Distribution of Copper in Sediments from Fluvial Reservoirs Treated with Copper Triethanolamine Complex Algicide
- 157 Downloads
The control of algal growth in water reservoirs with copper-based algicides leads to elevated sediment Cu concentration and thus could affect long-term water quality. To assess the potential mobility of sediment-associated Cu, a study was conducted using samples from three drinking water reservoirs treated with Cutrine®, a copper triethanolamine complex algicide. Total Cu (CuT) in treated reservoir sediment ranged from 13.3 to 139.9 mg Cu kg−1 and was on average 1.5 times the level in streams (48 mg Cu kg−1) flowing into the reservoirs. Sediment CuT and algicide application history indicated the retention of 82–93% of the algicide Cu applied. Sequential extraction showed that Cu primarily accumulated in the residual fraction (60%), whereas the potentially mobile pools (water extractable: CuH2O, exchangeable: CuEX, organic bound) accounted for <10% of CuT. The leachable Cu fraction (extracted with 1 M acetic acid) also amounted to <9% of CuT and was related negatively to C/N and positively to H/C ratios of organic matter. In addition, these potentially mobile fractions were found to be related, not to total organic C, but to sediment respiration suggesting that the potentially mobile Cu fractions were primarily associated with aliphatic and readily biodegradable C (more so than total organic C). During a 2-year period without algicide treatment (that followed 4 years of repeated algicide applications to one of the studied reservoirs), mean dissolved Cu (micrograms per liter) in the reservoir (39.2) was similar to levels measured at locations upstream (43.3) and downstream (47.2) from the reservoir. These results indicate that the bulk of sediment Cu is associated with geochemically stable solid phases and thus should alleviate concerns about Cu transfer into the water column.
KeywordsAlgicide Fluvial reservoirs Mobile Cu fractions Labile C Copper retention
The author thanks Rosalice Buehrer, Jennifer Faust, Brandon Lewis, and Lora Shrake for their assistance in the laboratory. Robert E. Hall assisted with field sampling and preparation of maps. The study was funded through the Office of Professional Development Grant-in-Aid program (IUPUI). The 2003 sediment sampling program was funded by the central Indiana Water Resources Project, a research and development program funded by Veolia Water Indianapolis, LLC. Logistical support provided by the Center for Earth and Environmental Science (CEES) is gratefully acknowledged.
- Anderson, J. P. E. (1982). Soil respiration. In A. L. Page, R. H. Miller & D. R. Keeney (Eds.), Methods of soil analysis. Part II (2nd ed., pp. 831–872). Madison: American Society of Agronomy and Soil Science Society of America.Google Scholar
- Barnett, R., & Tognazzini, M. (1987). Current methodology for the control of algae in surface reservoirs. American Water Resources Foundation, Report 905222.Google Scholar
- EPA (1998). Toxicity characteristics leaching procedure (TCLP). Federal Register, 40 CFR, vol. 51, No. 256, Appendix 2, Part 268: 40643. United States Environmental Protection Agency (EPA).Google Scholar
- EPA (2007). National primary drinking water regulations for lead and copper: short-term regulatory revisions and clarifications, 40 CFR Parts 141 and 142. United States Environmental Protection Agency (EPA).Google Scholar
- McBride, M. B. (1994). Environmental chemistry of soils. Oxford: Oxford Univ. Press.Google Scholar
- Raftis, R. (2007). Internal cycling of phosphorus in an urban drinking water reservoir. M.S. thesis, Indiana University.Google Scholar
- Sauve, S., Dumestre, A., McBride, M., & Hendershot, W. (1998). Derivation of soil quality criteria using predicted chemical speciation of Pb2+ and Cu2+. Environmental Toxicology & Chemistry, 17, 1481–1489.Google Scholar
- Tedesco, L. P., Atekwana, E. A., Filippelli, G. F., Licht, K., Shrake, L. K., Hall, B. E., et al. (2003). Water quality and nutrient cycling in three Indiana watersheds and their reservoirs: Eagle Creek/Eagle Creek Reservoir, Fall Creek/Geist Reservoir, and Cicero Creek/Morse Reservoir. CEES publication 2003–01 (p. 163). Indianapolis: Central Indiana Water Resources Partnership.Google Scholar