Abstract:
The objective of this research was to evaluate the efficacy of cinnamon wood biochar (CWBC) in adsorbing
sulfamethoxazole (SUL), which alleviates bioavailability and plant uptake. Batch studies at various pH, contact
times, and initial SUL loading were used to study SUL adsorption in CWBC, soil, and 2.5% CWBC amended soil.
SUL mitigation from plant uptake were examined using Ipomoea aquatica at different SUL contamination levels in
the soil. The kinetic results were described by pseudo-second-order with maximum adsorption capacities (Qmax)
of 95.64 and 0.234 mg/g for pristine CWBC and amendment, respectively implying that chemical interactions are
rate-determining stages. Hill and Toth’s model described the isotherm data for pristine CWBC, soil and CWBC
amended soil as Qmax of 113.44, 0.72, and 3.45 mg/g. Column data showed a great mobilization of SUL in loamy
sand; however, when CWBC was added to the loamy sand, the mobilization was drastically reduced by 98.8%.
The Ipomoea aquatica showed a great potential to SUL uptake and it depended on the contamination level; the
SUL accumulation in plant was 9.6–13.8 and 19.1–48 mg/kg when soil was spiked with 5 and 50 mg/kg,
respectively. The addition of 2.5% CWBC reduced root and shoot uptake by 30 and 95%, respectively in 5 mg/kg
of SUL, whereas with 50 mg/kg of SUL, the root and shoot uptake was reduced by 60 and 61%, respectively. The
current study suggested CWBC as a possible adsorbent that may be employed to reduce SUL bioavailability in
environmental matrices.
