Thioguard ® TST A common sense solution for wastewater management October 28, 2005

It is an environmentally safe, less expensive replacement for caustic soda that provides many valuable benefits in wastewater collection and treatment. Mg(OH) 2 Produced from natural deposits or extracted from seawater, Thioguard solves many of the problems facing wastewater professionals today. Thioguard is a registered trademark of Premier Chemicals and is patented for use in municipal collection systems under U.S. patent numbers: 5,718, ,833, ,554, ,834,075, 6,056,997 Thioguard is a registered trademark of Premier Chemicals and is patented for use in municipal collection systems under U.S. patent numbers: 5,718, ,833, ,554, ,834,075, 6,056,997 Thioguard is Mg(OH) 2, milk of magnesia.

We’re an industry leader in the production and application of Magnesia Specialty Chemicals. Premier has been in the business for over 50 years.

Headquarters Philadelphia, PA Manufacturing Facilities   Port St. Joe, FL   Gabbs, NV   Brownsville, TX   York, PA Toll Manufacturing   Santa Fe Springs, CA   Phoenix, AZ   New Bern, NC Sales Office Cleveland, Ohio Headquarters Philadelphia, PA Manufacturing Facilities   Port St. Joe, FL   Gabbs, NV   Brownsville, TX   York, PA Toll Manufacturing   Santa Fe Springs, CA   Phoenix, AZ   New Bern, NC Sales Office Cleveland, Ohio Premier Chemicals Locations

Biological, Chemical and Bio-chemical Interactions and Mechanisms The Culmination of 20 Years of Magnesia Field Application and Research in Wastewater Treatment Thioguard ® TST

In general, municipal wastewater treatment plants and collection systems operate better under proper, stable pH with lower acidity and adequate alkalinity.

Alkalinity contributes to the properties of wastewater, many of which positively affect the physical, biological and chemical processes required for treatment. For example…

NitrificationNitrification Every molecule of ammonia-N requires one molecule of alkalinity. 1 mg/L NH 4 -N = 7.14 mg/L CaCO 3 = 5.50 mg/L NaOH = 5.50 mg/L NaOH Every molecule of ammonia-N requires one molecule of alkalinity. 1 mg/L NH 4 -N = 7.14 mg/L CaCO 3 = 5.50 mg/L NaOH = 5.50 mg/L NaOH

Acidity, Alkalinity & pH

The term “pH” stands for the “power of Hydrogen” pH is a measurement of the free hydrogen ion in a solution. pH = -log [H+] pOH = -log[OH-] pH + pOH = 14

1A 37 Rb 38 Sr 11 Na 12 Mg 3 Li 4 Be 19 K 20 Ca 1 H 2A Sodium AN 11, AM Magnesium AN 12, AM Potassium AN 19, AM Calcium AN 20, AM Commercial Sources of Alkalinity (OH - ) Na, Ca, Mg and K Commercial Sources of Alkalinity (OH - ) Na, Ca, Mg and K Monovalent Divalent NaOH KOH NaOH KOH Mg(OH) 2 Ca(OH) 2 Mg(OH) 2 Ca(OH) 2

Caustic Soda – NaOH Despite hazardous handling, environmental concerns, and wide price fluctuations, it has been the most commonly used acid neutralization reagent for industrial or municipal purposes. NaOH has been favored for ease of application and soluble by-products. Lime Slurry - Ca(OH) 2 Commonly used for settling, alkalinity, metals removal, and biosolids handling. Limited because of hazardous handling, equipment requirements and insoluble by-products. Not recommended for municipal wastewater addition. Magnesium Hydroxide - Mg(OH) 2 “Milk of Magnesia” is a safe, cost-effective alternative to caustic soda and lime. Safer handling, better cost stability, soluble by-products and measurable benefits increase its attractiveness for wastewater applications compared with NaOH and lime. Caustic Soda – NaOH Despite hazardous handling, environmental concerns, and wide price fluctuations, it has been the most commonly used acid neutralization reagent for industrial or municipal purposes. NaOH has been favored for ease of application and soluble by-products. Lime Slurry - Ca(OH) 2 Commonly used for settling, alkalinity, metals removal, and biosolids handling. Limited because of hazardous handling, equipment requirements and insoluble by-products. Not recommended for municipal wastewater addition. Magnesium Hydroxide - Mg(OH) 2 “Milk of Magnesia” is a safe, cost-effective alternative to caustic soda and lime. Safer handling, better cost stability, soluble by-products and measurable benefits increase its attractiveness for wastewater applications compared with NaOH and lime. Commercially Available Options

Solubilities and Stoichiometry 2NaOH  2Na + + 2OH - 2(40) g/mol  2(23) g/mol + 2(17) g/mol 2(40) g/mol  2(23) g/mol + 2(17) g/mol Typical Dosage: 68.5 mg/L 100% Solubility  High pH triggers carbonate formation and bacterial kills Ca(OH) 2  CaOH + + OH -  Ca OH - (74) g/mol  (57) g/mol + (17) g/mol  (40) g/mol + 2(17) g/mol (74) g/mol  (57) g/mol + (17) g/mol  (40) g/mol + 2(17) g/mol Typical Dosage: 63.5 mg/L 100% Solubility  High pH triggers carbonate formation and bacterial kills Mg(OH) 2  MgOH + + OH -  Mg OH - (58) g/mol  (41) g/mol + (17) g/mol  (23) g/mol + 2(17) g/mol (58) g/mol  (41) g/mol + (17) g/mol  (23) g/mol + 2(17) g/mol Typical Dosage: 50 mg/L 18% Solubility  Moderate pH favors bicarbonate formation and bio-stability For 50 mg/L Mg(OH) 2 Equivalence:

Properties of Bases Property50% NaOH30% Ca(OH) 2 60% Mg(OH) 2 % Hydroxide Solubility (H 2 O, g/100ml) Per million gallons 1750 tons 7.7 tons 75 lbs Reactive pH Freezing Point °F Weight Equivalency Mg(OH) 2 provides non-toxic, non-carbonate source of slowly released (on demand) alkalinity

One Truckload of 50% Thioguard One Truckload of 50% Thioguard 1.37 Truckloads of 50% NaOH 1.37 Truckloads of 50% NaOH 1 Ton of Thioguard = 1.37 Tons of Caustic Soda At say $400/ton, Thioguard costs $292 on an equivalent use basis. It’s not only less expensive, it provides many more benefits.

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).

High pH zone ~ 10.5 Slowly Dissolving Mg(OH) 2 Particle Surface Undissolved magnesium hydroxide particles react directly with H 2 S converting H 2 S to magnesium polysulfide.

NitrificationNitrification Every molecule of ammonia-N requires one molecule of alkalinity. 1 mg/L NH 4 -N = 7.14 mg/L CaCO 3 = 5.50 mg/L = 5.50 mg/L NaOH = 4.16 mg/L Mg(OH) 2 = 4.16 mg/L Mg(OH) 2 Every molecule of ammonia-N requires one molecule of alkalinity. 1 mg/L NH 4 -N = 7.14 mg/L CaCO 3 = 5.50 mg/L = 5.50 mg/L NaOH = 4.16 mg/L Mg(OH) 2 = 4.16 mg/L Mg(OH) 2

Caustic Soda Addition pH distributions across a basin are less stable and contribute to variability away from optimal biological operating conditions. Because it is highly soluble, caustic causes “HOT” zones near the addition point.

With Thioguard With Thioguard, an even distribution of alkalinity and pH balance provides a bacteria friendly working environment.

Added directly to wastewater it stops odors, corrosion and grease buildup (FOG) that cause blockages (SSO’s), and sewer failures. Thioguard ® Total System Treatment And Magnesia is environmentally safe, saves chemical costs, improves wastewater treatment and discharge water quality. And Magnesia is environmentally safe, saves chemical costs, improves wastewater treatment and discharge water quality.

Collection System Odors Corrosion Fats, Oils, Grease Headworks Bar Screen Grit Chamber Odors Corrosion Aeration Basin Bio-Reactor Primary Clarifier Odors Corrosion Settling FOG ADD THIOGUARD TST Secondary Clarifier Process Efficiency Capacity Odors Corrosion Settling FOG Disinfection Effluent Odors, Corrosion Chemical Efficiency UV Efficiency Digestion Bio-Solids Processing Odors Corrosion Process Odors Dewatering Conditioning Disposal Land Application When added in the collection system, Thioguard TST can reduce odors and corrosion system-wide and improve overall treatment plant performance. SAR Plant Efficiency Scrubbers/ Filters Odors Chemicals Energy Typical Wastewater Treatment Concerns WATER SOLIDS AIR

 Odors  FOG  Loading control  Aeration  Foaming  SVI (filaments)  Effluent quality  Clarifier denitrification  Odors  FOG  Loading control  Aeration  Foaming  SVI (filaments)  Effluent quality  Clarifier denitrification  Inhibited nitrification  Filter performance  Chlorine demand  Stable disinfection  Improves digestion  Biosolids handling and disposal cost  Energy cost  Inhibited nitrification  Filter performance  Chlorine demand  Stable disinfection  Improves digestion  Biosolids handling and disposal cost  Energy cost Benefits To The Plant

  Without Thioguard FOG Accumulation Odors Pin Floc Floc Carryover High MLSS High VSS%   Without Thioguard FOG Accumulation Odors Pin Floc Floc Carryover High MLSS High VSS%   With Thioguard Reduced FOG Marked Odor Decrease Better Clarification and Settleability Improved VSS Reduction Increased Sludge Blanket Density Improved O 2 Efficiency   With Thioguard Reduced FOG Marked Odor Decrease Better Clarification and Settleability Improved VSS Reduction Increased Sludge Blanket Density Improved O 2 Efficiency

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

Mg 2+ affects bioflocculation or aggregation of microbes.

Divalent Cations Compete With Monovalent Ions For Sites on Exocellular Biopolymers

Divalent Bridging Improves Floc Matrix ++ +

FOG Floating on the water surface, low density FOG’s are less accessible to bacteria for digestion. Broken down into glycerols and organic salts by Thioguard, FOG’s are more evenly distributed throughout a body of water and more accessible to bacteria. NOTE: Excess pH during the saponification process can lead to insoluble soap salts. Floating on the water surface, low density FOG’s are less accessible to bacteria for digestion. Broken down into glycerols and organic salts by Thioguard, FOG’s are more evenly distributed throughout a body of water and more accessible to bacteria. NOTE: Excess pH during the saponification process can lead to insoluble soap salts.

Saponification CH2 RCO- O || R’CO- O || R”CO- O || FATTY ACID OH- GLYCEROL CARBOXYLATE SALTS - SOAP TG HYDROXYL IONS Thioguard slowly releases hydroxyl ions which breakdown low-density, large-chain fatty acids (FOG) into glyerol and various types of soap, both of which are more readily digested by bacteria in wastewater. The soaps that are produced further facilitate the breakdown of accumulated blankets by solubilizing FOG’s. Low-density, long-chain fatty acids accumulate on the water surface of low velocity structures and can build up on pipe walls causing occlusion and eventually SSOs.

FOG causes odor, increases maintenance costs and contributes to SSO’s.

Most systems require only 30 Gal/MGD for adequate treatment.

*American Society Of Civil Engineers “U.S. Water Infrastructure Needs” 3/28/01 American wastewater systems currently require $12 billion* a year more than available funds to replace failing infrastructure. And the shortfall is increasing every year…

In 1977 the clean water act increased treatment requirements for municipal wastewater.

This legislation required secondary treatment and it has contributed to subtle, but important changes in wastewater chemical needs.

Data provided by the City of Los Angeles Data courtesy of the City of L.A., CA More Corrosion Today, wastewater infrastructure is often subject to about one order of magnitude more acid corrosion than before 1980.

In 2000 the EPA estimated municipal sewers subject to corrosion were failing six times faster than the rate they’re being repaired.

By 2016 the EPA now expects more than 50% of the country’s 600,000 miles of major sewer lines will be in poor, very poor or inoperable condition. Tucson, Arizona

Other bacteria present in the water convert sulfates to sulfides. This causes the rotten egg smell, hydrogen sulfide gas (H 2 S). When the dissolved oxygen concentration falls below 0.1 mg/l, the water becomes septic. H 2 S Gas pH ~ 7 D.O.<0.1 mg/l Bacteria in the wastewater consume oxygen. O2O2 O2O2 O2O2 Sewer Wastewater Bacteria

SO HS - H2SH2S H2SH2S H 2 S Gas H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S In water at pH 7, about 50% of the dissolved sulfide converts to H 2 S gas. Skip

And virtually nothing is being done to stop it from happening. On the surfaces above the water, H 2 S gas is converted to strong sulfuric acid by Thiobacillus bacteria. This acid corrosion, not “aging”, then dissolves the infrastructure. SO HS - H2SH2S H2SH2S H2SH2S Thiobacillus + O 2 = H 2 SO 4 Acid Attacks Concrete

Collapses routinely occur when preventable corrosion is allowed to continue unchecked. SO HS - H2SH2S H2SH2S H2SH2S + O 2 = H 2 SO 4 Acid Attacks Concrete Once rebar is exposed, the sewer is structurally compromised.

Corrosive surface conditions are can easily be detected using a simple, inexpensive surface pH test.

Unfortunately, it is rarely being done. Rather, most cities implement expensive CCTV, coring and capital intensive system evaluations.

Take home message…

Surface pH tells the whole … Surface pH tells the whole story…

Red is bad, green is good. 7= Neutral Above 7 = Basic Below 7 = Acidic

Source L.A.County San District Corrosion Rate (in./year) pH Corrosion Range years Years of Life (2” of sacrificial concrete) 100 Surface

Surface pH ≥ 4; Life Cycle = 100 yrs Sewer design life is generally based on 100 years of useful service.

Source L.A.County San District Corrosion Rate (in./year) pH Corrosion Range years of useful life 8 years Years of useful life >200 years of corrosion life

When the surface pH falls below four, sewer life cycle costs increase exponentially… 1250% For example, the difference in annual cost between surface pH 4 and 2 is…

Surface pH of two or lower is now common. But most cities (or consulting firms) don’t measure for it.

Red is bad, green is good. What color is your system?

SO HS - H2SH2S H2SH2S H 2 S Gas H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S Recall this slide showing the relationship between wastewater pH and hydrogen sulfide gas?

Wastewater Mg(OH) 2 (S)  Mg OH - OH - causes a shift in the soluble sulfide equilibrium: H 2 S  H + + HS - The amount of gas produced is affected by the wastewater pH. Higher pH = less gas.

Hydrogen Sulfide Performance H 2 S Gas X X Thioguard X Mg(OH) 2 addition

Corrosion which limits system life expectancy X X Thioguard X Thioguard extends the useful life of the system while controlling odors and FOG

Typical Reduction in Hydrogen Sulfide Gas

Corrosion Rate Vs. Wastewater pH With Thioguard > 80% Less Corrosion Corrosion Without Thioguard

The Benefits of Thioguard Addition Safety and Compliance Safety and Compliance System Wide Odor Control Treatment Enhancement Effluent Quality and Plant Capacity - BOD, COD, SVI, TSS, MLSS, MLVSS, RAS, DOC Biosolids Volume and Disposal Biosolids Volume and Disposal System Wide Corrosion Control System Wide FOG Control

Approximately 150 direct addition sites. In the greater Los Angeles area alone, Thioguard is used to treat nearly 200 million gallons per day

Thioguard has proven cost effective and has now been accepted for wastewater system treatment by over 60 cities across the U.S.

Thioguard is safe for personnel, the environment and the wastewater system.

Thioguard ® TST