等离子体烟气脱硫技术现状与关键问题讨论

介绍了ＳＯ２的３条去除路径,高能电子的解离还原路径;自由基的氧化路径;以及与氨的热化学反应路径。提出ＳＯ２浓度测试要先去氨及ＮＯＸ测试先去ＳＯ２的方案。分析了温度、氨量、烟气组分及供电情况对ＳＯ２去除的影响。认为ＮＯ２及硫酸气溶胶的存在促进ＳＯ２去除的作用和脱硫与除法结合问题。最后提出利用氨与等离子体的协同作用,以热化学反庆为主路径,以等离子体活化反应为补充的脱硫思路。     

新型单级A/O程序无回流复合膜生物反应器处理氨氮废水的试验

采用单级A/O程序复合膜生物反应器(HSMBR)处理高氨氮废水,研究在低DO浓度下系统对有机物、氨氮和总氮的去除效率。研究结果表明:在低DO浓度下,CODCr、氨氮的平均去除率分别为94.4%和92.8%。由于进水CODCr/TN值仅为2.01,则使得总氮平均去除率仅为69.4%,但是当系统亚硝化累积率从60.5%～67.1%提高到83.5%～86.4%时,系统总氮去除率提高了17.7%。另外,维持低DO浓度可以实现亚硝酸型同时硝化反硝化反应。     

Accounting for variation in prey selectivity by zooplankton

An ingestion-based prey selectivity function (IS) is described specifically to aid the simulation of zooplankton activity in circumstances in which selectivity varies, for example, as functions of prey palatability or abundance. In IS, the ultimate control of the rate of predation is not the external concentration of prey but the total rate of prey capture relative to predator demand. Further, “preference” is not an input (as it is for most prey selection functions) so that the selection or deselection of any or all prey can be freely altered. Hence, if required, all prey could be deselected, or the impact of inert materials or turbulence adversely affecting capture rates of any or all prey can be considered. Capture kinetics are not fixed at a common value for all items. In its basic form IS contains no more variables than other selectivity functions. The construction and use of switches to vary grazing in response to changes in abundance of alternative prey types or in prey nutritional (stoichiometric) quality is demonstrated. The advantages of using IS instead of the widely used ratio-based selectivity function is demonstrated with reference to model fits to experimental datasets for microzooplankton activity.     

高压实新疆阿尔泰膨润土微观结构随吸力变化特征

采用压汞法(MIP)和扫描电镜(SEM)法,在自由和侧限状态下,试验研究了高压实新疆阿尔泰膨润土在不同吸力条件下的微观结构变化特征。吸力的控制采用了气相法和渗析(液相)法。研究结果表明:(1)低吸力范围内,自由膨胀和侧限条件下的高压实膨润土土水特征存在明显差异;(2)膨润土在自由和侧限状态下的水化过程中呈现出了截然不同的微结构变化特征。自由膨胀条件下,土的吸水膨胀量主要来自土中大孔隙的逐渐膨胀。侧限状态下,随着控制吸力的降低,膨润土的大孔隙逐渐被压缩,较小孔隙的数量不断增加,土中孔隙分布变得更加均匀。     

Parental phenols exposure and spontaneous abortion in Chinese population residing in the middle and lower reaches of the Yangtze River

Widespread use of phenols has led to ubiquitous exposure to phenols. In experimental animals, phenols increased resorptions, reduced live litter size and fetal body weights. However, there are limited epidemiological evidences of the relationships between exposure to phenols and pregnancy outcomes. We evaluated the associations between parental urinary levels of various phenols and spontaneous abortion in a Chinese population residing in the middle and lower reaches of the Yangtze River. A case-control study was conducted that included 70 case couples with medically unexplained spontaneous abortion and 180 control couples who did not have a history of spontaneous abortion and had at least one living child. Both parental urinary phenols were measured by ultra-high performance liquid chromatography-tandem mass spectrometry including bisphenol A (BPA), benzophenone-3 (BP-3), 2,3,4-trichlorophenol (2,3,4-TCP), pentachlorophenol (PCP), 4-n-octylphenol (4-n-OP) and 4-n-nonylphenol (4-n-NP). Compared with the low exposure group, there was an increased risk of spontaneous abortion with high paternal urinary PCP concentration [odds ratio (OR) = 2.09, 95% Confidence Interval (CI), 1.05–4.14], and maternal exposure to 4-n-OP and alkylphenol(s) also significantly increased the risk of spontaneous abortion (OR = 2.21, 95% CI, 1.02–4.80; OR = 2.81, 95% CI, 1.39–5.65, respectively). Our study firstly provides the evidence that paternal PCP exposure, maternal 4-n-OP and alkylphenol(s) exposure are associated with spontaneous abortion in humans.     

Hexabromocyclododecanes in limnic and marine organisms and terrestrial plants from Tianjin,China: Diastereomer- and enantiomer-specific profiles,biomagnification, and human exposure

To interpret the distribution of hexabromocyclododecanes (HBCDs) in various organisms, we measured the concentrations and diastereomer and enantiomer profiles of HBCDs in 21 different species of limnic and marine cohorts from Tianjin, China. The concentration ranges of HBCDs in limnic and marine organisms were 64.3–1111 ng g⁻¹ lw and 85.5–989 ng g⁻¹ lw, respectively. Living habitat and feeding habits had important impacts on HBCD diastereomer distribution. Most of the species appeared to preferentially select (+)-α-, (−)-β- and (−)-γ-HBCD. There is a tendency that the total and α-HBCDs were magnified as trophic level increased with trophic magnification factors (TMFs) around 2. The concentrations of HBCDs in the limnic and marine fishes were highest in the liver, followed by the gill, skin, and muscle. In terrestrial plants, the highest concentrations of HBCDs were observed in the leaf, followed by the root and the rhizosphere soil. Plants showed enantioselectivity for HBCD enantiomers, which varied with plant species and organs (leaf vs. root) of the same plant. Higher estimated daily intakes (EDIs) of HBCDs were observed from fish than from wheat.     

Development and application of LC–APCI–MS method for biomonitoring of animal and human exposure to imidacloprid

Imidacloprid (IMI) is a relatively new neuro-active neonicotinoid insecticide and nowadays one of the largest selling insecticides worldwide. In the present study a LC–APCI–MS based method was developed and validated for the quantification of imidacloprid and its main metabolite 6-chloronicotinic acid (6-CINA) in urine and hair specimens. The method was tested in biomonitoring of intentionally exposed animals and subsequently applied for biomonitoring of Cretan urban and rural population.     

Molecularly imprinted polymer for analysis of trace atrazine herbicide in water

A molecularly imprinted polymer (MIP) for atrazine was synthesized by non-covalent method. The binding capacity of MIP was 1.00 mg g^{? 1} polymer. The selectivity and recovery were investigated with various pesticides which are mostly, found in the environment, for both similar and different chemical structure of atrazine. The competitive recognition between atrazine and structurally similar compounds was evaluated and it was found that the system provided highest recovery and selectivity for atrazine while low recovery and selectivity were obtained for the other compounds. The highest recovery was obtained from MIP compared with non-imprinted polymer (NIP), a commercial C₁₈ and a granular activated carbon (GAC) sorbent. The method provided high recoveries ranged from 94 to 99% at two spiked levels with relative standard deviations less than 2%. The lower detection limit of the method was 80 ng L^{? 1}. This method was successfully applied for analysis of environmental water samples.     

Evaluation and validation of two different chromatographic methods (HPLC and LC-MS/MS) for the determination and confirmation of ochratoxin A in pig tissues

This study was undertaken to compare two different analytical methods for the determination and confirmation of ochratoxin A (OTA) in blood serum, kidney and liver of pigs. Sample clean-up was based on liquid-liquid phase extraction. The detection of OTA was accomplished with high-performance liquid chromatography (HPLC) combined either with fluorescence detection (FL) or electro spray ionization (ESI+) tandem mass spectrometry (MS–MS). Comparative method evaluation was based on the investigation of 90 samples of blood serum, kidney and liver per animal originating from different regions of Serbia. The analytical results are discussed in view of the respective method validation data and the corresponding experimental protocols. In general, analytical data obtained with (LC–MS–MS) liquid chromatography electro spray tandem mass spectro metry detection offered comparable good results at the sub-ppb concentration level. The results indicate that the liquid chromatography electro spray tandem mass spectrometric (LC-MS/MS) method was more specific and sensitive for the analysis and confirmation of ochratoxin A in pig tissues then high pressure liquid chromatography (HPLC) method after methylation of OTA.     

Screening Capsicum chinense fruits for heavy metals bioaccumulation

Elevated concentrations of heavy metals in edible plants could expose consumers to excessive levels of potentially hazardous chemicals. Sixty-three accessions (genotypes) of Capsicum chinense Jacq, collected from 8 countries of origin were grown in a silty-loam soil under field conditions. At maturity, fruits were collected and analyzed for seven heavy metals (Cd, Cr, Ni, Pb, Zn, Cu, and Mo) concentrations. The main objectives of this investigation were: 1) to determine the concentrations of seven heavy metals in the soil and monitor their accumulation in mature fruits, 2) to categorize the pepper accessions as low or high heavy metal accumulators, and 3) to determine if heavy metal content of the pepper fruit was lower than the permitted limits. Concentrations and relative proportions of heavy metals in pepper fruits of C. chinense varied among accessions. Fruits of Plant Introduction (PI) 355820 accumulated significant concentrations of Cd (0.47 μ g g^?1dry fruit). PI-260522 accumulated the highest concentration of Pb (2.12 μ g g^?1 dry fruit) among the 63 accessions tested. This accession (PI-260522) contained about twice the Pb limit on a fresh weight basis. Among the 63 accessions analyzed, PI-238051 contained the highest levels of Ni (17.2 μ g g^?1). We concluded that high accumulator genotypes may be useful for phytoremediation, while, low accumulator accessions might be appropriate selections for growing on Cd-, Pb-, or Ni-contaminated soils to prevent potential human exposure to heavy metals and health hazards through the food chain.