Measurement of heavy metals in natural waters: Zinc dynamics in the southern basin of Lake Michigan

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:5674223

Keel, R T

The principal goal of this research was to develop methodology capable of measuring heavy metals at natural levels and to apply it to the study of zinc in the southern basin of Lake Michigan. The approach taken involved the preconcentration of dithiolate-reactive elements using ammonium pyrrolidine carbodithoic acid (APDC) as a complexing ligand and cadmium ion as a carrier. The precipitates were collected onto membrane filters and analyzed as thin film samples utilizing energy dispersive X-ray fluorescence spectrometry (EDXRF). All reagents and materials used in the process were purified to insure that contamination of the samples did not occur. An extensive number of measurements were carried out in the southern basin of Lake Michigan to determine whether spatial and temporal variations in zinc concentrations could be observed. It appears that atmospheric inputs effect the concentrations of zinc in the surface waters during the period of thermal stratification. Concentrations in the epilimnetic waters may increase to a maximum value during the late summer months. An efficient mechanism for removal of zinc to the hypolimnetic waters may occur annually due to coprecipitation of the element during the carbonate whiting events of late summer. The mean zinc value determined as a part of this work was 760 {plus minus} 572 ng/l. Using this data, an estimate was obtained for the distribution of zinc between soluble and particulate phases and estimated that the residence time for zinc in the southern basin of Lake Michigan is less than 2.5 years. The author attempted to estimate the atmospheric flux of zinc to the basin. Two different approaches were taken yielding estimates of 680 and 3500 tonnes per year. The results agree well with previous estimates.

• Research Organization: Clemson Univ., SC (USA)
• OSTI ID: 5674223
• Country of Publication: United States
• Language: English

Related Subjects

520200* -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
CHEMICAL ANALYSIS
ECOLOGICAL CONCENTRATION
ELEMENTS
GREAT LAKES
LAKE MICHIGAN
LAKES
MEASURING METHODS
MEMBRANES
METALS
NONDESTRUCTIVE ANALYSIS
POLLUTION
PRECIPITATION
QUANTITATIVE CHEMICAL ANALYSIS
REMOVAL
SAMPLE PREPARATION
SEASONAL VARIATIONS
SEPARATION PROCESSES
SURFACE WATERS
TEMPERATURE DEPENDENCE
TRACE AMOUNTS
VARIATIONS
WATER POLLUTION
X-RAY EMISSION ANALYSIS
X-RAY FLUORESCENCE ANALYSIS
ZINC