interfere with washing clothes and corroding plumbing fixtures.

For aesthetic reasons, a limit of 500 mg/l (milligrams per liter) has been established as part of the Secondary Drinking Water Standards.

An approximation of the Total Dissolved Solids:

A. The total dissolved solids concentration can be related to the conductivity of the water, but the relationship is not a constant.

B. The relationship between total dissolved solids and conductivity is a function of the type and nature of the dissolved cations and anions in the water and possible the nature of any suspended materials.

C. For example, a NaCl solution and KCl solution with a conductivity of 10000 umhos/cm will not have the sample concentration of NaCl or KCl and they will have different total dissolved solids concentration.

D. Conductivity is measured through the use of a meter and is usually about 100 times the total cations or anions expressed as equivalents and the total dissolved solids (TDS) in ppm usually ranges from 0.5 to 1.0 times the electrical conductivity.

Total Dissolved Solids can be measured in the field using an electronic pen.

Many of these devices actually measure the conductivity of the water, i.e., the ability of the water to carry a charge, and not the actual total dissolved solids.

These devices than calculate the total dissolved solids assuming that the primary dissolved minerals are either a combination of NaCl or KCl.

\1. Filter your water sample through a rinsed and dried glass fiber filter.

Collect the filtrate (liquid) and rinse water in a flask.

The minimum sample volume should be 100 ml and you should use at least 3 rinses of 20 to 30 ml volumes.

(Recording your data)- Record weigh of container and volume of filtrate - do not include the volume of the rinse water).

The rinse water should be deionized water. Do not touch container with bare hands.

2.Transfer the filtrate to a ceramic or glass Pyrex container.

The container should be weighed to the nearest 0.0000 g and place the container in the drying oven, which is set at 103 C.

Add the filtrate to the container and allow the sample to stay in the oven at 103 C for 24 hours.

If possible, increase the temperature of the drying oven to 180 C and allow the sample to dry for up to 8 hours.

Remove the container - Remember it is very hot.

After removing from the drying oven, the sample should be placed in a desiccator to cool in a dry air environment for at least 3 to 4 hours.

If the sample cooled in a moist environment, the sample would increase in weight because of the addition of water vapor from the air.


Remember the sample is very hot and can melt plastic.

Do not touch container with bare hands.

3.After the container cools, reweigh the container at least three times to the nearest 0.0000 g (Recording your data)
4.Subtract the initial weight (in grams) of the empty container from the weight of the container with the dried residue to obtain the increase in weight.

Then do the following:


A- Weight of clean dried container (0.0000 grams)
B- Weight of container and residue (0.0000 grams)
C- Volume of Sample (do not include rinse water ) ( 100 mls)
Concentration (mg/L) = ((B - A)/ C)* (1000 mg/g) * (1000 ml/L)
Example
A= 100.0001 g
B = 100.0020 g
C = 100 mls
Concentration (mg/L) = ((100.0220 - 100.0001)/ 100) * 1000 * 1000 = 219 mg/L

Interpreting Test Results

The Environmental Protection Agency (EPA) establishes standards for drinking water which fall into two categories -- Primary Standards and Secondary Standards.

primary Standards are based on health considerations

and

Secondary Standards are based on taste, odor, color, corrosivity, foaming, and staining properties of water.

There is no Primary drinking water standard for total dissolved solids, but the Secondary standard for TDS is 500 mg/L.

Options

The treatment options for an elevated total dissolved solids really depends on the nature of the cations and anions.

If the elevated total dissolved solids is due to cations like: calcium, magnesium, and iron, it may be possible to remove these ions using a water softener.

This process may not reduce the total dissolved solids concentration, but reduce the aesthetic problems with the water.

If the problem is associated with an elevated concentration of sodium, potassium, etc, the primary recommendations would include a reverse osmosis system or distillation unit.

Summary

An elevated total dissolved solids concentration does not mean that the water is a health hazard, but it does mean the water may have aesthetic problems or cause nuisance problems.

These problems may be associated with staining, taste, or precipitation.

With respect to trace metals, an elevated total dissolved solids may suggest that toxic metals may be present at an elevated level.

It is important to keep in mind that water with a very lower TDS concentration may be corrosive andcorrosive waters may leak toxic metals such as: copper and lead from the household plumbing.

his also means that trace metals could be present at levels that may pose a health risk.

water is not a health hazard, but dealing with hard water in the home can be a nuisance.

How do you reduce or remove the TDS in your water?

1. Carbon Filters (very slight reduction)
2. Reverse Osmosis (R.O.) (extremely high reduction and great tasting water )
3. Distillation (total reduction - flat taste)
4. DI Deionization (usually a final polishing filter following a RO Reverse Osmosis filtration system to eliminate TDS)


Reducing TDS Levels in Water

TDS is the catchphrase today in the world of water purifiers.
The total dissolved solids (TDS) in water comprising virus, bacteria, pesticides, lead, and other contaminants are a cause of concern in contemporary times; reverse osmosis water purification is the most recommended method to reduce the TDS levels.
There are both advantages and disadvantages of using an RO water purifier.
On the advantageous side the purification mechanism removes excess TDS which can be dangerous for health, removes disease causing germs, converts saline water into fresh water, and more.
The purified water cooks food faster besides lowering the running costs compared to boiling or bottled water.
On the disadvantage aspect, 75% of the water gets wasted during the purification process and the water is rid of the naturally occurring minerals vital to the human body.

The water you receive in your tap comes contaminated even though it gets treated in the municipal body's water treatment plant.
The consequence is a high TDS content in the water.
The phenomenal rise in water pollution has led manufacturers revolutionize the concept of water purification.
The result is the globally accepted water purifiers, especially reverse osmosis water purification systems.

Boiling the water is considered to be the safest water purification method; however, it might prove quite expensive in the long run.
The RO water purifier comes embedded with modern purifying mechanisms resulting in purifying water that is organically, physically, and microbiologically safe to drink.



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.
Pure Aqua, Inc. 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 380 GPD to 180,000 GPD. Pure Aqua is also capable of manufacturing custom built Reverse Osmosis plants.
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.
RO Systems
We offer RO Systems that are based on proven technologies that make them reliable as well as cost effective answer to contaminated high TDS water. Careful designing before the manufacturing stage ensures a long life of membranes & trouble-free operations. RO Systems effectively removes 90-98% of total dissolved salts from water.

Features:

• Consumes low energy
• User friendly unit as it does not require continuous monitoring
• Comes with compact robust mild steel powder coated frame
• Efficiently helps in removing up to 95-98% of total dissolved solids (TDS) or salinity, thus producing water that is clear and pleasant to taste
• Comes in a wide range of models with capacities from 200 LPH upto 30,000 LPH
• Comes with built in safety features for protecting high pressure pump & membranes
• Capable of handling waters that have TDS levels upto 6000 LPH & even more.
• Fully assembled & tested before dispatch
• On-line device for monitoring treated water quality
• Many more options for all Automation.

Specifications:

• Cartridge pre-filter for FRP pressure vessels
• Various types of membrane elements
• Stainless Steel multistage vertical pumps
• High Pressure piping of SS / CPVC / UPVC.
• Low feed pressure switch for pump protection
• Motor contractor with thermal overload protection feature
• Sample valves for feed, product & concentrates
• Automatic feed shut-off valve
• Cleaning connections
• Full Automatic control panel of PLC / Elect.
• Instrumentation of various types
• Pressure indicators at all stages
• Feed and permeate flow meters
• TDS / Conductivity meters
• Indicators for all functions
• Auto Flushing, Level Controls, TDS controls, etc.

Unique source for your water purification needs:
Reverse Osmosis systems from Pure Aqua 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. Pure Aqua is also unique in design and operation of these units. We build the complete machine, but Pure Aqua, Inc. stock all major RO systems components, such as membrane elements, controls, filters and high pressure pumps.
With expertise of Pure Aqua, you will receive economical solution that creates value for you while reducing your operating costs for reverse osmosis systems.

Reverse osmosis, also known as hyper filtration, is used to purify water and remove 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 dalton.
• 8" TFC spiral wound membranes
• FRP membrane housing
• Epoxy painted steel frame
• Stainless steel multi-stage pump with TEFC motor
• 5 micron cartridge prefilter
• Power supply: 460V/3Ph/60Hz
• PLC based control panel
• Programmable time delay and set points
• Status lamps
• 115V/60Hz control voltage
• Motor starter
• NEMA 12 enclosure with disconnect and interlocking rotary handle
• Low pressure switch
• High pressure switch
• Liquid filled pressure gauges, panel mount for pump suction, membrane feed, and final concentrate
• Permeate conductivity monitor
• Permeate & concentrate flow meters
Industrial Brackish Water Reverse Osmosis Systems RO-400
Model No. Permeate HPP @ 3 years Membranes Approx Wt.
(Lbs)
GPD GPM PSI HP
(50Hz) HP
(60Hz) Qty. Array
TW-28K-1480 28,800 40 240 7.5 10 4 1 2,300
TW-36K-1580 36,000 44 225 10 10 5 1 2,400
TW-43K-1680 43,000 48 225 15 10 6 1 2,500
TW-57K-2480 57,000 57 230 15 15 8 1:01 2,600
TW-72K-2580 72,000 67 250 20 15 10 1:01 2,700
TW-87K-3480 87,000 83 230 20 20 12 2:01 2,800
TW-108K-3580 108,000 100 235 25 25 15 2:01 3,200
TW-130K-3680 130,000 120 235 25 25 18 2:01 3,500
TW-144K-4580 144,000 134 235 25 25 20 2:02 4,200
TW-173K-4680 173,000 160 230 25 25 24 3:01 4,750


WHAT IS OSMOSIS AND REVERSE OSMOSIS?

Osmosis originates from the Greek word 'osmos' meaning push, pressure. It is the ability of a fluid and thereby its soluble content to permeate through a membrane to bring about the same concentration on both sides of a membrane. Passage of water from weak solution to strong solution through a semi-permeable membrane is called as Osmosis.

The membrane is permeable for one substance but not for another (semi-permeable) and it can be used for separating both the substances.

Osmosis is very important in the living organism because the cell wall comprises the membrane through which nutrients and metabolic products diffuse. In nature the water is purified and transported by means of osmosis, e.g. in the body and in plants. The plants uptake of water from the earth and partly also transport of water between the cells occur through osmosis.

Reverse Osmosis (abbreviation R.O.) is a process in which osmosis is used with the aid of technology (by introducing and raising the pressure of the "contaminated" fluid) for forcing the water through a synthetic semi-permeable membrane that allows only water molecules to pass through.

When pressure is applied to the concentrated solution (contaminated fluid), the direction of water passage through the membrane is reversed and the process that we refer to as Reverse Osmosis is established i.e. the membrane's ability to selectively pass water in unchanged, only the direction of water flow is changed.


WHAT ARE THE COMMON PROBLEMS ASSOCIATED WITH HIGH CONCENTRATION OF CHEMICAL CONTAMINANTS?
Chemical Constituents Requirement
(Desirable Limits)
IS 10500-1991
Drinking water

specifications Deleterious effect
outside desirable limit

Total Hardness as CaCo3 mg/lit, Max 300 Encrustation in water supply lines/ structure, scaling in utensils and adverse effects on domestic use.

Total Dissolved Solids Mg/lit, max 500 Taste and Palatability of water decreases beyond this limit. It cause gastro-intestinal irritation.

Iron as Fe mg/lit, max 0.3 Appearance, Taste & Palatability gets affected beyond this limit. Has adverse effect on domestic uses and water supply lines. It also promotes iron bacteria.

Chlorides as Cl mg/lit max 250 Beyond this limit corrosion Increases and taste/palatability decreases.

Nitrate as NO3 mg/lit, max 45 Beyond this limit methaemoglob-
inemia takes place.

Mercury as Hg mg/lit, max 0.001 Beyond this limit water becomes
toxic.

Arsenic as As mg/lit, max 0.05 Beyond this limit water becomes
toxic.

Lead as Pb mg/lit, max 0.05 Beyond this limit water becomes
toxic.

Pesticides mg/lit, max Absent Carcinogenic and toxic


IS REVERSE OSMOSIS SUITABLE FOR PURIFICATION?

Reverse osmosis is an advanced technique, which has the ability to separate smallest of the particles, molecules and ions.

Reverse osmosis supplements conventional techniques; it takes up where the conventional methods are unable to show satisfactory effects.

R.O. is especially suitable for areas with high level of Total Dissolved Solids (T.D.S.) and Hardness. R.O. makes saline and brackish water palatable and tastier by reducing TDS and hardness.

R.O. also makes the water both chemically and microbiologically safe by reducing Pesticides, Fluoride, hazardous metals contaminants like Lead, mercury, Arsenic etc. and eliminates water borne disease-causing micro-organisms.

An R.O. water purification device is equipped with a Membrane filtration module having very fine pore size of 0.0001 micron.

Raw water is pushed under a high pressure through this membrane filter.

The output water that finally comes through the membrane filter is free from Total Dissolved Solids, Hardness, Micro-organisms and chemical contaminants.

IS OSMOSIS WATER DRINKABLE?
The best water currently obtainable is osmosis water. Drink plenty of osmosis water and feel good! It is almost heresy to allege that drinking osmosis water would result in loss of immunity, the splitting of cells, internal bleeding etc. The Navy marines throughout the world consume R.O. water produced in the submarines from sea water. U.S. navy has been consuming R.O. water for decades now.

Everyone would agree that fitness for soldiers is paramount and they rely on R.O. water. Most of the Arabic world has scarcity of fresh water. They rely on industrial R.O. plants for production of drinking water from sea water.

Industries which produce Packaged Drinking Water, Beverages and Pharmaceuticals use R.O. technique for water purification.

SOMETIMES R.O. WATER TASTES SOMEWHAT BITTER. IS IT OK?

Certain types of water which do not have high T.D.S., tastes bitter if treated with an R.O. system.

This happens because of slight reduction in the pH of the produced water.

This is not a cause of worry because the allowable drinking water pH as per W.H.O. is 6.5 8.5.

IS R.O. SUITABLE FOR TREATING BRAKISH AND SALINE WATER?

Yes, R.O. is especially suitable for treatment of Brackish, Hard and saline water. It makes Brackish, Hard and saline water sweet, potable and soft.

HOW DOES R.O. MAKE WATER SAFE?

With OSMOTIC, you do not have to worry about the water quality. R.O. makes saline and brackish water palatable, sweet and tastier by reducing Hardness and Total Dissolved Solids (T.D.S.).

OSMOTIC makes the water safe and potable by eliminating Pesticides, Fluoride, hazardous metal contaminants like Lead, Mercury, Arsenic and many other toxic chemical contaminants.

R.O. makes the water microbiologically potable by eliminating water borne disease-causing micro-organisms like bacteria, viruses and cysts.

IS IT TRUE THAT R.O. DEVICES REDUCE THE MINERALS FROM THE DRINKING WATER WHICH ARE GOOD FOR HEALTH?

Nutrients and minerals are definitely essential for the body. These minerals are mainly provided by the food and fruit that we eat. The uptake and utilization of minerals by the body happens largely from the diet that we take. Drinking mineral-rich water is not a replacement for a healthy diet and it does not eliminate the need for a nutritious diet.

APART FROM PURE WATER, WHAT ARE THE OTHER BENEFITS OF USING R.O. WATER?

R.O. provides excellent results with regard to purity; close to 100% removal of almost any unwanted and harmful substance.

There are many more benefits of using R.O. water:

- You will be able to savor the real falvour of coffee and tea because R.O. water is truly clean and very soft.

- Taste will turn out much better when using water of the highest purity.
- Ice cubes will be the clearest you have ever seen.

- Great for making food, cuts down cooking time and cost.

- Appliances that use water (as for example your steam iron and electric kettle) will last longer and be more effective, because there will be no scaling.

HOW DOES R.O. WORK?

R.O. employs five stages for water purification.

STAGE No. Part Name Material Benefits

01 Sediment Pre-Filter Spun bonded polypropylene Removes fine suspended impurities like particles, rust and dust.

02 Pre R.O. GAC Cartridge Silver Impregnated Granular Activated Carbon Removes excess chlorine, color, odor and other Organic impurities.

03 Pre R.O. Activated Carbon Block Extruded Activated Carbon Acts as a dual filter-cum-adsorber. Reduces fine turbidity and polishes the water by adsorbing excess chlorine, color, odor and organic impurities.

04 Reverse OsmosisMembrane Thin film composite (TFC) 0.0001 micron TDS, Hardness, Fluoride, Pesticides, heavy metals like Lead, Mercury, Cadmium and Arsenic etc. Removes micro-organisms like Bacteria, Viruses and Protozoan Cysts.

05 Post R.O. Carbon Cartridge Silver Impregnated fine Granular Activated Carbon Imparts Bacteriostatic property to the stored
water and helps in reviving the original taste of water.


WHAT ARE THE PRECAUTIONS THAT ONE MUST TAKE WHILE INSTALLING THE R.O.?

- Install it in a dry, ventilated place. Keep it away from direct sunlight or below freezing temperatures.

- Connect it to only cold water supply. Filters can get damaged if connected to hot tap water.

- Ensure that the inlet water pressure is between 5-87 psi (0.34 - 6.0 bar).

- Make sure to connect your R.O. to 230 V power point.

- Do not install the R.O. in a place where water or rain could leak into it.

WHAT IS THE FUNCTIONAL ADVANTAGE OF AUTO FLUSHING & LOW PRESSURE CUT-OFF FEATURES?

Automatic flushing of the reverse osmosis membrane ensures the periodic removal of particulate deposits from the layers of the membrane filter thereby ensuring reliable operation and long life.

Low pressure auto cut-off prevents the pump from dry running in case the overhead tank or the pipe lines does not have water.

WHAT IS THE MAXIMUM ALLOWABLE TDS FOR USING HOME R.O. SYSTEM?

In case of R.O. the maximum allowable input T.D.S. is 2000 mg/l.


HOW MUCH REDUCTION OF TDS CAN BE ACHIEVED WITH R.O.?
= 90%

IS THERE WATER WASTAGE IN CASE OF R.O.?

In case of R.O., pure water is extracted from the impure supply water. R.O. produces 1 liter of purified water from 3 liters of raw impure water. Two liters of waste water is rejected. This waste water can be utilized for wiping the floor, car wash or watering the plants.

WHAT IS MEANT BY ELECTRONIC MONITORING?

An ideal water purifier should have a fail-safe mechanism.

It should be equipped with controls that shut off the machine and warn the user of a potential problem in the purification of the water.

Fail-safe mechanism is a monitoring system that continuously monitors the quality of the output water and shuts off the system automatically if purification levels drop below pre-determined standards.

The monitoring device consists of a photo resistor which is fixed onto the U.V. chamber.

It continuously senses the U.V. light pattern (low light output due to lamp weakening or dust/color/sediments in the U.V. chamber) then the water delivery is immediately shut-off and the alarm is raised.

This feature makes the system fail-safe.

HOW DO U.V. TECHNOLOGY BASED WATER PURIFIERS COMPARE WITH R.O. TECHNOLOGY?

Purification of water with ultraviolet treatment is internationally accepted and time-tested technology. Similarly, R.O. technology is also an advanced treatment method for water purification.

Both the technologies (U.V. and R.O.) to be effective must have adequate pre-treatment modules, like sediment filter and activated carbon, which remove physical and organic impurities.

The water in the final stage is then treated with either U.V. or M.F. The water that flows out is pure and safe for consumption.

The major difference lies in the fact that U.V. water purifiers do not reduce T.D.S. (and hardness) which R.O. water purifiers do with great efficiency. Reduction of T.D.S. is applicable for waters with unacceptably high level of T.D.S., like brackish and saline water.

Therefore if the T.D.S. of the water is within specified limits and there is no problem with the palatability of the water then a good U.V. purifier is adequate for water purification.

Sometimes, the T.D.S. is not so high but the water has hardness (which causes scaling in utensils & other appliances) then a simple solution is to attach the drinking water softener as a pre-treatment to the U.V. water purifiers.

Nowadays, heavy metal pollution is a serious water quality issue. R.O. is highly recommended for places where the water is polluted with arsenic, fluoride and or harmful metallic contaminants.