Chemical Feed & Disinfection

Page 1 Strantrol_2008.ppt Water TechnologiesProtection notice / Copyright notice

Siemens Water Technologies

Strantrol®Control SystemsChemical Feed & Disinfection – Municipal

For internal use only / Copyright © Siemens AG 2006. All rights reserved.


Today, disinfection and dechlorination in water can beprecisely controlled by High Resolution Redox® (HRR)a result of Siemens’ research.

In applications worldwide, HRR®

sensing is used to control the addition of chlorine, bromine, ozone, sulfur dioxide, sodium metabisulfite and sodium bisulfite.

Overview of Contents

Contents§ Introduction 3§ Technical Overview 5§ Product Portfolio 26§ Municipal Applications 34§ Implementation 38§ Service Capabilities 50§ References 53


Siemens – Innovation to Change

From the invention of the dynamo – to the world's most efficient gas turbines

Healthcare

Industry

Energy

From the first electronic controls – to fully automated factories

From the first views inside the body – to full-body 3D scans


Siemens Water Technologies

CF&D Global Headquarters – Vineland, New Jersey

Chemical Feed & Disinfection (CF&D) Group

§ Comprised of Wallace & Tiernan® and Stranco® products

§ In 2006, acquired ALTIVIA chlorine dioxide and Sunlight UV


Successful Disinfection:

Sufficient Quantity = Residual

+

Sufficient Time = Contact Time

A FEW ADDITIONAL FACTORS TO CONSIDER ABOUT DISINFECTION:

§ What is Required for Compliance?§ ORP vs. PPM§ Basic Process Chemistry§ Work Value Relationship of Your

Oxidant§ Benefits of the DOCS Hybrid Control

Technology

Strantrol®

Control Systems

Technical Overview


Technical Overview

Residual Control

§ All the measurements for residual only give the quantitative picture.

§ Typically measure chlorine residual in ppm.

EPA Observations“Chick’s Law does not accurately predict coliform numbers as a function of dose in the real-world, continuous flow systems….The observation has frequently been made that inactivation of organisms in batch experiments, even when the disinfectant is kept constant, does not follow the exponential decay pattern predicted”


00.20.40.60.8

11.21.41.61.8

2

1 2 3 4 5 6 7 8 9 10

Time

00.20.40.60.8

11.21.41.61.8

2

1 2 3 4 5 6 7 8 9 10

ORPORP Free ResidualFree Residual

Technical Overview


fecal coliform

time time

chlo

rine

resi

dual

fecal coliform

chlo

rine

resi

dual

Technical Overview

Disinfection Performance


Time ( 4 hours )

Free

Cl 2

( 0 -

3 pp

m )

+

++

+

+ +

+

+

+

++

+ +

+

+

+

+

Technical Overview

50% Correlation to kill


Time

OR

P ( 2

00 -

800

mV

)

+

++

+

+

++ +

+ + ++ +

Technical Overview

97% Correlation to kill


ClCl22 + H2O HCl + HOCl(Strong Acid + Weak Acid)

HOCl H+ + OCl-(Weak Acid Dissociates)

NaOClNaOCl + H2O NaOH + HOCl(Strong Base + Weak Acid)

HOCl H+ + OCl-(Weak Acid Dissociates)

Technical Overview

Basic Chlorine Chemistry


Typical pH Values

Free Residual measurement remains constant

6.5 7.0 7.5

92% 78% 50%

HOCl OCl-

Technical Overview


Typical pH Values

ORP Value Decreases

6.5 7.0 7.5

92% 78% 50%

HOCl OCl-

Technical Overview


Work Value of Chlorine Species

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

HOCl

Dichloramine

MonochloramineMonochloramine

TrichloramineTrichloramine

OClOCl

OrganochloramineOrganochloramine

Technical Overview


Wastewater Chlorination Chemistry

Inorganic Nitrogen

§ Ammonia

§ Nitrites

§ Nitrates

Organic Nitrogen

§ Amino Acids

§ Proteins

Technical Overview


Technical Overview

Relationship Between Ammonia and Free Chlorine Residual


Technical Overview

Chloramines Exhibit Lower ORP Values


Wastewater Chlorination Chemistry§ Oxygen

§ Alkalinity Cause

§ Temperature Nitrification/Denitrification

§ pH Episodes

§ Time

§ Loading

Nitrification:Oxidation of ammonium ion or ammonia to nitrite or nitrate ion. How ammonia affects the water chemistry and the disinfection process

Technical Overview


Technical Overview

Sensor Reads Both Sides of Zero

§ Overfeed looks at sulfite residual

§ Notice what’s going on near 0 mg/L

All the measurements for ORP givethe qualitative picture; i.e. therelative strength of disinfectant forbug kill.


Breakpoint Chlorination

Cl2 to NH3-N Ratio

7.65

NH3-N Conc.

Total ChlorineApplied

MeasuredChlorineResidual A

mm

onia

-N C

onc.

ppm

Chl

orin

e C

onc.

ppm

Breakpoint

Hump

Technical Overview


Technical Overview

Oxidative Disinfection

§ All oxidative disinfection can be measured and controlled by itsOxidation Reduction Potential.

§ Track & maintain the effectiveness of the disinfection program to ensure desired results.

§ Track & maintain the dechlorination process to maintain tight discharge limits.

Hypochlorite, gas chlorine, chlorine dioxide & ozone.


Typical Installation – Strantrol® 960

Implementing Strantrol®


Strantrol® 960 Design Philosophy

§ A new level of process and disinfection control§ Smooth transition through process changes§ Integrated software and control functions§ New Slo-logic § Window to upstream processes

Combine quantitative value of residual (PPM) with qualitative value of ORP (HRR)

Technical Overview


Strantrol® 960 Design Philosophy§ Any parameter change requires an offsetting change of another

parameter § Integrated software to evaluate and make required changes

based on actual conditions

Sufficient Quantity = Residual+

Sufficient Quality = ORP+

Sufficient Time = Contact Time

Technical Overview


Strantrol® 960 Control Capabilities

ORP

Residual

Fixed RateOutput

Flow Pace

Technical Overview


Strantrol® Controllers

§ High Resolution Redox® (HRR)§ Submersible Sensors§ Strantrol 880§ Strantrol 890§ Strantrol 960 (DOCS®)§ Strantrol FVC

Portfolio


High Resolution Redox® (HRR)

§ High purity platinum tip§ Porous Teflon® liquid junction§ Fouling resistant electrolyte gel§ Measures oxidant/reductant activity§ Precise disinfection control


Strantrol® Submersible Sensors


Strantrol® 880 Transmitter

§ Signal transmitter§ Stand-alone monitor§ RS-232 / RS-485 communication§ ORP or pH input§ 4-20 mA output


Strantrol® 890 Controller

§ Single channel controller§ ORP or pH§ 5 control modes§ 4 line / 20 character display§ Data logging§ Optional modem§ Open channel or closed loop

applications

Documents

Chemical Feed & Disinfection