Uptake of Sulfa Drugs from Aqueous Solutions by Marine Algae

Abstract

Marine algae Lessonia nigrescens Bory (L13) and Macrocystis integrifolia Bory (S12) were evaluated as adsorbents for the removal of sulfamethoxazole (SMX) and sulfacetamide (SAM). Batch adsorption of SMX and SAM was investigated as a function of pH, adsorbent dosage, initial sulfa concentration, and ionic strength. The maximum adsorption capacity of SMX followed the trend: L13 > S12 within the range 56.63-73.8 mg/g, whereas for SAM, it ranged between 177.94 and 163.67 mg/g with the trend: S12 > L13. Based on the results, the formation of hydrogen bonds as the main mechanism is proposed. A solution of 0.1 N NaOH recovered the adsorbents with a high efficiency for their use in repetitive cycles. FTIR and SEM techniques were utilized for the characterization of both adsorbents. The potential use of seaweed in the elimination of sulfas from residual water was explored as a low-cost and environmentally-friendly purification technique.

Keywords:

• biosorption
• isotherm
• marine algae
• pH
• sulfacetamide
• sulfamethoxazole