Evaluation of ionic contribution to the toxicity of a coal-mine effluent using Ceriodaphnia dubia

• Published in: Archives of environmental contamination and toxicology 2005-08, Vol.49 (2), p.155-162
• Main Authors: KENNEDY, A. J, CHERRY, D. S, ZIPPER, C. E
• Format: Article
• Language: English
• Subjects: 01 COAL, LIGNITE, AND PEAT; ACID MINE DRAINAGE; Acute toxicity; Animal, plant and microbial ecology; Animals; Applied ecology; Aquatic life; Aquatic organisms; Biological and medical sciences; Ceriodaphnia dubia; Chlorine - toxicity; Chronic toxicity; Coal mines; COAL MINING; DAPHNIA; Daphnia - drug effects; Daphnia - growth & development; DRAINAGE; Ecotoxicology, biological effects of pollution; Effluents; Environmental protection; ENVIRONMENTAL SCIENCES; Fresh Water - chemistry; Fundamental and applied biological sciences. Psychology; General aspects; Hardness; Ions - toxicity; Laboratories; Laboratory tests; LIQUID WASTES; SODIUM; Sodium - toxicity; SOLIDS; Solutions; Specific conductivity; STREAMS; SULFATES; Sulfates - toxicity; Total dissolved solids; TOXICITY; Toxicity Tests - methods; Wastewater discharges; Water Pollutants, Chemical - toxicity; WATER POLLUTION; WATER QUALITY
• ISSN: 0090-4341; 1432-0703
• DOI: 10.1007/s00244-004-0034-z

The United States Environmental Protection Agency has defined national in-stream water-quality criteria (WQC) for 157 pollutants. No WQC to protect aquatic life exist for total dissolved solids (TDS). Some water-treatment processes (e.g., pH modifications) discharge wastewaters of potentially adverse TDS into freshwater systems. Strong correlations between specific conductivity, a TDS surrogate, and several biotic indices in a previous study suggested that TDS caused by a coal-mine effluent was the primary stressor. Further acute and chronic testing in the current study with Ceriodaphnia dubia in laboratory-manipulated media indicated that the majority of the effluent toxicity could be attributed to the most abundant ions in the discharge, sodium (1952 mg/L) and/or sulfate (3672 mg/L), although the hardness of the effluent (792 +/- 43 mg/L as CaCO3) ameliorated some toxicity. Based on laboratory testing of several effluent-mimicking media, sodium- and sulfate-dominated TDS was acutely toxic at approximately 7000 microS/cm (5143 mg TDS/L), and chronic toxicity occurred at approximately 3200 microS/cm (2331 mg TDS/L). At a lower hardness (88 mg/L as CaCO3), acute and chronic toxicity end-points were decreased to approximately 5000 microS/cm (3663 mg TDS/L) and approximately 2000 microS/cm (1443 mg TDS/L), respectively. Point-source discharges causing in-stream TDS concentrations to exceed these levels may risk impairment to aquatic life.