P. Hendrix, J. Hamala, C. L. Langner
1983
Citations
0
Influential Citations
9
Citations
Journal
Chemosphere
Abstract
Abstract Experiments were conducted to estimate the effects of chlorendic acid and its neutralized form on laboratory aquatic ecosystems. In short-term flask studies, chlorendic acid concentrations of 500 mg/L (pH 3.5) completely inhibited algal growth and microfaunal activity, 250 mg/L (pH 4.1) inhibited microfaunal activity and reduced the abundance of all but one algal species, and 125 mg/L (pH 6.6) had no observable effects. Similar results occurred in longer term microcosm studies where, in addition, 500 and 250 mg/L chlorendic acid resulted in decreased oxygen production and respiration; altered chlorophyll a concentrations and bacterial populations; and increased concentrations of dissolved NO3-N, NH3-N, and PO4-P. In contrast, few distinct effects were observed in flasks or microcosms treated with the neutralized form of chlorendic acid. Results indicate that the observed effects were due primarily to increases in hydrogen ion concentration; direct toxicity also may have occurred at low pH where chorendic acid existed as the unionized species.