氮掺杂多孔污泥炭活化过二硫酸盐降解橙黄Ⅱ

Degradation of Orange Ⅱ by persulfate activated with nitrogen-doped porous sludge carbon

以市政污泥为碳源、碳酸氢钾为活化剂、尿素为氮源,制备了氮掺杂多孔污泥生物炭(NKBC),并采用N2吸附-脱附实验、SEM、XRD、XPS对其比表面积、表面特征进行了系列表征与分析,结果表明,NKBC具有较大的比表面积,由于N负载于NKBC孔道内,其表面褶皱、缺陷较多,活化位点较多。将NKBC用于活化过二硫酸盐(PDS)降解橙黄Ⅱ,考察NKBC/PDS体系降解橙黄Ⅱ的性能,结果表明,在加入PDS 20 min后,NKBC/PDS体系对橙黄Ⅱ的降解率高达99.7%;该体系可在较宽pH范围(3~11)及常见阴离子存在条件下发挥作用。自由基猝灭实验和EPR光谱结果表明,NKBC/PDS体系降解橙黄Ⅱ的主要活性物种有·OH、SO_(4)^(·-)和^(1)O_(2),且以^(1)O_(2)为主。该研究所构建的NKBC/PDS体系可应用于染料废水的处理,实现“以废治废”的目标。

A nitrogen doped porous sludge biochar(NKBC)was prepared using municipal sludge as carbon source,potassium bicarbonate as activator,and urea as nitrogen source.N2 adsorption-desorption experiments,SEM,XRD and XPS were used to characterize and analyze its specific surface area and surface characteristics.The results showed that NKBC had a large specific surface area.Due to N loading in the pores of NKBC,its surface was wrinkled,with many defects and activation sites.NKBC was used to activate the degradation of Orange Ⅱ by persulfate(PDS),and the performance of the NKBC/PDS system in degrading Orange Ⅱ was investigated.The results showed that after adding PDS 20 minutes,the degradation rate of Orange Ⅱ by the NKBC/PDS system reached 99.7%.This system could function over a wide pH range(3-11)and under common anionic conditions.The results of free radical quenching experiments and EPR spectroscopy indicated that the main active species for the degradation of Orange Ⅱ in the NKBC/PDS system were·OH,SO_(4)^(·-)and ^(1)O_(2),with ^(1)O_(2) being the main active specie.The NKBC/PDS system constructed in this research can be applied to the treatment of dye wastewater,achieving the goal of“treating waste with waste”.