【作者】 董入源；

【导师】 黄玉明；

【作者基本信息】 西南大学 ， 分析化学， 2010， 硕士

【摘要】 随着社会的进步,国家对经济发展重视的同时,对环境保护的关注也逐渐增加。水环境安全是环境保护中很重要的一方面,特别是在水资源比较匮乏的情况下,水环境更容易受到周围环境的影响。人们日常生活排放的污水或者很多行业生产过程中排放出来的工业废水对自然水体都会造成比较大的影响,从而间接对人的身体健康产生一定的危害。因此,对水环境的监测与治理是环境研究的重要方向。本研究对造成水环境污染的几种典型物质进行了检测和降解方面的研究,通过考察各项影响因素对检测和降解过程的影响,选择最优的实验条件,从而实现对目标物进行高效的检测和降解。主要研究结果如下：(1)建立了项空固相微萃取(HS-SPME)和气相色谱联用测定人工湿地废水中二甲基硫(DMS)和二甲基二硫(DMDS)的分析方法。选择75μm的CAR-PDMS纤维头,温度为15℃,pH值为中性,样品体积为20 ml,氯化钠加入量为6.5 g的最优实验条件,测定二甲基硫和二甲基二硫的线性范围分别是1060-13780 ng/L和159-4240 ng／L,检出限分别为1020ng/L和140 ng／L；相对标准偏差小于10%。以二甲基硫为内标物,将本方法用于实际废水样品中DMS和DMDS的测定获得了满意的结果,DMS和DMDS的回收率分别为85%和105%。(2)基于纳米四氧化三铁粒子具有类似过氧化氢酶的性质,能够催化提高过氧化氢氧化能力,建立了一种类似Fenton试剂原理的化学降解染料废水的方法。实验中详细比较了四氧化三铁纳米粒子浓度,过氧化氢浓度,pH值,反应时间,超声时问和超声温度几个条件对催化降解反应的影响作用。当四氧化三铁纳米粒子浓度为600 mg／L,过氧化氢浓度为0.32mol/L,pH值为5,超声3 min,超声温度为30℃,反应时间为2 h时为最优条件,降解实验室模拟的亚甲蓝染料废水,最后的去除率为92%,重现性良好。(3)利用纳米四氧化三铁粒子具有催化增强过氧化氢的氧化能力,降解表面活性剂SDBS。考察了四氧化三铁纳米粒子浓度,过氧化氢浓度,pn值,温度等因素对降解率的影响。当四氧化三铁纳米粒子的浓度480 mg/L,过氧化氢浓度0.05mol/L,pH值为3,反应时间3 h时为最优实验条件,降解模拟的SDBS废水,最大去除率达到84%。更多还原

【Abstract】 In this study, we investigated the analytical method for dimethyl sulfide and dimethyl disulfide, nanomaterial-based degradation methods for removal of methylene blue dye and SDBS surfactant. The main contents are as followings:1、A headspace solid phase microextraction (HS-SPME) combined with gas chromatography/flame photometric detection (FPD) has been developed for the determination of dimethyl sulfide and dimethyl disulfide in wastewater from constructed wetlands. The various parameters including type of fibers, extraction temperature, pH value, ionic strength, sample volume were investigated for optimization of HS-SPME performance for dimethylsulfide and dimethyldisulfide. The DB-VRX capillary column (1.4μm,60 m×0.25 mm) was used for separation of dimethylsulfide and dimethyldisulfide with 1 mL/min of high purity nitrogen as carrier gas by GC. The initial oven temperature was 50℃, then was programmed at a rate of 8℃/min until 120℃, holding 2 min, and then a rate of 6℃/min until 180℃, holding the final temperature for 3 min. The enriched targets were detected by FPD. Under the optimized conditions, the linear dynamic ranges were 1060-13780 and 159-4240 ng/L for dimethylsulfide and dimethyldisulfide, respectively. The detection limits (3σ) for dimethylsulfide and dimethyldisulfide were 1020 and 140 ng/L, respectively. The relative standard deviations for the determination of studied compounds were less than 7%. By using dimethyl sulphide as internal standard, the proposed method has been successfully applied to the analysis of dimethyl sulfide and dimethyl disulfide in wastewater and recoveries are in the range of 85-114% and 105-113% for dimethylsulfide and dimethyldisulfide, respectively.2、Ultrasound-assisted nano-Fe3O4 nanoparticles for catalyzed degradation of methylene blue dye wastewater in the presence of hydrogen peroxide. Based on the fact that nano-Fe3O4 has similar property of hydrogen peroxidase, nano-Fe3O4 is able to enhance the catalytic ability of hydrogen peroxide. The optimal experimental conditions were obtained as follows:600 mg/L of nano-Fe3O4, 0.32 mol/L of hydrogen peroxide, pH at 5,3 min of ultrasonic time,30℃of ultrasonic temperature, 2 h of reaction time. The 92% removal rate was obtained with good reproducibility. 3、Ultrasound-assisted nano-Fe3O4 nanoparticles for catalyzed degradation of SDBS surfactant wastewater in the presence of hydrogen peroxide. Various factors affecting the SDBS removal were investigated and the optimal degradation conditions were obtained as follows:480 mg/L of nano-Fe3O4,0.05 mol/L of hydrogen peroxide, pH at 3,3 h of reaction time. The 84% removal rate was obtained with good reproducibility.更多还原