Surface modification of sewage sludge derived carbonaceous catalyst for m-cresol catalytic wet peroxide oxidation and degradation mechanism

Abstract

Sewage sludge derived carbonaceous materials (SWs) treated with different kinds of acid were used as the catalysts for catalytic wet peroxide oxidation (CWPO) of m-cresol in batch reactor and continuous reactor, respectively. The results showed that SW treated with nitric acid (HNO 3 -SW) and sulfuric acid (H 2 SO 4 -SW) exhibited high catalytic activity in a CWPO reaction. The conversion of m-cresol reached 100%, after CWPO reaction for 3 h at an initial pH of 7 and a temperature of 25 C over a H 2 SO 4 -SW catalyst. The elements content and chemical state of SWs treated with different kinds of acids were measured by XRF, XPS and Mössbauer spectra, the results implied that ferric iron and surface functional groups might play the main role in m-cresol degradation. The intermediate oxidation products were identified by in situ NMR, GC-MS, IC and HRMS analyses. Based on a free-radical reaction mechanism, a m-cresol oxidation pathway in CWPO was proposed.

Surface-Modified Sewage Sludge-Derived Carbonaceous Catalyst as a Persulfate Activator for Phenol Degradation

“…As shown in Figure 8, high conversions and removal rates of phenol were maintained at pH 7 and pH = 10. Then we found out that the pH value of phenol solutions were decreased from 7.0 to 4.0 and 10.0 to 7.1 after the PS was added, which is consistent with the previous study [42]. Therefore, the reactions were under the pH of 4.0 and 7.1.…”

“…Res. Public Health 2020, 17, x 9 of 15 after the PS was added, which is consistent with the previous study [42]. Therefore, the reactions were under the pH of 4.0 and 7.1.…”

Visible Light Driven Organic Pollutants Degradation with Hydrothermally Carbonized Sewage Sludge and Oxalate Via Molecular Oxygen Activation

“…Pyrolysis is a conventional process to heat predried sewage sludge at temperatures of 350–800 °C in an anaerobic atmosphere . Besides being used as sorbents to remove harmful gases (e.g., SO 2 and H 2 S) or organic pollutants (e.g., dyes and chlorinated organics), ,− pyrolyzed sewage sludge was also explored for some new applications. ,− For instance, Dai’s group synthesized a sewage sludge-derived Fe-loading nanocomposite via a one-step pyrolysis method, and employed it as a stable heterogeneous photo-Fenton catalyst to remove rhodamine B and p -nitrophenol . Yuan et al prepared a composite TiO 2 photocatalyst with using sewage sludge as the support and the dopant source and found the resulting composite photocatalyst could remove p -nitrophenol more efficiently than TiO 2 P25 under visible light .…”

Performance of Supported Copper Catalysts for Oxidative Degradation of Phenolics in Aqueous Medium: Optimization of Reaction Conditions, Kinetics, Catalyst Stability, Characterization, and Reusability

“…Sewage sludge-derived AC-based catalysts have also been used during the catalytic wet peroxide oxidation (CWPO) of m-cresol (initial substrate = 100 mg/L). 33,34 The available large number of studies using AC-and Al 2 O 3 -supported catalysts investigated CWO performance with a single substrate (i.e., phenol). Moreover, it was observed that the majority of the studies used a low phenol concentration (=0.5−5.0 g/L) except few studies in which phenol concentration was varied from 1 to 10 g/L.…”

“…However, no information about carbon removal was provided. Sewage sludge-derived AC-based catalysts have also been used during the catalytic wet peroxide oxidation (CWPO) of m -cresol (initial substrate = 100 mg/L). , …”