Mn-Cu复合催化过硫酸盐降解木质素类污染物的研究

Study on Mn-Cu Composite Catalyzed Persulfate for Degradation of Lignin-like Pollutants

关键词:  过硫酸盐  Mn-Cu双金属复合催化剂  木质素  造纸废水  降解

Key Words:persulfate  Mn-Cu bimetallic composite catalyst  lignin  papermaking wastewater  degradation

摘要:本研究以二氧化锰、硝酸铜和二甲基咪唑为原料，采用共沉淀法制备了MnO₂-Cu(mIM)₂双金属复合催化剂，利用该催化剂活化过硫酸盐以降解木质素模型物香草酸。采用单因素法及响应面法研究催化剂制备和反应条件对催化剂催化活化效率的影响，进一步探讨了催化剂的催化机理。研究表明，在催化剂用量0.387 g/L、氧化剂初始浓度1.3 mmol/L、pH值为6.1的条件下，可以降解94.23%的香草酸；三维荧光检测表明，该催化剂可以有效催化氧化降解对造纸废水中污染物；电子顺磁共振表征表明，该降解体系中的主要反应活性物质是¹O₂、·OH和SO4-·，其中非自由基¹O₂起主要作用。

Abstract:MnO₂-Cu（mIM）₂ bimetallic composite catalyst was prepared by co-precipitation method using manganese dioxide， copper nitrate， and dimethylimidazole as raw materials. The catalyst was used to activate persulfate and degrade vanillic acid as a lignin model. The single factor method and response surface methodology were used to study the influence of the preparation conditions of catalysts and reaction conditions on the catalytic activation efficiency of catalyst， further explored the catalytic mechanism of catalysts. The results showed that 94.23% of vanilla could be degraded at the optimum conditions （catalyst dosage of 0.387 g/L， initial concentration of oxidant of 1.3 mmol/L， pH value of 6.1）. It was indicated that the pollutants in papermaking wastewater could be effectively catalytic activated degraded with the result of three position fluorescence detection. Characterization by electron paramagnetic resonance indicated that the main reactive species in the degradation system were ¹O₂， ·OH， and SO4-·， with non-free radical ¹O₂ playing a major role.