催化氧化技术降解碱性藏花红废水.pdf

催化氧化技术降解碱性藏花红废水 ＊ 王丽娟 1,2 黄继国 1 董莉莉 1 黄国鑫 3 林年丰 1 1.吉林大学环境与资源学院, 吉林 长春 130026; 2.东北制药总厂环保研究所, 辽宁 沈阳 110026; 3.中国地质大学北京市水资源与环境工程重点实验室, 北京 100083 摘要 采用自制的多金属氧酸盐 Zn1. 5PW12O40纳米管作为催化剂和分子氧作为氧化剂的催化氧化技术进行碱性藏花 红的降解实验。 结果表明 Zn1. 5PW12O40适合用作催化剂, 中空结构, 杂多酸型, 纳米级; 空气氧化体系中的催化氧化最 佳反应时间为 4 h, 降解率78、降解速率 665μ g h; 催化剂的活性和稳定性均较高, 循环使用 4次时, 降解率仍65。 关键词 纳米管 分子氧 碱性藏花红 降解速率 循环 ＊长春市科技基金资助课题 06GG01 ; 吉林省环保局科技基金资助 课题 2006 -12 ; 吉林大学“985 工程”资助。 0 引言 染料废水具有成分复杂、COD 浓度高、含盐量 高、 色度高等特点, 其所含污染物主要是各种化学染 料,如 活性染料 、 酸性染料、 阳离子染料等。近年来, 催化氧化技术处理此类废水的研究十分活跃 , 该技 术的核心在于催化剂和氧化剂的选用。 POM 是一类由杂原子 P 、 Si 、 Fe 等和多原子 Mo 、 W、 V 等按一定空间结构通过氧原子配位桥联组成的 多氧族金属配合物,其中杂多阴离子为 POM 的一级结 构。POM 及其衍生物的二级结构的独特性质包括 具 有确定的结构; 具有酸性和氧化还原性能; 具有一定的 选择性,可作为均相或多相催化剂 ,又可作为能同时传 递质子和电子的双功能催化剂 [ 1] 。 本实验采用自制难溶的多金属氧酸盐纳米管作 为催化剂, 及空气中的分子氧作为氧化剂 ,以碱性藏 花红废水为处理对象进行了催化氧化降解实验研究。 1 实验材料与方法 1. 1 催化剂的制备 将1 g 磷钨酸溶于 10 mL 水配成溶液 A,1. 5 g 醋 酸锌溶于 5 mL 乙醇配成溶液 B , 将 2 种溶液在迅速 搅拌过程中进行混合, 并持续搅拌 1 h 后形成溶胶, 通过抽滤将溶胶负载在滤纸上 ,并用蒸馏水和乙醇交 替抽洗10 次, 将得到的滤纸进行干燥, 放入坩埚内, 用马釜炉程控升温 10℃ min 至 460℃, 并保持 1 h, 即可得到粉末状 Zn1. 5PW12O40纳米管 [ 2] 。该管通过 X 射线粉末衍射 XRD 和透射电镜 TEM 表征。 1. 2 碱性藏花红废液的配制 碱性藏花红 Safranine T ,简称 ST 是1 种单价阳离 子染料,分子式为C20H19N4Cl, 外观为红棕色粉末,溶于 水呈红色,是 1种有代表性的水溶性难降解有机物质。 每升水中加入1 g ST ,配成储备液,使用时临时稀释。 2 结果和讨论 2. 1 Zn1. 5PW12O40的结构表征 Zn1. 5PW12O40的 XRD 图如图 1 所示 。图中所有衍 射峰都与 H3PW12O40标准谱图 JCPDS No. 41-0369 中 的特征衍射峰相符合, 表明 Zn1. 5PW12O40聚阴离子仍 保持着最初的 Keggin 型结构, 故 Zn1. 5PW12O40属于杂 多酸型催化剂 [ 3] 。 从透射电镜图可知, 其呈中空结构。经计算管长 在200～ 900 nm , 管外径 70 nm, 管内径约 20 nm。因 此,Zn1. 5PW12O40属于纳米级材料。 结合图 1 可知, Zn1. 5PW12O40的结构和尺寸均适合用作催化剂。 图 1 Zn1. 5PW12O40纳米管的 X 射线粉末衍射 2. 2 氧化剂的筛选 为了选择与催化剂协同作用效果最佳的氧化剂 , 探讨了空气和紫外2 种氧化体系。空气体系的操作条 件为室温、 常压下 ST 浓度 40 mg L、 ST 体积 100 mL 、 曝 气量0. 085 m 3 h、 催化剂 0. 15g 。紫外体系的操作条件 为室温、 常压下 ST 浓度 0. 12 mg L、 ST 体积 30mL、 紫外 20 环 境 工 程 2008年 6 月第26 卷第3 期 8 W,3 650 和催化剂0. 15 g 。实验以ST 降解率与降 解速率为考察指标对 2 种体系进行比较, 降解率与降 解速率随反应时间的变化关系见表 1。 表 1 降解率与降解速率随反应时间的变化 反应时间 h 空气氧化体系臭氧氧化体系 降解率 降解速率 μ gh- 1 降解率 降解速率 μ gh- 1 1451 800782 . 8 2601 200801 . 4 366880851 . 0 470700880 . 8 572576890 . 6 由表 1 可知, 2 种体系下 , 降解率均随反应时间 的增加而增加, 且空气氧化体系的降解率劣于臭氧体 系,但是前者的降解速率较后者可提高 643 ～ 960 倍。 此外, 分子氧廉价易得、无二次污染 、 工艺简单 、 能耗 低,而紫外光由于受透光率的影响对高浓度高色度废 水处理 效 果不 理 想、光 利用 率 低、量 子 效率 低 4 h 时 ,降解率不发生变化 ,故确定最佳反应时 间为 4h。两者对比可知 ,催化剂明显增强了分子氧 氧化降解 ST 的效能 ,且表现出较好的催化活性。 2. 4 催化剂循环利用 Zn1. 5PW12O40纳米管不溶于水和有机溶剂 , 在降 解ST 的过程中为非均相催化剂, 因此可以反应后过 滤回收催化剂, 以期循环使用 。 在相同的实验条件下 ,将回收的催化剂进行循环 使用次数实验, 循环次数与ST 降解率的关系见图 3。 图 3 循环次数对降解率的影响 由图 3 可知 , 当循环次数达到 4 次时 , 降解率 仍 65,表明催化剂的活性和稳定性均较高, 可以 达到循环使用的目的 。但是, 随着循环使用次数的增 加,降解率呈降低的趋势 ,表明在此催化氧化过程中 催化剂受到了一定程度的破坏 。 3 结论 1 Zn1. 5PW12O40适合于催化剂 , 其聚阴离子为 Keggin 型结构 ,属于杂多酸型催化剂 ,呈中空结构 ,属 于纳米级材料。 2 利用分子氧作为氧化剂时, 空气氧化体系的 降解率低于臭氧体系 ,但是前者的降解速率较后者可 以提高643～ 960 倍。 3 分子氧单独用于氧化时 , 降解率最大值为 32; 催化氧化时, 确定最佳反应时间为 4 h ,此时降 解率达到 78、降解速率达到 665 μ g h 。 4 催化剂的活性和稳定性均较高 , 可以达到循 环使用的目的。 参考文献 [ 1] Sun Y G, Xia Y N . Shape -controlled synthesis of gold and silver nanoparticles. Science ,2002, 298 2176 -2179 [ 2] Ma J H, Song W J, Chen C C, et al . Fenton degradation of organic compounds pro-moted by dyes under visible irradiation. Environ. Sci. Technol. , 2005, 39 5810 -5815 [ 3] 王元庆, 陈艳玲, 夏菲, 等. 用于稠油水热催化降黏的 Keggin 型 杂多酸盐的制备表征及应用. 地质科技情报, 2007, 26 2 81 -85 [ 4] 杨尧. 光催化氧化反应的研究进展. 浙江化工, 2007, 38 5 17 -21 作者通信处 黄继国 130026 长春市吉林大学环境与资源学院 电话 0431 8499792 E -mail huangxu67sohu. com 2007- 10-13 收稿 21 环 境 工 程 2008年 6 月第26 卷第3 期 POWDER ACTIVATEDCARBON -MEMBRANEBIOREACTORFORTREATMENT OF MUNICIPAL WASTEWATERPei Liang Yao Binghua7 Abstract The combined process of powdered activated carbonPACand membrane bioreactor MBRwas applied for treatment of municipal wastewater. The removal efficienciesof COD, NH 4-N and turbidity inthe combined processwere investigated. The result showedthat the combined process may achieve better removal efficiencies of COD,NH 4-N and turbidity, when water temperature is above 26℃, DO is above 4. 5 mg L and pH is between 6 and 9. The average removal efficiencies of COD, NH 4-N and turbidity in the combined process were 88, 98 and 98 respectively, and was better than that of single MBR process and conventional process. The effluent COD was less than 22 mg L andNH 4-N was less than 1 mg L, turbidity was less than 1NTU. It was better than that of water for domestic reuse stated by the Ministy of Construction CJ25. 1-89 . The fouled membrane was cleaned by water rinsing ,water -acid rinsing, water -alkali rinsing , which can let its flux be restored to 43, 81, 89 of a new membrane respectively. Keywords powder activated carbon membrane bioreactor domestic wastewater INACTIVATION OF MICROBE IN RUNNING WATER USING MICROWAVE ELECTRODELESS ULTRAVIOLET LIGHTLou Chaogang Xia Dongsheng Zhao Fan et al 10 Abstract E. coli and Bacillus subtilis were selected to express respectively the easily and difficultly inactivated microbe, and the best irradiationtime and the limit turbidity of microwave electrodeless ultraviolet UVirradiation were studied.In this condition, checking the disinfection of E. coli and Bacillus subtilis, and compared with mercury lamp of medium pressure.The results showed that when best irradiation time was 210 s, microwave electrodeless ultraviolet irradiation can achieve inactivation rate of 99. 92.In order to obtain the best results of disinfection effect, the water of turbidity was below 8 NTU, the limit turbidity of disinfection was 40 NTU;microwave electrodeless ultraviolet irradiation can achieve inactivation rate of 100with 180 s, and the Bacillus subtilis inactivation rate of 100with 300 s, it is more effective than mercury lamp of medium pressure disinfection. Keywords E. coli Bacillus subtilis limit turbidity drinking water disinfection efficiency electrodeless UV lamp STUDY ON THE BULKING SLUDGE INTHE PROCESS OF SHORT RANGE NITRIFICATIONOF HIGH AMMONIA WASTEWATERHou Qiaoling WenYibo Li Linbao et al 13 Abstract A O technique was used to treat simulated high ammonia wastewater, the stability short -cut nitrification could be implemented by controlling the right content accumulation rate≥80, the activated sludge had good settling property, in the late of the short-range nitrification it was degraded gradually . It is showed by the experimental results that increasing N P ratio in the wastewater can slightly dropSVI, but still can not effectively ease the sludge bulking.The bulking sludge would be occurredwhen COD load was above 0. 27 kg kgd .Controlled DO with 1. 5 to 2. 0 mg L, the solid-liquid separation result is good, and the removal rates of NH 4-N and COD, as well as the cumulative rate of nitrite nitrogen are greater than 90, sludge bulking can be effectively controlled. Keywords short -range nitrification sludge bulking A O process TREATMENT OF WASTEWATER CONTAINING CrⅥ BY PVA MICRO-BALL ENTRAPPED IRON POWDER AND ACTIVATE CARBONHuang Yi 15 Abstract Micro -ball entrapped iron powder activate carbonwas prepared by liquid -liquid phase separation and its effect on treating the simulationwastewater containing CrⅥ was investigated. The results showed that the removal rate of CrⅥ could reach 99 . 7 at pH value of 2 and treating time of 4 h. The effluent could reach the discharge standardof China, the treatment operated steadily and the iron powder and activate carbon did not agglomerate in the continuous removal process. So this is superior to the common iron -carbonmicro -electrolytic . Keywords entrapping iron powder activate carbon Cr Ⅵ TREATMENT OF NEOPRENE WASTEWATER WITHMICROELECTROLYSIS AND THREE -UNIT BIOCHEMISTRY PROCESSZhang Sheng Xu Lirong Zhu Jianrong et al 18 Abstract A pilot study on the treatment neoprene wastewater with integrated microelectrolysis and three -unit biochemistry process was done. The experiment results under the stable condition showed that COD removal rate was up to 97. 6, COD concentration of the effluent could be reduced to less than 300 mg L. Keywords microelectrolysis three -unit biochemistry process neoprene wastewater treatment of pilot scale DEGRADATION OF SAFRANINE T BY THE TECHNOLOGY OF CATALYTIC OXIDATION Wang Lijuan Huang Jiguo Dong Lili et al 20 Abstract The technology of catalytic oxidation is studied for degrading safranine T. The self-made polyoxometalate Zn1. 5PW12O40nanotube is used as the catalyst and dioxygen is used as the oxidizer. The results show Zn1. 5PW12O40is sutiable for catalyst, with the structure of the Zn1. 5- PW12O40being hollowed, the type of the Zn1. 5PW12O40being affiliated to the type of heteropoly acids, and the scale of the Zn1. 5PW12O40being nanometer -scale; in the oxidation system of air, the optimum reaction time is 4 hours, and correspondently the degradation rate and the degradation velocity are respectively 78 and 665μ g h; the activity and stability are both high, andwhen the circulation times are four, the degradation is still 65. Keywords nanotube dioxygen safranine T degradation rate circulation 2 ENVIRONMENTAL ENGINEERING Vol. 26, No. 3, June ,2008