"The purpose of this research study was to investigate the effect of biological activities on the desorption of pesticides from humic acid solids. The pesticides selected in this study are dieldrin and heptachlor, both of which have been commonly used in agricultural applications. The humic acid adsorbent was extracted from a coal-like substance called "leonardite", which has a humus content of as high as 53 percent by weight. The first step of this study involved a proper cultivation of biological culture so that the culture could be adapted to a test environment containing a high concentration of humic acids. The degree of acclimation and the corresponding biological activity were determined by the microbial capability of stabilizing sewage organics as well as glucose. The second step of the study involved the addition of pesticide-coated humic acid solids to a series of aeration units containing cultivated biological cultures. Each unit was subjected to a certain properly designed condition. The extent of pesticide desorption in each unit was carefully monitored. Results of this study indicate that although humic acids are not amenable to biodegradation, they do not inhibit any biological activity. Also, the active biological activities maintained in the aeration units do not appear to exert any significant influence on the dieldrin and heptachlor desorption from humic acids"--Abstract, pages ii-iii.
Huang, Ju-Chang, 1941-2018
Civil, Architectural and Environmental Engineering
M.S. in Civil Engineering
United States. Office of Water Resources Research
University of Missouri--Rolla
x, 99 pages
© 1972 Loh-Tien Chiang, All rights reserved.
Thesis - Open Access
Library of Congress Subject Headings
Pesticides -- Analysis
Sewage -- Purification -- Activated sludge process
Print OCLC #
Electronic OCLC #
Link to Catalog Record
Chiang, Loh-Tien, "Effect of biological activity on pesticide desorption" (1972). Masters Theses. 5123.