Premium
An Effective Minimum Concentration of Un‐ionized Ammonia Nitrogen for Controlling Prymnesium parvum
Author(s) -
Barkoh Aaron,
Smith Dennis G.,
Schlechte J. Warren
Publication year - 2003
Publication title -
north american journal of aquaculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 41
eISSN - 1548-8454
pISSN - 1522-2055
DOI - 10.1577/c02-046
Subject(s) - ammonia , ammonium , ammonium sulfate , nitrogen , biology , sulfate , environmental chemistry , nuclear chemistry , chemistry , chromatography , biochemistry , organic chemistry
The minimum concentration of un‐ionized ammonia nitrogen needed to kill the alga Prymnesium parvum in 24–48 h was determined from ammonium sulfate treatments. Five treatments [0, 3, 5, 10, and 15 mg (NH 4 ) 2 SO 4 /L] were tested at pH 8 and pH 9 and temperatures of 15, 20, and 25°C to generate various concentrations of total and un‐ionized ammonia nitrogen; their effectiveness in killing the alga was then monitored for 48 h. There was a strong relationship between treatment success and the level of ammonium sulfate or un‐ionized ammonia nitrogen. The ammonium sulfate treatments that killed the alga did so within the first 24 h, and their effectiveness at 48 h was not significantly different from that at 24 h. At pH 9, ammonium sulfate concentrations above 5 mg/L eradicated the alga approximately 90% of the time, compared with 33% for the other treatments. In terms of un‐ionized ammonia nitrogen, 0.055 mg/L was similar to the control in failing to kill the alga; however, 0.17 mg/L eradicated the alga 80% of the time. We suggest 0.17 mg/L of un‐ionized ammonia nitrogen as the minimum concentration for therapeutic control of P. parvum .