Sulfonamides (SAs) in the aquatic environment are a serious threat to human health, environmental ecology and water reuse . Natural organic matter and SAs are known to compete for adsorption sites on adsorbent. SAs adsorption by high silica ZSM-5 (HSZSM-5) affected by humic monomers remains unclear. The impact of representative humic monomers (HMs) (caffeic acid (CA) and vanillin (VNL)) on the sorption of SAs by HSZSM-5 at different pH was evaluated for the first time. Fourier transform infrared and X-ray photoelectron spectroscopy were used to obtain the group transformations. The presence of HM did not change the main adsorption mechanism of SAs on pristine and loaded HSZSM-5 (pH-dependent and hydrophobic interaction). Lewis acid-base electron interaction , π-π electron donor-acceptor (EDA), and H-bonding had a positive contribution to the adsorption of SAs by HSZSM-5 after HM coating. However, HM coating and competition reduced the adsorption capacity of HSZSM-5 towards SAs. In co-introduction system of HM and SAs, the reaction between C O in HM and N–H in SAs resulted in SAs and HM co-adsorbed on HSZSM-5. Meanwhile, CA concentration <20 mg/L was in favor of SMX adsorption. The findings give an insight into the interactions among HM and SAs in high silica zeolites adsorption system, thereby improving SAs removal in actual water.
An ozonation process combined with hydrophobic adsorbent high silica ZSM-5 (HSZSM-5) was designed to enhance sulfamethoxazole (SMX) removal and reduce the ozone consumption. The promoted effect of HSZSM-5 on SMX removal was investigated in terms of SMX removal and TOC removal efficiency as well as the ozone consumption. The impacts of pH and CO 3 2− /HCO 3 - were also analyzed. The presence of HSZSM-5 helped to increase the SMX degradation and TOC removal efficiency and their kinetics rate constants. HSZSM-5 adsorption behaviors for SMX and its degradation intermediates were responsible for the findings. Direct ozone oxidation was the main mechanism of SMX removal as HZSM-5 could not contribute to producing H 2 O 2 and •OH. Much higher CO 3 2− /HCO 3 - concentration (≥10 mM) and pH value (>7) were in favor of SMX degradation. HSZSM-5 had a positive contribution to SMX removal. The mass ratio of ozone consumption to the removed SMX reduced to 0.63 g O 3 /g SMX. This system of introducing high silica zeolite in the ozonation/adsorption process is an environmentally and economically sound technology to removal micropollutants.
Nanofiltration with high stable permeance is of great significance for wastewater treatment . Herein, we reported the novel polyamide thin-film composite (PA TFC) nanofiltration membranes prepared for the first time by blending nanometer cerium doped high silica ZSM-5 zeolites (CeO 2 @HSZSM-5, CHZ) in the aqueous phase followed by the classic interfacial polycondensation . The structural morphology of these membranes and their performance had been characterized. SEM and XPS characterizations clearly revealed the presence of inorganic CHZ in the PA layer. The results also showed that the CHZ-integrated inorganic-organic PA TFC membranes with a higher fraction of CHZ had a thinner PA active layer (28.3 ± 3.6 nm) and slightly enlarged pore size with lower crosslinking degree. The optimized membranes exhibited 1.65-folds pure water permeability of the traditional membrane, 20.3 L/(m 2. h . bar) with comparable Na 2 SO 4 and MgSO 4 rejection of 95.8% and 91.1%, respectively. The rejection of dyes stayed stable above 96.0% with boosted permeance, and the membrane almost completely removed CR and RB as well as natural organic matters. The composite membrane also sustained superior stability and excellent antifouling performance. The as-prepared CHZ-integrated PA TFC membranes with regulatable structural morphology and superior separation properties enables the potential practical application in wastewater treatment.
危险品化学品经营许可证（带存储）