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1.
建立了同时测定水中5种氯酚类化合物的离子色谱紫外检测法。水样经0.45μm水相针式滤器过滤后,以250 nm为检测波长,5%的氨水甲醇-1%的硫酸铵溶液(V∶V=80∶20)为流动相进行检测。结果表明,在2-氯酚质量浓度为0.1~1.6 mg/L,其余4种氯酚质量浓度为0.01~0.16 mg/L范围内,线性相关系数均>0.999;2-氯酚和2,4-二氯酚的检出限分别为0.03和0.004 mg/L,其余3种氯酚的检出限为0.003 mg/L。低、中、高3种加标浓度样品的加标回收率为94.1%~100.8%,相对标准偏差(RSD)为2.5%~9.9%。该方法前处理简单,灵敏度、准确度和精密度均较好,适用于基层检测机构对生活饮用水中5种氯酚类化合物的日常快速检测。  相似文献   

2.
温州临江垃圾焚烧发电厂飞灰的性质研究   总被引:1,自引:0,他引:1  
研究了温州临江垃圾焚烧发电厂生活垃圾焚烧产生飞灰的物理和化学性质。飞灰为含水率低、颗粒尺寸集中在43~175μm之间的灰色粉末,主要由Si、Al、Ca、Mg、Fe、Na、K、C和S元素组成。飞灰中Pb、Cd的浸出浓度在酸性条件下都不同程度地高于我国危险废物鉴别标准的允许浓度,其中Pb的浸出浓度在pH值1.06~13.69条件下远远超标,碱性条件下浸出毒性比酸性条件下小。矿物组成主要为石英(SiO2)、赤铁矿αFe2O3、钙长石CaO.Al2O3.2SiO2、钙铝黄长石2CaO.Al2O3.SiO2、KCl、NaCl、CaCO、PbO、TiO2、ZnCO3等,溶解盐含量高达19.5%,化学反应活性较强,热稳定性较差。  相似文献   

3.
对甲萘酚偶氮显色光度法测定水中苯胺的方法进行了验证性研究。结果表明,该方法具有简单、快速、稳定等优点。线性区间在0.05~5.5mg/L范围内,相关系数等于0.9997,苯胺浓度小于0.05mg/L或大于5.5mg/L时,测量误差比较大。还考察了NaCl、KCl、NaNO_3、KNO_3、Na_2SO_4、K_2SO_4、TiO_2、ZnO,苯酚,以及由吐温-80/苯/水/正丁醇组成的O/W微乳液对测量的影响。  相似文献   

4.
重金属离子对斜生栅列藻毒性的研究   总被引:2,自引:0,他引:2  
应用斜生栅列藻作为生物指示物,对16种重金属化合物的单一毒性进行毒性评价,并分别从微观和宏观角度分析了重金属的致毒机理。实验结果表明:它们的毒性大小顺序为Ag+Cd2+Cu2+Zn2+Sr2+Pb2+Hg2+Sn4+Al3+Cr+Ni2+Mn2+Ba2+Fe3+Co2+Li+。  相似文献   

5.
建立了水中2,4-二氯酚、2,4,6-三氯酚和五氯酚的顶空固相微萃取-气相色谱分析方法。研究确定以聚丙烯酸酯(PA,85μm)为萃取头,加入0.3 m L质量浓度为0.1 mol/L的H_2SO_4溶液和1.5 g的Na_2SO_4调节待测液的p H值和离子强度,萃取温度为80℃,萃取时间为50 min,搅拌速率为250 r/min时萃取效果最好;最佳解吸时间为5 min。在该优化条件下,3种物质在0.1~10 000μg/L范围内线性良好,相关系数R2均0.999,检出限为0.023~0.13μg/L,实际样品的加标回收率为82.5%~101.7%。该方法萃取过程不需有机溶剂,绿色、简便,且具有较高的灵敏度,适用于地表水、地下水等环境水样中氯酚类化合物的痕量检测与批量分析。  相似文献   

6.
采用水热合成法可控合成了磁性Fe 3O 4@SiO 2和Fe 3O 4@SiO 2@Cu^2+球状核壳介孔材料,研究了模板剂的种类及去除方式对形貌的影响,并将材料用作固相萃取剂选择性吸附水中微囊藻毒素,结合高效液相色谱定量分析来研究其对MC-LR的吸附性能。实验表明,十六烷基三甲基溴化铵(CTAB)模板剂更有利于壳层的形成,3次乙醇振荡萃取的方式对于两种材料均可达到很好的模板剂去除效果,对MC-LR的吸附率分别达到85%和95%以上,而马弗炉煅烧方式则适用于Fe 3O 4@SiO 2@Cu^2+介孔材料的制备。太湖水样中MC-LR的去除实验表明,两种材料能够很好地应用于实际水样处理。  相似文献   

7.
通过2018年在清水河流域布设32个采样点监测各水期Cu、Fe、Mn、Zn和Cd 5种重金属质量浓度,分析重金属污染状况和来源,并评价对人体产生的健康风险。结果表明:总体上清水河流域5种重金属质量浓度较低,除了Fe在丰水期平均质量浓度超过标准值外,其余均未超标。各采样点重金属质量浓度存在较大差异,总体表现为支流高于干流。受污染最严重的水期为丰水期,受污染最严重的区域为苋麻河,主要污染贡献因子为Fe。5种重金属产生的总健康风险最高为313×10-7 a-1,远低于USEPA推荐的最大可接受水平(1×10-4 a-1),其中致癌污染物Cd产生的健康风险最大。  相似文献   

8.
将表 1贴在分光光度计上对照使用可避免忙中出错或眈误时间。表 1 分光光度计常用元素、波长对照表元素 (项目 )分析方法波长 ( nm)As Ag-DDC 51 0S2 -对氨基二甲基苯胺 665Cr6 +总 Cr 二苯碳酰二肼 540CN-异烟酸 -巴比妥酸 60 0CN-吡啶 -巴比妥酸 580C6 H5 OH 4 -氨基安替比林 4 60Th 偶氮胂 660U TRPO-偶氮氯膦 665U TRPO-5Br-PADAP 578SO2 盐酸付玫瑰苯胺 (甲醛 ) 577NOx 盐酸萘乙二胺 540HCl Hg( SCN) 2 比色法 4 60NH3、NH3-N 纳氏试剂 4 2 0Cl2 甲基橙褪色法 51 5P2 O5 磷钼兰 680总 P 磷钼兰 70 0Mn 高碘…  相似文献   

9.
为了研究在线离子色谱法测定大气PM2.5中NH4^+、NO3^-、SO4^2-的不确定性来源,探讨了标准曲线的浓度范围及浓度梯度设置对离子浓度结果的影响,并对标准曲线设定方案进行了优化。结果表明:不同浓度范围的标准曲线对于NH4+的浓度结果有较大的影响,存在1. 87%~14. 91%的偏差,对于NO3^-、SO4^2-的影响较小,相对偏差分别为2. 94%和2. 82%;非均匀布点和均匀布点标准曲线定量NH4+的结果存在4. 15%~4. 25%的偏差,对于NO3^-和SO4^2-,相对偏差分别为0. 10%和5. 99%。对于二次拟合的NH4^+,在样品浓度波动较大时,可以将样品划分为低浓度范围和高浓度范围,分别选用低浓度段标准曲线和高浓度段标准曲线,以期得到更合理的浓度结果。  相似文献   

10.
2011年南京市春季大气颗粒物污染特征分析   总被引:2,自引:0,他引:2  
2011年江苏省环境监测中心对南京市鼓楼、建邺、栖霞3区8个采样点采集了TSP和PM10样品,进行颗粒物质量浓度、水溶性离子、无机元素以及碳成分分析。结果表明该市春季大气颗粒物污染以PM10为主,不同区域颗粒物污染特点不一;水溶性离子以Ca2+、NO3-及SO2-4居多;无机元素以Ca、Fe、Al为主,Pb与Zn浓度较Ni与V高;市内EC浓度较高,可能与裸露堆煤场有关。有关研究结果提交南京市政府部门,供决策时参考。  相似文献   

11.
Fumes from a group of gas metal arc welding (GMAW) processes used on stainless steel were generated using three different metal transfer modes and four different shield gases. The objective was to identify and measure manganese (Mn) species in the fumes, and identify processes that are minimal generators of Mn species. The robotic welding system was operated in short-circuit (SC) mode (Ar/CO2 and He/Ar), axial spray (AXS) mode (Ar/O2 and Ar/CO2), and pulsed axial-spray (PAXS) mode (Ar/O2). The fumes were analyzed for Mn by a sequential extraction process followed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) analysis, and by X-ray diffraction (XRD). Total elemental Mn, iron (Fe), chromium (Cr) and nickel (Ni) were separately measured after aqua regia digestion and ICP-AES analysis. Soluble Mn2+, Fe2+, Fe3+, and Ni2+ in a simple biological buffer (phosphate-buffered saline) were determined at pH 7.2 and 5.0 after 2 h incubation at 37 C by ion chromatography. Results indicate that Mn was present in soluble form, acid-soluble form, and acid-soluble form after reduction by hydroxylamine, which represents soluble Mn0 and Mn2+ compounds, other Mn2+ compounds, and (Mn3+ and Mn4+) compounds, respectively. The dominant fraction was the acid-soluble Mn2+ fraction, but results varied with the process and shield gas. Soluble Mn mass percent in the fume ranged from 0.2 to 0.9%, acid-soluble Mn2+ compounds ranged from 2.6 to 9.3%, and acid plus reducing agent-soluble (Mn3+ and Mn4+) compounds ranged from 0.6 to 5.1%. Total Mn composition ranged from 7 to 15%. XRD results showed fumes had a crystalline content of 90-99% Fe3O4, and showed evidence of multiple Mn oxides, but overlaps and weak signals limited identification. Small amounts of the Mn2+ in the fume (<0.01 to ≈ 1% or <0.1 to ≈ 10 microg ml(-1)) and Ni2+ (<0.01 to ≈ 0.2% or <0.1 to ≈ 2 mg ml(-1)) ions were found in biological buffer media, but amounts were highly dependent on pH and the welding process. Mn generation rates for the fractions were tabulated, and the influence of ozone is discussed. The conclusions are that exposures to welding fumes include multiple Mn species, both soluble and insoluble, and that exposures to Mn species vary with specific processes and shield gases.  相似文献   

12.
液相催化氧化法烟气脱硫热态试验   总被引:5,自引:0,他引:5  
采用液相催化氧化法和穿流式筛板吸收塔进行了规模为1000m3/h烟气脱硫热态试验。结果表明,当吸收液为浓度01M的Fe2++Mn2+水溶液,烟气风量在818~1418m3/h,液气比为1L/m3,SO2入口浓度在787~7821PPm范围内脱硫率可达49~69%。穿流式筛板塔具有处理能力大、阻力小、不易堵塞、结构简单、传质效果好等特点  相似文献   

13.
A detailed investigation on the kinetics of the oxidative degradation of a reactive dye, C. I. Reactive Red 2 by hydroxyl radicals generated by H202 and Fe2+ has been carried out in aqueous acidic media. Effects of different parameters like initial concentration of dye, H2O2, Fe2+, pH of the solution, reaction temperature and added electrolytes on the oxidation process have been studied. The results indicate that 1.63 x 10(-4) mol dm(-3) dye can be most effectively degraded at a dye: Fe2+: H2O2 molar ratio of 1:0.22: 8.13 at pH approximately 2.7 and at 299 K. The addition of excess 2-propanol or t-butyl alcohol, well known scavengers of hydroxyl radicals, almost stopped the degradation of the dye indicating the absence of any possible reductive pathways in the degradation. The results may be useful for designing the treatment systems of wastewater containing various reactive dyes.  相似文献   

14.
几种烟气脱硫剂的脱硫性能试验   总被引:3,自引:0,他引:3  
用添加Ca(OH)2的碱性水,含炉灰渣、赤泥的碱性工业废水及含有Fe2+、Mn2+催化剂的水溶液作为吸收液;以冷态模拟脱硫洗涤塔为吸收设备,研究了多种脱硫剂的脱硫效果。结果显示,Ca(OH)2、Fe2+、Mn2+催化剂对浓度为1000~2000ppm的SO2气体有较高脱硫效率;炉灰水、赤泥水对浓度为1000ppm左右的SO2气体有明显的脱硫效果  相似文献   

15.
In most natural ecosystems heterotrophic microorganisms encountercomplex mixtures of carbon sources, each of which is present at aconcentration of few micrograms per litre. This study examined the biotreatability and kinetics of an upflow anaerobic sludge blanket (UASB) reactor to complex mixtures of chlorophenols encountered in environmental conditions using on-line and off-line experimental studies. Results indicate that (1) steady-state concentration was quite lower (98.3 mg L-1) with complex mixture of chlorophenols than steady-state concentration achieved when only 2.4 dichlorophenol (124 mg L-1) was studied alone on the same reactor; (2) that toxiceffects of chlorophenols increase with increasing concentrationsof toxicant. (Onset of the inhibitory effect occurred at a lowerconcentration in multi-substrate than in single substrate utilization); (3) addition of alternative utilizable substrate can mitigate toxic effects and enhance degradation; (4) the relative concentration of substrate was critical in determiningutilization patterns. HPLC analysis of off-line experimental samples resulted in a steady-state treatment efficiency of68% for COD, 36% for 2-hlorophenol, 40.5% for 4-chlorophenol, 70.7% for 2,4-dichlorophenol, 53.2% for 2,4,6-trichlorophenol and 42% for pentachlorophenol in presence of glucose. Kinetic constant in terms of V max and K s were determined. K s for the five chlorophenols ranged between 0.016 and 0.117 kg m-3 day-1 while V max ranged between 0.056 and 0.244 kg m-3 day-1.  相似文献   

16.
Monitoring studies and thermodynamic modeling were used to reveal the changes of inorganic chemical species of some water pollutants (nutrients and trace metals such as Fe, Mn, Zn, Cu, Cd and Pb) inthe river-estuary-sea water system. The case studies were two rivers, Kamchiya and Ropotamo, representing part of the Bulgarian Black Sea water catchment area, and having different flow characteristics. There were no major differences in inorganic chemical species of the two river systems. NO3(-) and NO2(-) chemical species showed no changes along the river-estuary-sea water system. Concerning phosphates six different species were calculated and differences between the three parts of the systems were established. The HPO4(2-) and H2PO4(-) species were found to be dominant in river waters. The H2PO4(-) species quickly decreased at the expense of HPO4(2-) and Ca, Mg and Na phosphate complexes in estuary and seawater. Trace metals showed a great variety of chemical species. Fe(OH)2(+) species prevailed in river waters, and Fe(OH)3(0) species--in sea waters. Me2+ and MeCO3(0) (Me = Cu, Pb) and PbHCO3(+) were dominant in river waters, while Cu(CO3)2(2-) and PbCl(-) species appear also in sea waters. Cd2+ species prevailed in river and estuary waters, and CdCln(2-n) (n = 1-3) species, in seawater. Free Zn2+ species predominated in all systems but downstream their percentage decreased at the expense of Zn phosphates, carbonates,sulfates and chlorides complexes. Only free Mn2+ species were dominant along the systems.  相似文献   

17.
Arsenic (As) mobilization to the groundwater of Brahmaputra floodplains was investigated in Titabor, Jorhat District, located in the North Eastern part of India. The groundwater and the aquifer geochemistry were characterized in the study area. The range of As concentration in the groundwater varies from 10 to 440 μg/l with mean concentration 210 μg/l. The groundwaters are characterized by high dissolved Fe, Mn, and HCO3 ? and low concentrations of NO3 ? and SO4 2? indicating the reduced conditions prevailing in the groundwater. In order to understand the actual mobilization processes in the area, six core drilling surrounding the two target tube wells (T1 and T2) with high As concentration (three drill-cores surrounds each tube well closely) was done. The sediment was analyzed its chemical, mineralogical, and elemental compositions. A selective sequential extraction suggested that most of the As in the sediment is bound to Fe oxides fractions (32 to 50 %) and the competition for adsorption site by anions (PO4 3?) also accounts to significant fractions of the total arsenic extracted. High variability in the extraction as well as properties of the sediment was observed due to the heterogeneity of the sediment samples with different chemical properties. The SEM and EDX results indicate the presence of Fe, Mn coating along with As for most of the sample, and the presence of As associated minerals were calculated using PHREEQC. The mobilization of As into the groundwater was anticipated to be largely controlled by the reductive dissolution of Fe oxides and partly by the competitive anions viz. PO4 3?.  相似文献   

18.
The concentrations and distribution of the elements, including heavy metals such as As, Ba, Br, Co, Cr, Cs, Fe, Ga, K, Mn, Na, Rb, Sc, Sr, Th and Zn, were investigated in dated sediment cores of Nainital Lake located in the Himalayan region, in Uttar Pradesh state of India, which is considered as a remote background area. The concentrations of the elements were measured by instrumental neutron activation analysis using the k0 method. The International Atomic Energy Agency certified reference material SL-3 was used to evaluate the accuracy of the method. The normalized data for a series of elements were used to understand the source of loading. Elements like Br, Co, Cr, Fe, K, Mn and Zn show a negative correlation with increasing depth whereas elements like As, Ba, Cs, Na and Rb show a positive correlation with increasing depth. By considering the concentration for the bottom segments of the core as close to the baseline concentration, recent flux values for different elements were calculated. An increase in the flux value was observed for Br, Cr, Fe, K, Mn and Zn, which can be attributed to anthropogenic contribution in recent years.  相似文献   

19.
Probable sources and mechanisms of arsenic (As) release in shallow aquifer in eastern Bangladesh are evaluated using statistical analysis of groundwater compositions. Dissolved As in 39 samples ranged from 8.05 to 341.5 μg/L with an average of 95.14 μg/L. Ninety seven percent of wells exceed the WHO limit (10 μg/L) for safe drinking water. Principal component analysis is applied to reduce 16 measured compositional variables to five significant components (principal components—PCs) that explain 86.63% of the geochemical variance. Two component loadings, namely PC 1 and PC 2 (45.31% and 23.05%) indicate the natural processes within the aquifers in which organic matter is a key reactant in the weathering reactions. Four groups of wells are defined by the PCA and each group of wells represents distinct physicochemical characteristics. Among them, group III groundwater shows higher As concentration together with high concentrations of Fe, Mn, dissolved organic carbon, $\text{PO}_{4}^{3-}$ and $\text{HCO}_{3}^{-}$ than groups I and II. Speciation calculations suggest that only wells of group III are saturated with respect to siderite, and all groups of samples are supersaturated with respect of rhodochrosite. The relationship of As with these parameters in the different groups of wells of the study area suggests that reductive dissolution of Fe–Mn oxyhydroxides with microbially mediated degradation of organic matter is considered to be the dominant processes to release As in groundwater.  相似文献   

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