Póster presentado en la Virtual Session--Soils and Environmental Quality Poster in ASA, CSSA, SSSA International Annual Meeting, Salt Lake City, UT. (2021)
Biochar (BC) has been proposed as cost-effective and environmentally-friendly alternative to mitigate soil contamination produced by several veterinary antibiotics, such as sulfonamides. The intensification of agricultural and livestock activity has increased the environmental problems caused by their use. Although the sorptive behavior of biochars depends on the original feedstock and pyrolysis temperature, activation processes are being developed to increase the sorption by low-temperature biochars, which are the most suitable for soil fertility applications but have relatively low sorption capacities. In this study, we assessed the sorption, dissipation, and leaching of the antibiotic sulfanilamide in soil treated with low-temperature biochar and activated-biochar. The biochar used was a commercial wood biochar prepared at 500 ºC which was treated with KOH, NaOH, oxalic acid and FeNO3 at 10% (w/w) to improve its affinity towards the organic compound. The sorption capacities of the untreated and treated biochars were assessed in batch studies and revealed that only BC treated with FeNO3 (BC-Fe) noticeably increased sulfanilamide sorption. In the presence of soil, the dissipation of the antibiotic was similar in either untreated soil or soil treated with BC and BC-Fe added at 2 % (w/w). However, the simultaneous determination of sorption during the incubation experiment indicated that lower amount of sulfanilamide in the soil solution was bioavailable in soil treated with BC than in BC-Fe treated soil. The leaching column study indicated the ability of BC and BC-Fe to immobilize the compound in the first 5 cm of soil. Therefore, the decrease in bioavailability and movement of sulfanilamide in amended soils suggests that biochar can reduce contamination of water and soil due to this type of compounds. These results should be considered in order to optimize the performance of biochar-amended soils.
PID2019-109456RB-I00 of MCI/AEI and PY20-00746 of Junta de Andalucía, co-financed with FEDER-FSE funds.