Date of Graduation

Spring 2016

Document Type

Honors Research Project

Degree Name

Bachelor of Science


Chemical Engineering - Cooperative Education

Research Sponsor

Lu-Kwang Ju

First Reader

Bi-min Newby

Second Reader

Gang Cheng


The purpose of this experiment was to identify if a rhamnolipid could inhibit the growth of a biofilm on carbon steel coupons and result in less corrosion activity. This type of research impacts various industries (with one of the largest being the oil and gas industry). Multiple systems with varying concentrations of the rhamnolipid were created to determine, if any, the optimum concentration to inhibit biofilm growth. The systems were created and exposed to optimum physio-chemical environments to promote SRB induced corrosion. Coupons were immersed for 28 days. Seven systems were created with varying rhamnolipid concentrations; to ensure accurate results, duplicates of each system were created. Due to the complexity of creating samples and number of analysis techniques, time was the largest limitation in this experiment.

The systems were analyzed using a scanning electron microscope, weight loss analysis, infinite focus microscope, cell protein analysis, and confocal microscope. The results confirmed that corrosion activity was present in the systems. It was also established that the addition of a rhamnolipid decreased biofilm formation (and therefore corrosion) up to a concentration of 750 ppm, but accelerated corrosion at concentrations greater than that. A concentration of 750 ppm was identified as the optimum concentration.