NAPHTHALENE REMOVAL FROM AQUEOUS SYSTEMS BY SAGITTARIUS SP

ABSTRACT

Naphthalene is a polyaromatic hydrocarbon (PAH) present in many sediment-water systems. The uptake of naphthalene by an aquatic plant, arrowhead (Sagittaria sp.), was studied in a series of batch systems and continuous flow systems. Batch experiments were conducted in a fed-batch mode, and naphthalene was administered in consecutive spike doses. Results from batch experiments indicated that the rate of naphthalene removal by arrowhead in the presence of light was 0.114 ± 0.061 h⁻¹, at a 90% confidence interval. Naphthalene removal by arrowhead occurred even in the absence of light, although this rate was about 25% of that in the presence of light. Results indicated that repeated exposures to naphthalene for a single arrowhead plant may decrease its capacity for naphthalene uptake, particularly after the first exposure. Naphthalene tended to deposit out in CSTRs where no arrowhead was present, indicating that while the naphthalene may not have been present in the water column, it was not removed from the system. Results from CSTR experiments indicated that under well-mixed quasi-steady state conditions, naphthalene removal by arrowhead in the presence of light was about 40%. Photolytic degradation of naphthalene in the absence of arrowhead was about 15%, when additional mixing was provided to simulate scouring.

Keywords:

• Naphthalene
• Arrowhead
• Sagittarius sp.
• PAH contaminated sediments

ACKNOWLEDGMENTS

Support from the Graduate School, Bradley University, and the Department of Civil Engineering and Construction, Bradley University, is acknowledged.