pH值变化对B30铜镍合金腐蚀电化学行为的影响

采用电化学阻抗谱、动电位极化曲线等电化学测试方法,研究了NaCl（质量分数为3．5％）溶液中pH值变化对B30铜镍合金腐蚀电化学行为的影响。结果表明：随着溶液pH值升高,B30材料的腐蚀行为由均匀腐蚀变为点蚀;材料阻抗值和瞬时腐蚀速率提高,极化电流密度降低;材料发生点蚀的倾向增大。     

红外光谱技术结合聚类分析用于海洋绿藻分类研究

利用傅里叶红外光谱研究了10种南极绿藻和6种浒苔,结果显示,傅里叶变换红外光谱主要由蛋白质、脂类化合物及多糖的振动吸收带组成。通过比较两类绿藻原始谱图,发现它们极为相似,在2000～500 cm-1范围内,即多糖吸收区有较小的差别。选取2000～500 cm-1范围的一阶导数进行系统聚类分析。10种南极绿藻、6种浒苔按其红外一阶导数的内在数理统计规律划归两类,南极绿藻为一类,浒苔为一类。傅里叶变换红外光谱技术结合化学统计学方法,为海洋藻类的分类研究提供一种新的方法。     

基于液相31P核磁共振分析的沉积物样品制备方法研究

液相31↑P核磁共振（phosphorus-31 nuclear magnetic resonance,31↑P-NMR）是近年来用于分析沉积物有机磷组成的新技术.本研究围绕31↑P-NMR分析沉积物样品的制备过程（包括样品前处理方法、提取时间、提取剂比例、样品浓缩等）进行探讨.结果表明,采用风干的沉积物样品进行提取,...     

D60钢在模拟海岛环境中腐蚀产物的红外光谱研究

目的以弹药金属元件的主要材料之一D60钢为样品,在模拟海岛环境的高湿、高盐雾条件下研究D60钢的腐蚀过程。方法利用红外光谱法(IR)对腐蚀产物进行表征。结果腐蚀层中含有吸附水,在腐蚀的初期,腐蚀产物主要有γ-Fe OOH和δ-Fe OOH,但是随着腐蚀的继续,产物中出现α-Fe OOH,同时δ-Fe OOH逐渐减少至完全消失,在腐蚀的后期出现了Fe3O4,有Cl-参与下的腐蚀,腐蚀产物主要有α-Fe OOH,γ-Fe OOH和部分少量的δ-Fe OOH。结论 Cl-的加入加速了基体金属的腐蚀。     

污水厂深度处理过程中有机物三维荧光光谱的平行因子分析研究

基于三维荧光光谱考察了污水厂深度处理过程中溶解性有机物(DOM)的荧光组分特征,结合平行因子分析(PARAFAC)解析出3个荧光组分,包括2个腐殖质类物质(C1、C3)和1个色氨酸类蛋白物质(C2).臭氧工艺对组分C1、C2、C3去除率分别为69.1%、71.5%和66.5%,表明臭氧对DOM有较好去除效果.三维荧光光谱结合PARAFAC分析能够较好反映水中DOM的去除情况,有利于污水处理效果的定性分析、定量评价,易于实时在线监测.     

合成腐殖酸氧化还原能力与光学性质探究

本文以合成商业腐殖酸Aldrich humic acids(AHA)与国药化学试剂腐殖酸(TJHA)为研究对象,与铁氰化钾反应测定不同浓度AHA与TJHA还原前后氧化还原能力.研究发现,原态和还原态的HA均能向铁氰化钾传递电子,还原后两种HA的氧化还原能力均大于其原态的氧化还原能力.原态和还原态TJHA的单位碳电子转移数(原态1.49 meq·g C-1;还原态20.95 meq·g C-1)均大于AHA(原态0.52 meq·g C-1;还原态1.75 meq·g C-1).同时随着HA浓度的增加,两种HA的原态与还原态单位碳电子转移数均逐渐降低(AHA:0.91—0.52 meq·g C-1;TJHA:13.57—1.49 meq·g C-1),而AHA单位体积电子转移数目逐渐增大(0.002—0.072 meq·L-1),TJHA单位体积电子转移能力无明显变化.这是由于在HA与铁氰化钾电子转移体系中,氧化还原能力的高低与腐殖酸中氧化还原官能团数量和分布有关,与HA粒径大小,分子质量也有关系.进一步通过E465,E4/E6值表明两种HA E465值与浓度呈明显正线性关系,E4/E6值与浓度呈对数增加趋势.三维荧光分析发现,HA还原后,激发/发射(Ex/Em)峰出现蓝移,相对荧光强度降低,说明HA还原的过程中有π—π*的断裂.进一步对HA荧光测定发现TJHA中具有更多数量的氧化还原官能团而AHA中氧化还原官能团种类相对丰富.     

高锰酸钾预氧化强化混凝去除螺旋鱼腥藻的研究

以水华优势藻螺旋鱼腥藻为对象,研究不同高锰酸钾浓度氧化下,藻光合作用能力,藻液中Mn浓度,胞外有机物三维荧光和分子量分布的变化.研究发现高锰酸钾氧化作用主要在1 h内完成,1 h后藻液中残余Mn的含量达到1.23%~5.98%.藻光合能力随着高锰酸钾浓度上升而下降,随着高锰酸钾浓度升高,藻细胞分泌更多胞外有机物,同时藻细胞受到破坏,生成消毒副产物的前驱物腐殖酸.高锰酸钾预氧化1 h后进行混凝实验发现,藻的去除率显著升高,比直接混凝增加33.99%~36.35%.     

Influence evaluation of ionic liquids on the alteration of nitrification waste for thermal stability

Nitrification waste (NW) is the processed product of nitro compounds, flammable and explosive, and is prone to accidents due to thermal runaway. Ionic liquids (ILs) are widely used as flame retardants and have a good inhibitory effect. The effect of 1-butyl-3-methylimidazole hexafluorophosphate and 1-butyl-3-methylimidazole tetrafluoroborate as humectants on the thermal stability of NW was investigated in this paper. The microstructure and properties of the ionic liquid hybrid NW were first investigated using scanning electron microscopy. Secondly, thermogravimetric experiments were carried out on the ionic liquid mixed NW by thermogravimetric-infrared spectroscopy to analyze the decomposition law. Finally, six advanced linear regression thermokinetic models were used to calculate its apparent activation energy, pre-exponential factor, and other thermokinetic parameters, and the reaction model was simulated through multiple linear regression. The experimental research results in this paper can provide a reference for the storage and disposal of nitro compounds and their wastes.     

Surface-enhanced Raman spectroscopy for emerging contaminant analysis in drinking water

● Definition of emerging contaminants in drinking water is introduced. ● SERS and standard methods for emerging contaminant analysis are compared. ● Enhancement factor and accessibility of SERS hot spots are equally important. ● SERS sensors should be tailored according to emerging contaminant properties. ● Challenges to meet drinking water regulatory guidelines are discussed. Emerging contaminants (ECs) in drinking water pose threats to public health due to their environmental prevalence and potential toxicity. The occurrence of ECs in our drinking water supplies depends on their physicochemical properties, discharging rate, and susceptibility to removal by water treatment processes. Uncertain health effects of long-term exposure to ECs justify their regular monitoring in drinking water supplies. In this review article, we will summarize the current status and future opportunities of surface-enhanced Raman spectroscopy (SERS) for EC analysis in drinking water. Working principles of SERS are first introduced and a comparison of SERS and liquid chromatography-tandem mass spectrometry in terms of cost, time, sensitivity, and availability is made. Subsequently, we discuss the strategies for designing effective SERS sensors for EC analysis based on five categories—per- and polyfluoroalkyl substances, novel pesticides, pharmaceuticals, endocrine-disrupting chemicals, and microplastics. In addition to maximizing the intrinsic enhancement factors of SERS substrates, strategies to improve hot spot accessibilities to the targeting ECs are equally important. This is a review article focusing on SERS analysis of ECs in drinking water. The discussions are not only guided by numerous endeavors to advance SERS technology but also by the drinking water regulatory policy.     

Metabolic responses of indigenous bacteria in chicken faeces and maggots to multiple antibiotics via heavy water labeled single-cell Raman spectroscopy

The use of maggots derived from chicken faeces as fish diets might serve as a vehicle for the widespread of multiple antibiotic resistant bacteria(ARB) in the environment. Heavy water labeled single-cell Raman spectroscopy(D 2 O-Raman) was applied to detect the metabolic responses of indigenous bacteria in chicken faeces and maggots to different concentrations of combined colistin, kanamycin, and vancomycin. By incubating the samples with D 2 O and antibiotics, metabolically active bacterial cel...