聚铁硅盐掺杂羟基氧化铁类芬顿催化氧化苯酚

Fenton-like catalytic oxidation of phenol by polysilicate ferric doped iron oxyhydroxides

为解决非均相类芬顿法催化剂分离回收困难的问题,采用共沉淀法制备了催化剂聚铁硅盐掺杂羟基氧化铁(PFSC-FeOOH)。利用X射线衍射(XRD)、扫描电子显微镜(SEM)以及傅里叶变换红外光谱(FT-IR)等技术手段对催化剂进行了表征。以苯酚为目标污染物,分别考察了催化剂用量、H_(2)O_(2)用量、反应温度、苯酚初始浓度和pH对PFSC-FeOOH催化H_(2)O_(2)去除苯酚效果的影响,探究了可能的反应机理。结果表明:在反应时间为40 min、pH=4、H_(2)O_(2)投加量为297 mmol·L^(−1)、催化剂PFSC-FeOOH投加量为3 g·L^(−1)、反应温度为室温((25±1)℃)的条件下,苯酚去除率为90.48%;反应符合准一级反应动力学,速率常数为0.0415 min−1;反应过程中羟基自由基(·OH)起主要作用,苯酚的分子结构被氧化破坏;反应后,催化剂易于沉降分离,沉降速度为0.1 m·min−1。以上研究结果可为实际有机废水的处理提供参考。

To solve the problem of difficulty in the separation and recycle of heterogeneous Fenton-like catalyst,polysilicate ferric doped iron oxyhydroxides(PFSC-FeOOH)was prepared by the co-precipitation method.The catalyst was characterized by X-ray diffraction(XRD),scanning electron microscope(SEM),and Fourier transform infrared spectroscopy(FT-IR).Using phenol as the target pollutant,the effects of PFSCFeOOH and H_(2)O_(2) dosages,temperature,the initial concentration of phenol solution and pH on phenol removal by Fenton-like oxidation with PFSC-FeOOH catalyzing H_(2)O_(2) were investigated,and the reaction mechanism was explored.The results showed that the phenol removal rate was 90.48%at the reaction time of 40 min,pH of 3,the H_(2)O_(2) dosage of 297 mmol·L^(−1),the catalyst PFSC-FeOOH dosage of 3 g·L^(−1) and room temperature((25±1)℃).The reaction process conforms to the Quasi-first order reaction,and the rate constant was 0.0415 min^(−1).The hydroxyl radical(·OH)played a major role in the reaction process,and the molecular structure of phenol was destroyed.After reaction,the catalytic was settled and separated easily with the sedimentation speed of 0.1 m·min−1.The Fenton-like oxidation with PFSC-FeOOH as catalyst can effectively treat phenol wastewater which provides some references for degradation of organic wastewater.