【摘要】：采用鐵系氧化物作為催化劑,催化臭氧化處理苯酚模擬廢水,對(duì)比納米顆粒催化劑羥基氧化鐵(FeOOH NPs)、三氧化二鐵(Fe2O3NPs)和四氧化三鐵(Fe3O4 NPs)及相對(duì)應(yīng)的非納米顆粒催化劑FeOOH、Fe2O3和Fe3O4對(duì)苯酚降解效果。通過X射線衍射(XRD)、比表面積-孔徑分布(BET)和掃描電子顯微鏡(SEM)手段對(duì)催化劑進(jìn)行表征。研究結(jié)果表明:Fe3O4 NPs催化劑存在情況下對(duì)溶液TOC去除率最高,初始濃度1.0 mmol/L,pH為3.0,催化劑投量1.0 g/L,O3/O2流量200 ml/min(混合氣體中的O3濃度42.38 mg/L),反應(yīng)180min后,TOC去除率達(dá)80.0%。進(jìn)一步測(cè)定反應(yīng)液(無苯酚添加)中溶鐵(Fe2+)變化,結(jié)果表明Fe3O4 NPs,Fe2O3 NPs和Fe3O4溶出的Fe2+濃度會(huì)隨著時(shí)間的推移逐漸增加,240 min后分別達(dá)4.49 mg/L,0.9 mg/L和0.78 mg/L,而其它鐵系催化劑存在的溶液中Fe2+濃度非常低且?guī)缀醪浑S時(shí)間增加。在Fe2+存在條件下,鐵系氧化物催化臭氧化降解模擬廢水中的苯酚遵循以下反應(yīng)動(dòng)力學(xué)模型:-d[TOC]/dt=[TOC]t/(a+bt),并在一定條件下可簡化成擬一級(jí)反應(yīng)動(dòng)力學(xué),實(shí)驗(yàn)結(jié)果顯示,其動(dòng)力學(xué)可分別擬合成兩段,分別由誘導(dǎo)期和快速降解期構(gòu)成。結(jié)果顯示Fe3O4 NPs兩段的反應(yīng)速率常數(shù)均較其他催化劑大,分別為3.3×10-3 min-1和8.82×10-3 min-1,從而說明了Fe3O4 NPs的優(yōu)越的催化能力。本實(shí)驗(yàn)以Fe3O4 NPs為催化劑,以苯酚模擬廢水為研究對(duì)象,以總有機(jī)碳(TOC)降解率為目標(biāo)參數(shù),研究了反應(yīng)體系操作條件(O3/O2流量、Fe3O4 NPs投量和反應(yīng)溫度)對(duì)催化劑性能的影響。研究結(jié)果表明,在本實(shí)驗(yàn)條件范圍內(nèi),TOC去除率分別隨著臭氧量、Fe3O4 NPs投量和反應(yīng)溫度增加而增加,最佳條件為O3/O2流量200 ml/min,Fe3O4 NPs投量1.0 g/L和反應(yīng)溫度25℃,反應(yīng)180min后,TOC去除率可達(dá)80.0%。采用GC-MS對(duì)苯酚降解的中間產(chǎn)物進(jìn)行分析,并假設(shè)·OH為主要活性物種,從而提出Fe3O4 NPs作為催化劑,苯酚催化臭氧氧化的可能降解途徑。
[Abstract]:Phenol simulated wastewater was treated by catalytic ozonation with iron oxides as catalysts. The degradation effects of hydroxyl iron oxide (FeOOH NPs), iron trioxide (Fe2O3NPs) and iron tetrooxide (Fe3O4 NPs) and corresponding non-nanoparticles catalysts FeOOH,Fe2O3 and Fe3O4 on phenol degradation were compared. The catalysts were characterized by X-ray diffraction (XRD), specific surface area pore size distribution (BET) and scanning electron microscope (SEM). The results show that in the presence of Fe3O4 NPs catalyst, the removal rate of TOC in solution is the highest, the initial concentration is 1.0 mmol/L,pH, the amount of catalyst is 1.0 g / L, the flow rate of O _ 3 鈮，

本文編號(hào)：2498597