HNSE-P2-5. Synthesis and Characterization of Modified Walnut Shell Biochar

Maaike Parajes1
Suraj Pochampally1
Faculty Mentor: Jaeyun Moon, Ph.D.1
1Howard R. Hughes College of Engineering, Department of Mechanical Engineering

Biochar (BC) is a porous carbon material synthesized from different biomasses that are subjected to pyrolysis. This product is an efficient and eco-friendly alternative to conventional absorbents used for contaminant removal in groundwater systems. In this study, we aimed to develop efficient methods of preparing walnut shell-based biochar through acid, base, and steam modification and compare these modified biochars with the unmodified version. The preparation of biochar involved pyrolysis using an argon gas-filled chamber at a temperature of 900 °C. These BCs were then crushed and sieved to separate the microporous particles. To further evaluate the biochars’ characteristics, it was characterized using SEM, FTIR, EDS, BET, and contact angle measurements. The modification results showed that the modified biochars have different functional groups and are more hydrophilic than the unmodified biochar. Upon further investigation, the results can vastly improve the usage of biochar in the remediation process of contaminants to make the process economically feasible and environmentally friendly.


Nov 15 - 19 2021


All Day


HNSE: Poster Session 2
The Office of Undergraduate Research


The Office of Undergraduate Research


8 Replies to “HNSE-P2-5. Synthesis and Characterization of Modified Walnut Shell Biochar”

  1. Hi Maaike. Could you elaborate on how the FTIR results provides information on how the biochar is “improved” or not by modification? What do the different functional groups tell us?

    1. Hello Dr. Marti,

      Thank you for the question! FTIR further reinforces the idea that the adsorbant properties are determined by its functional groups. The water contact angle test determines the hydrophilipity of the biochar by measuring its angle. Through FTIR, we can identify the specific functional groups that make the modified biochar hydrophilic by detecting the peak intensities. In this case, we can see the effects of acid, base, and steam modification. For example, the larger intensity peak of the C-O group in pre-acid modification indicates that this compound is more hydrophilic compared to the post- acid modification. The importance of looking at these hydrophilic regions allows us to understand that biochar will be more interactive with a polar molecule such as water. Therefore, since the modified biochar has more interactions with water we notice the adsorbance properties.

  2. Hello! thank you for your response and question. Biochar has many implications from water treatment to soil remediation or fertilizer. It is a better alternative when it comes to exploring its adsorption capabilities since it is eco-friendly and cost-efficient. I hope I helped answer your question!

  3. Overall, a wonderful presentation and well organized research project! It is crazy to think that this small, porous compound is capable of serving as a contaminant remover. Biochar might be especially useful beyond the decontamination of water, but also the reduction of contaminants in the air such as reducing global green house gasses. I especially like how you included the comparison of modified and unmodified biochar. It provides insight on how the physical properties of biochar affects its function. A question I might have for future researchers on this topic is how do we utilize biochar beyond the purification of water?

  4. I was very intrigued by this study and makes me feel that biochar would prove more effective than using reverse osmosis to reuse and clean our water. 😀

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