Document Type


Date of Award

Spring 5-31-1990

Degree Name

Master of Science in Environmental Science - (M.S.)


Chemical Engineering, Chemistry and Environmental Science

First Advisor

Samir S. Sofer

Second Advisor

Richard B. Trattner

Third Advisor

David Kafkewitz


Cadmium uptake by cells of Gram-positive and Gram- negative bacteria was studied. Gram-positive and Gram- negative bacterial cells were separated from activated sludge collected from the Parsippany Troy Hills Water Pollution Control Plant (NJ) by isolating them on agar plates. These were grown separately and used for uptake experiments.

Gram-positive bacterial cells showed 17% more uptake of cadmium as compared to Gram-negative cells at 30°C and pH 6.6. More than 95% of the total cadmium removal from the solution was observed during first 5 min. of cell-metal contact time. In case of Gram-positive bacteria cadmium uptake decreased by 5-10% after cells were inhibited by contacting with 1M sodium azide for 45 min. In the case of Gram-negative bacteria, uptake decreased by 4-5% under same conditions.

Cadmium uptake increased by 13% in Gram-positive bacteria after addition of nutrients, suggesting some metabolic uptake of cadmium. Although cadmium uptake decreased by 4-5% after inhibition of cells with sodium azide, there was no significant increase in cadmium uptake by Gram-negative bacteria after nutrient addition.