Trichloroethylene (TCE) and tetrachloroethylene (PCE) are halogenated aliphatic organic compounds, widely used for their degreasing properties in both dry cleaning and industrial manufacturing. Improper disposal of TCE and PCE over the years has led to high concentrations contaminating groundwater. Because they are volatile, they rise towards the surface as vapors and also contaminate the air. TCE and PCE are toxic to humans and animals, leading to issues such as liver and heart disease, neurological impairments, cancer, and low birth weight. Biochar is a carbonaceous material made from a select biomass through pyrolysis. The porous structure of biochar makes it a good adsorbent for unwanted compounds by allowing them to bind and essentially get stuck within the pores. The objective of this study is to compare and contrast biochar made from different feedstocks at different temperatures with the purpose of finding which ones have the best adsorption potential. Biochar feedstocks selected were peanut, pine, pecan, and walnut. Multiple pyrolysis temperatures were tested to see which temperature produced biochar with the smallest water contact angle (demonstrating hydrophilic properties, meaning it would mix better with water). Vials with TCE/PCE concentrations ranging from 30-80 ppb were mixed with biochar doses ranging from 0-40 mg in an incubated orbital shaker for 72 hours. Samples were analyzed using gas chromatography-electron capture detector and results were plotted for % TCE/PCE remaining in the solution. For TCE removal, all biochars tested performed well. All samples were brought down to ~20% of their initial TCE concentrations with 20 mg or more of biochar used. When it comes to PCE removal, Walnut 900 was superior. Peanut, Pecan, and Pine biochars removed 40-60% of the PCE in solution when 20 mg was used. Walnut biochar brought samples below 5% of their initial PCE concentrations when 20 mg was used.

Evaluation of feedstock and Pyrolysis temperature on Biochar production for TCE and PCE removal in water

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ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.