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Civil Engineering Professor leads team effort to remove cancer-causing compounds from water using biochar derived from LA oak tree sawdust

A team of Civil engineering researchers have found a way to remove PFOA from water using biochar derived from Oak sawdust. This team consists of Daniel Gang, Ph.D., P.E. UL Lafayette Distinguished Professor of Civil Engineering, Xiaobo Lei, a 3rd year Ph.D. candidate, Pubali Sarker, a 1st year M.S. student, and Michael Gee, an NSF REU supported undergraduate from the University of California Berkeley.

Perfluorooctanoic acid (PFOA) was first manufactured in 1946 and dubbed the “modern miracle of chemistry” for its ability to repel water and oil. These “magical” properties made it highly applicable in countless industries and was used in everyday products such as waterproof clothing, nonstick cooking appliances, and fast-food wrappers. PFOA, like plastic, remains in the environment indefinitely, earning the nickname “forever chemicals.” PFOA has been found in lakes, marine life, and almost everywhere, including the snow in the Himalayas. However, decades later, researchers began linking PFOA exposure to serious adverse health effects, including cancer, thyroid disease, ulcerative colitis, and congenital disabilities. Hence, the Environmental Protection Agency has established the health advisory levels that stand at 70 parts per trillion.

Scientists and engineers have spent years developing mechanisms to remove PFOA from water. They found adsorption, especially activated carbons, to be the most effective and affordable treatment. Activated carbon technologies have traditionally been derived from coal a nonrenewable fossil fuel.

However, a team of environmental engineering researchers at the University of Louisiana led by Dr. Daniel Gang are challenging the conventional coal-derived activated carbons adsorbents by deriving a renewable biochar from Oak Sawdust. The research team chose Oak as the feedstock because of its abundance and properties. “Oak is a common native tree to Louisiana, and Oak sawdust is produced as a waste by-product of the Oak industry. Also, Oak contains less than 1% ash content.” indicated Dr. Gang, the Principle Investigator of the project and a distinguished Professor at UL Lafayette.

Dr. Gang’s lab optimized the adsorption capacity of the biochar through laboratory testing. They experimented with modifying with environmentally-friendly compounds to increase its specific surface area, performed hydrolysis to remove the modifying compounds, and finally carbonized the samples under different temperatures. Comparing with the traditional activated carbon, the Oak Tree Sawdust derived biochar has much higher adsorption capacity (83.7 mg/g).

“In addition, the disposal of enormous volumes of sawdust generated by the wood industry can be quite costly. However, more applications of oak sawdust, such as adsorption, could improve this industry’s profits and reduce waste,” Xiaobo Lei, a 3rd-year graduate student, explained.

Additionally, according to Michael Gee, an undergraduate from UC Berkeley supported by the National Science Foundation (NSF) Research Experience for Undergraduates (REU) program,  Advanced Infrastructure of Materials (AIM),  “The effectiveness, abundance, and potential low-cost of this adsorbent may provide a practical solution to reduce PFOA exposure to local communities and surrounding ecosystems.”

Recently, the US House of Representatives passed the PFAS Action Act of 2021 which directs the EPA to quickly reduce and remediate the chemicals known as PFAS. The bill passed on July 21 with a bipartisan vote of 241-183, and now awaits action in the US Senate. The Act would create a national drinking water standard for select PFAS chemicals, designate PFAS as hazardous substances, limit industrial discharges and provide $200 million annually to assist water utilities and wastewater treatment facilities.  The PFAS Action Act would require the EPA to establish within two years a national drinking water standard for the two most notorious PFAS chemicals – PFOA, formerly used to make DuPont’s Teflon, and PFOS, formerly an ingredient in 3M’s Scotchgard –that protects public health, including the health of the most vulnerable populations among other requirements.

Pictured are Dr. Daniel Gang, P.E (far left). UL Distinguished Professor, Xiaobo Lei (right center), a 3rd year Ph.D. candidate, Pubali Sarker (left center), a 1st year M.S. student, and Michael Gee (far right), an NSF REU supported undergraduate from the University of California Berkeley.

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