Sulfamethazine sodium

The biofiltering capacity, distribution patterns and degradation of the antimicrobial sulfamethazine (SMT) by halophyte Chenopodium quinoa under hydroponic conditions and its further biodegradation through anaerobic digestion were evaluated. C. quinoa was cultivated for a complete life cycle under different concentrations of SMT (0, 2 and 5mg/L) and sodium chloride (0 and 15g/L). C. quinoa is able to uptake and partially degrade SMT. The higher the SMT concentration in the culture medium, the higher the SMT content in the plant tissue. SMT has different distribution patterns within the plant organs, and no SMT is found in the seeds. Dry crop residues containing SMT have a great potential to produce methane through anaerobic digestion and, in addition, SMT is further biodegraded. The highest specific methane yields are obtained using crop residues of the plants cultivated in the presence of salt and SMT with concentrations between 0 and 2mg/L.

In this work, the novel application of chalcopyrite (CuFeS2) for sodium percarbonate (SPC) activation towards sulfamethazine (SMT) degradation was explored. Several key influencing factors like SPC concentration, CuFeS2dosage, reaction temperature, pH value, anions, and humic acid (HA) were investigated. Experimental results indicated that SMT could be effectively degraded in the neutral reaction media by CuFeS2/SPC process (86.4%, 0.054 min-1at pH = 7.1). The mechanism of SPC activation by CuFeS2was elucidated, which was discovered to be a multiple reactive oxygen species (multi-ROS) process with the coexistence of hydroxyl radical (·OH), carbonate radical (CO3·-), superoxide radical (O2·-), and singlet oxygen (1O2), as evidenced by quenching experiments and electron spin resonance (ESR) tests. The generated·OH via the traditional heterogeneous Fenton-like process would not only react with carbonate ions to yield other ROS but also involve in SMT degradation. The abundant surface-bound Fe(II) was deemed to be the dominant catalytic active sites for SPC activation. Meanwhile, it was verified that the reductive sulfur species, the interaction between Cu(I) and Fe(III) as well as the available O2·-derived from the activation of molecular oxygen and the conversion of·OH favored the regeneration of Fe(II) on CuFeS2surface. Furthermore, the degradation intermediates of SMT and their toxicities were evaluated. This study presents a novel strategy by integrating transition metal sulfides with percarbonate for antibiotic-contaminated water treatment.

This work presents a novel CuS/percarbonate/tetraacetylethylenediamine (CuS/SPC/TAED) process for the degradation of sulfamethazine (SMT). Results indicated that the CuS/SPC/TAED process enabled the efficient generation of peracetic acid (PAA), which can be efficiently activated by CuS in alkaline reaction media, and 93.6% of SMT was degraded in 30 min. Mechanism study revealed that the available reactive oxygen species (ROS) including hydroxyl radical (·OH), carbonate radical (CO3·-), superoxide radical (O2·-), singlet oxygen (1O2), and organic radicals (R-O·). Among them, R-O·(acetyloxyl radical (CH3CO2·) and acetylperoxyl radical (CH3CO3·)) were confirmed to be the primary species that contributed to SMT degradation. Simultaneously, the role of sulfur species and carbonate ions were explored. It was found that the reductive O2·-and sulfur species rendered the efficient redox of Cu species. Besides, the effects of key influencing factors including SPC/TAED mole ratio, CuS dosage, initial pH, temperature, and nontarget matrix constituents on SMT degradation were examined. Finally, the degradation intermediates of SMT was identified, and the toxicity of these products was estimated by quantitative structure-activity relationship (QSAR) analysis. Overall, this work offers a new and simple strategy for antibiotic-polluted water remediation.