Title: Estimation of fate of sulfamethoxazole in soil by adsorption test and diffusion cell test - a comparative analysis
Authors: Neelancherry Remya; Ankit Singh
Addresses: School of Infrastructure, Indian Institute of Technology Bhubaneswar, Odisha, 752050, India ' Civil Engineering Department, National Institute of Technology Calicut, Kerala, 673601, India
Abstract: The present study investigated adsorption of sulfamethoxazole (SMX), one of the antibiotics of sulfonamide group, in three soils by adsorption and diffusion cell test. The removal efficiency of SMX by adsorption in soil-1,-2 and -3 were 80.16%, 23.39% and 15.51% when the organic matter (OM) content was 6.05%, 9.22% and 11.10% respectively. The respective maximum adsorption capacities estimated by adsorption test in the three soils were 3.31, 3.13 and 2.47 mg/g. On the other hand, the corresponding adsorption capacity obtained by the diffusion cell test was 0.016, 0.010, 0.008 mg/g, which showed 15 to 30 times decrease compared to the estimated values by adsorption test. The adsorption results showed a weak interaction and negative correlation of SMX with OM. The retardation factor of SMX in the three soils-1, -2 and -3 were respectively 181.32, 47.26 and 34.04. At SMX concentration greater than 10 mg/L, leaching of SMX increased with increase in pH due to increased hydrophilicity resulted by speciation of SMX.
Keywords: sulfamethoxazole; soil; adsorption; isotherm; adsorption capacity; central composite design; response surface methodology; diffusion coefficients; organic matter; pH; retardation factor.
International Journal of Environment and Waste Management, 2020 Vol.25 No.4, pp.441 - 453
Accepted: 29 Dec 2018
Published online: 23 Mar 2020 *