Turbiditate

7/28/2019 Turbiditate

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--Turbidity is the optical property that causes light to be

lines through the sample.

.


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MUNICIPAL

Water Treatment Plants

Wastewater Treatment Plants

INDUSTRIAL

Metals and Mining

Chemical Processing

Pulp and Paper

Power

Food and Bevera e

Pharmaceuticals


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Plant Goal: Provide a Source of Safe and Reliable Drinking

.

Harmful Microorganisms Are Removed by a

Turbidity Measures the Adequacy of the Filtration

Why Measure Turbidity?

on or an mprove an c ency

Detect Filter Breakthrough Meet Regulatory and Governmental Requirements


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--Two Design Methods For Reporting Turbidity:

.

International Standards (ISO 7027)

Comparison of USEPA 180.1 and ISO 7027 Method

Item EPA 180.1 ISO 7027

Light Source Tungsten LampLED or Other

Filtered Source

Wavelength 400-600 nm 860 30 nm

Characteristics

Long Warm Up

Time Low Stray Light

More sensitive to

Smaller Particles

Less Sensitive to

Smaller Particles

Color Interferences

Interferences


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---- Different Units

NTU: Nephelometric Turbidity Units

FTU: Formazin Turbidity Units

FNU: Formazin Nephelometric Units

These Units, NTU, FTU, and FNU are Equivalent

Formazin is the Polymer Suspension Used to CalibrateTurbidity Sensors

Turbidity is Determined in a Nephelometric Instrument,

and Measures the Light that is Scattered at 90 from theLight Source


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Total Suspended SolidsTotal Suspended Solids -- DefinitionDefinitionTotal Suspended SolidsTotal Suspended Solids -- DefinitionDefinition

Definition:

A Measure of the Total Mass of Particles in a Sample

Determination of TSS: Filtering a Volume of Sample and Weighing the Mass of the

Dried Residue Retained on the Filter

e aue s acua e rom e ur yMeasurement

the User

,


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Turbidity is not the same as total suspended solids (TSS)

Both Turbidity and TSS Are Defined by the Method Used to MeasureThem

Filterable Material in the Sample

Turbidity is an Optical Measurement; it Depends on the Number of

For 100 mg of solid

particles in 1 L

TSS is 100 m /L.

TSS is st ill 100 mg/L.

Turbidity is different:

since there are more

Turbidity has

a certain value

particles and smaller

in size.

in half


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Turbidity Depends on:

Number of Particles Per Volume

ze o ar c es

Wavelength of Light Used for Measurement

Color of Particles

Refractive Index of Particles Presence of Air Bubbles


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Wine of Beer Was Determined by

Source and Look for SmallParticles.


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Size: Smaller Thank 1/10 the Size: Approximately 1/4 the

Description: Symmetric

Description: Scattering Concentratedin Forward Direction

Large Particles


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Light

Light Scattered

by Particles

Transmitted

Source

Light

Scattered

Light at 90

DetectorTurbidity is the measure of the amount of light scattered by

particles in a sample. A beam of light passes through a samplecontaining suspended particles. The particles interact with the

light and scatter the light. A detector at 90measures theintensity of the scattered light.


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u yu y -- ..Collimator

Transmitted

Light

Scattered Li ht at 90

LightSource

Optical Filter

DetectorEPA Method 180.1 requires:

1. Tungsten Lamp Light Source with Filament Temperature Between 2200 - 2700 K3. Detector Response Between 400 and 600 nm

4. Scattered Light be Measured at 90 30

5. Total Path Length Through Sample Less Than 10 cm


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u yu y --

TransmittedLight

LightScattered Li ht at 90

DetectorISO Method 7027 requires:

1. The Wavelength of the light to be 860 nm 30 nm2. The Measuring angle to be 90 2.5

3. Light Source Using a Laser, LED, or Tungsten Filament Lamp with Filter


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Complete System Sin le or Dual Sensor In ut

Debubbler/Measuring Chamber

USEPA Method 180.1 or ISO Method ISO 7027

0 - XXX NTU Range

Resolution X.XXX NTU

Analyzer

Suitable for Wastewater / Discharge / Industrial /rocess a er pp ca ons


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Turbidity Sensor

Debubbler/Measurement Chamber


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Three Turbidity Calibration Methods:. ser repare o u on

2. Commercially Available Standard Solution3. Comparison with a Referee Turbidity Instrument

Note: The USEPA Does Not Recommend Calibrating an On-line Turbidityme er y omparson w a enc e e

Dry Calibration Standard Available for Checking the Performance

Total Suspended Solids Calibration Method:

Enter an Equation into the Analyzer to Convert Turbidity to a TSSReading


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Turbidity Sensor

Debubbler/Measurement Chamber


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Not Not

Recommended Good BEST METHOD!

Sample Line

Sample Line Sample Line

(water)

(water)

(water)

(water)

Sediment Sediment Sediment Sediment

Process PipeProcess Pipe Process PipeProcess Pipe


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Quantity of analyzers depends

on w e er e wa er use s

in a closed circuit or from a

once-through natural source

Turbidity


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--Polymer

Chlorine

Addition

Turbidity monitors the

River WaterOr GroundWater

present

Sludge

To CoolingSystem

TClT

ar er

Turbidity monitorsfor particulatebreakthrou h


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CausticFerric

Tank

Clarifier

or e

Tank

Industrial

Waste Water

further

T

CleanWater

rea men

pH

Flocculants are used to remove

suspended solids from water. slime Optimum removal depends on pH.

Turbidity is used to control addition ofto landfill


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Overview

Efficiency reductions and equipment failures due

to corrosion and deposition cost the power

indust ry billions of dollars every year.

Good water chemistry can help to

mitigate some of these effects

and is best achieved with

online liquid analysis

and control.

ApplicationsDemineralization (Make-up Water)

Condensate Returns

Cooling Water Systems

Scrubbers

Waste Treatment

MeasurementsConductivity, Cation Conducitivity,

pH & ORP, Dissolved Oxygen,

Chlorine, Ozone, Turbidity,

Silica, Sodium, Phosphate,

Hydrazine


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--

Plant IntakeSettling basinFilter wastewater backwash

Filter bed effluent (individual and combined)


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Two USEPA Rules to Monitor Turbidity for Drinking Water Treatment Plants--. ,

Combined Filter Effluent (CFE) Water Turbidity:


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--Second Rule ..

2. Plants Serving


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--Regulations for Turbidity Requirements for Drinking WaterTreatment Plants Outside the USA

These Plants Have Either ...

Adopted the USEPA Standards,

Developed Their Own Regulations, o Follow the World Health Organization (WHO)

Recommendations of 1 NTU


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