Tuesday, December 18th, 2018
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Water Treatment Chemicals

Water & Wastewater Treatment Chemicals


Water 2000, Inc is currently providing complete chemical solutions to water related problems for the following main applications

  •     Reverse Osmosis Chemicals
  •     Boiler Water Treatment
  •     Cooling Water Treatment
  •     Antiscalents (Process water, residential/commercial water)
  •     Descalers
  •     Waste Water Treatment 
    • Coagulant aids
    • Polymers
    • Bacteria Products
  •     Specialty and Bulk Pool Chemicals


Reverse Osmosis Chemicals ( Advanced RO Technology)

Water 2000, Inc is an innovative, industry leading supplier of technologically advanced reverse osmosis chemicals and associated RO products. Our extensive range of high performance chemicals includes RO antiscalants and scale inhibitors, membrane preservatives, cleaners, biocides and disinfectants, flocculants, corrosion inhibitors, de-chlorinators, and manual and automatic Silt Density Index ( SDI ) kits. Our products are available internationally and are used across most industrial, commercial, municipal, government and non-profit sectors.

Our range of technologically advanced chemicals has been carefully developed following extensive operational and scientific research activities. Each product is designed to ensure that your reverse osmosis and desalination plant installations operate at peak performance. For more information on our range of products please contact our office or 



Hemical Feed Systems for swimming pools





Silt Density Index Kits ( SDI )

The Silt Density Index (SDI) test is used to determine the fouling potential of water feeding a membrane filtration process such as a reverse osmosis (RO) system. We offer two SDI test kits in both manual and automatic forms as follows:
Silt density Index Kit – Manual

Silt Density Index Kit - Automatic

Best Practice Knowledge Centre

We have compiled an extensive collection of best practice guides that deal with many aspects associated with the effective operation of reverse osmosis plant and equipment. Simply send us your last two month RO log sheet data, we will provide you best solution for your system…….

De-chlorinators - Our range of technologically advanced reverse osmosis de-chlorinators have been carefully developed to ensure that your RO membranes and plant installations operate at peak performance. For more information on our range of de-chlorinators please select one of the links below.

 

Sodium Meta-Bisulphite

Sodium Bi-Sulphite

Scale Inhibitors & Antiscalants - Our range of technologically advanced reverse osmosis antiscalants have been carefully developed to ensure that your RO plant installations operate at peak performance. For more information on our range of scale inhibitors please contact our office or e-mail.

Membrane Cleaners - Our range of technologically advanced reverse osmosis RO membrane Cleaning Chemicals have been carefully developed to ensure that your RO membranes and plant installations operate at peak performance. For more information on our range of biocides please contact our office or e-mail..

Biocides - Our range of technologically advanced reverse osmosis biocides have been carefully developed to ensure that your RO plant installations operate at peak performance. For more information on our range of biocides please contact our office or e-mail.

AN EFFECTIVE WATER TREATMENT PROGRAM CAN CONVERT ENERGY LOSES TO ENERGY SAVINGS

Water is an universal solvent and dissolves to varying degrees anything it comes into contact with. Whether ground or surface water, it can be expected to contain the following in varying amounts:

Dissolved inorganic compounds such as bicarbonates, carbonates, sulfates, nitrates, chlorides of calcium, magnesium, sodium, and potassium (picked up from the earth's crust as water accumulates on the ground) and inorganic suspended materials such as clay, silt, sand, soil and metal oxides, etc.,

Dissolved organic compounds such as humic acid, fulvic acid and tannins; insoluable organic matter such as leaves, dead bactera and other biological products and industrial waste,

Dissolved gases such as oxygen, nitrogen, carbon dioxide, sulphur dioxide, methane and hydrogen sulphide absorbed from the atmosphere and subsurface sources, and

Micro organism such as bacteria , algae and fungi,

The type and quantity of impurities present determine the quality of the water and the subsequent problem that can arise from its use in various domestic, commercial, industrial, municipal and agricultural applications.

In various residential, commercial and industrial installations, water plays a major part in the personal uses, health, goods manufacturing, heating and cooling, washing, control of our environment etc., If left uncontrolled, any of above impurities may cause a loss of system capacity, reduced energy efficiency and shortened equipment life. If a process heating, cooling or waste water system fails, often the entire plant or facility must shut down and suffer the economic consequences. Lack of attention to water-related problems is often the cause for failures that cost time, money, production and aggravation.

Treatment for an industrial, commercial or residential application depends on the systems selected for the specific purpose, quality of water available and system design & operating parameters.

To overcome effects of above these impurities, a total water treatment approach (normally two types of water treatments solutions) is being used to get full control of water related problems as scaling, corrosion, microbiological growth or other related problems in systems containing water. i.e., External Treatment & Internal Treatment.

External Treatment is use of some technique or system by changing water analytical parameters to make it more safe for a particular application. Some of the external water treatment systems are Filtration (cartridge, sand, carbon), softening, deionization, reverse Osmosis, Sterilization, etc. This treatment is applied well ahead of the system where water is to be sued.

When it is not possible to control the problem indication outside any system, internal treatment approach is utilized to basically control of water related products inside the system by utilizing different types of chemical.

The nature and use of chemicals are different for different problems and systems. For the following three main water problems water as scaling, corrosion or rusting, fouling & microbiological growth we have developed various programs to control level of these problems for all system utilizing water in its any form.


Calculate LSI

Langelier saturation Index (LSI)

The Langelier Saturation Index (LSI; also called Langelier Stability Index) is a calculated number used to predict the calcium carbonate stability of water; that is, whether a water will precipitate, dissolve, or be in equilibrium with calcium carbonate. Langelier developed a method for predicting the pH at which water is saturated in calcium carbonate (called pHs). The LSI is expressed as the difference between the actual system pH and the saturation pH.

If the actual pH of the water is below the calculated saturation pH, the LSI is negative and the water has a very limited scaling potential. If the actual pH exceeds pHs, the LSI is positive, and being supersaturated with CaCO 3 , the water has a tendency to form scale. At increasing positive index values, the scaling potential increases.

 

LSI

Scale Potential

- negative

Less than zero

+ positive

Greater than zero

close to zero

No Scale Potential

Water will dissolve CaCO3

Scale can form

CaCO3 precipitation may occur

Borderline scale potential. Water quality and temperature changes, or evaporation could change the index.

     


    Note that the LSI only indicates the presence of a driving force; it does not guarantee that the tendency to scale will actually occur.

In order to calculate the LSI, it is necessary to know the alkalinity (mg/l as CaCO3), the calcium hardness (mg/l Ca+2 as CaCO3 ), the total dissolved solids (mg/l TDS), the actual pH, and the temperature of the water (oC).

LSI = pH - pH s

pH s = (9.3 + A + B) - (C + D)

where: A = (Log 10 [TDS] - 1) / 10
B = -13.12 x Log 10 (_C + 273) + 34.55
C = Log 10 [Ca+2 as CaCO3 ] - 0.4
D = Log 10 [alkalinity as CaCO3 ]

Concentration and Temperature Effects

Higher concentrations of calcium, total dissolved solids, and alkalinity all promote a greater tendency for scale. This explains why scale or hardness spots form where water has evaporated.

Scaling potential increases with increasing temperature. This explains that while water inside a manifold may not form scale at room temperature, scale could deposit during a cage wash cycle.

SI Values and Recommended Treatment

 

Boiler water treatment chemicals

Water is the essential medium for steam generation. Conditioning it properly can increase the efficiency of boiler and as well as extend the boiler's life. Treating boiler water also insures safe and reliable operation: without proper treatment, severe problems can develop, some so severe that boiler itself can be destroyed. Boiler water problem generally falls into classes: deposit related and corrosion related. Because the two often interact, it is very common to find a boiler experiencing both simultaneously. There are many instances where deposit causes corrosion and corrosion causes deposits. The other problem is of steam purity.  

Therefore the aim of the boiler water treatment chemical is  
1)       To prevent the formation of scales and deposits on heating surface

2)       To prevent corrosion in the boiler and steam system.

•  To maintain high level of steam purity.

The pressure and design of boiler determines the quality of water it requires for steam generation. The sequence of treatment depends on the type and concentration of the contaminants found in water supply and the desired quality of finished water to avoid three major problems in boiler systems – Deposits, Corrosion and Carryover.

Scaling
One of the aims of boiler water treatment is to prevent the formation of scales and deposits in the boiler systems. Scale can be prevented by external method or by conditioning with internal treatment. At times combination of both external and internal treatment is done.

Water gets evaporated due to high heat transfer rate. This concentrates the water and scale precipitates. The type of scale will depend upon the chemical composition of the concentrated water.

Scales formed in boiler systems can be divided into four groups:-

  •       Scale due to calcium & magnesium
  •     Scale due to iron oxide
  •     Scale due to copper
  •     Scale due to silica


The combination in which they exist will not be same. It will vary from boiler to boiler. In some boiler the scale can be due to Calcium and in some due to Iron.  

Scale forms as the solubilities of the scale forming salts in water decreases and the temperature and concentration increases. When feed water temperature is elevated to boiler water temperature, the solubility of scale forming salt is decreased, and solid scale begins to form on the boiler system. Thus we can say that Scale formation is a function of two criteria:-

(a) The concentration and solubility limits of the dissolved salts.

(b) The retrograde solubility (inversely proportional to temperature) characteristics of some salt.  


Causes of deposit formation in boiler water

Boiler deposits result from the impurities carried in with feed water. Their source is either make up water containing mineral salt, condensate containing process contaminants, corrosion products or in the case of condensers – in leaking cooling water. Deposits can also be formed due to the internal chemicals used.


 


 

Boiler Water Problems





Scaling
As water is heated and converted into steam, contaminants brought into a boiler with makeup water are left behind. The boiler functions as a distillation unit, taking pure water out as steam, and leaving behind concentrated minerals and other contaminants in the boiler. Scale forms as a result of the precipitation of normally soluble solids that become insoluble as temperature increases. Some examples of boiler scale are calcium carbonate, calcium sulfate, and calcium silicate.

Corrosion
Corrosion is a general term that indicates the conversion of a metal into a soluble compound. In the case of boiler metal, corrosion is the conversion of steel into rust. In a boiler, two types of corrosion are prevalent: 1.) Oxygen pitting corrosion, seen on the tubes and in the preboiler section. 2.) Low pH corrosion, seen in the condensate return system. Corrosion of either type can lead to failure of critical parts of the boiler system, deposition of corrosion products in critical heat exchange areas, and overall efficiency loss.

Carryover
Carryover is caused by either priming or foaming. Priming is the sudden violent eruption of boiler water which is carried along with steam out of the boiler, usually caused by mechanical conditions. Priming can cause deposits in and around the main steam header valve in a short period of time. Foaming causes carryover by forming a stable froth on the boiler water, which is then carried out with the steam. Over a period of time, deposits due to foaming can completely plug a steam or condensate line.

Cooling Water Problems




Scaling
Water formed deposits result from naturally occurring minerals precipitating from water to form scale. The most common scales are calcium carbonate, calcium sulfate and silica or silicates. Scale buildup on surfaces can be extremely hard and difficult to remove. Scaling will drastically reduce heat transfer capacity and system energy efficiency. 

Corrosion
Cooling systems are exposed to many types of corrosion, from general electrochemical corrosion, to pitting caused by deposits, electrolysis, or microorganisms. Corrosion can reduce the life-span of equipment by years, requiring expensive replacement. It can lead to costly equipment repairs and production downtime. Corrosion related deposits lead to reduced capacity and wasted energy because of heat transfer efficiency losses.

Fouling
Fouling occurs when solid materials form or contribute to the formation of deposits on equipment surfaces. They are introduced to the system as suspended solids and may enter by the makeup water, from corrosion by products, or as airborne materials. Examples include mud, sand, silt, clay, oils, debris, organics, microbes, etc. These materials adhere to heat transfer surfaces and reduce heat transfer and water flow.

Microbial
Microbial problems associated with industrial cooling water systems are caused by algae, fungi, and bacteria. They cause plugging, fouling, corrosion, and destruction of wooden cooling tower components. Many different bacteria species may exist in cooling water systems. Some of the problems caused include severe bacterial slimes and fouling, sulfuric acid, underdeposit corrosion and health hazards.

Corrosion  
Corrosion is the destructive attack of metal by chemical or electrochemical reaction. Corrosion is always because of chemical reaction. Physical deterioration is termed as erosion, wear or galling. Deterioration can be due to both chemical and physical attack.  




Water corrosiveness is determined by the impurities present in it. Oxygen, dissolved solids, and dissolved acids in water attack the common construction material. Alkali can also be corrosive, at high temperature, as in boiler.

Problems due to corrosion  

•  Thinning of metal 

•  Development of crack

•  Pitting of metal

•  Metal perforation

•  interference with heat transfer

•  Contamination of water

Corrosion is a complex problem and many factors influence corrosion. The factors to be considered are physical, chemical and biological.

Factors influencing corrosion

Physical Factors

1.       System construction

2.       System Pressure  

3.       Temperature
    
5.       Water Chemistry  

4.       Flow Velocity  
    

 Chemistry plays a very important role in corrosion. We have already explained earlier that corrosion is electrochemical reaction and is influenced by chemical factors like pH, alkalinity, dissolved salts and others.

a) Alkalinity
Alkalinity in water is due to presence of Bicarbonates, carbonates and hydroxyl ions. In raw water alkalinity is mainly due to bicarbonates. Some times carbonates ions may also be present. Carbonates and particularly hydroxyl ions are rarely encountered in untreated waters. Hydroxyl ions normally get introduced during treatment of water.

Alkalinity is determined by using standard acid solution using methyl or phenolphthalein indicator. Alkalinity determined by using methyl orange indicator is termed as M-Alkalinity or Total Alkalinity. P-Alkalinity is determined by using phenolphthalein as indicator. The different type of alkalinity present in water supplies can be calculated from M and P-Alkalinity value determined by titration. Alkalinity is the ability of natural water to neutralize acid. This happens because of buffering mechanism. Alkalinity in raw water is primarily composed of bicarbonates and carbonates. Acid compounds having free h+ ions react with CO3 and HCO3 ions and conversely Oh ions also reacts with CO3 and HCO3 ions.

CO 3 2- + H + ® HCO 3 -  

HCO 3 - + H + ® H 2 CO 3

HCO 3 - + OH - ® CO 3 2- + H 2 O

In either case acid or base is neutralized by the carbonate or bicarbonate. Thus it can be seen that when Acid (or caustic ) is added to water having high concentration of bicarbonate or carbonate the pH of water does not change much compared to when the same amount of acid(or caustic) is added to pure water. This is known as buffering capacity.

b) pH 
When pure water dissociates, the number of hydrogen ions is equal to number of hydroxyl ions. Such a solution is called neutral solution . pH is defined as negative logarithm of H+ ions.

Solution having pH less than 7 are acidic and those greater than 7 are basic. Low pH is Corrosive and high pH is protective to pipe. Very high can cause scaling and deposits.

c) Dissolved Oxygen  
Oxygen is considered has one of the most corrosive components in water chemistry. Dissolved O2 with traces of chlorides or solids can cause pitting corrosion of metallic surface. The resulting condition may be severe, even at low pressure.

d) Dissolved Solids  
Dissolved solids or salt content of water present as ion increases electrical conductivity of water. Higher the conductivity, greater the potential for corrosion. Some salts like CaCO3 are involved in scale forming and thereby reducing corrosion.

e) Hardness
Hardness is generally associated with scale forming. Hardness is composed primarily of Ca & Mg ions but may also include other metallic ions like iron and manganese. All hardness ions have the property of forming scales. One of the methods for corrosion control is by planned deposition of CaCO3

•Chloride & Sulphate  

Chloride and sulphate ions inhibit the formation of scale by keeping hardness ions in solution. Trace amount of Chlorides even with dissolved oxygen can cause corrosion in boiler.


Type Of Corrosion  

The type of corrosion classified with respect to outward appearance or altered physical properties are

Uniform attack
Pitting  
Cavitations erosion  
Dezincification & parting  
Intergrannular corrosion  
Cracking  

Oxygen Corrosion
Water coming out of deaerators has residual oxygen. As explained earlier even a trace amount of oxygen can cause corrosion. This last trace of oxygen is removed chemically. Sodium Sulphite and hydrazine or one of its product is used for removal of residual oxygen. Sodium Sulphite is used for low pressure boiler. Amine is preferred in high pressure boiler because it does not add to TDS, unlike Sodium Sulphite.

Effect of pH 
Both high and low pH can cause corrosion in boiler. In acidic range the protective layer of magnetite is not able to form and it cause corrosion. In very high pH range the protective layer of magnetite breaks down and this leads to caustic corrosion. For corrosion prevention maintaining proper pH and alkalinity is very important.

Acid Corrosion
Excess acid cause damage at more rapid rate than excess base. Simply because this happens, it should not be taken as an operating guideline. Magnetite film forms due to corrosion but once formed adhere tightly and acts as a barrier between boiler water and steel. Acids are capable of destroying this film and hence water chemistry must be so maintained that the protective film is not disrupted. This can be done by keeping the water in alkaline range.

Caustic Corrosion .
Feed water is maintained at alkaline pH. Alkali is added to provide optimum pH in the feed water to prevent corrosion of piping and equipment. Caustic soda (sodium hydroxide) is generally added for this purpose. Sometimes sodium carbonate is also added. Even though caustic soda is added with control, there are occasions when pH increases and cause corrosion as shown by the equation below. The damaged caused by excess alkali is because it dissolves the magnetite film forming sodium hypo ferrite and sodium ferrite both of which are soluble in hot concentrated caustic soda. In addition concentrated reacts directly and more rapidly with iron to form hydrogen and sodium Ferro rate.

Fe 3 O 4 + 4NaOH ® 2 NaFeO 2 + Na 2 FeO 2 +H 2 O
Fe + 2NaOH ® Na 2 FeO 2

Caustic attack on boiler can two forms - Gouging or cracking. Caustic cracking is also known as caustic embrittlement.

Caustic gouging causes deep elliptical depression in boiler metal surface. This occur in areas of high heat flux or under heavy porous deposits. Underneath these deposits , boiler water can concentrate to the point where high concentrate of caustic can accumulate causing a localized corrosion. This action can be rapid.

Boiler water chemistry if properly maintained will prevent caustic gouging.

Caustic embrittlement or cracking is a form of stress corrosion. Cracks occur rapidly and are often undetectable leading to sudden failure of boiler –at times causing a violent failure. All parts of boiler are subjected to this type of corrosion. The only way to stop this type of corrosion is to prevent high concentration from forming.

Caustic corrosion is generally confined to

a)       Water cooled tubes in region of high heat flux.

b)       Slanted and horizontal tubes.

c)       Location beneath heavy deposits.

d)       Heat transfer region at or adjacent to packing rings.

Caustic corrosion is prevented by coordinate caustic program. Phosphate ions act as a buffer ion. It does not allow pH to increase in water, no matter how concentrated OH ions become. Buffer ions are also useful in avoiding similar high OH concentration which leads to stress corrosion cracking (caustic embrittlement). In low pressure boiler sodium nitrate is added in a definite ratio to caustic alkalinity to prevent caustic embrittlement.



Galvanic corrosion
We have already explained what galvanic corrosion is. A metal or alloy if it is electrically coupled, galvanic corrosion occurs. Corrosion by copper is the most common form of galvanic corrosion in boiler system. Copper can be carried from pre boiler section. Water deposits copper as decomposition of bicarbonates or as ammonia complexes. Pitting of boiler tubes has been reported due to copper deposit.

Iron Oxide deposits
In boiler the steel reacts with water in absence of oxygen to form a magnetite film. This film than acts as a protective layer for further corrosion. Iron oxide also enters with feed water into boiler as corrosion product. This layer is very porous and can be easily penetrated. This allows boiler water to seep through and flash into steam leaving behind dissolved solids which concentrates in localized areas. This excessive concentration can lead to metal dissolution and metal failure.  

Condensate corrosion  
Steam generated in boiler is transported to point of use through pipes. Steam condensate is also returned to boiler feed water. Corrosion of steam lines and condensate return line occurs because of the low pH. The chief source of acid in steam is carbon di oxide. High temperature and pressure decomposes alkalinity to carbon di oxide, some of which dissolves in steam making it acidic. This lowers the condensate pH and leads to corrosion of return lines. Oxygen can enter a condensate system from other sources even if the deaerator is functioning properly. Oxygen causes a deep pitting of condensate lines.  

High Velocity and low pH can result in extremely severe corrosion conditions. The best way to minimize this is by keeping the pH above 9.0 Other gases which can be corrosive in the condensate system are Ammonia, Hydrogen sulphide and sulphur di oxide.  

Impure steam can create problems of carryover, priming and foaming in boiler. Steam gets contaminated because of the boiler water it carries with it or because of salt and silica which are, soluble in steam at high pressure. Solids carried over with steam can get deposited on super heater and turbine. Carryover can also effect the product quality.

Carryover:Carryover is defined as contamination of steam with droplets of boiler water. Carry over can be due to entrainment of water drops in steam or due to property of certain salt like silica in boiler water to get vaporized and get into steam.

The factors responsible for carry over are
a)       Amount of dissolved solids in boiler water.  
b)       Chemical nature of dissolve solids.  
c)       Suspended solids in boiler water  
d)       Boiler design  
e)       Boiler operating condition  

Many factors, both mechanical and chemical contribute to carryover.

Mechanical Causes  
Boiler design & operating conditions plays an important role in carryover. Without going into details we can say that major design & operating factors responsible for carryover are :

•  Design pressure  

•  Steam drum size

•  Design generating rate  

•  Circulation rate.

•  Arrangement of down comers and risers  

•  Type of mechanical separating equipment.

For example even when the TDS is within the limit, carryover can still occur because of change in operating condition. For example sudden increase in steam demand may lower the steam header pressure. This reduces drum pressure and water in the drum gets mixed with steam bubbles and the level rises. The rise in the drum level can cause carryover.

Chemical Causes  
Priming and foaming are two terms used with carryover. Priming is the surging of water in the steam outlet and is caused by factors like high water level in boiler, steaming rate, load fluctuations and boiler design. Priming is thus due to mechanical factors.

Foaming is formation of stable bubbles. The bubbles don't break because of high surface tension . Causes of foaming are :  

a. High Alkalinity : Caustic soda (NaOH) or sodium carbonate (Na2CO3) have greater influence on foaming than neutral salts.  

b. High TDS : High TDS causes carryover. For a given boiler design and a given set of operating   condition There is a limiting dissolved solid content above which a serious steam contamination occurs. Reducing blow down by small amounts every few days and measuring steam purity this limiting TDS value can be found out. This value is found by keeping boiler operating conditions and other operating variables such as feed water composition and treatment constant. If a graph is plotted between conductivity of condensed steam & boiler water TDS the limiting figure is that corresponding to slightly less than where steam quality deteriorates.

c. Suspended solids also cause foaming

d. Oil is not present n boiler water. It can enter boiler system through leaks in condenser or other heat exchanger. Oil can also system because of lubrication of steam driven reciprocating equipment. Oil is undesirable in boiler for two reason (1) It acts as binder to form scale, (2) It also causes foaming . Even a very small amount can cause severe foaming and hence immediate action should be taken for complete removal of oil.

e. Silica is another chemical which causes carryover. This is dealt separately.

 


Silica 
All natural water contains silica. Like calcium and magnesium silica also forms scale. Removing silica from water is more difficult than removing Hardness (calcium and magnesium ). At high temperature Silica volatizes and gets carried into steam and forms hard coating on turbine blades. Silica can form various kind of scale such as amorphous silica or magnesium Silicate. Amorphous silica scale forms like a glassy deposit which is very difficult to remove. Hydrofluoric acid is used to remove such scales. Silica scale is generally found in low pressure boiler because only softener is used and softener does not remove silica. Silica is not considered to be a big problem in low pressure boiler.

An effective, well designed water treatment program for cooling systems can result in higher process yields, longer production runs, lower operation cost, reduced scheduled maintenance time, energy savings and reduction in capital expenditures through extension of equipment life.

The need to remove unwanted heat is a common occurrence in manufacturing processes and commercial and institutional air-conditioning systems, cooling towers, molding machines. Water is the most commonly used media for removing unwanted heat. As a result large quantities of water are used for industrial and institutional cooling purpose. Due to the increased water consumption, cooling water systems are designed to re-use water.

Dissolved solids, dissolved gases and suspended matter as mud, sand, dirt or other particles entering a cooling water system either as airborne contamination or a part of the system's make-up effects the cooling efficiency of the system.

This water causes corrosion, deposition and microbiological growth results in decreasing operating efficiency and increase in plant maintenance cost.

The cooling tower is an excellent example of a contained water system that provides optimum conditions for microbiological growth (Algae, Bacteria, and fungi), Temperature and pH are usually within the ideal ranges and generally there is an abundance of nutrients required for their growth, organic matter, inorganic salts and sunlight.

Continuous accumulation and growth of micro organism in a cooling water system increases difficulty in controlling corrosion and deposition.

Normally two types of water treatments solutions are being used to get full control of water related problems as scaling, corrosion, microbiological growth in systems containing water. i.e., External Treatment & Internal Treatment.

External Treatment is use of some technique or system by changing water analytical parameters to make it more safe for a particular application. Some of the external water treatment systems are Filtration (Cartridge, sand, carbon), softening, deionization, reverse Osmosis, Sterilization, etc. This treatment is applied well ahead of the system where water is to be sued.

Internal treatment is basically control of water related products inside the system by utilizing different types of chemical.

Application & Procedure Descaling chemical

Application and Procedure of Descaling Chemical:-
Off-stream soaking
General
Dosage - Suggested solution strength is 1 - 5% by weight. One liter of NORCHEM CLN 1120/1130 will remove approximately 0.7 - 0.95 kg of scale. More rapid cleaning can be achieved with a 10% solution, but corrosion potential is increased, especially if elevated temperatures (54-60oC) are used.

Solution Temperature - Cool solution of NORCHEM CLN 1120/1130 will dissolve scale, but the action speeds up as the temperature increases . Normally 49 - 54 oC is suggested with a maximum of 60 oC.

Cleaning Time - Generally 2 - 12 hours - varies with dosage, solution temperature, type and amount of scale of deposit.

Procedure 

1. Connect a hose or piping to the lowest inlet on the equipment and extend it above the highest outlet to prove sufficient head for complete filling.

2. Install (for closed systems) a vent line to a top outlet to provide for safe removal of gases formed during cleaning. The vent outlet sparks and areas where possible discharge might splash on workers or equipment. 

3. Clean (boil-out) equipment with NORCHEM CLN 1144 to remove oil, grease, dirt, sulfate & organics at 10% solution for 4 hrs. soaking.

4. Clean & wash with D.M. or Soft water.

5. In a separate tank, make up the required solution of NORCHEM CLN 1120/1130 in water - always add acid to water.

6. Introduce NORCHEM CLN 1120/1130 solution gradually through the hose or piping via a rubber or polyethylene funnel. If the solution is not pre-mixed, fill the unit approximately 50% with water, add required NORCHEM CLN 1120/1130 and then completely fill with water. 

7. Allow equipment to stand for 4- 8 hours until scale has been removed or NORCHEM CLN 1120/1130 has been exhausted. Titration with NORCHEM CLN 1120/1130 Control Test will indicate solution strength. Descaling may be considered complete when the pH remains constant (in the 1.5-2.0 range) for 15-30 minutes. If the descaling is not complete after 8-12 hours, the unit should be drained and a new solution added. This is required because dissolved iron salts may catalyze corrosion.

8. After descaling is complete, flush out loosened, scale with fresh water and neutralize unit with 2% solution of NORCHEM CLN 1155 (caustic soda or soda ash can be substituted).

Off-stream Circulation

General :- 
Dosage, temperature and time information same as “off-stream soaking”.

Procedure :-

1.Clean (boil-out) and thoroughly rinse equipment with NORCHEM CLN 1155 to remove oil, grease, dirt, sulfates, organics and silica.

2. Wash and rinse with water 

3. In a separate tank, make up the required solution of NORCHEM CLN 1120/1130 in water - always add acid to water.

4.  Using an acid – resistant or expendable pump, circulate the cleaning solution through the equipment from the bottom up to ensure contact with all pockets. Intermittent circulation may accelerate the cleaning action. (e.g., run the pump one out of every five or ten minutes.)

5.  Titrate Solution with NORCHEM CLN 1120/1130 Control Test. Descaling may be considered complete when the pH remains constant (in 1.5-2.0 range) for 15-30 minutes. If descaling is not complete after 8-12 hours, the unit should be drained and a new solution added. This is required because dissolved iron salts may catalyze corrosion.

6.  After descaling is complete, flush out loosened scale with fresh water and neutralize unit with fresh 2% solution of NORCHEM CLN 1120/1130 (caustic soda or soda ash can be substituted)


On – stream descaling

General.

Dosage – Dosage will depend on the amount of scale in the system. One liter of NORCHEM CLN 1120/1130 will remove approximately0.7 – 0.95 kg. of scale. Suggested minimum solution strength is 0.1 – 0.5% (by weight).

T emperature - Suggested maximum is 60 oC.

Procedure

1.      Reduce the flow of water through the equipment to as low a rate as possible.

2.      Pump a concentrated (25-50%) solution of NORCHEM CLN 1120/1130 in to the water on an intermittent basis. This allows full water flow to be restored periodically to minimize temperature buildup.

3.      Stop chemicals feed it equipment starts vibrating from pressure buildup during cleaning. Slow cleaner injection may be resumed when vibration ceases.

4.      Cleaning effectiveness is determined by:

    Dissolved solids testing on cleaning solution during cleaning. A “ Bell Curve” for D.S indicates complete cleaning with a constant pH between 1.5 and 2.0
    Heat transfer rates (temperature readings) can be used as indicators of cleaning effected.
    Increased flow rates also reflect desired cleaning.

Parts Cleaning – Immersion

General
Solution Strength – Varies from 5% to a neat (100%) solution of NORCHEM CLN 1120/1130

Solution temperature – Cool solutions are recommended because of high concentration used and possible corrosive fumes.

Cleaning time – Will vary with concentration, type and amount of deposit.

Procedure

 11. Thoroughly clean equipment of parts with an alkaline NORCHEM CLN 1155 to remove oil, grease and dirt.

2. Rinse in clean water (warm or hot if available)

3. Immerse in NORCHEM CLN 1120/1130 solution descaling / derusting.

4. Remove part and rinse with warm or hot water. Immediate drying after rinsing will minimize
“flash rusting”.

5. Parts may be dipped in NORCHEM CLN 1120/1130 water – displacing or soluble oil inhibitor after acid cleaning to provide storage corrosion protection.

Descaling chemical
Norchem – CLN 1120 /1130  
Product Benefits

•  Attacks rust, scale and deposits but not on the base metal

•  Cleans complex equipment with out dismantling.

•  Penetrates and disperses acid soluble deposits.

•  Provides moderate foaming to minimize acid fuming.

Principle Use:-

1. Norchem – CLN 1120 /1130   quickly removes hardness and metal oxide deposits from boilers, heat exchangers, condensers, evaporations. cooling jackets, process vessels, piping and other equipment. It can be used while the equipment is on-stream or shut down.

2.  Norchem – CLN 1120 /1130   can be used for removes of rust and oxide / heat scale along with black oxide coating and chromium, zinc, And cadmium plate via the ”immersion dip method” in metal processing applications.

3.  Norchem – CLN 1120 /1130   can also be used to chemically clean well screens. It removes hard water scale, corrosion Products and iron deposits

Note:
1. Norchem – CLN 1120 /1130   is normally not recommended for Stainless Steel, Aluminium, Galvanized Metals, or zinc Alloys. An exception would be one-time cleaning of stainless steel parts in a metals shop where chloride stress corrosion is not a factor. 

2. Aluminium, zinc, galvanized metals and some stainless steels are attacked by Norchem – CLN 1120 /1130   Pre-testing in the desired solution is recommended if these metals are present.

General Description
Norchem – CLN 1120 /1130   is a carefully engineered blend of HCL with an acid inhibiting and surfactant chemical. The surfactant increases deposit penetration and provides controlled foaming action.

Form Liquid

Colour Colourless to Yellow

Flash Point None

Specific Gravity 1.14

PH (1% Solution ) 1.45

Density 1.13 gm/cc

Odor Acidic, pungent

Freezing Point < -- 46 oC

Rinsability Excellent.

Handling Descaling chemical

Handling and Storage of Descaling Chemicals

Warning: 
Causes burn. Do not get in eyes, on skin or on clothing. Wear goggles or face shield when handling. Avoid breathing of vapor. Use with adequate ventilation. Do not take internally. Keep container closed when not in use. In case of contact, immediately flush with large amounts of water for at least 5 minutes; for eyes, also get medical attention. Remove contaminated clothing.

Other Handling procedure of Descaling Chemical:
1.       Keep drum upright to prevent leakage.  
2.       Keep drum out of sun and away from heat, oil, and grease.  
3.       Relieve internal pressure when received and at least weekly thereafter by slowly loosing closure.  
4.       Never use pressure to empty the drum.  
5.       Replace closure after each withdrawal.  
6.       In case of spillage, flush with large amounts of water.  

Caution: During use, keep solutions of NORCHEM CLN 1120/1130 away from flames or points of ignition. Various gases may be generated. Provide adequate ventilation.

NORCHEM CLN 1120/1130 has a shelf life of 2 years

Safety Practice Descaling chemical

Safety Practices:-

1. Do not permit NORCHEM CLN 1120/1130 or prepared solutions to come in contact with skin or clothing or to splash into eyes.

2. Do not permit NORCHEM CLN 1120/1130 to splash on concrete floors, as it attacks lime in the concrete. If solution does get on concrete surface, apply an alkaline solution to neutralize.

3. Descaling operations should be performed away from all fire, sparks or other ignition sources.

4. Depending on type of scale being removed and the metals with which the solution will come in contact, various gases will be formed. Under ordinary conditions the action of NORCHEM CLN 1120/1130 solution on lime scale and rust results in the formation of harmless gases. However, when the solution comes in contact with Aluminium, Zinc, Cadmium, tin, sulfates, arsenic or cyanides, other gases, some poisonous and some explosive may be generated. The best practice when descaling is being done is closed equipment is to install proper ventilation to carry the gases away. When an open tank is used gases should be diluted by adequate air flow above the tank.

5. Always fill closed units from the bottom up.

6. Be sure that there are no leaks in heat exchange systems that will permit the solution to leak into the opposite side of the solution. Good practice is to fill the opposite side with water to a level higher than the NORCHEM CLN 1120/1130 solution

7. Use an acid-proof or an expendable pump.

8. When mixing with water, pour NORCHEM CLN 1120/1130 in to water, never add water to acid. 

9. Do not agitate acid solution with air.

10. Application of NORCHEM CLN 1120/1130 should be followed by a through rinsing, then neutralization with NORCHEM CLN 1120/1130 to remove all acidic residue. 

11. If the NORCHEM CLN 1120/1130 is to be held for any length or time, either an acid-proof, wooden or synthetic rubber lined steel con short-time, either an acid-proof, wooden or synthetic rubber lined steel container should be used. For short-time holding (8-12 hours maximum), an ordinary steel is acceptable.

12. If possible, dissimilar metals should be removed prior to descaling to prevent electronic action that might interfere with inhibiting action. Do lot use NORCHEM CLN 1120/1130 to descale Zinc, Aluminium, Stainless or Galvanized metals.

Disposal Consult with the appropriate regularity agency concerning requirements for discharge of acid solution. 

Control Test Refer to Control Test for Norchem CLN 1101/1104

Shipping NORCHEM CLN 1120/1130 is shipped in non-returnable, 200 Ltr. Drums containing approximately 232 Kg. Net weight and also in 30 liter jerry cans containing approximately 35 kg net weight.  


Clarification, Flocculation Chemicals
Water 2000, Inc deals is a wide range of clarriication / flocculation chemical for wide range of application is water and wastewater treatment 

Inorganic Chemicals : Alum, Polymeric Alum, Ferric/ Ferrous Sulphate, Ferric/ Ferrous Sulphate 

Polymers : Cationic, Anionic, Non-anionic 

Clarifiaction technology -Fundamentals:-
In fundamentals of clarification technology we will discussed about Coagulation, flocculation and sedimentation phenomena. 

Description:-
Clarification removes suspended matter from wastewater. Surface waters require clarification because they have moderate to high levels of suspended matter. Well waters do not require clarification because they have low levels of suspended matter.

The suspended matter in water includes two kinds of particles:
o Settle-able Particles (macro-particles, typically visible to the eye)
o Non-Settle-able Particles (micro-particles, normally visible through a microscope)

Settle-able particles are particles in water that settle out over time. The water itself is clear, indicating an absence of suspended matter (turbidity). If non-settle-able particles had been in the water, the water would not be clear. This "turbidity" would have indicated the presence of non-settle-able particles. Turbidity is an indirect measurement of the amount of suspended matter (settle-able particles and on-settle-able particles) in water. Clarification uses chemicals and sedimentation to remove suspended matter (settle-able particles and non-settle-able particles). Several steps are involved. 

First, coagulation destabilizes the particle surface charge that keeps the particles in solution. Once destabilized, the particles no longer repel one another and come together as floc.

Second, floc agglomerate into larger particles and Polymers are used to enhance the flocculation process. 

Third, sedimentation causes agglomerated floc to settle out. The settled floc is collected and concentrated for discharge to waste, called clarifier blowdown, or recycled to the coagulation step, called sludge recycle. Clarified water is collected and flows out of the clarifier.

Coagulation:-
The first step of the clarification process in wastewater treatment is coagulation. Particles in water have a naturally occurring negative charge. This causes them to repel each other and stay in suspension. When this charge is destabilized, the particles no longer repel one another, and can come together in closer proximity. A chemical salt, called a coagulant, is mixed with the inlet water to destabilize the charge. Common coagulants are aluminum sulfate (alum), ferric sulfate, ferric chloride and organic coagulant. The coagulants provide a positive charge, in the form of metallic cations, that destabilize the natural negative charge of the particles. The metallic cations combine with hydroxide in the water to form a metallic hydroxide that is an insoluble compound. The destabilized particles and metal hydroxide precipitates agglomerate into small, visible particles called floc. Color, organic matter and colloids, including colloidal silica, are removed by becoming bound up in the floc. The precise mechanism for removal- absorption, adsorption, co-precipitation, or a combination-is not fully understood.

The addition of too much coagulant can cause the suspended matter to be re-dispersed with the opposite charge. The amount of removal is dependent upon the coagulant dosage and the pH.

Alum (aluminum sulfate), ferric sulfate, ferric chloride and organic coagulants are acidic salts and decrease the pH of the influent water. Because of this, the pH of the water must be adjusted with caustic (sodium hydroxide) or another alkaline (high pH chemical).The adjustment is to a pH of 5.5 to 6.5 and is done to achieve the lowest residual of suspended matter. Lime is used as the coagulant when the treatment objective is hardness reduction. The dosage depends on the desired operating pH of the clarifier. For the greatest removal of hardness, the pH range is 9.5 - 10.5. Feed of coagulant alone does not produce satisfactory floc in waters having a low suspended matter concentration. In this instance, bentonite clay is added. Bentonite clay creates an artificial base of settleable macroparticles that seed the growth of floc.

Polymers are added to reduce the amount of coagulant required, broaden the working pH range and create denser, heavier floc that settles out more easily. Polymers are long-chain organic compounds of high molecular weight that bridge floc particles together or modify their surface charge.

In almost all cases, the water to be treated is disinfected with either gaseous chlorine or sodium hypochlorite. This oxidizes organic matter in the water that has taste and odor and certain metals, such as manganese and iron. When oxidized, these constituents are transformed into a form that can be removed during clarification. Their removal is important because they can cause fouling of process components.

Coagulation is carried out in a fast mix chamber. Fast mix is required because the coagulant and water must be thoroughly mixed to allow the suspended matter and coagulant to come into contact with each other. If it is not fast mixed, some suspended matter may not come into contact with coagulant, the surface charge will not be destabilized and flocculation will not occur. As flocculated water flows into the slow mix chamber, polymer is added.

Flocculation:-

In the next step of clarification, the small floc (microfloc) is allowed to grow into larger floc, called macrofloc or agglomerated floc. This process, called flocculation. Flocculation is accomplished by gently stirring the coagulated water to assure contact between microfloc particles and polymer. The polymer enhances agglomerated floc formation. As the agglomerated floc continues to grow, it becomes denser and heavier, allowing it to settle. Mixing too rapidly can create what is called floc shear. Shear is the breaking apart of existing floc particles. The agglomerated floc, or macrofloc, is sheared back into microfloc.

Mixing too rapidly can create what is called floc shear. Shear is the breaking apart of existing floc particles. The agglomerated floc, or macrofloc, is sheared back into microfloc.

Sedimentation:-

The final step of the clarification process is sedimentation. In this step, agglomerated floc settles out to form sludge and the sludge is transported to the sludge concentration chamber by the scraper. The sludge thickening pickets concentrate the sludge. The sludge is discharged to waste in a process called clarifier blowdown. Above the sludge, clarified water is collected in the outlet launder and flows forward for use or further treatment.=

Swimming Pool Chemicals

Water 2000, Inc offers a full range of bulk and specialty pool chemicals for all your pool needs.

chemicals

The aqua products line of specialty pool chemicals will help keep your pool water sparkling and safe.