Nonoxidizing Biocides by xl771209

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									Nonoxidizing Biocides, Thermal Shocking, Desiccation, Oxygen Deprivation, Carbon Dioxide and Low Frequency Agitation
Robert F. McMahon Department of Biology The University of Texas at Arlington Arlington, Texas 76019

What is a Nonoxidizing Molluscicide?

• • • •

A molluscicide which does not act as a chemical oxidant Does not induce corrosion of metallic surfaces Organic or metallic molluscicides Typical oxidizing molluscicides • Chlorine, Sodium Hypochlorite • Chlorine dioxide • Chloramine • Bromine • Bromine, Bromine/Chlorine • Ozone • Potassium Permanganate, • Hydrogen peroxide

COMMERCIAL NONOXIDIZING MOLLUSCICIDES
Poly[oxyethlene(dimethyliminio)ethylene (dimethylimino)ethylene dichloride] Bulab 6002 (Buckman Laboratories) 0.5 ppm for 826 h - 100% Adult Mortality 2 ppm for 313 h - 100% Adult Mortality 8 ppm for 197 h - 100% Adult Mortality 2-(Thiocyanomethythio)benzothiazole Bulab 6002 (Buckman Laboratories) 0.5 ppm for 758 h - 100% Adult Mortality 2 ppm for 313 h - 100% Adult Mortality 4 ppm for 260 h - 100% Adult Mortality Didecyl dimethyl ammonium chloride H-130 (Calgon) 1 ppm for 24 h - 100% Adult Mortality N-alkyl dimethyl benzyl ammonium chloride &Dodecylguanidine hydrochloride Clam-trol - 1 or CT-1 (Betz Industrial) 15 ppm for 12 h at 11°C - 100% Adult Mortality after 48 h 15 ppm for 14 h at 14°C - 100% Adult Mortality after 48 h 15 ppm for 6 h at 20°C - 100% Adult Mortality after 24 h 15 ppm for 14 h at 20°C - 100% Adult Mortality after 48 h

N-alkyl dimethyl benzyl ammonium chloride Clam-trol-2 or CT-2 (Betz Industrial) 2-5 ppm applied for 6-24 h - 100% Adult Mortality N-alkyl dimethyl benzyl ammonium chloride Clam-trol - 4 or CT-4 (Betz Industrial) 13 ppm for 72 h at 5° or 10°C - >90% Adult Mortality 13 ppm for 48 h at 15°C - 100% Adult Mortality 13 ppm for 12 h at 20°C - 90% Adult Mortality Akyldimethylbenzyl ammonium chloride & Akyldimethylethylbenzyl ammonium chloride Mactrol 9210 (Nalco) 0.5 ppm for 249 h at 18°C - 100% Adult Mortality 0.5 ppm for 120 h at 22°C - 100% Adult Mortality 2.0 ppm for 65 h at 18°C - 100% Adult Mortality 2.0 ppm for 45 h at 22°C - 100% Adult Mortality

Compound with Primary and Secondary Aminated Carbon Chains Mexel 432 (Mexel) 2 ppm for 1.5h/day for 30 days - 40% Adult Mortality 10 ppm for 1.5 h/day for 30 days - 62-77% Adult Mortality
Dichloro-2'nitro-4' salicylanilide Bayluscide (Bayer) 0.05 ppm for 24 h - 70% Adult Mortality 0.1 ppm for 24 h - 100% Adult Mortality

N-triphenylmethyl-morpholine Frescon (Shell) 0.5 ppm for 24 h - 70% Adult Mortality 0.9 ppm for 24 h - 100% Adult Mortality
Benzalkonium chloride (Fish Culture Disinfectant) 10 ppm for 20 min - 43% Veliger Mortality after 24 h 100 ppm for 20 min - 80% Veliger Mortality after 24 h 1000 ppm for 20 min - 100% Veliger Mortality after 24 h Tert-butyhydroxyquinone in paints TBHQ Can reduce but not eliminate settlement Butylated Hydroxytoluene in paints BHT Can reduce but not eliminate settlement Surfactant Agent TD-2335 (Elf Atochem North America) 1-1.5 ppm for 6-8 h - 100% Adult Mortality 48 hr LC50 = 0.48 ppm (juveniles), 0.59 ppm (adults)

1,1'-(Methyliminio)bis(3-chloro-2-propanol), polymer with N,N, N',N'-tetramethyl1,2-ethanediamine Bulab 5001 (Buckman Laboratories) 3 ppm for 1295 h at 20°C - 100% Juvenile Mortality 9 ppm for 346 h at 20°C - 100% Juvenile Mortality 3 ppm for 1295 h at 20°C - 100% Adult Mortality 9 ppm for 633 h at 20°C - 100% Adult Mortality Petroleum Jelly, Lanolin, Zinc oxide, Talc, Petroleum distillates (Major ingredients), Panthenol, Sorbitan sesquioleate, cetylridinium chloride, Allantoin, Witch Hazel (Minor ingredients) Penaten-Creme (Johnson and Johnson Co.) Diaper ointment used in Europe as an antifoulant compound. Inhibits adult mussel byssal re-attachment and pediveliger initial attachment Aluminum sulfate (Alum) Al (SO ) Copper sulfate in Solution CuSO 100 ppm for 5 h at 22.5°C - 40% Adult Mortality 300 ppm for 5 h at 22.5°C - 55% Adult Mortality

Tri-butyl tin oxide Applied in Surface Coatings Every 1-2 Years Inhibits Settlement (Not generally permitable) Zinc Hot Metal Spray, in Paints or Galvanization Inhibits Settlement Copper Hot Metal Spray, in Paints or Galvanization Inhibits Settlement Ions in solution (cathodic release) 5 ppm for 24 h - 100% adult kill Potassium ion in solution As 160-640 ppm KH PO - 100% Veliger Mortality As 10 ppm KOH - 100% Veliger Mortality As 50 ppm KCl - 100% Adult Mortality

NONCOMMERCIAL NONOXIDIZING MOLLUSCICIDES
Saponin Compounds Extracted from the Berries of the African Soapberry Plant Endod 15 ppm continuously applied - 100% Adult Mortality Alkaloid Extract of Capsaicin Pepper Plants Capsaicin

20.1±1.10 µM continuous - 90% inhibition of byssal attachment without mortality N-vanillylnonanamide 25.4±5.3 µM for 48h - 90% inhibition of byssal attachment without mortality
N-benzoylmonethanolamine benzoate 58.4±4.6 µM for 48 h - 90% inhibition of byssal attachment without mortality (+)-Butanedioic acid, Mono[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)2H-1-benzopyran-6-yl]ester 50 ppt for 48h – Inhibits byssal attachment (+-)-3,4-Dihydro-6-hydroxy-2,5,7,8-tetramethyl-2H-1-benzopyran-2-carboxylic acid 50 ppt for 48h – Inhibits byssal attachment (Poly-N-acetyl--D-glucosamine)-protein 100 ppt for 48 h – 100% adult mortality

Marine Extracts of Macrophytic Algae (Fucus and Ulva) In coatings (Experimental) Inhibits pediveliger settlement and adult byssogenesis

Comparison of Nonoxidizing and Oxidizing Molluscicides
ADVANTAGES of NONOXIDIZING MOLLUSCICIDES • Fewer precautions required for on-site storage • Fewer safety hazards in handling and use • May have greater toxicity than oxidizing agents • Do not generally induce valve closure • Surfactant agents may be less toxic to nontarget organisms than oxidizing molluscicides • Due extensive surface area of living epithelial tissue in bivalves • Application technology and hardware is often inexpensive and readily installed • Readily and simply deactivated in effluents • Generally noncorrosive to metal, silicone and rubber based seals • Do not produce carcinogenic by-products (THMs)

Nonoxidizing Molluscicide Application Strategies

• Periodic Mitigation • Continuous Application • Intermittent Application • Semicontinuous Application

Periodic Application
Short-term molluscicide addition at elevated concentrations mitigating established populations • Applied at a frequency preventing system degradation (1-3 times annually)

• Adjusted to local population reproductive cycles
Advantages: •Low annual cost and molluscicide usage
Disadvantages: • Requires extensive and continuous monitoring • Allows mussel fouling to become established • May release shells and bodies into system • High application levels may require discharge detoxification

Continuous Application
Continuous application at low concentrations • Prevent pediveliger settlement • Prevent survival of translocating juvenile mussels Advantages: • Prevents establishment of mussel fouling • Application technology is relatively simple • Discharge molluscicide concentrations are low, but continuous • Reduces microbially influenced corrosion (MIC) • Extensive mussel monitoring is not required Disadvantages: • Relatively high annual use of molluscicide • Relatively high costs • High annual release of molluscicide

Intermittent Application
Daily, bidaily, or tridaily at intermediate concentrations for 0.5 to 3 hours per addition • Prevents pediveliger settlement Advantages: • Slows establishment of mussel fouling • Discharge of molluscicide reduced compared to continuous application • Reduces costs • Reduces microbially influenced corrosion (MIC) • Can be limited to mussel spawning periods Disadvantages: • Cannot mitigate pre-established fouling • Will not generally prevent fouling by translocating juvenile and adult mussels • Must monitor juvenile and adult settlement

Semi-continuous Application
Rapid, on-off cycling of molluscicide addition at low concentrations as used in continuous application • On 15-30 min followed by off periods of 15-90 min • Applied at low concentrations as in continuous application Advantages: • Prevents establishment of mussel fouling • Discharge of molluscicide reduced compared to continuous application, reducing costs • Reduces microbially influenced corrosion (MIC) • Will mitigate pre-established mussel fouling Disadvantages: • Involves larger annual use of molluscicide than in periodic or intermittent application • Application technology may be complex

Conclusions

• Nonoxidizing molluscicides offer a viable alternative
to oxidizing molluscicides for zebra mussel fouling

• Wide variety of nonoxidizing molluscicides available • Are highly effective against zebra mussels and some
are relatively benign to nontarget species compared to oxidizing molluscides

• Application technology and storage are simple • Costs can be competitive with oxidizing biocides • Can reduce microbially influenced corrosion (MIC) • Readily applied to low volume facilities and systems • Choice of agent and application technology can be
customized to facility requirements and limitations on a site-by-site basis

Thermal Control Strategies

• Zebra mussels are northern temperate species • Results in having reduced tolerance of elevated
temperatures

• Can tolerate 0°C throughout the winter • Do not tolerate prolonged exposure to 30°C • Low upper lethal limits make zebra mussels
susceptible to thermal mitigation/control technologies

• Incipient upper thermal limit

• Two basic thermal treatment technologies
• Chronic thermal treatment • Acute thermal treatment

ACUTE THERMAL TOLERANCE

• Tolerated temperature in response to rapidly
increasing temperature or instantaneous exposure to a lethal temperature

• Affected by of rate of temperature increase and prior
temperature experience
CHRONIC THERMAL TOLERANCE

• Tolerance time when continuously exposed to
temperatures

lethal

• Affected by exposure temperature and prior
temperature experience

ACUTE versus CHRONIC THERMAL TREATMENT Acute Treatment
Upper Lethal Threshold

Chronic Treatment
Upper Lethal Threshold

Temperature

Time

Temperature

Time

Acute Temperature Tolerance
41
Acclimation Temperature
30°C

Applications
Steam or hot water injection > 38°C (100°F) produces near instantaneous death under all conditions Embayments Completely heat Dewatering technique Injection into piping

Tolerated Temperature (LT50 in °C)

40
25°C

39 38 37 36 35 34 33 0.00 0.20 0.40 0.60

20°C 15°C 10°C 5°C 0°C

0.80

1.00

Temperature Increase Rate (°C/min)

Steam or Hot Water Injection Raising Embayment Surface Water to a Lethal Temperature

Dewater Embayment Exposing all of Walls to Hot Water

Acute Thermal Treatment of Embayments

Intake Structure

Circulating Water System

Intake

Service Water System

Source Water

Re-circulation of Thermal Effluents
Valve

Discharge

CHRONIC THERMAL TREATMENT

Chronic Temperature Tolerance
250

200

Acclimation Temperature
30°C

Survival Time (h)

150

25°C 20°C

Applications
Re-circulation of discharge water into intakes to raise and hold system temperatures at lethal levels (> 33°C, 91°F) for long enough to mitigate zebra mussel infestations

100

15°C 10°C

50

5°C 0°C

0 31 32 33 34 35 36 37

Treatment Temperature (°C)

Seasonal Thermal Acclimatization of Zebra Mussels will also Affect Choice of Temperature and Application Times in Chronic Thermal Treatments
Mean Survival Time at 33°C (Hours)
70 60 50
Mississippi River at Baton Rouge, LA 5°C Acclimated 15°C Acclimated 25°C Acclimated

40 30 20 10 0

0

5

10

15

20

25

30

Ambient Water Temperature at Collection (°C)

Desiccation
Zebra mussels are highly intolerant of emersion and desiccation Makes dewatering of mussel infested structures a efficacious alternative to chemical mitigation Three available strategies
Ambient air exposure, forced warmed air, or freezing At ambient temperatures Increased kill rates at higher temperatures Decreased kill rates at higher R.H. Rapid kill in air warmed above lethal temperature

Desiccation tolerance of zebra mussels at different ambient air temperatures and relative humidities

400 350

100% 80% 60% 40% 20% 0%

LT

50

Hours Survived

300 250 200 150 100 50 0 0

5

10

15

20

25

30

TEMPERATURE (°C)
800 700

Hours Survived

100% 80% 600 60% 40% 500 20% 400 0%
300 200 100 0 0 5 10

LT

100

15

20

25

30

TEMPERATURE (°C)

Survival of Zebra Mussels after Emersion in a Lethal Air Temperature of 35°C
50

35°C
40
LT 50 LT100 100% Sample Mortality

Hours Survived

30 20 10 0 < 5% 33% 53% 75% Relative Humidity > 95%

Note that survival is reduced in higher relative humidities

Freezing
Zebra mussels are highly intolerant of emersion in subfreezing temperatures Could mitigate mussel infestations by dewatering during freezing conditions

Milton Matthews

Tolerance of Aerial Freezing in Separate and Clustered Zebra Mussels
30
LT 50 - Separate

> 48 h
SM 100 - Separate LT 50 - Clustered

> 48 h

25

Hours Survived

20 15 10 5 0 -10

SM 100 - Clustered

-7.5

-5

-3.0

-1.5

0.0

Air Temperature (°C)

Field Test of Freeze Treatment
Black Rock Lock, Buffalo, New York, dewatered over a 6 hour period during January 1995 Infesting mussels were alive on all levels of the lock walls after dewatering when air temperatures were > 0°C Air temperatures fell to -5°C over night 100% mortality of exposed mussels the following morning Lock mussel infestation was completely mitigated

Oxygen Deprivation
Zebra mussels have very poor tolerance of hypoxia compared to other freshwater bivalves Survival times are shorter and minimal tolerated levels of hypoxia are greater Survial times decrease with decreasing oxygen concentration and increasing temperature Could be used for nonchemical mitigation/control of zebra mussel fouling

Methods: Anoxia / Hypoxia Tolerance
Mussels acclimated to 5°, 15° or 25°C for > 14 days Respiratory responses to progressive hypoxia determined at 5°, 15° and 25°C Tolerance of 0, 5, 10% of air oxygen saturation tested Po = 0.0, 7.9 and 15.9 Torr
2

Responses of both D. polymorpha (zebra mussels) and D. bugensis (quagga mussel) tested

Analysis of Oxygen Uptake Rates in Response to Progressive Hypoxia using % Oxygen Regulation Values
90%

Oxygen Uptake Rate

80% 70% 60% 50%

Oxygen Concentration
Full air oxygen saturation (159 Torr)

100
Percent O 2 Regulation

Dreissena bugensis Dreissena polymorpha

80 60 40 20 0

5

15

20

25

Acclimation / Test Temperature (°C)

LT50 values (days) (Kaplan-Meier Survival Analysis) and Log Rank Statistic comparing the hypoxia (5% air O2 saturation) and anoxia tolerances of specimens of D. bugensis and D. polymorpha.
Species D. bugensis D. polymorpha D. bugensis D. polymorpha D. bugensis D. polymorpha D. bugensis D. polymorpha D. bugensis D. polymorpha D. bugensis D. polymorpha Condition 5%O2 5%O2 5%O2 5%O2 10%O2 10%O2 10%O2 10%O2 Anoxia Anoxia Anoxia Anoxia Temp. LT50 Log Rank 15°C 19 Days A 15°C 24 Days B 25°C 6 Days A 25°C 5 Days A 15°C 26 Days A 15°C 28%@ 30 Days B 25°C 6 Days A 25°C 15 Days B 15°C 18 Days A 15°C 32 Days B 25°C 5 Days A 25°C 16 Days B

Carbon Dioxide Treatment

• Carbon dioxide is a weak acid

• Bivalves do not have pH buffering blood proteins • Increased CO2 concentration in medium increases • Slight reductions in blood pH induce stress and • Inexpensive, readily stored on site, easily applied,
highly biodegradable CO2 concentration in blood lowering its pH

• CO2 + H2O → H2CO3 → H+ + HCO3- → 2 H+ + CO32-

mortality so that CO2 could act as a molluscicide

• Utilized by aquatic plants, algae and bacteria

Methods: Carbon Dioxide Tolerance

• Treatment temperature = 25°C • Mussels exposed to 5% and 10% CO2 • Pco2 = 38 and 76 Torr, respectively • Tolerance times determined • Mussels allowed to byssally attach to clear plastic
plates over the course of the exposures

• Number of new byssal attachment produced
determined daily

Mortality in 10% CO2 / 19% O2 / 71% N2
100

Cumulative % Mortality

LT = 2.59 Days 50

80 60 40 20 0 0 4

LT = 5.63 Days 50

LT = 4.73 Days 50

8

12

16

20

Days of Exposure

The Effects of Exposure to 5% CO2 on the Rate of Byssal Thread Production
12

Air 5% CO 2

Threads / Day

10 8 6 4 2 0 0 1 2 3

4

5

6

7

8

9

10 11

Days

The Effects of Exposure to 5% CO 2 on the Percent of Mussels Remaning Byssally Attached
100 90 80 70 60 50 40 30 20 10 0 0 1 2

Percent Attached

Air 5% CO 2

3

4

5

6

7

8

9

10 11

Days

Low Frequency Agitation

• Low frequency agitation (20-60 cps) can inhibit
production of byssal threads and induce byssal release in zebra mussels

• May be the reason that adult mussels are not found in
shallow waters agitated by wave action

• Could be used as a nonchemical method for
controlling or mitigating fouling

• • •

Low frequency agitators in embayments Flutter valves in water lines or intake tunnels Bubble Sreens, Bubbler Systems

• Higher frequency sound has not proven successful

Methods: Low Frequency Agitation

• Mussels allowed to attach to plastic plates • Water agitated back and forth past the plates
• 0, 10, 20, 30, and 40 cycles/min (cpm)

• Number of byssal threads produced counted daily • Number of mussels sontaneously releasing from
byssus observed

Effect of Low Frequency Agitation on Cumulative Byssal Thread Production
100
0 CPM 10 CPM

Mean Byssal Thread Number

80

15 CPM 30 CPM 40 CPM

60

40

20

0

2

4

6

8

10 Days

12

14

16

18

20

Effect of Low-frequency Agitation on Mean Number of Byssal Threads Produced after 21 Days
120 Above 40 cpm all mussels spontaneously released from the plastic plate 100

Mean Byssal Thread Number

80

60

40

0

10 20 Agitation Rate (CPM)

30

40

Use of Bubble Screens and Plates for Mitigation of Zebra Mussel Macrofouling

TRACK

PLATE WALL AIR STREAM AIR DISPERSER PIPE

Conclusions

• Thermal treatments successfully mitigate and control dreissenid
macrofouling

• Anoxia/hypoxia could be efficacious for mitigation of zebra
mussel infestations

• • • • • • • • • •

Acute and chronic treatments

• Desiccation has been successfully used to control mussel
macrofouling
Draw-down during warm summer or freezing winter periods Dewatering components Forced warm air 10% will kill mussels, 5% stimulates release from byssus

Best applied during warmer months Will require reducing oxygen concentrations to less than 15% of full air oxygen staturation Drawing from deoxygenated hypolimnetic waters

• Carbon dioxide injection could an efficacious mitigant
•

• Low frequency agitation could be an effective mitigant

> 50 cpm causes 100% byssal release < 40 cpm inhibits production of byssal threads Flutter valves, agitators or bubble screens could prevent settlement


								
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