Marlan Zha ’27, Chemistry

Marlan Zha ’27

Major

Chemistry

Project Title

Nitrogen Cycling in the Ocean

Presentation Link

View Marlan's Presentation

Minor(s): Climate Science, Materials Science and Engineering

Nitrogen-based compounds are essential to the survival of all marine organisms. Thus, understanding nitrogen species availability can provide insight into the types of organisms living at varying depths in the ocean. I contributed towards two main projects with the Ward Lab — analyzing nitrate concentration and the rate of nitrite oxidation in the southern Pacific Ocean. To gather nitrate concentration data, I injected samples into an NOx analyzer which measured the total concentration of nitrite and nitrate in each sample and then subtracted the total concentration and the nitrite concentration to determine nitrate concentration. To measure the rate of nitrite oxidation, I first removed excess nitrite in the samples and adjusted the pH of each sample to neutral. Then, I injected bacteria into the samples that converted the nitrate in the samples to nitrous oxide, which is detectable on our gas chromatography isotoperatio mass spectrometer (GC-IRMS). Finally, I ran the samples on the GC-IRMS to analyze the concentration of nitrate in each sample. I have always been interested in environmental science, and it was eye-opening to learn about the biogeochemical processes that occur in the ocean, which has motivated me to learn even more about the environment.