Adsorption of Fluoroquinolone Antibiotics by Wastewater Sludge Biochar: Role of the Sludge Source

Adsorption of fluoroquinolone antibiotics using sludge-derived biochar made of various wastewater sludges was investigated. The sludge-derived biochar had relatively large Brunauer-Emmet-Teller specific surface areas that were beyond 110.0 m(2)g(-1) except the biochar made from the sludge collected from traditional sludge drying bed. The mesopore capacity was more than 57 % of the total pore capacity of all sludge-derived biochar except that made from the sludge dried through traditional sludge drying bed technique. High adsorption capacity of sludge-derived biochar was observed with a highest adsorption capacity of 19.80 +/- 0.40 mgg(-1). High correlation between the adsorption capacity of sludge-derived biochar and the volatile content in the sludge source was observed. The Freundlich model (r(2) values were in the range of 0.961-0.998) yielded the best fit with the experimental data of all the produced biochar. Fluoroquinolone antibiotics were readily adsorbed onto sludge-derived biochar. These findings suggest a new approach for the pollution control of fluoroquinolone antibiotics using low-cost sludge-derived biochar.