UBC Theses and Dissertations
Application of semipermeable membrane devices (SPMDs) to the monitoring of kraft mill effluents with emphasis on potential fish-tainting compound Rohr, Annette Christine
The use of Semipermeable Membrane Devices (SPMDs) for monitoring pulp mill effluents containing potential fish tainting compounds was investigated. SPMDs are lipidfilled polyethylene bags which appear to mimic bioconcentration phenomena in aquatic organisms. They have been used as in situ, passive monitors of organic contaminants such as polynuclear aromatic hydrocarbons (PAHs) in aqueous environments, and were used here in a pulp mill setting. Preliminary method development work included investigating the effect of tubing segment location within the roll of polyethylene on uptake of 2,2’ ,5 ,5 ‘-tetrachlorobiphenyl (TCB), a reference compound. Tubing segment location was determined to have no significant effect on degree of uptake. In addition, polyethylene consistency was investigated by subjecting tubing to various batch solvent extraction conditions. Selected tubing extracts were also analyzed by gas chromatography/mass spectrometry (GCIMS), and the contaminating compounds were identified. Hexane exposures showed that a 24 hour hexane extraction with no solvent replacement was sufficient for the adequate removal of contaminating compounds associated with the polyethylene tubing. Three model compounds were chosen on the basis of their significant presence in kraft mill effluent as well as their potential propensity to taint fish. Octanol-water partition coefficients (KowS) were determined for the compounds, alpha-pinene, guaiacol and dehydroabietic acid, and for 2,2’ ,5 ,5 ‘-TCB. Compound uptake into SPMDs and dialytic recoveries from SPMDs were determined. Generally, the model compounds were not sequestered efficiently by SPMDs, and their dialytic recoveries were low. The behaviour of the compounds was explained on the basis of their KowS, polarities, volatilities and water solubilities. SPMDs were exposed to both untreated and biotreated full-strength unbleached kraft mill wastewater under static conditions. In addition, SPMD exposures were carried out using several concentrations of treated effluent in continuous flow systems. In both types of exposures, SPMDs were found to sequester many compounds, as evidenced by gas chromatograms. Of particular interest was the uptake of compounds which may be responsible for the tainting of eulachons (Thaleichthys pacWcus) in the Kitimat River, B.C. Eulachons are small smelts with a high lipid content which traditionally have been consumed by the Haisla Indians living in the area, but have not been used in this capacity since the early 1970s due to a noticeable off-flavour. Five compounds identified in tainted eulachon were identified in SPMD dialysates after GC/MS analysis. Based on the results shown in this research, SPMDs appear to show significant promise as passive monitors for the detection and possible quantification of tainting compounds in aqueous environments. Their specificity for nonpolar compounds may diminish their usefulness in pulp mill settings, where ionic and polar compounds such as resin acids and phenols are common constituents of wastewaters.
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