Abstract:

It has a good application potential for coal gasification slag by modifying and regulating the physicochemical properties of it, which can be used to the catalytic removal of organic pollutants, especially electron rich organics. This study focuses on the catalytic application of coal gasification fine slag of space furnace for the removal of bisphenol A by activating persulfate (PMS). Specifically, the coal gasification slag was modified with various concentrations of acid (HCl), alkali (NaOH), and metal salt (ZnCl₂) and used it in the BPA degradation process. The effect of modifier concentration on its catalytic performance was investigated. Besides, the performance of alkali modified coal gasification slag in the degradation of BPA by activating PMS under different reaction conditions was investigated with the active substances that play a dominant role in the catalytic degradation of BPA were further explored through XRF, XRD, SEM-EDS, FTIR, BET characterization and free radical quenching experiments. It was shown that all three modification methods can enhance the catalytic performance of coal gasification slag in degrading BPA, with NaOH modification shown the best performance. For the 5.5NaOH-FS/PMS system, 15 mg/L BPA can be achieved complete removal within 60 minutes under the conditions of 30℃, catalyst dosage of 2 g/L, and PMS dosage of 10 mmol/L. XRF/XRD/SEM-EDS/FTIR analysis showed that the active Fe₂O₃ component was retained in the structure of NaOH modified coal gasification slag, as well as the carbon content reached to 52.7% after NaOH modification. It promoted the BPA degradation. The free radical quenching experiment proved that ·O${}_{\mathrm{2}}^{-}$ and ¹O₂ were the main reactive oxygen species during the degradation of BPA by 5.5NaOH-FS/PMS. Moreover, the presence of carbon defects can directly participate in the oxidative degradation of BPA by forming intermediate complexes with PMS through non-free radical pathways. The research results provide a basis for the resource utilization of coal gasification slag, especially for its application as a catalyst in the field of organic pollutant removal.

Key words: coal gasification slag, modified, catalyst, activation, BPA degradation

摘要：

以航天炉煤气化细渣为研究对象，以双酚A（BPA）为模型污染物，以过硫酸盐（PMS）为氧化剂，对煤气化渣进行酸、碱、盐改性处理，探究了改性煤气化渣活化PMS降解BPA的性能。研究表明，三种改性方式均可提升煤气化渣活化PMS降解BPA的性能，其中NaOH改性效果最佳。对NaOH改性浓度研究发现，5.5NaOH-FS/PMS/BPA体系中，在30℃，催化剂投加量2 g/L，PMS投加量10 mmol/L的条件下，15 mg/L BPA在60 min内可以实现完全去除。XRF、XRD、SEM-EDS、FTIR分析表明，NaOH改性煤气化渣中保留了活性Fe₂O₃组分，并且碳含量最高，达到52.7%，其存在加速了BPA的降解。自由基淬灭实验证明，5.5NaOH-FS/PMS降解BPA过程中，·O${}_{\mathrm{2}}^{-}$与¹O₂为主要活性氧物种。研究成果为煤气化渣作为催化剂在污染物去除领域中的应用提供了一定的基础数据。

关键词: 煤气化渣, 改性, 催化剂, 活化, BPA降解