A Combination Treatment Shows Highest Efficacy in Bioremediation of Petroleum Contaminated Soil

AJAS · 2022 Environmental Science

Parmesh Sivakumar

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Overview

The world runs on oil. While notable oil spills involving tankers catch the eye of the public, oil spillage caused by other anthropogenic activities such as consumer use often goes unnoticed and is the major cause of petroleum contamination. Petroleum components include hazardous organic chemicals that pose a threat to environmental and human health. In this experiment, a potential solution involving the microbial bioremediation for degrading petroleum-contaminated soil was examined. Bioremediation stands as an internationally accepted, cost-effective, eco-friendly technique that can enhance the removal of petroleum pollutants. The gravimetric method was utilized to monitor the reduction of total petroleum hydrocarbon over a period of 30 days in six soil samples exposed to a petroleum concentration of 8% (w/w). The soil samples were amended using Bacillus subtilis for bioaugmentation (introduction of hydrocarbon utilizing microorganisms), cow manure for biostimulation (addition of nutrients to stimulate microbial growth), and potato peels for biosorption (allows for adsorption of pollutant) as well as combination treatments. It was hypothesized that the combination treatment of bioaugmentation and bio-stimulation would offer the highest percent of petroleum degradation due to the unique partnership between highly productive petroleum degrader B. subtilis and nutrient-rich bio-stimulant cow manure which is essential to microorganism activity. Overall, the average percent of petroleum degraded was the highest at 63% in the combination treatment of bioaugmentation and bio -stimulation which validates the hypothesis. Among the individual treatments, bioaugmentation showed the highest average percent degradation at 54% conveying that the application of microbes to contaminated soil is effective. The control showed around 11% average degradation signaling that petroleum degradation in untreated soil is inefficient.

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From the student

Hi, my name is Parmesh Sivakumar. I am a Junior at Methacton High School, Eagleville, PA. I play tennis and collaborate with friends on creating and maintaining student-run companies in my free time. Likewise, I am a student representative at my local township and volunteer at various events sponsored by the township Parks & Recreation Board. Believe it or not, I started participating in science fairs since first grade. Over the years, my area of research has narrowed to Environmental and Earth Sciences. My experiments ranged from recycling paper at home, making environment-friendly biodiesel, and making cellulosic bioethanol. I enjoy performing science projects at home, and my parents set up a mini-lab area for me, complete with a centrifuge, orbital shaker, etc. It is an honor to represent my school and present my findings at various science competitions like the Pennsylvania Junior Academy of Science (PJAS), Montgomery County Science Research Competition, Delaware Valley Science Fairs, and win several awards. I am a very hands-on person, and doing research is very rewarding. In 2018, as a middle school student, I was recognized as one of the Broadcom Masters Top 300. Last year, I wrote a research paper for my English class, and the topic I chose was related to the human rights violation in the Niger Delta community stemming from large-scale oil spills. It inspired me to research how petroleum-contaminated soil can be remediated effectively to render it safe for vegetation in least amount of time. This would also help people living in such areas avoid developing diseases like cancer. Communities that are affected by petroleum contamination but at the same time rely on agriculture can greatly benefit from knowing the results of experiments like mine. Although this is my 5th year at PJAS, I am extremely elated to explore my opportunities as a first-time AJAS delegate. I am looking forward to learning a lot from my peers, great scientists, and overall thoroughly enjoying the experience.

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Transcript

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Hi, I’m Parmesh Sivakumar. I am form Collegeville, Pennsylvania.

We all have watched the Dawn dish liquid commercial where ducks that were exposed to oil spills are cleaned. But, have we ever thought how the soil that’s exposed to oil spills can be cleaned?

Last year, I wrote a research paper for my English class on the human rights violation in the Niger Delta community stemming from large-scale oil spills. It inspired me to investigate how petroleum-contaminated soil can be remediated effectively to render it safe for vegetation in the least amount of time.

The world is very dependent on petroleum. Oil-spills are an inevitable problem we face. Oil contamination is toxic to humans and animals. Furthermore, it reduces the ability of soil to support the growth of plants. Bio-remediation: refers to the eco-friendly removal or transformation of contaminants to harmless or less harmful substances.

There are three main bioremediation techniques -

Bioaugmentation where exogenous microbes are added to breakdown the petroleum hydrocarbons

Bio-stimulation where the soil is amended to stimulate indigenous bacteria

Biosorption which Leads to adsorption of the contaminant by affinity of the surface to bind with the pollutant through the porous structure of the sorbent material

I wanted to test the effectiveness of each of these techniques individually and in combination.

My hypothesis was that the combination treatment of bioaugmentation and bio-stimulation would offer the highest percent of petroleum degradation due to the unique partnership between the highly productive petroleum degrader Bacillus subtilis and nutrient-rich bio-stimulant cow manure which is essential to microorganism activity.

As a result of the experiment, my hypothesis was validated; the combination treatment with cow manure and Bacillus subtilis proved to be the most effective. Within a span of 30 days which is a relatively short amount of time considering how long most bio-remediation methods take, the percentage of petroleum present was able to decrease greatly in the combination treatments as opposed to individual treatment.

Communities that depend on both agriculture and petroleum extraction can benefit greatly from knowing the results of my experiment.