Removal of pharmaceuticals using biochar

Full title: Removal of pharmaceuticals using biochar: Low-cost solutions to improving the water quality of wastewater effluent

Presented on April 27, 2022, by Marlene Carla Ndoun - Pennsylvania State University - at the 2022 Emerging Contaminants in the Environment Conference (ECEC22)

Once administered, 30% of the active ingredients in pharmaceuticals are absorbed by the body, while 70% are excreted unaltered or as active metabolites that become part of the influent to wastewater treatment plants (WWTPs). This raises concerns regarding the potential ecological effects of these contaminants, particularly on non-target organisms, such as fish. Moreover, interactions between pharmaceuticals and natural organic matter in wastewater sources can lead to an overall increase in net synergy and as a result, can become more difficult to remove with standard treatment technologies. This study explores biochars from cotton gin waste and walnut shells as potential adsorbents for the removal of pharmaceuticals (acetaminophen, ibuprofen, sulfapyridine, and docusate) and humic acids from aqueous solution. Physico-chemical properties of the biochar were characterized by Brunauer-Emmett-Teller (BET) analysis, scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), pH and point of zero charge (pHPZC). Results showed that adsorption onto biochars was influenced by the solution pH, surface area, net charge, and functional groups of the biochars. The mechanisms for removal involved hydrophobic interactions, hydrogen bonding and pi-pi electron donor acceptor interactions. Results show that biochars could be used as cost-effective, environmentally friendly alternatives for the removal of contaminants from aqueous solutions.