51395-19-8

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InChI:InChI=1/C12H14N4O3S/c1-7-11(17)8(2)15-12(14-7)16-20(18,19)10-5-3-9(13)4-6-10/h3-6,17H,13H2,1-2H3,(H,14,15,16)

Upstream product

• 57-68-1 sulfadimesine 

Relevant academic research and scientific papers

The performance and degradation mechanism of sulfamethazine from wastewater using IFAS-MBR

Sulfamethazine (SMZ) is an important sulfonamide antibiotic. Although the concentration in the environment is small, it is harmful. The drug residues can be transferred, transformed or accumulated, affecting the growth of animals and plants. In this study, the integrated fixed-film activated sludge membrane bioreactor (IFAS-MBR) were constructed to investigate the performance and degradation mechanism of SMZ. The addition of SMZ had a significant impact on the removal of the chemical oxygen demand (COD) and ammonia nitrogen (NH4 +-N). The optimal operating conditions were hydraulic retention time (HRT) at 10 h and solid retention time (SRT) at 80 d, respectively. On this basis, the effects of different SMZ concentrations on nutrient removal, degradation, and sludge characteristics were compared. The removal efficiency of SMZ increased with the increase of SMZ concentration. The maximum removal rate was as high as 87%. The SMZ dosage also had an obvious effect on sludge characteristics. As the SMZ concentration increased, the extracellular polymer substances (EPS) concentration and the membrane resistance both decreased, which were beneficial for the reduction of membrane fouling. Finally, seven kinds of SMZ biodegradation intermediates were identified, and the possible degradation pathways were speculated. The microbial community results showed that the microbial diversity and richness in the reactor decreased after adding SMZ to the influent. The relative abundance of Bacteroidetes, Actinobacteria, Saccharibacteria and Nitrospirae increased at the phylum level. Sphingobacteria and Betaproteobacteria became dominant species at the class level. The relative abundance of norank-p-Saccharibacteria and Nitrospirae increased significantly, and norank-p-Saccharibacteria may be the dominant bacteria for SMZ degradation.

Photolysis and photocatalytic decomposition of sulfamethazine antibiotics in an aqueous solution with TiO2

Photo-decomposition of sulfamethazine (SMT) involves photolytic and photo-catalytic reactions, which occur simultaneously. The relative contributions of these two reactions to the overall SMT photo-decompositions by TiO2 and the intermediates of SMT photo-decompositions were systematically examined with the effects of TiO2 loading, and the pH and the initial SMT concentrations in the solutions. The apparent rate constants of SMT photo-decomposition reactions, which were well described by the pseudo-first-order kinetic model, ranged from 0.24 to 1.61 h-1. The overall photo-decomposition efficiencies of 0.072 mM SMT were the highest at pH 5.5 with 0.5 g L-1 TiO2 due to the adsorption-induced photocatalytic decomposition of SMT on TiO2. However, the SMT photolysis occurred more rapidly at pH 10. Two reactive species of holes and hydroxyl radicals concurrently participated in the photocatalytic decomposition of SMT, and the latter dominated the oxidative reactions of SMT on TiO2. Eight intermediates of SMT photo-decomposition were determined using LC-MS. Their time-dependent distributions indicated that the photo-decomposition of SMT was triggered by hydroxylation on aniline and dimethylpyrimidinyl moieties, followed by the cleavage of the S-N bond of SMT. Our results illustrated that the intermediates with dimethylpyrimidinyl groups possess strong resistance to photo-decomposition and played a determinant role in the photo-decomposition of SMT.