生物炭负载纳米零价铁活化过硫酸盐降解双酚A性能及机理研究

Study on Performance and Mechanism of Bisphenol A Degradation by Activated Persulfate with Nano Zero Valent Iron Supported on Biochar

摘要: 双酚A (BPA)作为一种类雌激素物质，对人类的健康和生态系统的稳定造成了严重威胁。过硫酸盐(PMS)高级氧化法在BPA去除方面表现出了极大的潜力。本论文以秸秆为生物质，采用碳热还原法原位制备了生物炭/Fe⁰复合材料，并以其作为催化剂活化PMS降解BPA。结果表明，秸秆经碱水解后表面产生了大量的羧基和羟基基团，有利于Fe²⁺在其表面的负载。复合材料催化PMS降解BPA的性能随着Fe⁰负载量的增加而增强。在复合材料投加量为0.15 g∙L⁻¹、PMS投加量为0.20 g∙L⁻¹，溶液pH为8.0的条件下，BPA的降解率达到了98.5%。自由基淬灭实验表明，硫酸根自由基与羟基自由基均参与BPA的降解过程，但前者对降解反应起主导作用。本研究有望为催化PMS降解BPA的高性能催化剂的设计和制备提供了新思路。

Abstract: Bisphenol A (BPA), as an estrogen-like substance, has posed a se-rious threat to human health and ecosystem stability. Persulfate (PMS) based Advanced Oxidation Processes (AOPs) have shown great potential in the removal of BPA. In this paper, biochar/Fe⁰ composites were prepared in situ by using straw as biomass by carbon thermal reduction method, and were used as a catalyst to activate PMS to degrade BPA. The results showed that a large number of carboxyl and hydroxyl functional groups were produced on the surface of straw after alkali hy-drolysis pretreatment, which was beneficial to the loading of Fe²⁺ on the surface of straw. The catalytic performance of PMS for BPA degradation was enhanced with the increase of Fe⁰ loading. Addi-tionally, BPA removal efficiency increased to 98.5%, when the dosage of composite material was 0.15 g•L⁻¹ and PMS was 0.20 g•L⁻¹, and the solution pH was 8.0, respectively. The results of free radical quenching showed that both sulfate radical and hydroxyl radical were involved in the degradation of BPA, but the former played a dominant role in the degradation. This study is expected to provide a new idea for the design and preparation of high-performance catalysts for the degrada-tion of BPA by PMS.