A novel, simple and sensitive resonance scattering spectral method for the determination of chlorite in water by means of rhodamine B

A new resonance scattering method was proposed for the determination of chlorite, basing on the resonance scattering effect of rhodamine dye. In HCl-sodium acetate buffer solution, chlorite oxidizes 1- into 12 and the reaction of 12 and excess 1- results in If. It is respectively combined with rhodaminc dyes, including rhodamine B （RhB）, butyl rhodamine B （b-RhB）, rhodamine G （RhG） and rhodamine S （RhS）, to form association complex particles, which exhibit stronger resonance scattering （RS） effect at 400 nm. The chlorite concentration of ClO2 in the range of 0.00726-0.218 μg/ml, 0.0102-0.292 μg/ml, 0.00726-0.145 μg/ml and 0.0290- 0.174 μg/ml is respectively linear to the RS intensity of association complex particle systems at 400 nm for the RhB, b-RhB, RhG and RhS. The detection limits of the four systems were respectively 0.00436, 0.00652, 0.00580 and 0.01450μg/ml ClO2^-. In the four systems, the RhB system possesses good stability and high sensitivity. It has been applied to the analysis of chlorite in wastewater with satisfactory results.     

胶州湾围隔实验中溶解有机物三维荧光特征

利用三维荧光激发发射矩阵光谱法(EEMS),测定胶州湾围隔实验中不同营养盐条件下产生的溶解有机物的三维荧光特性.结果显示,浮游植物可产生类蛋白和类腐殖质荧光,类蛋白荧光峰由类酪氨酸(tyrosine-like)荧光峰和类色氨酸(tryptophan-like)荧光峰组成,主要位置为Ex_max/Em_max=270 nm/290～310 nm,Ex_max/Em_max=270～290 nm/320～350 nm的荧光峰强度比较弱;在Ex_max/Em_max=250～260 nm/380～480 nm(A峰)、Ex_max/Em_max=310～320 nm/380～420 nm(C峰)和Ex_max/Em_max=330～350 nm/420～480 nm(M峰)位置均出现零散的类腐殖质荧光峰,其中以A峰为主.类酪氨酸荧光强度明显高于类腐殖质荧光强度.浮游植物量降低时,类酪氨酸荧光强度与叶绿素a浓度呈明显的负相关.硅藻和甲藻产生的类酪氨酸和类色氨酸荧光强度之间具有较好的相关性,两者来源相似, 并且甲藻与硅藻相比能够产生更多的类蛋白荧光物质.不同环境下类腐殖质混合物的组分比例不同,甲藻生长环境下相对于硅藻具有较低的A/C比值.     

氯菊酯农药间接酶联免疫吸附测定法的建立

为测定环境样品中氯菊酯农药残留,用活泼酯法将氯菊酯半抗原(Py)与卵白蛋白(OVA)偶联,制备合成抗原Py-OVA作包被原,建立间接竞争酶联免疫吸附测定法.方阵滴定确定了抗血清最佳稀释度(1∶2 500),包被抗原的最适工作浓度0.45μg/mL,并建立了标准工作曲线.工作曲线表明在10～800μg/L浓度范围内呈良好的线性关系,回收率>97%.     

水体中微囊藻毒素-LR的间接竞争ELISA检测

在自制包被完全抗原浓度为5μg/mL、单克隆抗体工作稀释度为1∶3 000、酶标二抗鼠工作稀释度为1∶3 000、微囊藻毒素-LR浓度在0.001～30μg/L、显色底物为邻苯二胺,采用间接竞争酶联免疫吸附试验对水体中的微囊藻毒素-LR进行检测,结果表明,该方法与高效液相色谱的检测结果相关系数大于0.99,多次重复实验相对标准偏差小于10%,最低检测限能达到0.01μg/L,定量检测区间为0.01～3μg/L,该方法对[4-精氨酸]微囊藻毒素能特异性识别,对来自实际水样中的干扰有相当的耐受力.     

Oxidation inhibition of sulfite in dual alkali FGD system

A laboratory-scale well-mixed thermostatic reactor with continuously blasting air was used to investigate the oxidation inhibition of sulfite in dual alkali flue gas desulfurization （FGD） system. The effects of operating parameters such as pH value and catalyst concentration on the oxidation were studied. Sodium thiosulfate was used in the system, and was found that it significantly inhabited the sulfite oxidation. In the absence of catalyst, sodium thiosulfate at 12.67 mmol/L had an inhibition efficiency of approximately 98%. While in the presence of catalyst, sodium thiosulfate at 26.72 mmol/L had an inhibition efficiency less than 85.0%. The oxidation reaction order of sulfite in the sodium thiosulfate was determined to be -1.90 and 4）.55 in the absence and presence of the catalyst, respectively. Apparent activation energy of oxidation inhibition was calculated to be 53.9 kJ/mol. Pilot tests showed that the consumption rate of thiosulfate agreed well with the laboratory-scale experimental results.     

异养硝化-好氧反硝化菌脱氮同时降解苯酚特性

研究了异养硝化-好氧反硝化菌Diaphorobacter sp. PDB3去除氨氮同时降解苯酚的特性.在最佳碳氮比7和摇床转速160r/min下,该菌在21h内对初始浓度365mg/L苯酚的降解率达94.9%,总有机碳去除率达90.8%,同时40mg N/L氨氮被完全去除,中间代谢物硝态氮和亚硝态氮逐渐积累并在后期降低.氮平衡分析表明,52.3%的氨氮转化为胞内氮,37.2%转化为氮气,菌株主要通过细胞同化作用和异养硝化-好氧反硝化作用去除氨氮.检测到羟胺氧化酶、硝酸还原酶及亚硝酸还原酶活性,表明菌株PDB3具有完整的异养硝化-好氧反硝化偶联途径.随着苯酚浓度升高,抑制作用增强,脱氮效率降低.     

酶催化光度法测定雨水中微量H_2O_2的研究

研究了过氧化氢酶/4-氨基安替比林/苯酚/过氧化氢催化体系显色反应的最佳条件,实验发现:在温度为25℃,pH为7.0的条件下催化反应30min,所形成的催化反应产物在505nm处有最大吸收,H2O2在0.003～0.3000μmol/mL呈良好线性关系,其检测限达0.002μmol/mL(S/N=3),相对标准偏差RSD=0.24%(C=0.1000μmol/mL,n=10)。该法具有所用仪器简单,操作方便,灵敏度高等特点,应用于雨水中微量过氧化氢的测定,结果满意。     

OH自由基绝对标定系统的建立和研究

利用H2 O在 1 85nm紫外光照射下产生定量OH自由基 ,用低压扩散激光诱导荧光技术建立了OH自由基标定系统 .在实验条件下 ,体系产生OH自由基的浓度范围为 3× 1 0 7— 2× 1 0 9个·cm- 3,得到归一化荧光信号 (S)与OH自由基浓度的定量关系为S =6 0 4× 1 0 - 9[OH]- 0 0 4 0 7(R2 =0 987) ,并研究和讨论了饱和效应以及体系中可能存在的干扰 .     

Growth and photosynthesis responses of Phaeodactylum tricornutum to dissolved organic matter from salt marsh plant and sediment

The effects of allochthonous dissolved organic matter (DOM) on the growth and photosynthesis of Phaeodactylum tricornutum were investigated. P. tricornutum incubated in f/2 medium was exposed to DOM additives, which were extracted from the plant and sediment samples of a salt marsh in North Branch of the Yangtze estuary, China. During 12 days incubation, the chlorophyll fluorescence parameters of P. tricornutum were measured by a Phyto-PAM phytoplankton analyzer. Spectral properties of DOM in algae filtrates were also observed. The concentrations of chlorophyll a, active chlorophyll a, and the maximum quantum yield of photosystem II significantly decreased after four days of incubation, suggesting that the growth and photosynthetic e ciency of P. tricornutum were inhibited. After adding sediment-DOM extract, both a250/a365 (the ratio of the absorption coe cients at 250 and 365 nm) and S values (spectral slope coe cients) of algae filtrates declined in the first two days, which demonstrated a loss of low molecular weight DOM. Parallel factor analysis of fluorescence spectra of DOM in algae filtrates revealed that DOM could be classified into two humic-like and two protein-like components. The fluorescence intensity of tyrosine-like component originating from algae increased significantly during incubation. This study supports the hypothesis that allochthonous DOM derived from salt marsh plant and sediment have a strong influence on the adjacent aquatic ecosystems.     

Adsorption of humic acid from aqueous solution on bilayer hexadecyltrimethyl ammonium bromide-modified zeolite

Surfactant-modified natural zeolites (SMNZ) with different coverage types were prepared by loading hexadecyltrimethyl ammonium bromide (HTAB) onto the surface of a natural zeolite. The adsorption behavior of humic acid (HA) on SMNZ was investigated. Results indicate that the adsorbent SMNZ exhibited a higher affinity toward HA than the natural zeolite. HA removal efficiency by SMNZ increased with HTAB loading. Coexisting Ca²⁺ in solution favored HA adsorption onto SMNZ. Adsorption capacity decreased with an increasing solution pH. For typical SMNZ with bilayer HTAB coverage, HA adsorption process is well described by a pseudo-second-order kinetic model. The experimental isotherm data fitted well with the Langmuir model. Calculated maximum HA adsorption capacities for SMNZ with bilayer HTAB coverage at pH 5.5 and 7.5 were 63 and 41 mg·g⁻¹, respectively. E2/E3 (absorbance at 250 nm to that at 365 nm) and E4/E6 (absorbance at 465 nm to that at 665 nm) ratios of the residual HA in solution were lower than that of the original HA solution. This indicates that the HA fractions with high polar functional groups, low molecular weight (MW), and aromaticity had a stronger tendency for adsorption onto SMNZ with bilayer HTAB coverage. Results show that HTAB-modified natural zeolite is a promising adsorbent for removal of HA from aqueous solution.     

高效液相色谱法测定水中微量酚

本文报道了水中11种微量酚的高效液相色谱测定方法。用氯化四丁基按作为阳离子对萃取剂。二氯甲烷章取水中微量酚，除本酚外，水中10种微量酚的回收率大于90％。用MicropakMCH－5色谱柱，醋酸—水—乙睛流动相，uv254um和280um双波长检测，流速1ml／min下，对水中11种微量酚进行了分离和定量、11种酚的检测极限是0.1mg／L～1.26mg／L；检测范围为0.1mg／L～7mg／L。对2—甲基—4，6—二硝基酚的峰高与浓度进行了线性回归，γ＝0.9993；该法适用于水中11种微量酚的同时测定。     

松花湖沉积物溶解性有机质荧光光谱特性

溶解性有机质(DOM)对于湖泊的主要污染指标(如COD等)有着较大的影响,而沉积物亦是湖泊污染的主要来源,因此沉积物DOM荧光光谱特性的研究对进一步揭示湖泊污染本质有重要意义.采集了松花湖20个点位的沉积物,利用激发发射矩阵光谱-平行因子分析(EEM-PARAFAC)技术对沉积物中的DOM组分进行了解析,从光谱学角度明确沉积物DOM的特性,并对DOM与水体富营养化水平之间的关系进行了初步探索.结果表明,从松花湖沉积物DOM中分离出4个组分：类腐殖质C1(330/415 nm)、 C2(255/440 nm)、 C3(365/470 nm)和类蛋白C4(280/355 nm).较高的HIX和低BIX表明沉积物DOM的来源以陆源为主,包含一部分生物源.4个组分的荧光强度存在关联,空间分布较为相似,均表现为上游(S1～S7)荧光强度高于下游(S8～S20).而辉发河、松花江和蛟河这3条主要入湖河流携带的悬浮颗粒物(SPM)在入湖段大量沉积是导致这种空间分布的主要原因.松花湖水体中富营养化状况(上游富营养化水平高于下游)与沉积物DOM的荧光强度分布状况相似,同时松花湖下游水体富营养化水平与沉积...     

氢化物发生-原子荧光光谱法测定水中微量砷

用氢化物发生－原子荧光光谱法测定天然水及废水中的微量砷，讨论并确定了试验的最佳测定条件。结果表明：砷的测定线性范围为１￣１００ｎｇ／ｍＬ，回收率为９６％￣１０８％，对含０．５ｎｇ／ｍＬ砷溶液１２次平行测定变异系数为１．９％，检出限为０．２５ｎｇ／ｍＬ。     

催化动力学分光光度法直接测定天然水体中痕量锰

海水中溶解态痕量元素锰(Mn)是国际GEOTRACES科学计划确定的关键参数之一,通常用作示踪剂探讨海洋中氧化还原环境的变化。本文对高碘酸钠氧化隐色孔雀绿测定海水中溶解态Mn的方法进行了优化,最佳实验条件为:在10 mL体系中,反应pH为4.00.2,隐色孔雀绿用量为35 mol/L,高碘酸钠用量为4 mmol/L,氨三乙酸的用量为8 mmol/L,显色时间选择4.00.2 h,在615~620 nm处测定反应产物的吸光度。结果表明:本方法不存在其他金属离子的干扰,可通过标准加入的方式去除基体效应。应用本方法对空白和浓度为5.5 nmol/L的样品分析的精密度分别为6.8%和2.7%(n=13),检出限为0.6 nmol/L(3倍标准偏差)。应用本方法分别测定环境标准样品(GSB 07-1189-2000)和加拿大标准海水样品(NASS-6),测定值与推荐值无显著性差异(t检验,P=0.95)。运用本方法测定了东海陆架黑潮深水区溶解态Mn的垂直分布,测得的剖面结果与国际已发表同区域结果无显著性差异(t检验,P=0.95)。     

铜绿微囊藻胞内DOM光降解及其对芘结合能力的影响

利用紫外可见吸收光谱法及荧光光谱法研究有氧和缺氧条件下紫外线A波段(UV-A)辐照对铜绿微囊藻(Microcystis aeruginosa)胞内溶解性有机质(IDOM)(M. aeruginosa-IDOM)光降解行为,并考察光降解对其与芘结合能力的影响.结果表明,M. aeruginosa-IDOM经6d光降解后,有氧组中溶解性有机碳(DOC)浓度及其吸收系数a₃₅₅降解幅度均高于缺氧组.有氧及缺氧状态下M. aeruginosa-IDOM光降解过程中吸光度比值E2/E3(250nm/365nm)变化相似,但254nm处比紫外吸收值(SUVA₂₅₄)变化不同.激发–发射三维荧光光谱法(EEMs)结合平行因子(PARAFAC)分析,结果显示, M. aeruginosa-IDOM中类蛋白C1、长波激发类腐殖质C2及短波激发类腐殖质C3荧光强度在两种光降解条件下变化趋势不同. M. aeruginosa-IDOM光降解过程符合一级降解动力学特征的参数,在有氧组中降解半衰期均短于缺氧组.此外,光降解过程中,有氧组M. aeruginosa-IDOM与芘结合能力降低,但缺氧组M. aeruginosa-IDOM与芘结合能力先下降后增加.     

环糊精对Fe(Ⅲ)引发双酚A光降解的影响

环糊精口α-CD、β-CD和γ-CD能分别与双酚A形成1:1主-客体包结物.在250W金属卤化物灯(λ≥365 nm)光照下,研究了在Fe(Ⅲ)-OH配合物体系中,不同环糊精对双酚A光降解的影响.结果表明,β-CD能较大地促进双酚A的光降解,α-CD次之,而γ-CD对双酚A的光降解存在一定的抑制;并且CDs浓度的变化对双酚A光降解的初始速率有明显的影响.双酚A光降解的初始速率随着β-CD和α-CD浓度增大而增加,当β-CD=60μmol/L时达到最大,然后随着浓度增大而降低,而BPA的光降解初始速率随γ-CD浓度的增加总的趋势是减小的.通过计算机软件Gaussian98,采用PM3方法模拟了环糊精与双酚A的包结行为,进一步说明3种环糊精与双酚A形成主-客体包结物对光降解的影响.     

Characterization of dissolved organic matter fractions from Lake Hongfeng, Southwestern China Plateau

With XAD-series and ion exchange resins, dissolved organic matter (DOM) from Lake Hongfeng in Southwestern China Plateau was isolated into 6 fractions, i.e., humic acid (HA), fulvic acid (FA), hydrophobic neutrals (HON), hydrophilic acids (HIA), hydrophilic bases (HIB) and hydrophilic neutrals (HIN). Those fractions were characterized by high performance size exclusion chromatography, fluorescence spectroscopy and UV absorbance. Among the 6 fractions, FA was predominant and accounted for 51% of the total DOM. The weight-average (M_w) and number-averaged (M_n) molecular weight of these fractions ranged from 1688 to 2355 Da and from 1338 to 1928 Da, respectively. A strong correlation was observed between specific UV absorbance at 280 nm, E₂/E₃ (absorbance at 250 nm to 365 nm), and the molecular weight for DOM fractions. UV-Vis fulvic-like fluorescence peaks were found in all fractions. Protein-like fluorescence peaks existed in HON may indicate that microbial activity was severely in Lake Hongfeng. There was a significant relationship between fluorescence intensities and specific UV absorbance at 254 nm for those DOM fractions, suggesting their similar luminescence characteristics. The values of fluorescence index (f_450/500) indicated that hydrophobic fractions may derive from terrestrial sources, and the hydrophilic fractions from microbial and terrestrial origins. Those results suggest that there were inter-relationships between molecular weight, fluorescence and absorbance characteristics, and also subtle consistencies between the hydrophilic and hydrophobic properties and the sources for these 6 fractions from Lake Hongfeng.     

阳离子共聚物的反相悬浮聚合

采用反相悬浮聚合方法合成颗粒状的阳离子型高分子絮凝剂。选用丙烯酰胺(Am)和氯化[N,N,N-三甲基乙醇丙烯酸酯]盐(AQ)两种单体,研究反应体系的特征及影响分子量的基本因素,诸如温度、单体浓度、引发剂浓度、分散剂浓度、水相和油相的体积比(Vw/Vo)对分子量的影响。为了选择出最佳原料比,本文对两种单体的原料比进行了研究。实验中还发现亚硫酸钠是一种优良的缩短反应诱导期、加速反应进程的试剂。     

流动注射荧光光度法测定水中ppb级挥发性酚

本文以测定299nm酚的荧光(激发波长为269nm)为基础,提出了一个适于测定河水和工业废水中挥发性酚的流动注射荧光分析方法。该法具有简单、快速和灵敏的特点。当酚含量在0—100ppb时,荧光峰高与酚浓度之间有良好的线性关系。该法的采样频率为120h_-1,检测限为0.7ppb。并将该法与4-AAP萃取比色法进行了比较。      

2-酮基-L-古龙酸的高效液相色谱测定方法和条件

为了快速准确的检测维生素C(VC)生产工艺中VC的重要前体物2-酮基-L-古龙酸(2-KLG)浓度,采用高效液相色谱法进行测定,选用6×250 mm Carbohydrate分析柱,乙腈:磷酸二氢钾=60∶40的流动相,在波长210 nm处紫外光检测,控制流速为1 mL/min和温度45℃。结果表明2-KLG在6 min左右出峰,与VC具有较好分离度;2-KLG标准曲线的回归方程为y=0.776x-13.46,相关系数达到99.9%,检出限为0.5 mg/L;回收率为96.3%~104%,RSD为6.28%(n=5)