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1.
袁芳  胡春  李礼 《环境工程学报》2011,5(9):1968-1972
采用UV/2O2工艺去除水体中的喹诺酮类抗生素环丙沙星(CIP)。考察了溶液pH值、2O2投加量以及水体基质对环丙沙星降解效率的影响,分析了降解产物的生成情况。研究表明,环丙沙星的降解符合拟一级反应动力学模型。降解速率受溶液pH值的影响,酸性及中性条件,有利于环丙沙星的降解。2O2投加量的增大,使得降解速率逐渐增大,但速率增幅逐渐变缓;最佳2O2/环丙沙星摩尔比为2 000。实际水体中存在的NOM、NO-3,促进了单独UV作用下,环丙沙星的降解。水体中的?OH焠灭剂,抑制了UV/2O2联合作用下,环丙沙星的降解;实际水体中的光解速率常数低于超纯水中的光解速率常数。GC-MS分析表明,UV/2O2工艺,使环丙沙星氧化降解生成氨基乙酸、丙二酸、丙三醇和对苯二甲酸等小分子有机物。  相似文献   

2.
O3、H2O2/O3及UV/O3在焦化废水深度处理中的应用   总被引:1,自引:1,他引:0  
采用O3、H2O2/O3和UV/O3等高级氧化技术(AOPs)对某焦化公司的生化出水进行深度处理,考察了O3与废水的接触时间、溶液pH、反应温度等因素对废水COD去除率的影响,确定出O3氧化反应的最佳工艺参数为:接触时间40 min,溶液pH 8.5,反应温度25℃,此条件下废水COD及UV254的去除率最高可达47.14%和73.47%;H2O2/O3及UV/O3两种组合工艺对焦化废水COD及UV254的去除率均有一定程度的提高,但H2O2/O3系统的运行效果取决于H2O2的投加量。研究结论表明,单纯采用COD作为评价指标,并不能准确反映出O3系列AOPs对焦化废水中有机污染物的降解作用。  相似文献   

3.
UV/H2O2/Fe-FeOxH2x-3和UV/H2O2工艺降解水中富里酸的研究   总被引:1,自引:0,他引:1  
采用硼氢化钠还原法制备核-壳结构的Fe-FeOxH2x-3复合材料,研究了富里酸在UV/H2O2和UV/H2O2/FeFeOxH2x-3两种不同反应体系下的降解情况.结果表明,核-壳结构Fe-FeOxH2x-3的存在,提高了UV/H2O2降解富里酸的反应速率,TOC去除达到84%.采用XAD树脂吸附法对反应前后的富里酸进行化学分级表征,结果表明,富里酸经反应后憎水酸(HoA)、弱憎水酸(WHoA)和憎水中性物质(HoN)都有所减少,进而转化为亲水性物质(HiM);用超滤膜法对富里酸进行物理分级表征,考察了富里酸在反应前后分子量分布的变化情况.同时,富里酸经过反应后生成的中间产物降低了三氯甲烷生成趋势.  相似文献   

4.
利用Ce-Fe/Al2O3为催化剂的非均相光Fenton体系降解阳离子红GTL模拟废水,考察了H2O2浓度、催化剂用量、初始pH值及不同工艺过程对降解效果的影响,通过紫外-可见漫反射光谱、红外光谱、XPS手段研究铁在反应中的价态变化。结果表明,在11 W低压汞灯照射下,非均相光Fenton体系能够有效地降解结构稳定的阳离子红GTL,在pH 6,反应温度20℃,时间90 min,Ce-Fe/Al2O3 2 g/L,H2O2浓度340 mg/L,含50 mg/L阳离子红GTL模拟废水TOC去除率为92.40%;光Fenton反应中Fe(Ⅲ)转化为Fe(Ⅱ)。  相似文献   

5.
用H2O2/Fe3+处理高浓度含甲醛废水的研究   总被引:1,自引:0,他引:1  
研究采用H2O2/Fe3+催化氧化处理高浓度含甲醛废水,探讨了双氧水和催化剂投加量、反应pH及反应温度等操作条件对处理效果的影响,并通过酸溶解回用失活催化剂。结果表明,较优的操作条件为:H2O2/COD(质量比)=2.2~2.6,Fe3+/H2O2(摩尔比)=0.048~0.058,反应pH 1.80~2.68,反应温度50℃,反应时间40 min;在上述操作条件下,甲醛去除率达到99%以上,COD去除率达到85%以上。失活的催化剂可通过稀酸溶解后循环使用,其效果与三价铁盐作催化剂的基本相同。采用H2O2/Fe3+处理含甲醛废水具有比采用H2O2/Fe3+较优的效果。  相似文献   

6.
采用O3、UV/O3高级氧化法对水中六氯苯(HCB)的降解效果及机理进行了研究,并对结果进行了比较,结果表明,UV本身对HCB的去除率贡献不大,HCB可被O3、UV/O3快速降解,即UV<O3<UV/O3;O3、UV/O3作用时,提高体系的初始pH值不利于HCB的降解,在pH=3,HCB=0.2 mg/L,反应40 min时,HCB的去除可达50%左右,酸性条件下有利于降解反应的进行;无论是O3单独作用还是UV/O3联合作用,HCB的降解基本上满足准一级反应动力学规律,如果体系的pH值基本保持恒定,这种规律就更为明显。根据离子色谱(IC)、GC对六氯苯降解中间产物进行了测定,探讨了O3、UV/O3降解六氯苯的途径和机理。  相似文献   

7.
以钛酸四丁酯为原料,空心微珠为载体,采用溶胶凝胶法制备TiO2/beads光催化剂载体,然后浸渍法制备出H4SiW12O40/TiO2/beads表面负载修饰型复合光催化剂,并运用SEM、XRD、FT-IR和DRS对催化剂进行表征和分析。研究了H4SiW12O40/TiO2/beads对亚甲基蓝降解的光催化活性,考察了光强度、pH值、曝气量、底物浓度和催化剂用量等对催化效率的影响。实验结果表明,在中性条件下,H4SiW12O40/TiO2/beads催化剂的投加量为0.25 g/L,浓度为7.5 mg/L的亚甲基蓝溶液在250 W的紫外灯和600 W的可见光灯下光照60 min降解率分别可达到94.5%和55%。  相似文献   

8.
油脂废水是一种重要的水污染源。研究了表面活性剂和H2O2对洋葱伯克霍尔德氏菌(Burkholderia cepacia)降解油脂的影响。结果表明:适量的表面活性剂和H2O2促进油脂的降解。表面活性剂可以增强油脂在水相中的溶解度,提高油脂在水中的乳化程度从而增加其生物可利用性。当Tween-80浓度600mg/L时,油脂降解率达到91%。低浓度H2O2不仅能刺激微生物生长,而且使培养液中的pH值保持相对稳定,提高了微生物对油脂的降解率。H2O2在浓度为400mg/L时,能使油脂降解率达到90%。  相似文献   

9.
采用vis/H2O2/草酸铁法,对活性艳红染料废水进行处理。研究了H2O2、K2C2O4和Fe2(SO4)3·7H2O的投加量、pH值和光照时间等因素对染料废水处理效果的影响和最佳处理条件。结果表明,pH值2.5;30%H2O2的投加量0.1 mL;0.1 mol/L Fe2(SO4)3·7H2O的投加量1.0 mL;0.1 mol/L K2C2O4的投加量1.5 mL;光照时间40 min的最佳条件下,70 mg/L的活性艳红模拟染料废水脱色率可达99.82%。通过对vis/H2O2/草酸铁法和Fenton法、H2O2法、草酸铁法等方法进行对比实验,vis/H2O2/草酸铁法明显优于其他方法,是一项有研究价值和开发应用前景的污染治理新技术。  相似文献   

10.
采用溶胶-凝胶法制备了La2O3/ZnO/TiO2复合光催化剂,以紫外灯为光源,活性艳红K-2BP为模型降解物,研究了La2O3/ZnO/TiO2的光催化性能。结果表明:当锌和镧的掺杂量w(ZnO)=20%, w(La2O3)=0.5%, 煅烧温度为500℃时,La2O3/ZnO/TiO2复合光催化剂的光催化活性最高;当催化剂投加量4 g/L,通气量800 mL/min,初始pH值3.12时,La2O3/ZnO/TiO2对活性艳红K-2BP的降解效果最好。实验证明,La2O3/ZnO/TiO2对活性艳红K-2BP的降解遵从Langmuir-Hinshelwood动力学模型,测得其反应速率常数k=11.5 mg/(L·min);吸附常数K=2.88×10-2 L/mg。  相似文献   

11.
二甲基亚砜(DMSO)废水因其COD高、可生化性差的特性而较难处理。本实验以采用硫酸二甲酯法生产DMSO的某化工厂废水为研究对象,设计并建立了组合式光催化氧化装置联合水解酸化+MBR工艺的中试系统,探讨了组合式光催化氧化装置、氧化剂投加量、pH、反应时间和水力停留时间对系统处理效果的影响。结果表明,组合式光催化氧化装置可有效提高DMSO废水的可生化性。最优工艺参数为:按H2O2与原水COD质量浓度比为2∶1投加H2O2,在pH值为4、反应时间为6 h、水力停留时间为4 h的条件下,该系统对原水COD(5 000 mg/L)去除率大于98%,出水COD达到《污水综合排放标准》(GB 8978-1996)一级要求。  相似文献   

12.
采用O3/H2O2法对嘧啶废水进行处理,考察了不同反应条件对嘧啶和COD去除率的影响,并对O3/H2O2降解嘧啶的反应机制和动力学进行了初步探讨.实验结果表明,在pH值为11,反应时间为70 min,O3流量为4g/h,H2O2投加量为50 mmol/L的条件下,废水的嘧啶和COD的去除率分别达到86.46%和74.9...  相似文献   

13.
双频超声辐射协同H2O2降解偶氮染料废水的研究   总被引:2,自引:2,他引:0  
采用双频超声协同H2O2降解酸性绿20染料废水,考察超声功率密度、染料初始浓度和pH、饱和气体及H2O2投加量等因素对酸性绿20降解效果的影响,结果表明,在给定实验条件下,双频降解效果优于单频超声波,且降解率随超声功率密度的增大而增大。酸性条件有利于酸性绿20的降解,当染料废水初始pH=4可取得最佳的降解效果;酸性绿20的降解效率随染料初始浓度的增大而降低,其优化初始浓度为40 mg/L。在反应体系中通入空气并投加H2O2,可取得最佳的降解效果。在优化实验条件下, 采用双频超声协同H2O2降解5 h,酸性绿20的色度和TOC去除率分别为94.6%和36.3%;分析降解前后的紫外可见光谱图可知,酸性绿20并非完全被降解为CO2和H2O,而是生成一些小分子有机中间体。  相似文献   

14.
The degradation of paracetamol in aqueous solutions in the presence of hydrogen peroxide was carried out by photochemistry, electrolysis and photoelectrolysis using modified 100 pores per inch reticulated vitreous carbon electrodes. The electrodes were coated with catalysts such as TiO2 and CuO/TiO2/Al2O3 by electrophoresis followed by heat treatment. The results of the electrolysis with bare reticulated vitreous carbon electrodes show that 90% paracetamol degradation occurs in 4 h at 1.3 V vs. SCE, forming intermediates such as benzoquinone and carboxylic acids followed by their complete mineralisation. When the electrolysis was carried out with the modified electrodes such as TiO2/RVC, 90% degradation was achieved in 2 h while with CuO/TiO2/Al2O3/RVC, 98% degradation took only 1 h. The degradation was also carried out in the presence of UV reaching 95% degradation with TiO2/RVC/UV and 99% with CuO/TiO2/Al2O3/RVC/UV in 1 h. The reactions were followed by spectroscopy UV-Vis, HPLC and total organic carbon analysis. These studies show that the degradation of paracetamol follows a pseudo-first order reaction kinetics.  相似文献   

15.
Y. Xu   《Chemosphere》2001,43(8):1281
The degradation of a common textile dye, Reactive-brilliant red X-3B, by several advanced oxidation technologies was studied in an air-saturated aqueous solution. The dye was resistant to the UV illumination (wavelength λ  320 nm), but was decolorized when one of Fe3+, H2O2 and TiO2 components was present. The decolorization rate was observed to be quite different for each system, and the relative order evaluated under comparable conditions followed the order of Fe2+–H2O2–UV  Fe2+–H2O2 > Fe3+–H2O2–UV > Fe3+–H2O2 > Fe3+–TiO2–UV > TiO2–UV > Fe3+–UV > TiO2–visible light (λ  450 nm) > H2O2–UV > Fe2+–UV. The mechanism for each process is discussed, and linked together for understanding the observed differences in reactivity.  相似文献   

16.
为了有效地改善养猪场污水的质量,以H2O2为药剂,对污水进行了水浴加热和超声波辅助的对比实验,考察了超声波发生器输出端电流强度、处理时间、H2O2用量对污水的COD、氨气及颜色的影响,并进行正交实验优化。结果表明,超声波协同H2O2处理养殖污水是一种切实可行的方法,超声波协同H2O2处理污水的最佳工艺条件:电流0.7 A、处理时间2 min、H2O2用量3%,在此条件下降低COD量可达95%以上,氨氮的含量可降至14~15 mg/L,氨臭味大大得到了改善,并将原污水由黑色变为浅黄色。  相似文献   

17.
针对TNT炸药废水具有成分复杂、排放量大、有毒等特点,立足于炸药废水在排放前的降解处理,研究开发一种基于核壳结构Fe3O4@SiO2/TiO2纳米颗粒的高效、可控回收、无二次污染且成本低的光催化降解方法。利用高温碳还原法和溶胶凝胶法制备了具有核壳结构的Fe3O4@SiO2/TiO2纳米颗粒。XRD分析表明,内核Fe3O4呈现磁铁矿特征,表面覆盖的纳米TiO2为锐钛矿型。磁滞回线测试结果显示,复合颗粒的饱和磁化强度为46.5 emu/g,N2吸附-解吸分析结果表明,该颗粒具有典型的介孔结构。使用Fe3O4@SiO2/TiO2纳米颗粒在紫外光下对含TNT废水进行降解,降解率达到81.9%,且颗粒的回收率达到88.4%,为实现高效、可控回收、无二次污染光催化-吸附降解TNT奠定了基础。  相似文献   

18.
Photochemical degradation of fluoroquinolone ciprofloxacin (CIP) in water by UV and UV/H2O2 were investigated. The degradation rate of CIP was affected by pH, H2O2 dosage, as well as the presence of other inorganic components. The optimized pH value and H2O2 concentration were 7.0 and 5 mM. Carbonate and nitrate both impeded CIP degradation. According to liquid chromatography–tandem mass spectrometry analysis, four and 16 products were identified in UV and UV/H2O2 system, respectively. Proposed degradation pathways suggest that reactions including the piperazinyl substituent, quinolone moiety, and cyclopropyl group lead to the photochemical degradation of CIP. Toxicity of products assessed by Vibrio qinghaiensis demonstrated that UV/H2O2 process was more capable on controlling the toxicity of intermediates in CIP degradation than UV process.  相似文献   

19.
The degradation of atrazine in aqueous solution by UV or UV/H2O2 processes, and the toxic effects of the degradation products were explored. The mineralization of atrazine was not observed in the UV irradiation process, resulting in the production of hydroxyatrazine (OIET) as the final product. In the UV/H2O2 process, the final product was ammeline (OAAT), which was obtained by two different pathways of reaction: dechlorination followed by hydroxylation, and the de-alkylation of atrazine. The by-products of the reaction of dechlorination followed by hydroxylation were OIET and hydroxydeethyl atrazine (OIAT), and those of de-alkylation were deisopropyl atrazine (CEAT), deethyl atrazine (CIAT), and deethyldeisopropyl atrazine (CAAT). OIAT and OAAT appeared to be quite stable in the degradation of atrazine by the UV/H2O2 process. In a toxicity test using Daphnia magna, the acute toxic unit (TUa) was less than 1 of TUa (100/EC50, %) in the UV/H2O2 process after 30 min of reaction time, while 1.2 to 1.3 of TUa was observed in the UV process. The TUa values of atrazine and the degradation products have the following decreasing order: OIET> Atrazine> CEAT≈CIAT> CAAT. OIAT and OAAT did not show any toxic effects.  相似文献   

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