Fenton氧化处理甲基橙染料模拟废水的动力学研究

采用Fenton试剂降解含甲基橙染料的模拟废水,通过对甲基橙染料处理过程中UV-Vis吸收光谱的分析,证明了Fenton氧化法对甲基橙染料的处理效果。进一步研究了Fenton氧化降解甲基橙废水的反应动力学,并建立了反应动力学模型。结果表明,Fenton氧化过程中,影响甲基橙降解速率的主要因素为H2O2和甲基橙的初始浓度。H2O2和甲基橙初始浓度与反应速率常数之间的关系可分别归纳为:kRH=0.05c(H2O2)1.4和kRH=0.023c(RH)-1.3。     

Enhanced removal of sodium salts supported by in-situ catalyst synthesis in a supercritical water oxidation process

For practical applications of supercritical water oxidation to wastewater treatment, the deposition of inorganic salts in supercritical phase must be controlled to prevent a reactor from clogging. This study investigated enhanced removal of sodium salts with titanium particles, serving as a salt trapper and a catalyst precursor, and sodium recovery by sub-critical water. When Na(2)CO(3) was tested as a model salt, sodium removal efficiency was higher than theoretically maximum efficiency defined by Na(2)CO(3) solubility. The enhanced sodium removal resulted from in-situ synthesis of sodium titanate, which could catalyse acetic acid oxidation. The kinetics of sodium removal was described well by a diffusion mass-transfer model combined with a power law-type rate model of sodium titanate synthesis. Titanium particles showed positive effect on sodium removal in the case of NaOH, Na(2)SO(4) and Na(3)PO(4). However, they had negligible effect for NaCl and negative effect for Na(2)CrO(4), respectively. More than 99% of trapped sodium was recovered by sub-critical water except for Na(2)CrO(4). In contrast, sodium recovery efficiency remained less than 50% in the case of Na(2)CrO(4). Reused titanium particles showed the same performance for enhanced sodium removal. Enhanced salt removal supported by in-situ catalyst synthesis has great potential to enable both salt removal control and catalytic oxidation.     

Combining photo-Fenton process with biological sequencing batch reactor for 2,4-dichlorophenol degradation.

The effect of the photo-Fenton process on biodegradability enhancement of 100 mg x L(-1) aqueous 2,4-dichlorophenol (2,4-DCP) solution has been investigated. An initial concentration of 65 mg x L(-1) H2O2 and 10 mg x L(-1) Fe (II) during 35 minutes of irradiation time was sufficient for total 2,4-DCP removal. At these working conditions, biodegradability, measured as BODS/COD ratio, was increased from 0 for the original solution up to 0.15. Biological oxidation of photo-Fenton pre-treated solutions was performed in a sequencing batch reactor (SBR). After 32 days of start-up, the reactor was fed with different pre-treated solutions and cycle duration was reduced progressively. TOC removal efficiencies in the SBR went from 30 up to 70%.     

高COD洗舱含油废水混凝破乳-芬顿氧化预处理工艺研究

船舶洗舱废水直接排放会污染环境,排放前必须经过各种处理工艺的净化,而含油废水处理是其中的重点和难点。实验选取重庆某公司洗船中心最不利工况下的高COD洗舱含油废水,通过混凝破乳和芬顿氧化进行处理,分析了混凝破乳过程中混凝剂种类、投加量、pH值和搅拌时间等影响因素,确定了芬顿氧化过程的适宜条件,包括H₂O₂浓度、Fe²⁺浓度、反应时间等,并通过正交实验确定了洗舱含油废水预处理的最优条件。结果表明：PAC为适宜的无机混凝剂,其混凝破乳适宜的投加量为75 mg/L、初始pH值为8、搅拌时间为3 min;芬顿氧化适宜的H₂O₂和Fe²⁺浓度分别为12 500和1 250 mg/L、反应时间为120 min。在最优条件下,实验水样的COD总去除率可达70%,TP和石油类几乎全部去除。本研究成果为长江沿岸某城市港口洗舱废水处理项目的预处理工艺提供了工程设计和调试运行的理论指导。     

Effective degradation of para-chloronitrobenzene through a sequential treatment using zero-valent iron reduction and Fenton oxidation

In this study, zero-valent iron (ZVI) was used to pretreat para-chloronitrobenzene (p-CNB), and the major product was para-chloroaniline (p-CAN). By adding H(2)O(2) directly, further p-CAN degradation can be attributed to Fenton oxidation because ferrous ions (Fe(2+)) released during the ZVI corrosion could be used as an activator for H(2)O(2) decomposition. In the reduction process, the reduction efficiency of p-CNB as well as Fe(2+) concentration increased with increasing iron dosage and decreasing solution pH. Under the optimal conditions, 25 mg L(-1) of p-CNB could be transformed in 3 h when initial solution pH was 3.0 and ZVI dosage was 2.0 g L(-1). A sufficient amount of Fe(2+) (50.4 mg L(-1)) was obtained after the above reaction to activate H(2)O(2). In the Fenton process, the oxidization of p-CAN was also more effective in acidic conditions and it increased with increasing H(2)O(2) concentration. The control experiments showed that the sequential treatment was more effective than Fenton oxidation alone in treating p-CNB wastewater since the removal rate of total organic carbon (TOC) was improved by about 34%. It suggested that the amino function group is more susceptible to oxidative radical attack than the nitro function group. Therefore, sequential treatment using zero-valent iron reduction followed by Fenton oxidation is a promising method for p-CNB degradation.     

Fenton高级氧化技术去除水中有机污染物2-MIB的影响因素研究

针对目前比较关注的致嗅物质污染问题,选用Fenton高级氧化技术研究了其对水中致嗅物质2-甲基异莰醇（2-MIB）的去除,探讨了Fenton反应对水中致嗅物质的去除效能及H2O2/Fenton摩尔比、Fe2＋浓度、反应时间和溶液pH值各因素对氧化反应的影响。提出了Fenton氧化反应去除2-MIB的最佳反应条件。实验结果表明：Fenton高级氧化能有效去除水中的2-MIB。在H2O2/Fenton摩尔比为3.0、Fe2＋浓度10 mg/L、反应时间10 min和溶液pH值为3.0时,去除效率达到97.9%。Fenton氧化反应的操作条件（浓度、pH值等）比较容易实现,因此Fenton氧化技术在实际污染处理中有很大的应用前景。     

Quantum efficiencies of the photo-Fenton degradation of atrazine in water

An experimental work in a well-stirred batch recycling reactor for the photo-Fenton degradation of atrazine in water is presented. A study of the quantum efficiency is performed to assess the effectiveness of the photo-Fenton process on the atrazine degradation and total organic carbon (TOC) mineralization. Apparent and absolute quantum efficiencies of degradation and mineralization of an atrazine-based commercial herbicide are determined under different experimental conditions. Higher apparent efficiencies were found for both atrazine degradation and TOC mineralization when the ferric ion and hydrogen peroxide concentrations are increased. Because of the well known stability of the triazine ring, atrazine was not completely mineralized by the photo-Fenton process. However, a TOC reduction of 40% was achieved, being 62.5% of the maximum value that can be reached.     

Fenton试剂-石英砂工艺处理铁锰矿井废水

针对铁锰矿井废水中锰离子难去除的问题,本试验采用Fenton试剂-石英砂工艺研究了锰离子的去除效率与机理。结果表明:加入H2O2比不加入对锰离子的去除效果好,各因素的最佳值分别为:当H2O2投加量为0.15mg/L、滤速为8 m/h,pH为7,石英砂粒径为1.0 mm时,锰的最高去除率可达到90.7%。     

铁炭微电解-Fenton试剂氧化-二级A/O工艺处理化工废水工程实例

采用铁炭微电解结合Fenton试剂的化学氧化做预处理,二级A/O结合PACT工艺做后处理,混凝沉淀做辅助处理工艺处理含硝基苯的化工废水。介绍了工艺流程、主要参数和运行效果,同时讨论了该工艺的影响因素。工程监测结果表明:设计进水水量为600im~3/d,COD为5000mg/L时,预处理出水COD降至约1500mg/L,BOD/COD从0.1上升到0.3以上,后处理出水COD约为150mg/L,辅助处理出水COD小于100mg/L,COD总去除率可达97％。该工艺根据废水呈酸性的特点并合理利用废铁刨花,具有以废治废的特点,处理效果好,成本低,操作维护方便。     

Fenton反应催化降解苯胺及影响因素研究

对Fenton反应催化降解水中苯胺和影响催化氧化效果的几种因素进行研究和探讨。试验表明,除废水pH,Fenton试剂用量是影响苯胺降解的主要因素外,水中Cl-也对催化性能产生明显的抑制作用。虽单纯的Fenton反应对苯胺的催化降解率可达98%以上,但CODCr去除率却相对较低,表明Fenton反应对苯胺降解后的某些中间产物难于再进一步矿化,而紫外线辐照可提高Fenton反应的催化降解性能和CODCr去除率,实现对某些中间产物的持续矿化作用。     

Fenton and photo-Fenton treatment of a synthetic tannin used in leather tannery: a multi-approach study.

The aim of this work was to compare the behaviour of Fenton and photo-Fenton (UV-A, UV-C) processes to treat synthetic tannin (syntan) used in leather tannery which is one of the most polluting industries, releasing many xenobiotics. Both oxidation processes were performed at pH 3.0 and temperature 40-45 degrees C, which is the original temperature of the re-tanning process, in synthetic solutions containing 100 and 300 mg/L of COD equivalent of syntan. The efficiency of the applied oxidation processes was monitored by chemical oxygen demand (COD), oxidation redox potential (ORP) and aromaticity (UV280) and double bond (UV254) absorbance measurements. Acute toxicity test on Daphnia magna was performed to monitor toxicity in untreated and treated syntan solution. Gas chromatography-mass spectrometry (GC-MS) was applied to identify by-products of partial oxidation occurring in treated samples. The effective ratio of H2O2/FeSO4 for photo-Fenton processes was found to be feasible in terms of reagents used in the process.     

Fenton试剂催化降解有机废水的研究进展

Fenton技术作为一门高级氧化技术(AOPs),在降解废水中的有机污染物这一领域极具优势,是一种非常理想的有机污水处理工艺,另外,在基于普通Fenton技术上延伸出来的新的类Fenton技术、电Fenton(EF)、光Fenton技术等,与传统的Fenton技术相比较,也各有精进之处.综述了Fenton及类Fento...     

UV/H_2O_2降解微囊藻毒素的人工神经网络模型

试验建立了UV/H_2O_2高级氧化工艺降解微囊藻毒素MC-LR的人工神经网络模型.研究了UV强度、H_2O_2投加量、MC-LR初始浓度、pH等对降解速率的影响,并以反向传播算法的神经网络模型对多因素条件下的降解效果进行仿真预测.结果表明,降解速率不受初始MC-LR浓度的影响;UV的加强及H_2O_2投加量的增加能有效提高MC-LR的降解速率;pH的降低能大幅度改善降解效果,尤其在酸性条件下,pH的变化对降解速率的影响程度更大.     

UASB-水解酸化-接触氧化工艺处理阿维菌素废水

采用UASB-水解酸化-接触氧化法处理阿维菌素废水,其中高浓度废水直接采用UASB处理,出水和综合废水混合经水解酸化后利用接触氧化法进行处理,系统处理效率高,运行稳定,CODCr去除率为97%,出水水质达到<污水综合排放标准>(GB 8978-1996)二级标准.     

Fenton氧化预处理磷酸酯阻燃剂生产废水

针对磷酸酯阻燃剂生产废水中COD质量浓度高,含有微生物难降解的成分,是一种难处理的有机废水的现实,利用Fenton氧化工艺对磷酸酯阻燃剂生产废水进行预处理,测定水中COD质量浓度的变化情况,以评价Fenton氧化工艺的处理效果,并考察Fe SO4·7H2O投加量、H2O2投加量及不同酸调节p H值对处理效果的影响。结果表明,最佳工艺条件为:Fe SO4·7H2O加入量为5 g/L,H2O2加入量为5.55 g/L;用硫酸调整p H值优于用盐酸调整p H值。     

Fenton氧化深度处理柠檬酸生产废水

采用Fenton氧化深度处理柠檬酸废水通过正交试验和单因素轮换试验,分析pH、H_2O_2投加量、反应时间、H_2O_2/FeSO_4四个主要因素对COD_(Cr)去除效果的影响。试验结果表明影响效果从大到小依次为pHH_2O_2/FeSO_4反应时间H_2O_2投加量,单因素试验确定最佳的反应条件为:pH为3.5、反应时间为2 h、30%H_2O_2投加量0.9 mL/L,FeSO_4用量为223.4 mg/L,此条件下COD_(Cr)去除率达到约75%。氧化去除COD_(Cr)过程符合准一级反应,表观速率常数0.012 9 min~(-1),设计连续流全混反应器中停留时间为2 h。在最佳药剂投加量下,中试连续运行出水COD_(Cr)40 mg/L,实际出水COD_(Cr)与理论拟合值接近。     

响应面法优化Cu-BiVO_4可见光催化降解扑热息痛污染物工艺研究

Cu-BiVO4可见光催化方法是一种去除环境中扑热息痛污染物的有效绿色方法。采用研制出的Cu-BiVO4催化剂在可见光条件下降解扑热息痛,运用响应变量控制法,研究了催化剂负载量、催化剂投加量、初始溶液pH值等工艺条件对降解效果的影响。在可见光照射下5h降解扑热息痛的最佳工艺条件为:催化剂投加量为80mg、催化剂负载量为5%、溶液初始pH值为6,在此工艺条件下降解扑热息痛的效率为72.6%。     

Optimization of photo-Fenton process of RO concentrated coking wastewater using response surface methodology

The objective of this study was aimed at investigating the removal of chemical oxygen demand (COD) from reverse osmosis (RO) concentrated coking wastewater by the photo-Fenton process. The optimum extraction conditions for the photo-Fenton process by Box-Behnken design (BBD) and response surface methodology (RSM) to establish a predictive polynomial quadratic model were discussed based on a single factor test. Optimized parameters validated by the analysis of variances (ANOVA) were found to be H(2)O(2) concentration of 345.2 mg/L, pH value of 4.1 and reaction time of 103.5 minutes under ultraviolet irradiation. The experimental results of the COD removal under the optimized conditions presented better agreement with the predicted values with deviation error of 3.2%. The results confirmed that RSM based on BBD was a suitable method to optimize the operating conditions of RO concentrated coking wastewater.     

铁碳微电解——ABR——接触氧化工艺处理糠醛废水

糠醛废水是一种高浓度难处理的有机废水,介绍了铁碳微电解—ABR—接触氧化工艺在实际工程中处理糠醛废水的启动与运行。结果表明,该工艺对CODCr、BOD5、SS等污染物的去除效果较好,同时指出工程在启动运行中存在的一些问题。     

负载型纳米TiO2光催化降解罗丹明B动力学与机理研究

采用负载型纳米TiO2/AC在流化床反应器中降解罗丹明B染料废水。研究了罗丹明B的光催化降解反应动力学与降解机理。结果表明,负载型纳米TiO2光催化降解罗丹明B过程符合一级动力学方程,降解机理首先是罗丹明B分子发色基团苯氨基、羰基键被破坏,然后是无色中间产物的逐渐降解。