Transcript UN-IONIZED AMMONIA, NH3 - Oregon State University

Risks Associated with the Use of Chemical
Amendments in Aquaculture Pond
Management
Claude E. Boyd
Department of Fisheries and Allied Aquacultures
Auburn University, Alabama 36849 USA
and
Laurence Massaut
Fundación CENAIM-ESPOL
Guayaquil, Ecuador
Three types of risks were evaluated:
Environmental (ES)
Food safety (FS)
Handling (HS)
Four levels were assigned to each type of risk:
No risk = 0
Low risk = 1
Medium risk = 2
High risk = 3
Common nitrogen fertilizer compounds.
Compound
Application rate
Urea
(H2NCONH2)
5-10 kg/ha at
1-4 wk intervals
Risk level and type
HS = 1; explosive, irritant, possible mutagen.
ES = 1; if spilled, eutrophication, ammonia
toxicity, acidity.
FS = 0; none.
Ammonium sulfate
((NH4)2SO4)
10-20 kg/ha
at 1-4 wk
intervals
HS = 1; explosive, irritant, avoid inhalation.
ES = 1; if spilled, eutrophication, ammonia
toxicity, acidity.
FS = 0; none.
Ammonium nitrate
(NH4NO3)
5-10 kg/ha
at 1-4 wk
intervals
HS = 1; explosive, irritant, avoid inhalation.
ES = 1; if spilled, eutrophication, ammonia
toxicity, acidity,
FS = 0; none.
Sodium nitrate
(NaNO3), potassium
nitrate (KNO3), and
calcium nitrate
(Ca(NO3)2)
20-30 kg/ha
At 1-4 wk
intervals
HS = 1; explosive, prolonged KNO3 exposure
may produce anemia, irritant.
ES = 1; if spilled, eutrophication, ammonia
toxicity.
FS = 0; none.
Common phosphorus fertilizer compounds.
Compound
Application rate
Risk level and type
Triple
superphospahte
(Ca(H2PO4)2)
5-10 kg/ha at
1-4 wk intervals
HS = 0; none.
ES = 1; if spilled, eutrophication.
FS = 0; none.
Mono- and diammonium
phosphate
(NH4H2PO4 and
(NH4)2HPO4)
5-10 kg/ha
at 1-4 wk intervals
HS = 1; irritant, monoammonium
phosphate is explosive.
ES = 1; if spilled, eutrophication
FS = 0; none.
Phosphoric acid
(H3PO4)
5-10 kg/ha
at 1-4 wk intervals
HS = 1; irritant.
ES = 1; if spilled, acidity, toxicity, and
eutrophication.
FS = 0; none.
Other fertilizer materials.
Compound
Application rate
Potassium chloride
or muriate of
potash (KCl)
1-2 kg/ha at
1-4 wk intervals
Sodium silicate
(Na2SiO3)
Manure, grass and
human wastes
100-500 kg/ha in
inland shrimp
ponds
Risk level and type
HS = 1; irritant.
ES = 1; if spilled, eutrophication.
FS = 0; none.
1-5 kg/ha
HS = 0; none.
at 2 wk intervals ES = 0; none
FS = 0; none.
100-500 kg
dry wt/ha/wk
HS = 0; none.
ES = 1; potential oxygen depletion,
eutrophication.
FS = 1; disease transmission to humans,
heavy metal contamination
Other fertilizer materials.
Compound
Application rate
Risk level and type
Trace and secondary
element mixes
(contains various
compounds of Fe, Zn,
Cu, B, and Mo)
50-100 g/ha per
month
Fertilizer enhancers
(e.g., humate)
10-100 kg/ha per HS = 0; none.
month
ES = 0; none.
FS = 0; none.
Mixed fertilizers
25-100 kg/ha per HS = 0; none.
month
ES = 1; if spilled, eutrophication.
FS = 0; none.
Potassium
magnesium sulfate
500-1,000 kg/ha
in inland shrimp
ponds
HS = 0; none.
ES = 1; if spilled, metal toxicity.
FS = 0; none.
HS = 1; irritant.
ES = 1; if spilled, eutrophication.
FS = 0; none.
Common liming materials.
Compound
Application rate
Risk level and type
Agricultural
limestone (CaCO3
or CaCO3 MgCO3)
1-5 tons/ha
annually
HS = 0; none.
ES = 0; none.
FS = 0; none.
Burnt lime (CaO or
CaO MgO)
0.5-1 tons/ha
annually
HS = 1; strong caustic, irritant.
ES = 1; if spilled, high pH.
FS = 0; none.
Hydrated lime
(Ca(OH)2 or
Ca(OH)2 Mg(OH)2)
0.5-1 tons/ha
annually
HS = 1; caustic, irritant.
ES = 1; if spilled, high pH.
FS = 0; none.
Common oxidants.
Compound
Potassium
permanganate
(KMnO4)
Application rate
Risk level and type
2-8 mg/L
HS = 1; explosive if in contact with organic
substances, irritant
ES = 1; if spilled, toxicity.
FS = 0; none.
Hydrogen peroxide
(H2O2) or calcium
peroxide (CaO2)
Up to 100 kg/ha
HS = 1; H2O2 concentrated form is irritant.
ES = 1; if spilled, toxicity.
FS = 0; none.
Calcium hypochlorite
(Ca(OCl)2)
30 mg/L before
stocking
HS = 1; irritant, poisonous.
ES = 1; formation of trihalomethanes and
chlorinated hydrocarbons that are
suspected carcinogens, toxic.
FS = 0; none.
Sodium, potassium,
or calcium nitrate
(NaNO3, KNO3, or
Ca(NO3)2)
1-5 mg/L
HS = 1; explosive, prolonged KNO3 exposure
may produce anemia, irritant.
ES = 1; if spilled, eutrophication.
FS = 0; none.
Common coagulants.
Compound
Application rate
Risk level and type
Aluminum sulfate
(Al2(SO4)3 14H2O)
15-40 mg/L
HS = 1; irritant, acidic.
ES = 1; if spilled, acidity and toxicity.
FS = 0; none.
Ferric chloride
(FeCl3)
15-40 mg/L
HS = 1; irritant, acidity.
ES = 1; if spilled, acidity and toxicity.
FS = 0; none.
Calcium sulfate
(CaSO4 2H2O)
200-500 mg/L
HS = 0; none.
ES = 0; none.
FS = 0; none.
Common osmoregulators.
Compound
Application rate
Risk level and type
Salt (NaCl)
100-2,000 mg/L
HS = 1; irritant.
ES = 1; increase in salinity.
FS = 0; none.
Calcium sulfate
(CaSO4 2H2O)
100-400 mg/L
HS = 0; none.
ES = 0; none.
FS = 0; none.
Common algicides.
Compound
Application rate
Risk level and type
Copper sulfate
(CuSO4 5H2O)
0.5-2 mg/L
HS = 1; strong irritant.
ES = 2; toxicity.
FS = 0; none.
Chelated copper
compounds
0.2-1 mg/L
HS = 0; none.
ES = 2; toxicity.
FS = 0; none.
Diuron
Dyes (food
coloring
compounds)
0.01 mg/L;
maximum of
nine times/yr
1-5 mg/L
HS = 1; irritant.
ES = 2; toxicity.
FS = 1; possible residues.
HS = 0; none.
ES = 0; none.
FS = 0; none.
Common piscicides.
Compound
Teaseed cake
(active ingredient
is sapogenin
glycosides)
Rotenone
(C23H22O6)
Lime
Application rate
15 mg/L
0.25-2.0 mg/L
1-2 tons/ha
Risk level and type
HS = 0; none.
ES = 1; foam strongly, form oil-in-water
emulsions and act to protect
colloids.
FS = 0; none.
HS = 1; irritant.
ES = 1; toxicity.
FS = 0; none.
HS = 1; caustic, irritant.
ES = 1; if spilled, high pH.
FS = 0; none.
Common probiotics.
Compound
Application rate
Risk level and type
Live bacterial inocula
(non-pathogenic
organisms and usually
Bacillus species)
1-2 mg/L at 1 or 2 days to
1 week intervals
HS = 0; none.
ES = 0; none.
FS = 0; none.
Fermentation
products rich in
extracellular enzymes
1-2 mg/L at 1 or 2 days to
1 week intervals
HS = 0; none.
ES = 0; none.
FS = 0; none.
Miscellaneous compounds.
Compound
Zeolite (aluminosilicate clay)
Yucca extracts
Bactercides: BKC
(alkyldimethylbenzylammonium chloride),
providone, iodine
(polyvinylpyrrolidone iodine),
glutaraldehyde, formalin
Application rate
Risk level and type
20-50 kg/ha weekly
HS = 0; none.
ES = 0; none.
FS = 0; none.
1-2 mg/L monthly
HS = 0; none.
ES = 0; none.
FS = 0; none.
1-10 mg/L
HS = 0; none.
ES = 1; toxicity.
FS = 1; possible
residues.
Miscellaneous compounds.
Compound
Sodium bicarbonate
(NaHCO3)
Iron oxide (FeO)
Application rate
25 mg/L or higher
HS = 0; none.
ES = 0; none.
FS = 0; none.
1 kg m2
HS = 0; none
ES = 0; none.
FS = 0; none.
KILOL (extracts of grapefruit
seed)
Dipterex (OP insecticide)
Risk level and type
HS = 0; none.
ES = 0; none.
FS = 0; none.
1-2 mg/L
HS = 2; toxicity
ES = 2; toxicity
FS = 1; possible residue (?)
Substances that could enter aquaculture ponds through contamination.
Compound
Risk level and type
Insecticides
HS = 2; toxic.
ES = 3; bioaccumulative.
FS = 3; bioaccumulative.
Pesticides
HS = 2; toxic.
ES = 3; bioaccumulative.
FS = 3; bioaccumulative.
Heavy metals: lead, mercury,
arsenic, beryllium, cadmium,
chromium, manganese, silver, and
zinc
HS = 3; most are toxic to humans if
absorbed, some carcinogenic.
ES = 3; bioaccumulative.
FS = 3; bioaccumulative.
Aluminum, antimony, barium, copper, HS = 2; less toxic than above, but high
cyanide, iron, nickel,
concentrations when absorbed
and selenium
will be toxic.
ES = 2; not bioaccumulative.
FS = 3; not bioaccumulative.