Cr(VI) and phenol are toxic contaminants that need to be treated, and different methods have been researched to simultaneously remove these two contaminants from industrial wastewater. In this study, Cr(VI) was used as a novel Fenton-like catalyst in phenol degradation by H2O2. In the pH range of 3.0‒11.0, the degradation efficiency of phenol decreased with elevated pH. At pH = 3.0, 100 mg/L phenol was effectively degraded by 2 mmol/L Cr(VI) and 20 mmol/L H2O2. At pH = 7.0 and the same conditions as those of pH = 3.0, 79% of 100 mg/L phenol was removed within 6 h, which was an improvement in pH limitation compared with the Fe(II)-mediated Fenton reaction. Quenching experiments indicated that ·OH generated from the catalysis of H2O2 by Cr(V) instead of Cr(VI) was the primary oxidant that degraded phenol. When pyrophosphate was added in the Cr(VI)/H2O2 system, complexes with the Cr(V) intermediate rapidly formed and inhibited H2O2 decomposition, implying that the decomposition of H2O2 to ·OH was catalyzed by Cr(V) instead of Cr(VI). The presence of anions such as chloride and sulfate had insignificant effect on the degradation of phenol. TOC and UV analyses suggest that phenol could not be completely oxidized to CO2 and H2O, and the intermediates identified by high performance liquid chromatography further indicates that maleic acid and benzoquinone were intermediates which may be further degraded into short chain acids, primarily maleic, formic, acetic, and oxalic acids, and eventually into CO2 and H2O. Considering that more than 50% Cr(VI) can also be removed during this process, the Cr(VI)/H2O2 system is more appropriate for the simultaneous removal of Cr(VI) and phenol contaminants from industrial wastewater.
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1.
偶氮染料废水是一种有机物含量高、成分复杂、色度高、可生化性差的难降解废水,其处理方法已引起广泛关注。用Fenton氧化法研究了五种偶氮染料(橙黄Ⅱ、橙黄Ⅳ、铬黑T、皂黄和酸性铬兰K)的降解脱色情况。研究结果表明,这几种偶氮染料均有显著的降解。当偶氮染料浓度为200ppm、H2O2(30%)的用量为0.2ml、Fe SO4·7H2O用量为83.4mg,反应1小时后,橙黄Ⅱ和铬黑T在p H=10时的脱色降解率高达94.55%和88.19%;橙黄Ⅳ和酸性铬兰K在p H=12时降解脱色率是最高的,达到了98.74%和96.97%;而皂黄则在p H=2时的降解脱色率最好,高达97.36%,是一个降解高浓度染料废水的有效方法。根据偶氮染料降解后的UV-Vis图谱,简单探讨了氧化过程中可能的反应机理。 相似文献
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以半导体材料二氧化钛为催化剂,对偶氮染料甲基橙溶液进行了电催化氧化降解实验;考察了催化剂量、槽电压、pH值、电解质浓度、反应时间等因素对处理效果的影响.实验结果表明:二氧化钛的催化效果显著,其色度和COD去除效果可比无催化剂时效果分别提高35%和28%;去除机制主要是电催化体系中产生的·OH对有机物的氧化、降解. 相似文献
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研究了甲基橙等有机染料在太阳光和Fenton试剂联合作用下的降解动力学。采用单因子法考察了硫酸亚铁用量、氧化剂双氧水用量和辐射光源等因素对降解效果的影响。结果表明:在优选实验条件下甲基橙的降解效果较好,有机染料的降解过程符合一级动力学。辐射光源对甲基橙的降解速率影响非常大,降解速率随紫外光强度的增强而加快。太阳光下甲基橙的降解速率常数是室内3～4倍,该反应体系在太阳光利用方面具有一定的应用价值。 相似文献
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研究了pH值、温度、反应时间、过氧化氢用量、染料初始浓度等对辣根过氧化物酶（HRP）催化过氧化氢氧化降解橙黄Ⅱ染料溶液的影响.结果表明在pH值为2、温度为43℃、反应时间为12 min、H2 O2用量为2.0 mmol·L-1、染料初始浓度0.8 mmol·L-1时橙黄Ⅱ的降解最为理想,脱色率可达到83.7％. 相似文献
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Groundwater remediation by nanoparticles has收稿日期increasing interest in recent years. This report presents a thorough evaluation of hexavalent chromium removal in aqueous solutions using iron (Fe0) nanoparticles. Cr(Ⅵ) is a major pollutant of groundwater. Zero-valent iron, an important natural reductant of Cr(Ⅵ), is an option in the remediation of contaminated sites, transforming Cr(Ⅵ) to essentially nontoxic Cr(Ⅲ). At a dose of 0.4 g/L, 100% of Cr(Ⅵ) (20 mg/L) was degraded. The Cr(Ⅵ) removal efficiency decreased significantly with increasing initial pH. Different Fe0 type was compared in the same conditions. The reactivity was in the order starch-stabilized Fe0 nanoparticles＞Fe0 nanoparticles＞Fe0 powder＞Fe0 filings. Electrochemical analysis of the reaction process led to the conclusion that Cr(OH)3 should be the final product of Cr(Ⅵ). Iron nanoparticles are good choice for the remediation of heavy metals in groundwater. 相似文献
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采用沉积沉淀法制备了四氧化三铁负载磷酸银（Ag3PO4/Fe3O4）可见光磁性催化剂,利用透射电子显微镜（TEM）、扫描电子显微镜（SEM）对催化剂的微观形貌进行了表征。用甲基橙的光催化降解评价了不同负载量的Ag3PO4/Fe3O4复合催化剂的光催化性能。结果表明：当Ag3PO4负载量为50%时光降解效果最好,在模拟太阳光下,辐照80 min后的降解率可达到90%以上。 相似文献
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通过溶胶-凝胶法制备了Mo不同掺杂量的纳米TiO2光催化剂,进行了UV—Vis分析,并在紫外光源下对降解甲基橙光催化活性进行了测定．最后建立L-H模型和GM（1,1）模型,考查了Mo／TiO2对甲基橙的降解动力学,并对模型进行了比较．结果表明,纳米TiO2当煅烧温度为500℃时,Mo的最佳掺杂量为0．05mol％,L-H模型对有些Mo掺杂纳米TiO2光催化降解甲基橙存在偏差,且Andrews型稳健回归优于最小二乘算法的模拟结果．而GM（1,1）模型对Mo掺杂纳米TiO2光催化降解甲基橙能进行很好的实验模拟． 相似文献
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采用新型电沉积 生物膜复合工艺处理含重金属离子 (Cr3 + )有机废水 ,阐述其作用机理 .实验废水中的有机物由生物膜中的复合微生物菌群作为营养源而消耗 ;重金属离子则一部分通过电沉积去除 ,另一部分通过生物膜吸附而去除 ,净化后废水能够达到工业回用水标准 .探讨了培养、驯化后的复合微生物降解有机物动力学速率 ,并将采用复合工艺与单纯的电沉积工艺及生物膜工艺处理含重金属离子有机废水的实验结果进行对比 ,结果表明 ,C6H12 O6含量为 5 0 0mg·L-1及Cr3 + 含量为 10mg·L-1的废水 ,利用复合工艺净化处理后 ,C6H12 O6含量为 2 0— 30mg·L-1,Cr3 + 含量低于 1mg·L-1. 相似文献
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研究了催化剂、光源、溶液初始浓度、溶液初始pH值等因素对甲基橙光催化氧化降解反应的影响．实验结果表明,最佳实验条件为：以灼烧的TiO2为催化剂,催化剂的投加量为0,8g·L^-1,采用浸波式紫外灯作光源,甲基橙初始浓度为20mg·L^-1,溶液初始pH=3．该实验条件下,甲基橙一小时脱色率可达81．3％．该研究可为偶氮染料降解提供新的思路． 相似文献
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高硫煤矸石中的FeS2在水中氧化分解为Fe2+,能将废水中的Cr6+还原为Cr3+,高硫煤矸石中的C对Cr6+具有较好的吸附、还原作用,从而表现出对含铬(Ⅵ)废水具有较好的净化作用。在处理含铬(Ⅵ)废水过程中,废水的pH值、反应时间、高硫煤矸石粒度、加入量对Cr6+的去除率影响较大。高硫煤矸石对含铬(Ⅵ)废水的吸附行为符合Langmui等温方程,在3 50℃～4 00℃高温处理后对Cr6+的去除效果明显提高,且反应速度加快。 相似文献
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对乙酰基偶氮羧光度法测定痕量铬的研究 总被引：1，自引：0，他引：1
研究了对乙酰基偶氮羧与Cr_2O_7~(2-)的褪色反应,建立了一种新的测定痕量Cr(Ⅵ)的光度方法,发现其在高氯酸介质中具有高灵敏的褪色反应,摩尔吸光系数达到3.0×10~6 L·mol~(-1)·cm~(-1)Cr(Ⅵ),量在0～50μg范围内符合比耳定律. 相似文献
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本文以Cu(NO3)2.3H2O为铜源,浓氨水为络合剂和NaOH调节溶液的pH,采用化学浴法(CBD)制备了CuO薄膜。通过X-射线衍射(XRD)和扫描电子显微镜(SEM)对其光催化前后的结构和形貌进行了表征。将CuO薄膜放在含有H2O2的甲基橙溶液中,经不同光源照射一定时间后,取其溶液进行可见分光光度分析来研究CuO薄膜的光催化性能。试验结果表明:紫外灯光源下,当催化剂CuO薄膜的表面积为12.50cm2、3.0%H2O2用量为40.0ml、pH=7时,降解甲基橙溶液的效果较好,光照10min后降解率就达到100.0%;不加H2O2时,需光照40min降解率才能达到100.0%,说明H2O2对CuO膜光催化降解甲基橙起到协同促进作用。 相似文献
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INTRODUCTION Chromium is a commonly identified soils andgroundwater contaminant. Cr(VI) is toxic, carcino-genic, and has great subsurface mobility. In contrast,Cr(III) is relatively non-toxic and immobile. Muchresearch focused on the remediation of Cr(VI) such asadsorption by zeolites (Bowman, 2003) or silicas(Hideaki et al., 2002), chemical reduction by ferrousiron (Buerge and Hug, 1999; Fendorf and Li, 1996) orzero-valent iron (Powell and Puls, 1997; Alowitz andScherer, 2002), b… 相似文献
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The effectiveness of vitamin C in treating Cr(Ⅵ)-contaminated water is being evaluated. Cr(Ⅵ) is an identified pollutant of some soils and groundwater. Vitamin C, an important biological reductant in humans and animals, can be used to transform Cr(Ⅵ) to essentially nontoxic Cr(Ⅲ). The removal efficiency was 89% when the mass concentration of vitamin C was 80 mg/L in 60 min, and nearly 100% Cr(Ⅵ) was removed when the mass concentration was 100 mg/L. Our data demonstrated that the removal efficiency was affected by vitamin C concentration, the reaction temperature and the dissolved oxygen concentration.The reaction mechanism of Cr(Ⅵ) by vitamin C was presented. Our study opens the way to use vitamin C to remediate Cr(Ⅵ)-contaminated soils and groundwater. 相似文献
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采用流延成膜法,以戊二醛为交联剂制备Ti O2/壳聚糖复合膜。用X射线衍射仪,傅立叶红外光谱仪以及扫描电镜对复合膜进行表征,并研究了不同戊二醛含量对壳聚糖膜溶胀率的影响。以甲基橙降解反应为模型,研究Ti O2/壳聚糖复合膜降解染料废水的性能。结果表明：Ti O2与壳聚糖相容性较好,加入Ti O2可提高复合膜的机械强度,戊二醛交联能有效抑制膜的过度溶胀;复合膜对甲基橙的降解效果良好：当复合膜用量为0.30g,初始浓度为5mg/L甲基橙溶液50m L,p H为2.36,紫外光照射80min,降解率可达到85%以上,具有较好的应用前景。 相似文献
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自行制备负载型TiO2催化剂,对苯胺水样进行了光助催化。探讨了初始底物浓度、催化剂用量、光照强度及微量H2O2对降解率的影响。结果显示,TiO2光助催化降解苯胺效果良好,当苯胺浓度低于2mmol.L-1时,降解率在98%以上,催化剂量、光源强度和微量H2O2都可提高苯胺的降解率。进一步研究可知苯胺经催化降解后,苯环被打开,有助于后续的生化处理。 相似文献
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