Thioguard

®

Non-hazardous chemistry for municipal wastewater

Thioguard

Total System Treatment

® TST

Added directly to wastewater Thioguard stops odors, corrosion and grease buildup that cause blockages and sewer failures. And Thioguard is environmentally safe and improves wastewater treatment and discharge water quality.

Introduction

• Premier has been in the magnesia business for over 35 years. We’re the largest U.S. producer of magnesia chemicals.

• Premier R&D developed Thioguard ® magnesium hydroxide for municipal collection systems. • Major plants in Nevada and Florida.

• Seven hydration facilities across the U.S. AZ, CA, FL, NC, NV, PA, TX.

During the past 25 years regulatory changes have fundamentally altered the physical, chemical and biological properties of municipal wastewater.

20 10 0 1980 DISSOLVED SULFIDE VS. TOTAL METALS HYPERION WWTP

Me tal s Su lfid es

15 10 5 Corrosion Threshold 1985 1990 0 1995

In the year 2000 the EPA estimated that municipal sewers subject to corrosion are failing six times faster than the rate at which they are being rehabilitated.

By 2016 the EPA projects more than 50% of the country’s 600,000 miles of sewers will be in poor, very poor or inoperable condition.

Thioguard ® is a safe, cost saving and environmentally responsible chemical strategy which prolongs infrastructure life, manages wastewater odor, prevents plant upsets, improves treatment and enhances biosolids quality.

While there are many more, here’re three simple reasons to consider this straightforward technology

1.) Reduced Corrosion and Odor Raising wastewater pH from 7 to 8 eliminates hydrogen sulfide gas and extends the useful life of infrastructure subject to corrosion by over 80%.

Modes of Action:

Henry’s Law - Gas/Liquid Phase Equilibrium SRB Inhibition - Sulfate Reducing Bacteria Sulfide Complexation - Magnesium Polysulfide Saponification - Fat and Grease Reduction

H

2

S and Wastewater pH

6.00

5.00

4.00

3.00

2.00

1.00

0.00

3 H 2 S (g) H 2 S (aq) 4 5 6 pH 7 8 9 HS 400 200 10 0 1200 1000 800 600

Here’s what Thioguard does.

6.00

5.00

4.00

3.00

2.00

1.00

0.00

3 H 2 S (g) H 2 S (aq) 4 5 6 Wastewater pH 7 HS 8

> 80% Reduction

400 200 9 10 0 1200 1000 800 600

Corrosion Vs. Wastewater pH 14 12 10 8 6 4 2 0 5 5.6 6.1 6.4 6.7 7 0.5 mg/L 10 mg/L 7.3 7.6 7.9 8.2 8.5 8.8 9.5

pH 2.0 mg/L 15 mg/L 5 mg/L 20 mg/L

Corrosion and wastewater pH

pH/Conc 0.5 mg/L 2.0 mg/L 5 mg/L 10 mg/L 15 mg/L 20 mg/L 7 0.168

0.671

1.678

3.356

5.034

6.712

8 0.031

0.122

0.305

0.611

0.916

1.222

8.5

0.010

0.042

0.104

0.208

0.312

0.416

pH 7 to 8 is an 81.8 % reduction in corrosion rate. At 8.5, 93.8 % reduction .

Corrosion: A function of surface pH

Corrosion begins about pH 5 and increases Rapidly below pH 4.

At pH 2 cast concrete corrodes at about 1/4 inch per year.

5 4 3 7 6 2 1 0 0.001

0.01

0.1

0.25

1.0

Corrosion Rate (in./year)

Source L.A.County San District

Why Magnesia?

Property % Hydroxide Solubility

(H 2 O, g/100ml) Per million gallons

Reactive pH Freezing Point °F Weight Equivalency 50% NaOH 42.5

42 1750 tons 14 61 1.37

30% Ca(OH) 2 45.9

0.185

7.7 tons 12.5

32 1.25

60% Mg(OH) 2 60.3

0.0009

75 lbs 9.0

32 1

City of L.A. Sanitary District

Headspace Hydrogen Sulfide Before and After Thioguard 600 500 400 Average BeforeTHIOGUARD 281 ppmv 300 200 100 300 200 0 17:00 21:00

Data logged with an Industrial Scientific STX 70

1:00 Average After THIOGUARD 9 ppmv (97% Reduction) 100 5:00

Time of Day

9:00

Baseline H2S Gas

13:00 17:00 0

H2S Gas With Thioguard Addition

600 500 400

City of St. Petersburg, FL

Headspace Hyrogen Sulfide Before and After Thioguard

Before Thioguard After Thioguard

Sulfate reducing bacteria (SRB) operate best at pH 6.6 to 6.8. A small amount of Thioguard raises wastewater pH to 8.0 - 8.5 reducing the efficiency of the SRB’s and causing less sulfide to be produced.

SRB Growth

Unlike other alkali choices, Thioguard contains slowly dissolving Mg(OH 2 ) particles. These particles have high surface pH and high surface area, but relatively low solubility.

(Surface area = nearly 1 acre per gallon).

Undissolved magnesium hydroxide particles react directly with H 2 S converting H 2 S to magnesium polysulfide. High pH zone ~ 10.5

Slowly Dissolving Mg(OH) 2 Surface Particle

University Research

Controlling Hydrogen Sulfide In Wastewater Using Base Addition Matthew J. Higgins, Bucknell University R. Dwayne Myers, Bucknell University Nicolle M. Sprague, Bucknell University Kevin Barron, Bucknell University The Effect Of Cations On The Settling And Dewatering Of Activated Sludges Matthew J. Higgins and John T. Novak The Effect of Influent pH on Aerobic and Anaerobic Treatment Systems Matthew J. Higgins, Assistant Professor Ezra Yarnell, Graduate Research Assistant Department of Civil Engineering Bucknell University Lewisburg, PA Equivalent Addition Of NaOH, Ca(OH) 2 , And Mg(OH) 2 Effect of pH On Kinetics Of Sulfate Reducing Bacteria Matthew J. Higgins, Ph.D.

Assistant Professor Department of Civil Engineering Bucknell University

Dewatering And Settling Of Activated Sludges: The Case For Using Cation Analysis Matthew J. Higgins and John T. Novak The Release of Nitrous Oxide Due to Nitrate Addition to Wastewater Matthew J. Higgins, Ph.D.

Department of Civil and Environmental Engineering Bucknell University Lewisburg, PA 17837 Controlling Hydrogen Sulfide In Wastewater Using Base And Nitrate Addition Matthew J. Higgins, Dwayne Myers, Nicolle Sprague, and Kevin Barron Civil Engineering Department Bucknell University Lewisburg, PA, 17837 The Effect of Base and Nitrate Addition on H 2 S Production in Wastewater Matthew J. Higgins Assistant Professor Bucknell University

2.) Reduced FOG Buildup (Fats, Oils and Grease) A large percentage of wastewater collection blockages (even in mains) can be traced to FOG. Blockages are serious, causing sewage spills, manhole overflows, or sewage backups in homes and businesses. Mild saponification eliminates downstream FOG blockages and odor.

Before Treatment

After Treatment

3.) Reduced Plant Upsets and Improved Treatment Biological treatment plants and collection systems operate better with wastewater that has proper, stable pH, lower acidity and higher available alkalinity.

Benefits of Thioguard in Bio-Treatment

Biological Treatment Removal of organics Biological conversion of ammonia to nitrate Reduction of sludge mass and volume

Effect of Mg 2+ on Secondary Treatment



Mg

2+

affects bioflocculation or aggregation of microbes

Importance of Bioflocculation

- Bioflocculation Affects: 1. Floc Size 2. Floc Density 3. Floc Strength - These parameters are key to good settling and dewatering

Importance of Settling and Dewatering

• Settling Affects Overall Plant Efficiency - Effluent Suspended Solids - Effluent BOD • Most Effluent Problems Associated with Poor Settling • Dewatering is a Large Proportion of O&M Costs in Activated Sludge Plants

Divalent Cation Bridging Theory

• Negatively charged sites on exocellular biopolymer are bridged by divalent cations such as Ca 2+ and Mg 2+ • This bridging helps to stabilize the microbe biopolymer floc matrix

Divalent Cations Can be Displaced by Monovalent Ions

+ + + + + + +

Schematic of Floc Matrix

++ ++ ++ ++

Plant Benefits

Headworks Corrosion Odor Grease Primary Treatment Settling Corrosion Odor Metals Removal BOD 5 COD

Plant Benefits

Biological Treatment pH Stability Nitrification MLSS MLVSS Energy Costs Secondary Treatment RAS Corrosion Odor Floc-formation Microbe Nutrition/Activity Filamentous Bulking Cation Balance Dewatering Corrosion Odor Polymer Use TSS BOD 5 pH Stability SVI COD

Plant Benefits

Digestion Alkalinity Microbe nutrition pH Stability Gas Production Corrosion Dewatering Phosphorus Sludge Conditioning Biosolids Quality SAR Disinfection Effluent Chlorine Demand Alkalinity TSS TDS Recycling Residual Chlorine

This one simple strategy provides:

System Wide Corrosion Control System Wide Odor Control Treatment Enhancement

Effluent Quality and Plant Capacity BOD, COD, SVI, TSS, MLSS, MLVSS, RAS, DOC

Better Biosolids Volume and Disposal Improved Safety and Environmental Compliance

Relative Chemical Costs

Thioguard 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Peak Sulfide Concentration (mg/l)

Thioguard

®

Total System Treatment

TST

Biosolids

For more information visit: www.thioguard.com