污泥生物炭负载钴铁双金属活化过一硫酸盐降解双酚F的机制

Degradation of bisphenol F by activated of peroxymonosulfate using sludge biochar loaded with cobalt iron bimetallic catalyst

  • 摘要: 近年来,污水处理厂的大规模建设导致污泥产量逐年增加,污泥的处理面临严峻挑战,双酚F (BPF)被广泛应用于工业中化学添加剂,在地表水、土壤和污泥中被频繁检出。本文利用市政污泥负载钴铁双金属制备了钴铁双金属@污泥生物炭(CoFeO@SBC)复合材料,通过活化过一硫酸盐(PMS)降解BPF来探究其催化性能。采用SEM、比表面积测定(BET)、IR、XRD和XPS等表征分析所制备材料的理化性质;并考察了材料投加量、PMS投加量、初始pH和无机阴离子对CoFeO@SBC/PMS体系降解BPF效果的影响。结果表明:CoFeO与SBC复合后孔隙结构显著优化,比表面积增加了6.0倍,且具备更丰富的氧空位和还原性—OH官能团,产生了更多的Fe(II)和Co(II)。因此,CoFeO@SBC具有优异的催化活性,投加量为0.04 g/L时可以在10 min内几乎完全降解BPF(5 mg/L),降解速率与CoFeO相比提高了62%;Cl和\mathrmNO_3 ^- 对体系降解效果影响较小,而\mathrmHCO_3 ^- 具有显著的抑制作用;通过EPR分析表明CoFeO@SBC/PMS体系存在羟基(•OH)和硫酸根( \mathrmSO_4^\text•- )自由基及单线态氧(1O2)和超氧(\mathrmO_2^ \text•- ),同时自由基淬灭实验证明,\mathrmSO_4 ^\text•- 是体系降解BPF的关键活性氧物种;最后通过液相色谱-质谱联用(LC-MS)对BPF的降解产物进行分析,揭示BPF在体系中的主要降解途径和机制。

     

    Abstract: In recent years, the large-scale construction of wastewater treatment plants has led to an increase in the production of sludge year after year, and the treatment of sludge is facing a serious challenge. Bisphenol F (BPF), which is widely used as a chemical additive in the industry, has been frequently detected in surface water, soil and sludge. By using municipal sludge loaded with cobalt-iron bimetal, cobalt-iron bimetallic@sludge biochar (CoFeO@SBC) were prepared, and the catalytic performance was assessed by activating peroxymonosulfate (PMS) to degrade BPF. SEM, specific surface area determination (BET), IR, XRD, and XPS were used to characterise and analyse the physicochemical properties of the prepared materials. The effects of the dosage of the materials, the dosage of the PMS, the initial pH, and the inorganic anions on the degradation of the BPF by the CoFeO@SBC/PMS system were investigated. The results showed that the pore structure of CoFeO was significantly improved after compounding with SBC, and the specific surface area was increased by 6.0 times. Moreover, CoFeO@SBC composites showed richer oxygen vacancies and —OH functional groups, which led to higher production of Fe(II) and Co(II). Therefore, CoFeO@SBC composites had excellent catalytic activity, which could almost completely degrade BPF (5 mg/L) within 10 min at the dosage of 0.04 g/L, and the degradation rate was 62% higher than that of CoFeO; Cl and \mathrmNO_3 ^- showed less influence on the degradation effect of the system, while \mathrmHCO_3 ^- had a significant inhibitory effect; EPR analysis shows that there are hydroxyl (•OH) and sulfate (\mathrmSO_4 ^\text•- ) free radicals as well as singlet oxygen (1O2) and superoxide (\mathrmO_2 ^\text•- ) free radicals in the CoFeO@SBC/PMS system. At the same time, the free radical quenching experiment, it is proved that \mathrmSO_4 ^\text•- is the key reactive oxygen species for the degradation of BPF in the system. Finally, the degradation products of BPF were identified by liquid chromatography-mass spectrometry (LC-MS), which could elucidate the primary degradation pathways and mechanisms in CoFeO@SBC/PMS system.

     

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