Drinking Water Industry SolutionsSafe and Reliable Liquid Analysis

WE START WITH ONE IDEA: MAKE IT SAFE

TRUSTED EVERYWHERE: THE MOST ADVANCED LIQUID ANALYSIS SOLUTIONS

Water is the most crucial element needed for

human activity on the planet, including

agricultural, industrial and domestic use.

Unfortunately, water quality around the world is

poor and getting worse. While over 70% of the

Earth is covered in water, only about 0.01% is

usable fresh water. And since water demand

increases with population, the re-use of water

and proper treatment methods have become a

critical necessity.

Water treatment plants come in awide variety of sizes, with no twoplants exactly alike. But whetherpublicly owned or privately held,they all share the same goal — toprovide a source of safe and reliabledrinking water to their communities.

Water treatment varies based onthe quality of the water source,size of the plant, and if groundwater or surface water is used.Smaller systems are likely to useground water, while larger systemsrely on surface water sources suchas rivers, lakes, and reservoirs.

As water travels through theground, or sits in lakes and rivers, itcomes in contact with organicmaterials, which dissolve in water.These organics in water become afood source for microorganisms.Even the most minute nutrientsources will support growth. Whilethat’s good news for microorgan-isms, it spells disaster for people,since these microorganisms (likeGiardia lamblia or the protozoaCryptosporidium) can be harmfulor even lethal to humans.

Poor Water Quality: Understanding the Problem

Some smaller treatment plantsusing ground water systems canmeet the local and nationalrequirements without anytreatment, but manyother systems needadditional treatmentand disinfection.Governmentalagencies such asthe USEnvironmentalProduction Agency(USEPA) protectthe public healthby specifyingwatertreatment com-ponents and appropriate disin-fection levels. To meet theserequirements, a variety of watertreatment methods are used toremove contaminants fromdrinking water, and are arranged ina sequence or a treatment train.

A combination of appropriate watertreatment processes is selected bythe water utilities to treat thecontaminants in the raw water

source used. Commonlyused processes include

pre-treatment, coagula-tion, flocculation, sedi-mentation, filtration,and disinfection.Other treatmentmethods couldinclude ion exchange,

reverse osmosis,and adsorption.

For theseapplications and

more, count on Emerson. Ourfull line of Rosemount Analyticalsensors and measurement solutionsfor drink-ing water are provensolutions. When you bring yourproblem to Emerson, consider it solved.

Comprehensive Solutions For Your Application

2

With so much at stake, you need a partner that

can deliver the best in knowledge and systems,

and do it quickly, thoroughly and cost-effectively.

The liquid analysis professionals at Emerson

Process Management are ready to put their 60-

plus years of experience to work for you. We’ll

evaluate your application and deliver an optimal,

real-world, customized solution for your specific

requirements, utilizing world-class Rosemount

Analytical sensors and instrumentation.

PlantIntake

Primary Disinfection(Ozone or Chlorine Treatment) Page 4

Flash Mixers

Flocculation Basin Page 5

Filter Beds Page 6

Secondary DisinfectionChlorine Addition (Ammonia Addition) Page 7

Water Tower

FilterWastewaterBackwash

Booster Station

Clear Well

To DistributionSystem Page 8

Homes

Industries

Settling Basin Page 5

Here’s a typical drinking water

plant. It takes water from a lake,

river or well and treats it through

primary disinfection, coagulation,

sedimentation, filtration and sec-

ondary disinfection to purify it

into safe drinking water.

Harmful organisms are killed by a

combination of ozone, chlorine

and ammonia addition. The

disinfection process is monitored

and controlled by continuous

measurement of ozone and/or

chlorine. Particles are removed

and filtered out, and require

continuous turbidity

measurement for reporting

purposes and indicate filter

performance. Particle Counters

are gaining more acceptance since

they provide a quantitative

measurement of drinking water

clarity and are being used to antic-

ipate filter breakthrough.

CO N T E N T S

Pretreatment 4

Primary Disinfection 4

Coagulation, Flocculationand Sedimentation 5

Lime in Water 6

Filtration 7

Secondary Disinfection 8

Final Treatment 9

Distribution Monitoring 11

Desalination 12

PlantWeb 13

Instrumentation 14

Pretreatment

DRINKING WATER TREATMENT OVERVIEW

3

To better define the dynamics of the raw watersource being used by a treatment plant, a number ofliquid analytical measurements are made prior toentering the treatment process. Influent monitoringmeasurements could include pH, conductivity,temperature, turbidity, dissolved oxygen, and TotalOrganic Carbon (TOC). Some plants also keep apermanent record of each of these measurementsfor future reference or for detecting seasonalchanges in the source water.

Before water is clarified, it passes through coarsefilters to remove sticks, leaves, fish, and other largeobjects, preventing them from entering the watertreatment plant. Pretreatment also includes primarydisinfection using either chlorine or ozone to treatalgae growth and for oxidation of chemicals andmicroorganisms.

Caustic soda is one of the basic building blocks ofchemistry and as such it finds diversifiedapplications. One use is in water treatment.Municipal water treatment facilities use caustic sodafor pH adjustment, ion exchange regeneration, andon-site generation of sodium hypochlorite. Causticsoda, especially when used for pH control,neutralization of waste acids, and similarapplications, competes with other alkalies,particularly sodium carbonate (soda ash). Thecommon factors for selecting caustic soda are itsstronger basicity and easier storage and handling.

For water treatment, this is one of the first steps towater treatment and is prior to the filter bed at themixing tank. Measuring whether caustic soda is inthe stream, which indicates whether the feed pumpsare working, can be achieved with toroidalconductivity. Toroidal conductivity sensors are longlasting in this application and indicate by the drop inconductivity, that the pump is not feeding causticinto the water stream. The Model 228 toroidalconductivity sensor in a loop with theModel 1056 analyzer work toindicate the feed pump isworking or not.

Since water is a universal solvent,

it comes in contact with several

different pathogens (bacteria,

viruses, and parasitic protozoa),

some of which are well know and

potentially lethal. Both surface

water and groundwater sources

can be contaminated by these

pathogens, and inactivation is

accomplished through chemical

disinfection and mechanical

filtration treatment.

Chlorine was used first used in theUSA in 1908 as a chemicaldisinfectant of drinking water.

Ozone (O3) is also a powerfuldisinfectant first used in water treat-ment in Europe in 1886. Ozone consists of three oxygen atoms anddegrades back to oxygen forming afree oxygen radical, which survivesless than 30 minutes. The rate ofdegradation depends on the waterchemistry, pH and temp-erature.Since ozone is unstable, it isgenerated on site.

Ozone is a very powerful oxidantand it disinfects in less time than isrequired with chlorine. Ozone

attacks the chemical bonds ofpathogens in the water, reducingthe concentration of organic materi-al, iron, manganese, sulfur, andreducing or eliminating odor andtaste problems. Chlorine is a slowoxidizer, has limited effect on bacte-ria, and Cryptosporidium andGiardia are extremely resistant tochlorine disinfection. Ozonetreatment is gaining popularity as afast and effective treatmenttechnology for disinfection in theprimary disinfection stage.

Ozonated air is bubbled up throughthe water in contact chambers. Bythe time the water reaches the endof the contact chambers, primarydisinfection is complete and theozone has converted back tooxygen. For proper ozonedisinfection to occur, suitablecontact time and the proper ozonedosage are required.

Chemical Oxidation Potential (volts)

Ozone 2.08

Hydrogen Peroxide 1.78

Hypochlorous Acid 1.48

Chlorine Gas 1.36

Hypobromous Acid 1.33

Chlorine Dioxide 0.95

Hypochlorite 0.81

Relative Oxidation Power of Various Chemicals

PRIMARY DISINFECTIONPRETREATMENT

The Ozone sensor Model499AOZ is used to monitorozone dosage and residualsin the contact chamber.

4

Model 228 ToroidalConductivity Sensor

Coagulation and Focculation

Smaller particles combine or coagu-late into larger fluffy particles calledfloc and settle out of the raw watersource as sediment. The coagulationprocess is promoted by the additionof chemical coagulant such as alum,iron salts or synthetic organicpolymers. After chemical addition,

the water flows through a mixingchannel where the water and chemi-cals are flash mixed.

The floc is mechanically stirred toattract suspended solids andmicroorganisms. The pHmeasurement plays an importantrole in the coagulation process.Keeping the pH at the proper levelsimproves the coagulation process,lowers the turbidity and alsoimproves TOC removal as the pH is lowered.

If the raw water source has anunusually high hardness, chemicalsare added such as lime and soda ashto reduce the levels of calcium andmagnesium. Lime softening can

After pretreatment and primary

disinfection, the clarification of

raw water is usually a multiple

step process for reducing

turbidity and suspended solids.

A Model 3900 pH sensor is used to monitorand control the addition of chemicals for pHadjustment. Available with SMARTcapabilities.

COAGULATION, FLOCCULATION AND SEDIMENTATION

SMART pH measurement loops which include SMARTpH sensors and SMART-enabled instruments have theadvantage of not requiring calibration of pH sensorsin the field. All SMART sensors automaticallydownload critical calibration data and performanceparameters to the instrument upon calibration in thelab. Simply reconnect the pre-calibrated sensor to aSMART-enabled field instrument and the pH loop isautomatically calibrated.

Sensor data transferred to analyzer

Rosemount Analytical Smart technology – The SMART solution for pH measurement

5

produce water from 60 to 120 ppmhardness, but will result in a higherpH. Therefore, the treated water isbuffered to reduce the pH to makeit acceptable for further processing.

Sedimentation

Floc settles to the bottom to form asludge in sedimentation basins. Thecombined weight of the dirt andchemical agent become heavyenough to sink to the bottom, andthe settling or sedimentation occursnaturally as larger particles settleout. Sludge is removed by mechani-cal scrapers and disposed of proper-ly. Water is skimmed from thesurface of the settling basins andflows into settled water channels.

6

Lime is used by many

municipalities to improve water

quality, especially for water

softening and arsenic removal. In

terms of annual tonnage, lime

ranks first among chemicals used

in the treatment of potable and

industrial water supplies. Lime

has multiple applications:

pH Adjustment/Coagulation -Hydrated lime is widely used toadjust the pH of water to prepare itfor further treatment. Lime is alsoused to combat "red water" by

LIME IN WATER TREATMENT

neutralizing the acid water, therebyreducing corrosion of pipes andmains from acid waters. Thecorrosive waters contain excessiveamounts of carbon dioxide. Limeprecipitates the CO2 to formcalcium carbonate, which provides aprotective coating on the inside ofwater mains.

Lime is used in conjunction withalum or iron salts for coagulating sus-pended solids incident to theremoval of turbidity from "raw"water. It serves to maintain the prop-er pH for most satisfactorycoagulation conditions. In somewater treatment plants, alum sludgeis treated with lime to facilitatesludge thickening on pressure filters.

Effect on Pathogen Growth - By rais-ing the pH of water to 10.5-11through the addition of lime and

retaining the water in contact withlime for 24-72 hours, lime controlsthe environment required for thegrowth of bacteria and certain virus-es. This application of lime is utilizedwhere "phenolic water" exists,because chlorine treatment tends toproduce an unpalatable water dueto the phenol present. This process,called "excess alkalinity treatment,"also removes most heavy metals.

To accurately measure pH, theRosemount Analytical pH sensor,Model 3900 can be used forcontinuous online measurement ofpH. This general purpose sensor isdesigned for enhanced performanceand increased life with minimal glasscracking provided by field provenACCU-Glass pH glass formulation. Italso fits a large variety ofinstallations with both ¾” and 1”mounting threads.

A Model 3900 pH sensor – available withSMART capabilities.

Water flows through sand filtersand percolates down through acombination of sand, gravel,anthracite coal, and a mixture ofsupport gravel fine sand. Larger par-ticles become trapped first andsmaller particles such as clay, iron,manganese, microorganisms,organic matter, precipitates fromother treatment processes, and siltare also removed resulting in crystalclear water.

The filtration stage also removesresidual matter resulting from theoxidation of organic chemicals andmicroorganisms in the primarydisinfection stage. Finally, micro-organisms resistant to chlorine orozone disinfection in thepretreatment stage are effectivelyremoved during filtration.

Periodically, the filter must be backwashed to remove the fine suspend-ed matter and accumulatedsediment that collects in the filtermedia. As an indication of filter per-formance and the need tobackwash filters, the effluent fromthe filter beds is continuously moni-tored with a turbidimeter. Turbidityis the clarity of the sample, and thecloudy appearance is caused by tiny

particles in the water. The Clarity IIOn-line Turbidimeter can be used tomonitor and report the turbidity ofthe filter effluent. Turbiditymeasurements also help monitorand improve plant efficiency.

High turbidity levels are an indicationthat the filter is not operating proper-ly, and back washing is necessary.

Government rules and regulationsapply to public water systems, andwater treatment plants are requiredto achieve a minimal reduction ofharmful microorganisms andviruses. Filtration systems arepresumed to achieve the minimalpercent reduction of harmfulCryptosporidium, Giardia and virus-es by meeting certain turbiditylimits in combination with adequatedisinfection. The adequacy of the fil-tration process and the removal ofthese microorganisms aredetermined by measuring theturbidity of the combined filtereffluent water to meetgovernmental criteria. This criteriaincludes the turbidity monitoringfrequency, the maximum turbiditylimit, and the approved turbiditymeasuring methods.

Two approved measuring methodshave been accepted for makingturbidity measurements forcompliance monitoring purposes,the USEPA Method 180.1 and the ISOMethod 7027. USEPA method is usedin the United States and some othercountries. The ISO method is usedoutside of the United States, such asin Canada, Europe, Latin America andAsia. A comparison of the two meth-ods is shown in the table above.

Keeping water systems safe is anational priority. To monitor onlinemultiple parameters, Emerson has aconfigurable system, the WaterQuality System, model WQS, to meetyour particular system and regulatoryrequirements. The system assists inmeeting the requirements of theSurface Water Treatment Rule.

The sedimentation process

removes particles 25 microns

and larger, but the process is not

100% efficient, and filtration is

required. The turbidity is

between 1 and 10 NTU as it

enters the filtration stage.

Comparison of USEPA 180.1 and ISO 7027

Item EPA 180.1 IS0 7027

Light Source Tungsten Lamp LED or Tungsten Lamp

Wavelength 400-600 nm 860 ± 30 nm

Characteristics Long Warm- Low Stray Up Time Light

More Sensitive Less Sensitiveto Smaller to SmallerParticles Particles

Color Low ColorInterferences Interferences

Water Quality Monitoringreviewed by EPA

The Clarity II On-Line Turbidimeter is usedto monitor and report the turbidity of thefilter effluent.

FILTRATION

7

In compliance with the regulations

requiring post residual disinfec-

tion, plants use chlorination as

secondary disinfection in the final

treatment step. Ozone does not

provide germicidal or a long-

lasting disinfection residual to

inhibit or prevent re-growth of

pathogens in the water

distribution system.

SECONDARY DISINFECTION

Today, chlorine is added as chlorinegas (Cl2), sodium hypochlorite(NaOCl), or chlorine dioxide (ClO2)as the secondary disinfection agent.Secondary disinfection prevents

Model TCL Total ChlorineSample Conditioning System

the re-growth of certain pathogensthat may enter the treatment plant or be introduced by back-flow contamination.

When chlorine is added to water,free chlorine forms a mixture ofhypochlorous acid (HOCl) andhypochlorite ion (OCl-). The relativeamount of each is dependent on thepH, and the total of HOCl and OCl-

is defined as free chlorine.

For disinfecting water, hypo-chlorous acid is not only more reac-tive than hypochlorite ion, but isalso a stronger disinfectant and oxi-dizer. Hypochlorous acid is 80 to100 times more effective thanhypochlorite ion.

To accurately measure free chlorineconcentrations, the RosemountAnalytical three electrode chlorinesensor Model 498CL can be used forcontinuous measurement of freechlorine. Neither a pH sensor,sample conditioning, nor reagent is required.

Chlorine diffuses through a semi-per-meable membrane and develops acurrent proportional to the chlorineconcentration inside the sensor.

Chlorination by-products werediscovered in drinking water in1974, and can form when chlorinereacts with bromide and naturalorganic materials present in thewater source. These by-productshave a potential health effect onhumans. Fears that these by-products could be potential humancarcinogens has led the USEPA to

8

The MonochloramineMeasuring System Model

MCL directly measuresmonochloramine without

chemical reagents tocondition the sample.

establish maximum levels for thesedisinfection by-products.

Alternates to chlorine disinfectionexist, such as chloramines. Thisprocess involves adding chlorineand ammonia compounds to thewater that, when properlycontrolled, form chloramines.

Compared to chlorine, chloraminesproduce fewer disinfectionbyproducts and exist as mono-chloramine, dichloramine ortrichloramine. The ratios of thesethree depend on the pH, physicalproperties of the water source, chlo-rine contact time, and the ratio ofchlorine to ammonia. Monochlora-mine is the most desirable of thethree forms, since it contributeslittle or no taste or odor, and is considered to be the most effectiveat disinfecting water.

Plant operators using chloraminationfor disinfection need to accuratelydetermine monochlora-mine levelsin the water treatment systems.Rosemount Analytical offers a com-plete Monochloramine MeasuringSystem Model MCL capable ofdirectly measuring monochloramine.No chemical reagents are needed tocondition the sample.

For Total Chlorine measurement, wehave the Model TCL Total ChlorineMeasuring System. The TCL useshousehold vinegar and potassiumiodide as reagent.

9

The U.S. specifies the optimal

level of fluoride to range from 0.7

to 1.2 mg/L (milligrams per liter,

equivalent to parts per million),

depending on the average

maximum daily air temperature;

the optimal level is lower in

warmer climates, where people

drink more water, and is higher in

cooler climates.

The Centers for Disease Control andPrevention have developedrecommendations for waterfluoridation that specifyrequirements for personnel, report-ing, training, inspection,monitoring, surveillance, andactions in case of overfeed, alongwith technical requirements foreach major compound used.

FINAL TREATMENT

Water districts that monitor the lev-els of fluoride in the drinking watersupply can be required to monitormultiple measurement points. Grabsamples with resulting temperaturefluctuations could give erraticresults and require a time burden onthe maintenance staff and result inreduced plant efficiency. An inlinefluoride ion selective sensor, special-ly engineered to water applications,with a rugged fluoride mono-crystalion sensing element, and a virtuallymaintenance-free solid statereference system is recommended.

Water fluoridation is the controlledaddition of fluoride to a public watersupply to reduce tooth decay.Fluoridated water has fluoride at alevel that is effective for preventingcavities; this can occur naturally orby adding fluoride. Fluoridation

does not affect the appearance,taste, or smell of drinking water. It isnormally accomplished by addingone of three compounds to thewater: sodium fluoride, fluorosilicicacid, or sodium fluorosilicate. Thesecompounds were chosen for theirsolubility, safety, availability, andlow cost. The U.S. specifies the opti-mal level of fluoride to range from0.7 to 1.2 mg/L (milligrams per liter,equivalent to parts per million),depending on the averagemaximum daily air temperature; theoptimal level is lower in warmerclimates, where people drink morewater, and is higher in cooler

Ion Selective Electrodes(ISE's) for fluoride and

ammonia determination.

10

climates. Fluoride ISE measuring

systems are complete systems that

measure fluoride ion activity and

are available in single or dual panels.

Many water systems already have

ammonia in their water or add

ammonia during their treatment

process. Excess free ammonia in

water distribution systems

promotes biological growth and

nitrification. If the systemexperiences isolated areas of water

quality degradation that affect the

aesthetic quality of the water, which

may generate customer complaints

due to taste, odor, and particles in

the water, or if the system has areas

where it’s difficult to keepacceptable chlorine levels, thismight be a direct result of biologicalgrowth and nitrification.

The term “free ammonia” is usedwhen naturally occurring ammoniais present in water and/or whenchloramines are used to disinfectwater. During chloramination, chlo-rine and ammonia are added towater to form monochloramine.The portion of ammonia that hasnot combined with chlorine is calledfree ammonia, and exists as eitherNH4+ or NH3 depending on the pHand temperature of the water.At typical water pH of 7.0 to 7.8 andtemperature of 12 to 24 degreesCelsius, more than 96 percent ofammonia is in the ionized form ofammonium (NH4+). As the pH and

FINAL TREATMENT continued

temperature increase, the amountof NH3 increases and the amount ofNH4+ decreases.

The only accurate way to determineif treated water contains ammoniais to perform an ammonia analysis.If ammonia is detected, additionalsampling on the distributionsystem for free ammonia should beexplored. Ground water may haveammonia levels ranging between0.2 to 2.0 mg/L. Municipal drinkingwater plants carefully control theirlevel of free ammonia (often alsodescribed as total nitrogen of NH3-N)and chloramine (also calledmonochloramine or MCL) used toensure that the water remains suit-able for human consumption. Thereare panels available in single or dualmeasuring systems.

Drinking Water Panels for fluoride,ammonia, and monochloramine allow forfast, easy determinations with virtually no

operating costs.

11

The prevention of contamination

in the distribution system, thereby

reducing the risk of water borne

diseases, requires regular

monitoring for disinfectant levels,

microbial levels, and corrosion

products. Although water may be

safe upon leaving the treatment

plant, it is important to monitor

for contamination by growth of

microorganisms, pressure

problems, and water main breaks.

Monitoring can also indicate

formation of biofilms, malfunc-

tioning piping and valves or other

threats to the system.

Because pathogens can enter the dis-tribution system through cracks andjoints in pipes, water systems are alsorequired to provide continuous disin-fection of the drinking waterentering the distribution system, andmaintain a detectable residual levelwithin the distribution system.

Regular monitoring includes micro-bial monitoring to meet publichealth standards. Chlorine residualsin the distribution system also needto be checked. The pH is monitoredto confirm that the properapplications of corrosion controlchemicals are being applied at thetreatment plant.

A minimum of 0.2 mg/L of chlorineresidual is advisable at the last tapon the distribution system, andprompt investigation is required tocorrect a low or no residual reading.

Water quality within thedistribution system can bemonitored on a continuous basis,and several large water utilities haveinstalled automatic samplingsystems throughout their district.

A continuous on-line chlorine meas-urement is especially important inensuring adequate disinfectionlevels throughout the distributionsystem; it can be accomplished byusing one of three measurement

systems available from Rosemount:free chlorine, monochloramine ortotal chlorine. The monitoring datacan be transmitted back to the plantand automatically stored for futurereference, historical trends, anddetection of seasonal fluctuations.

Additional functionality can beobtained if the FCL is ordered withthe Model 56 analyzer. Thisinstrument includes the datalogging feature and stores up to 30days of data. Logging of events, likecalibrations, power outages andfaults & warnings can beaccomplished easily on the Model56. Data logging is valuable forreviewing data when troubleshoot-ing sensor and process out of rangereadings. The data can bedownloaded onto a flash drive usinga USB port in the front panel.

Free Chlorine Measuring System, ModelFCL, is suitable for compliance monitoringwhen calibrated against a grab samplethat has been analyzed using a laboratorytest acceptable to EPA. Refer to EPAMethod 334.0 for more details.

DISTRIBUTION MONITORING

12

Contacting ConductivityENDURANCE™ Sensors are used

to monitor the reverse osmosistreatment process and are available in a

variety of mounting options.

Seawater Reverse Osmosis (SWRO)using membrane technology isanother way of accomplishingdesalination. RO is a technique inwhich water is forced through semi-permeable membranes, andrequires pretreatment consisting ofcoagulation and filtration.

The passage of dissolved salts andmicroscopic particles is blocked,and relatively ion-free water (called-permeate), passes through themembrane. Contacting conductivitysensors placed in the feed-waterand permeate let operators monitorthe overall water quality andefficiency of the RO treatment.

Newer aromatic polyamide compos-ite membranes are more resistantto chemical attack at extreme pHvalues than cellulose acetatemembranes. However, both typesbenefit from careful pH control toprevent precipitation of sparinglysoluble salts and to extendmembrane life. A general purposesensor such as Model 399 cancomplete this measurement.

Desalination refers to the water

treatment process of removing

salts from water. Of all the earth’s

water, 94% is salt water and less

than 1% is accessible fresh

surface water.

With the improvements in

desalination technologies over the

past 50 years, and the growing

demand for fresh water, there are

more than 16,000 desalination

plants worldwide. This compares

to only 5 plants in 1960. Cities and

major industries have developed

with the availability of fresh water

produced from seawater.

Thermal techniques, such as multi-stage flash desalination (MSF) distil-lation, and membrane technologies,such as reverse osmosis (RO), arethe two major competing tech-niques used in the desalination

of seawater, and both makeseawater drinkable.

About half the world's desaltingplants produce fresh water usingheat to distill water from sea water.Hybrid plants combine a steampower plant and a desalinationplant. The latent heat of conden-sation from the power plant isreused to increase the temperatureof the incoming sea-water. The mainbenefit of this dual-purpose plant isthe reduction of fuel used.

Multi-Stage Flash Distillation is oneof the most commonly used types.Typically, the salt water is heated inthe brine vessel for the separation ofwater and salt. The heated water issent to another vessel where it boilsrapidly and flashes to create steam.The steam is then captured andimmediately cooled to convert itback into a liquid that has beendesalinated and is ready for use.Desalination plants can haveanywhere from four to 40 differentstages of flashing. Scaling is one ofthe biggest problems in multi-stagedistillation applications. Maintaininga pH balance of 5.7 or less is crucialto minimize scaling. This can beachieved by using a RosemountAnalytical pH/ORP sensor model 399with the 1056 dual channel analyzer.

Scaling also causes a problem whenthe feed solution becomes saturatedwith calcium sulfate. It is importantto maintain a concentration levelbelow the saturation point. Using theRosemount Analytical toroidalconductivity sensor model 228 alongwith a 1056 two channel analyzer,will insure that no excessive build upof dissolved solids takes place andminimizes fouling in the evaporator.

DESALINATION

Rosemount Analytical’s instru-ments are part of Emerson ProcessManagement’s PlantWeb® field-based architecture: a scalable wayto use open and interoperabledevices and systems to build

process solutions. The PlantWebarchitecture consists of intelligentfield devices, scalable platformsand standards, and integratedmodular software, all workingtogether to create, capture,

Emerson Process Management isthe proven supplier of RosemountAnalytical on-line electrochemicalsensors and instrumentation withover 60 years experience indrinking water treatment, wastetreatment and process control. Inrecognition of our dedication tocustomer service, productexcellence, and qualitywe have received the#1 ReadersChoice Awardfrom ControlMagazine for thesixteenth consecutive year.

With a fixed amount of fresh wateravailable for consumption and our

worldwide increased demand foraccess to safe water, continuousmonitoring and measuring of thewater treatment process and waterquality becomes one of the mostimportant elements to preventwater-related diseases caused by pathogens.

Producing a source of safe andreliable drinking water and the

removal of harmful microorganismsare the primary goals of every

drinking water treatment plant.Thousands were killed each year dueto cholera, typhoid fever, dysenteryand hepatitis before cities begantreating drinking water withchlorine. Today, chlorine, ozone and

use, and distributeinformation andprocess control data.

This architecture can reduce yourcapital and engineering costs,reduce operations andmaintenance costs, increaseprocess availability, reduce processvariability, and streamlineregulatory reporting.

To see what PlantWeb can do foryour operation, call or visit us atPlantWeb.com/RunSafe

UV are being used in primarydisinfection at the pre-treatmentstage and secondary disinfection inthe final stage to inhibit or preventregrowth of pathogens in the waterdistribution system.

Accurate on-line process instrumen-tation, such as pH, conductivity,chlorine, dissolved ozone, turbidity,and particle counters, plays a criticalrole in achieving the plant objectiveand meeting regulatory complianceat the local and federal level. Counton Emerson for the systems andsolutions you need in an ever-chang-ing, dynamic world. See us on theweb at RAIhome.com.

EMERSON PROCESS MANAGEMENT: THE PROVEN SOURCE

PLANTWEB® BRINGS IT ALL TOGETHER

ROSEMOUNT ANALYTICAL INSTRUMENTATION

Features 1056 Series 1057 Series 56 Series

Power 115 - 230 VAC or 115 - 230 VAC or 115 - 230 VAC Requirement 24 VDC 24 VDC or 24 VDC

Number of 4-20 Two Four four mA Outputs

Number of Two Three TwoSensor Inputs

Available pH/ORP/ISE, Conduc- pH/ORP/ISE, pH/ORP, resistivity/Measurements tivity, Resistivity, Contacting conductivity/TDS,

% Concentration, Conductivity % concentration, ratio Dissolved Oxygen, conductivity, total and Ozone, Flow,* free chlorine, dissolved O2, Turbidity,*Chlorine dissolved ozone, turbidity, (Total, Free, Mono- pulse flow, temperature chloramine, pH and raw 4-20mA inputIndependent Free Chlorine)

SMART pH Yes Yes Yes

HART Yes No YesCompatible

FOUNDATION fieldbus No No NoCompatible

Wireless THUM Yes No YesAdaptor compatible

Multi-lingual Menus Yes Yes Yes

Relays 4 4 4

PID Control Timer control only Timer control only Yes

Advanced Diagnostics Yes Yes YesCapability

Area Class I, Div 2 Class I, Div 2 Class I, Div. 2Classifications

Available Approvals FM, CE, CSA, UL CE, UL, CSA Pending

Emerson Process Management

provides the type of instrumenta-

tion your plant needs to monitor

all aspects of water quality.

Whether you need four-wire,

two-wire or can make use of the

advantages offered by wireless,

we have your instrument.

Four-wire instruments

1057 - Choose pH/ORP/ISE orContacting Conductivity/Resistivity,in any combination. Like the Model1056 it has:•A large, easy-to-read display of

process measurements. Operatorsknow at a glance if the process iswithin allowable parameters

• The units are easy to install andwire with modular boards, remov-able connectors, and easilyconnected sensors.

•Commissioning is easy withintuitive menu screens andadvanced diagnostics and helpscreens.

The new Model 56 with a high reso-lution, full color screen shows faultsand warnings in color for immediaterecognition for an out of rangeparameter. • Pinpointing process disruptions

can be viewed n the colortrending graphs. The user can

zoom in to a specific time framefor detailed on-screen evaluation.Information can be downloadedin Excel format to a USB memorydevice.

• Proportional, Integral andDerivative (PID) control allow the

analog current outputs to adjust acontrol device and any currentoutput can be programmed forPID functions.

•Basic TPC (time proportional con-trol) timer functions settings areavailable.

14

FO U R-W I R E

ROSEMOUNT ANALYTICAL INSTRUMENTATION

15

Features 6081 Series 5081 Series 1066 Series

Power Lithium power 24 VDC 24 VDCRequirement module

Number of 4-20 Wireless One TwomA Outputs

Number of One One OneSensor Inputs

Available pH and Select one: pH, Select one: pH, Measurements contacting ORP, Conductivity,

conductivity Resistivity, Dissolved Resistivity, DissolvedOxygen, Ozone, Oxygen, Ozone, Chlorine, Gaseous ChlorineOxygen

SMART pH Yes No Yes

HART Yes Yes YesCompatible

FOUNDATION fieldbus No Yes YesCompatible

Wireless THUM NA Yes YesAdaptor compatible

Multi-lingual Menus Yes No Yes

Relays NA NA NA

PID Control No Yes/Ff Future/Ff

Advanced Diagnostics Yes Yes YesCapability

Area Class 1, Div. 1 Class I, Div. 1 & Div. 2, Class I, Div. 1 & Div. 2Classifications Explosion proof

Available Approvals CE, CSA, ATEX CE, FM, CSA, ATEX PendingSpectrum Approvals

Wireless instrumentation

Remote locations and engineeringcosts are no longer barriers togetting the process and diagnosticinformation you require for criticalapplications. Wireless can do thisefficiently and cost-effectively.•High accuracy and reliability for

monitoring and controlapplications

• Self-organizing network for highdata reliability and network stability

• Industry leading wireless security

Two-Wire instruments

The Model 5081 is for applicationsrequiring NEMA 7 housing for Class I,Div 1 and 2 explosion proof applica-tions.

The Model 1066 is a two-wire liquidinstrument with a broad range ofmeasurement parameters,advanced communications capabili-ty, and unique ease-of-use. TheRosemount Analytical Model 1066Transmitter is suitable for manyindustrial applications includingthose with exacting performancerequirements such aspharmaceutical and food and bever-age, and in difficult environmentssuch as chemical plants, metals pro-cessing, and effluent monitoring.

For host monitoring andconfiguration, the unit uses HARTversion 7 and Foundation fieldbusdigital communication protocols.

The large, easy-to-read display givesusers information on their processmeasurements at a glance. Thedisplay has user-definable measure-ment diagnostic parameters.

“The flexibility of Emerson’s self-organizingwireless technology makes it much easier totroubleshoot problems as well as evaluatenew applications.”

Jan HuijbenTechnochem

W I R E L E S S T WO -W I R E

91-6030 6.11

MORE ANALYTICAL SOLUTIONS FROMEMERSON PROCESS MANAGEMENTEmerson is the world’s largest provider of gas chromatography, process gas, combustion and environmental analysis solutions.

HEADQUARTERSEmerson ProcessManagementAnalytical Division2400 Barranca ParkwayIrvine, CA 92606T 949.757.8500T 800.854.8257F 949.474.7250

Emerson's Rosemount Analytical Liquid Division provides technologies and services for the analysis of liquid processes. For a wide range of applications,Emerson provides more than 60 years of expertise in high-precision analytical sensors, instrumentation and services. For information, call 800.854.8257.

Emerson Process Management, Rosemount Analytical, ENDURANCE and PUR-Sense are marks of Emerson Process Management group of companies. Allother marks are the property of their respective owners.

The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure its accuracy, they are not tobe construed as warranties or guarantees, expressed or implied, regarding the products or services described herein or their use or applicability. All sales aregoverned by our terms and conditions, which are available on request. We reserve the right to modify or improve the designs or specifications of suchproducts at any time without notice.

© Rosemount Analytical Inc. 2011. All rights reserved. Printed in the U.S.A.

Online ordering available.

www.raihome.com

ASIA-PACIFICEmerson ProcessManagementAsia Pacific Private Ltd.1 Pandan CrescentSingapore 128461Republic of SingaporeT 65.6.777.8211F 65.6.777.0947

EUROPEEmerson Process ManagementServices Ltd.Blegistrasse 21P.O. Box 1046CH 6341 BaarSwitzerlandT 41.41.768.6111F 41.41.761.8740

MIDDLE EAST AND AFRICAEmerson FZEP.O. Box 17033,Jebel Ali Free Zone - SouthDubaiUnited Arab EmiratesT +971.4 8118100F +971.4 8865465

GAS CHROMATOGRAPHY AND PROCESS GAS SOLUTIONSRosemount® Analytical is a leading supplier of analyzersand systems for process and environmental gas analysis.We offer an array of gas analysis solutions, including:

> Single- or multi-component process gas analyzers> Continuous emissions monitoring systems> Process gas chromatographs> Engineered systems> Custom service modules

Call 866.422.3683, or see us on the web atwww.raihome.com

COMBUSTION SOLUTIONSCombustion analysis needs to be accurate anddependable – all day, every day – or your operationsuffers. With the largest installed base of combustionanalyzers worldwide, Emerson Process Management istrusted more than any other company to deliverprovable, worry-free Rosemount® Analytical combustionanalysis solutions:

> In situ Flue Gas Oxygen Transmitters> O2 Combustibles Transmitters> Opacity Monitors> Carbon Monoxide Analyzers

Call 800.433.6076, or see us on the web atwww.raihome.com

LATIN AMERICAEmerson ProcessManagementAnalytical Division11100 Brittmoore Park Dr.Houston, TX 77041T 713.467.6000F 713.827.3329