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对O3/H2O2氧化页岩气产出水降解有机物动力学、特征污染物苯胺降解动力学及机理进行实验分析,研究结果表明:页岩气产出水有机物、苯胺降解符合一级反应动力学;臭氧分子的分解符合零级反应动力学。通过液相色谱-质谱(LC-MS)分析O3/H2O2氧化苯胺降解过程中间产物,发现O3/H2O2氧化法不能完全 将页岩气产出水矿化为二氧化碳和水,只是将复杂有机物分子转化为结构简单的直链烷烃或者羧酸类物质,需与其他氧化方式相结合才可将有机物完全去除,并提出了降解返排液中苯胺的两条可能途径,为O3/H2O2氧化工艺实际应用提供理论依据。 相似文献
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臭氧氧化法处理高浓度苯酚废水 总被引:6,自引:0,他引:6
采用臭氧氧化技术对高浓度含酚废水进行了研究.考察了臭氧进气量、反应时间、温度及溶液初始pH值等因素对苯酚COD的去除率的影响.研究表明:在一定范围内,随臭氧进气量的增加、反应时间的增长,COD去除率增大;温度对COD去除率的影响不大;溶液的初始pH值对臭氧氧化有比较重要的影响,在pH值为11~12左右时,COD的去除率最大;在臭氧氧化处理高浓度含酚废水的过程中,酚的降解规律符合表观一级反应. 相似文献
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超声-双氧水和亚铁离子体系处理含酚废水研究 总被引:3,自引:2,他引:3
在实验装置上对超声-双氧水和亚铁离子体系联合处理含酚废水进行了实验研究。主要考察了废水初始pH值、初始双氧水浓度、超声功率、反应时间等因素对酚去除率的影响。实验结果表明:超声辐射可以在双氧水和亚铁离子体系氧化过程中起加速反应的作用,而且随着超声功率的增大,加速反应的能力增强;实验条件下废水初始pH值为4~6.8,初始双氧水浓度为140mg/L时酚去除效果最佳;超声-双氧水和亚铁离子体系处理含酚废水过程中苯酚的降解规律符合表现一级反应。 相似文献
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采用树脂负载零价纳米铁(NZVI-resin)作为铁源,活化过硫酸钠,产生硫酸根自由基氧化降解偶氮染料甲基橙。考察了温度、NZVI-resin加入量、pH值及过硫酸钠的浓度等因素对甲基橙降解率的影响,并对其降解动力学规律作了初步探讨。结果表明:降解反应遵循准一级反应动力学,在pH=3.0、Fe0=0.2 g.L-1、Na2S2O8=1.33 g.L-1的条件下,30 mg.L-1的甲基橙溶液降解率为99.7%。 相似文献
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Fenton试剂对亚甲基蓝氧化褪色的反应动力学实验研究 总被引:9,自引:0,他引:9
为了提高Fenton试剂处理有机污染物的效率,探索最佳处理条件,以亚甲基蓝溶液为模型污水,进行了Fenton试剂氧化亚甲基蓝褪色反应的影响因素实验。对不同条件下的时间过程进行了在线动力学跟踪、拟合和比较。研究发现:Fenton试剂高级氧化的反应动力学过程可分为三阶段。反应前期符合一级动力学,后期符合二级动力学,两者之间存在一个过渡性阶段。一级动力学期的反应速度快,氧化能力高,对于污染物的化学处理是比较合理的,实验还确认了反应前期的Fe(II)浓度对过程的支配作用。 相似文献
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本文以沉淀法制备的TiO2为催化剂,紫外杀菌灯为光源,对阳离子艳红染料的光催化降解进行动力学研究.实验结果表明TiO2光催化降解低浓度阳离子艳红的反应为一级反应,反应动力学行为符合Langmuir-Himshelwood方程,其反应速率常数为1.87 mg/L·min. 相似文献
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《资源开发与市场》2017,(4)
针对普通方法难以降解水中农药废水的问题,运用紫外(UV)/过氧硫酸氢钾(PMS)系统降解高效氟吡甲禾灵,探讨溶液中反应污染物的初始浓度、氧化剂PMS添加量、腐殖酸浓度、初始pH值和常见无机阴离子等的影响因素。结果显示:UV通过催化PMS产生氧化性很强的活性自由基(·SO_4~-、·OH),能有效降解水中高效氟吡甲禾灵,降解反应符合拟一级动力学模型(R~20.98),反应污染物的初始浓度与降解速率呈负相关;氧化剂PMS添加量与降解速率呈正相关。添加的腐殖酸浓度越高,抑制降解反应的作用越明显,中性和弱碱条件下降解效果较好。当pH=7.41时,具有最大去除率(56.82%);少量的HCO_3~-对降解高效氟吡甲禾灵具有促进作用,高浓度则会抑制降解。在c(HCO_3~-)=10mmol/L时最大,Cl~-会抑制其降解;添加乙醇和叔丁醇淬灭剂,kobs均大量减小,UV/PMS的活性氧化物主要是·SO_4~-。 相似文献
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In this study, the photo-Fenton process for the degradation of formaldehyde was investigated in lab-scale experiments. Results showed that methanol, the additive chemical in a commercial product of formaldehyde, was also decomposed during the formaldehyde oxidation reaction. The oxidation reaction was in three-stages. The first stage was the Fe(2+)/H(2)O(2) reaction in which both formaldehyde and methanol were swiftly decomposed. The second and the third stages exerted a somewhat less rapid degradation of both chemicals. The first stage of the oxidation reaction can be discussed by means of the initial average rate and the third stage or Fe(3+)/H(2)O(2) stage was found to follow the first order reaction rate. The reaction was influenced by the initial pH, the concentration of hydrogen peroxide, the amount of ferrous ions. The initial pH at 2.6 provided the highest removal efficiencies in this system. In addition, the competition between formaldehyde and methanol was investigated and described as r(m)/r(f), where r(m) and r(f) were the initial rates of methanol and formaldehyde, respectively. The addition of methanol exhibited a competitive effect on formaldehyde degradation. The removal of formaldehyde decreased with increasing methanol concentration. At the high concentrations of methanol, the oxidation reaction of formaldehyde was repressed. It appears that all values of r(m)/r(f) obtained from the experiments are lower than the theoretical values. 相似文献
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This paper studies the reaction products of alpha-pinene, beta-pinene, sabinene, 3-carene and limonene with OH radicals and of alpha-pinene with ozone using FT-IR spectroscopy for measuring gas phase products and HPLC-MS-MS to measure products in the aerosol phase. These techniques were used to investigate the secondary organic aerosol (SOA) formation from the terpenes. The gas phase reaction products were all quantified using reference compounds. At low terpene concentrations (0.9-2.1 ppm), the molar yields of gas phase reaction products were: HCHO 16-92%, HCOOH 10-54% (OH source: H2O2, 6-25 ppm); HCHO 127-148%, HCOOH 4-6% (OH source: CH3ONO, 5-8 ppm). At high terpene concentrations (4.1-13.2 ppm) the results were: HCHO 9-27%, HCOOH 15-23%, CH3(CO)CH3 0-14%, CH3COOH 0-5%, nopinone 24% (only from beta-pinene oxidation), limona ketone 61% (only from limonene oxidation), pinonaldehyde was identified during alpha-pinene degradation (OH source H2O2, 23-30 ppm); HCHO 76-183%, HCOOH 12-15%, CH3(CO)CH3 0-12%, nopinone 17% (from beta-pinene oxidation), limona ketone 48% (from limonene oxidation), pinonaldehyde was identified during alpha-pinene degradation (OH source CH3ONO, 14-16 ppm). Pinic acid, pinonic acid, limonic acid, limoninic acid, 3-caric acid, 3-caronic acid and sabinic acid were identified in the aerosol phase. On the basis of these results, we propose a formation mechanism for pinonic and pinic acid in the aerosol phase explaining how degradation products could influence SOA formation and growth in the troposphere. 相似文献
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UV-H_2O_2联用工艺去除水中阿特拉津的研究 总被引:2,自引:0,他引:2
采用间歇式反应器考察了UV-H2O2高级氧化技术去除水中阿特拉津的效果及其影响因素,并进行了相关的反应动力学研究。结果表明,在pH值6.9,阿特拉津初始浓度500μg/L,紫外辐照强度172μW/cm2时,H2O2投加量50mg/L,反应10min后,阿特拉津的去除率90%。UV-H2O2联用工艺对阿特拉津的降解符合一级反应动力学。H2O2在该联用工艺降解阿特拉津中具有双重作用,一方面,当H2O2投加量较小时,一级反应速率常数随H2O2投加量的增加基本呈现线性增加的趋势;另一方面,当H2O2浓度增加到一定程度(90mg/L)后,阿特拉津的降解速率随H2O2浓度的变化已不明显,而H2O2浓度为102mg/L时,则出现了抑制作用。 相似文献
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The photocatalytic degradation of a dye derivative, C.I. disperse blue 1 (1), has been investigated under UV light irradiation in the presence of TiO2 and H2O2 under a variety of conditions. The degradation was studied by monitoring the change in substrate concentration employing UV spectroscopic technique as a function of irradiation time. The degradation was studied under different conditions such as different types of TiO2, reaction pH, catalyst and substrate concentration containing hydrogen peroxide (H2O2), besides molecular oxygen in the presence of TiO2. The degradation of dye was also investigated under sunlight and the efficiency of degradation was compared with that of the artificial light source. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst Degussa P25 was found to be more efficient for the degradation of the dye. 相似文献
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The oxidation of trace organic impurities in ultrapure water by ultraviolet light (UV), ozone, and the combination of UV/ozone
is investigated. The emphasis is on the development of a global model to simulate the process that take place in the typical
oxidation reactors used in ultrapure water plants. The study also focuses on reaction mechanism for oxidation of multi-component
organic impurities. Eighteen organic model compounds are chosen as representative contaminants. The results demonstrate and
confirm a significant synergistic effect between UV and ozone oxidation. A mechanism for the synergistic oxidation of organic
impurities is proposed and validated with experimental data. The combination of the reaction and the reactor models is used
to determine the fundamental kinetic parameters involved in the three oxidation processes.
Received: 3 July 1998 / Accepted: 4 September 1998 相似文献
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多元催化氧化技术实现了常温常压下有机物的氧化分解,催化氧化反应所产生的大量羟基自由基(·OH)具有极强的氧化能力,与不能或很难被生物降解的有机物都可以发生快速的链式反应,无选择地将高浓度难降解的有机物开环断链,氧化成简单的有机物、CO2和H2O。采用多元催化氧化装置处理石化碱渣废水,原水CODCr在4285~42,300mg/L之间,经催化氧化处理后,CODCr降至2000mg/L以下,出水水质稳定,为生化处理出水CODCr达标排放提供了可靠的技术保证。 相似文献
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Influence of pyrene combination state in soils on its treatment efficiency by Fenton oxidation 总被引:1,自引:0,他引:1
Interactions of hydrophobic organic compounds (HOCs) with soil organic matter (SOM) determine their combination state in soils, and therefore strongly influence their mobility, bioavailability, and chemical reactivity. Contact time (aging) of an HOC in soil also strongly influences its combination state and environmental fate. We studied Fenton oxidation of pyrene in three different soils to reveal the influences of SOM, contact time, and combination state on the efficiency of vigorous chemical reactions. Pyrene degradation efficiency depended strongly on the dose of oxidant (H(2)O(2)) and catalyst (Fe(2+)); the greatest degradation was achieved at an oxidant to catalyst molar ratio of 10:1. Pyrene degradation differed among the three soils, ranging from 65.4% to 88.9%. Pyrene degradation efficiency decreased with increasing SOM content, and the aromatic carbon content in SOM was the key parameter. We hypothesize that pyrene molecules that combine with the compact net structure of aromatic SOM are less accessible to Fenton oxidation. Furthermore, pyrene degradation efficiency decreased considerably after aged for 30 days, but further aging to 60 and 180 days did not significantly change degradation efficiency. The Fenton oxidation efficiency of pyrene in both unaged and aged soils was greater than the corresponding desorption rate during the same period, perhaps because Fenton reaction can make pyrene more accessible to the oxidant through the enhancement of HOCs' desorption by generating reductant species or by destroying SOM through oxidation. 相似文献