锰改性芦苇基生物炭的制备及其催化臭氧氧化效能

：To explore the utilization of wetland plants, biochar was prepared from Phragmites australis, a dominant wetland plant in the cold and arid regions of Northwest China, and its adsorption performance and catalytic ozona⁃ tion performance for the treatment of biochemical effluent from coking wastewater were investigated. During the bio⁃ char preparation process, manganese nitrate and iron nitrate were added to obtain Mn-and Fe-loaded modified bio⁃ chars of BCMn and BCFe, respectively. Characterization results showed that the specific surface area and total pore volume of BCMn and BCFe were significantly increased compared with the original biochar(BC), and BCMn per⁃ formed better. Adsorption kinetics studies indicated that the adsorption of phenol by BC, BCMn, and BCFe were all conformed to the pseudo-second-order reaction kinetic equation, and BCMn had the largest equilibrium adsorption capacity. The iodine adsorption value determination results also confirmed that BCMn had the best adsorption per⁃ formance. On this basis, BCMn was used as the catalyst for catalytic ozonation to treat the biochemical effluent from coking wastewater. The COD removal rate reached 66.8%, which was 1.6 times that of the single ozonation process. The final effluent COD was 83 mg/L, which was lower than the COD discharge limit (100 mg/L) stipulated in the Emission Standard of Pollutants for Coking Chemical Industry (GB 16171—2012). Three-dimensional fluorescence spectroscopy analysis showed that the removal rate of total fluorescent substances in coking wastewater by BCMn-catalyzed ozonation was 87.2%. The stability experiment showed that after reuse of BCMn three times, the COD re⁃ moval rate still remained at 60.00%, and the manganese leaching mass concentration (≤0.074 mg/L) was much lower than the total manganese limit (2.0 mg/L) in the Discharge Standard of Pollutants for Municipal Wastewater Treat⁃ ment Plant (GB 18918—2002). After treatment, the wastewater met the discharge requirements (≤0.1 mg/L) for total manganese of Class Ⅲ water in the Environmental Quality Standards for Surface water (GB 3838—2002).