Feasibility of using nanoscale zero-valent iron and persulfate to degrade sulfamethazine in aqueous solutions

• Published in: Separation and purification technology Vol. 194; pp. 388 - 395
• Main Authors: Lin, Chia-Chang, Chen, Yung-Hsuan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 03.04.2018
• Subjects: Antibiotic; Nanoscale zero-valent iron; Persulfate; Sulfamethazine; Nanoscale zero-valent iron; Antibiotic; Sulfamethazine; Persulfate
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2017.10.073

•An effective degradation of SMT by nZVI/PS process was achieved.•Complete degradation of SMT was obtained in 30 min by nZVI/PS process.•This study provides a novel treatment of SMT-contaminated wastewater. This study investigates the effectiveness of the nanoscale zero-valent iron and persulfate (nZVI/PS) process in degrading sulfamethazine (SMT) in aqueous solutions. nZVI was formed using a rotating packed bed with blade packings. The dominant generated free radical in the nZVI/PS process for degrading SMT was SO4−. nZVI can gradually release Fe2+, which subsequently activates PS to form SO4−, increasing the efficiency of degradation of SMT by this process. The effects of the PS/nZVI molar ratio, initial SMT concentration, and species of inorganic anions on the efficiency of degradation of SMT were also studied. A PS/nZVI molar ratio of 1/0.5 in the nZVI/PS process was chosen to reduce the required nZVI dosage at PS concentrations of 0.5, 1, and 2 mmol/L. The efficiency of degradation of SMT declined as the initial SMT concentration was increased. Inorganic anions (SO42−, HCO3−, NO3−, and Cl− ions) at high concentrations inhibited the degradation of SMT and their suppressive effects followed the order SO42− > HCO3− > NO3− > Cl−. The efficiency of degradation of SMT using the formed nZVI significantly exceeded that using commercial nZVI that was purchased from Centron Biochemistry Technology. At an nZVI dosage of 56 mg/L, a PS concentration of 2 mmol/L, and an initial SMT concentration of 10 mg/L, the efficiency of degradation of SMT was 93% after 5 min in the absence of inorganic anions. Therefore, the nZVI/PS process is highly effective in degrading SMT in aqueous solutions.