氨法脱硫试验研究分析

为研究氨法脱硫中气液比、吸收液pH值、吸收液浓度以及进口烟温对脱硫效果的影响,设计了一套实验台,以亚硫酸铵为吸收剂进行了实验研究和分析.结果表明,气液比越小,脱硫效率越高;吸收液pH值越大,脱硫效果越好;脱硫效率随吸收液浓度的增大先增加后减小,中间存在最大值;而温度对脱硫效果的影响不大.同时可根据此结果,气液比选择在0.2～0.25L/m3范围,pH值选择为6～7.5范围,吸收液浓度为5.5％左右时,可使脱硫效果达到最好.     

Positive relationships between phenol oxidase activity and extractable phenolics in estuarine soils

Decomposition of recalcitrant materials such as phenolics is known to play a pivotal role in organic matter decomposition and nutrient cycling in estuaries. The specific goals of this study were to determine temporal and spatial variations of phenol oxidase and phenolics in estuarine soils, and to elucidate controlling factors for phenol oxidase activity. To achieve these goals, phenol oxidase activity and phenolic content were measured in soils developed along the side of an estuary in the Han River, Korea. Soil samples were collected in three locations with different vegetation: mud flats, Zizania-dominated soils, and Salix-dominated soils. Monthly measurements were also made in a Zizania-dominated site over a year period. Phenol oxidase activity varied between 0.00 and 0.28 diqc min^?1 g^?1, whilst phenolic content ranged from 0.0–10.5 μg g^?1. A correlation analysis revealed that phenol oxidase activity exhibited positive correlations with phenolic content in both seasonal and spatial data. The same relationship was found when the data were analysed separately for each site. Unlike peatlands or upland forest soils where negative correlations were often found between phenol oxidase activity and phenolics, substrate induction appears to account for the positive correlation in the present study.     

六溴环十二烷对发育期大鼠脑单胺类神经递质质量比及单胺氧化酶活性的影响

通过研究发育期大鼠脑单胺类神经递质质量比及单胺氧化酶活性,探讨环境暴露水平的六溴环十二烷对发育期大鼠的神经毒性作用。选择10μg/kg、50μg/kg、100μg/kg、300μg/kg的剂量对新生3 d大鼠进行暴露,饲养42 d后断头取脑组织,测定多巴胺(DA)、去甲肾上腺素(NE)、5-羟色胺(5-HT)的质量比及单胺氧化酶(MAO)的活性。结果表明,在10~100μg/kg的暴露剂量范围,DA质量比随暴露剂量的升高而下降,NE质量比呈现上升趋势,5-HT质量比则极显著性升高(p<0.01);与此同时,MAO的活性随剂量增加而升高,在100μg/kg剂量出现显著性升高(p<0.05)。而300μg/kg的剂量作为较高暴露水平的参照,只对DA产生显著性影响(p<0.05)。DA、5-HT、NE的质量比及MAO活性的变化可能在大鼠的中枢神经系统的发育障碍中发挥了重要作用,并且环境暴露水平的HBCD对发育期大鼠脑具有低剂量高效应的毒性反应特征。     

壬基酚对大鼠5-羟色胺分解代谢通路的影响

为探讨壬基酚对5-羟色胺(5-HT)代谢网络分解代谢通路的毒性作用机制,将24只SD雄性大鼠分为阴性对照组和壬基酚低、中、高剂量组[30,90,270mg/(kg·bw)],隔日玉米油灌胃染毒28d后检测大鼠血浆及肝匀浆中单胺氧化酶(MAO)活性和血浆中5-HT含量,并称量肝、肾和睾丸重量.结果显示,壬基酚暴露高剂量组大鼠体质量增量极显著低于对照组(P<0.01);染毒至第3周起,各组大鼠平均食物利用率有统计学意义(P<0.05);与对照组相比,高剂量组肝脏、肾脏脏器系数均有统计学意义(P<0.01),中、高剂量组睾丸脏器系数均有统计学意义(P<0.05);中、高剂量组血浆MAO酶活性极显著低于对照组(P<0.01),中、高剂量组肝匀浆MAO酶活性显著低于对照组(P<0.05);中、高剂量组血浆5-HT含量极显著高于对照组(P<0.01).壬基酚暴露剂量与大鼠体内MAO酶活性及5-HT水平均呈剂量-效应关系,壬基酚可通过分解代谢通路影响5-HT的代谢网络.     

紫外/亚硫酸盐高级还原工艺加速降解水中难降解含碘造影剂

紫外/亚硫酸盐（UV/SO₃^2-）是一种基于紫外活化SO₃^2-离子依靠生成还原性自由基——水合电子降解目标污染物的高级还原工艺.本文研究了UV/SO₃^2-加速降解含碘造影剂泛影酸钠（DTZ）的效能、机制与影响因素以及UV/SO₃^2-降解DTZ的路径.结果表明,UV/SO₃^2-降解DTZ符合一级动力学模型,降解速率快于单独UV和紫外/过氧化氢工艺,且降解速率随SO₃^2-浓度的增加而升高.弱碱性或碱性水质可强化UV/SO₃^2-降解效率,背景有机物对降解DTZ有一定抑制作用.DTZ降解机制包括直接光解和还原性自由基攻击,其中自由基攻击占主要部分.DTZ在UV/SO₃^2-的降解路径包括取代、脱羧基羟基化和酰胺键断裂等.     

2×600MW机组脱硫石膏亚硫酸钙含量超标原因分析及对策

石灰石—石膏湿法脱硫系统工艺复杂,影响石膏中亚硫酸钙含量的因素很多,各因素之间又相互作用。分析了某电厂2×600MW机组脱硫石膏亚硫酸钙含量超标的原因,在试验研究及系统改造的基础上指出了石灰石原料不合格是石膏品质变差的主要原因。应加强石灰石原料质量监督,以满足脱硫系统要求。     

Ozone affects pollen viability and NAD(P)H oxidase release from Ambrosia artemisiifolia pollen

Air pollution is frequently proposed as a cause of the increased incidence of allergy in industrialised countries. We investigated the impact of ozone (O₃) on reactive oxygen species (ROS) and allergen content of ragweed pollen (Ambrosia artemisiifolia). Pollen was exposed to acute O₃ fumigation, with analysis of pollen viability, ROS and nitric oxide (NO) content, activity of nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase, and expression of major allergens. There was decreased pollen viability after O₃ fumigation, which indicates damage to the pollen membrane system, although the ROS and NO contents were not changed or were only slightly induced, respectively. Ozone exposure induced a significant enhancement of the ROS-generating enzyme NAD(P)H oxidase. The expression of the allergen Amb a 1 was not affected by O₃, determined from the mRNA levels of the major allergens. We conclude that O₃ can increase ragweed pollen allergenicity through stimulation of ROS-generating NAD(P)H oxidase.     

锌、铁等离子对氧化锌烟气脱硫工艺中亚硫酸锌氧化的影响

在氧化锌法脱除烟气SO2工艺中,脱硫产物亚硫酸锌的氧化是实现锌、硫资源回收的关键环节。在pH为4～5,25℃等条件下,考察了锌、铁、镉离子对亚硫酸锌氧化过程的影响。结果发现,铁离子对亚硫酸锌氧化过程有较强的催化作用,锌离子有一定的催化作用,而低浓度的镉离子几乎不影响氧化过程。进一步的研究表明,锌、铁离子的独自催化氧化速率对各自的浓度均为0．5级响应,但在混合状态下,锌离子对铁离子的催化过程有抑制作用。     

亚硫酸钙脱硫法及其机理

针对石灰乳直接脱硫存在的结垢问题,提出了亚硫酸钙脱硫法,并研究了该法的反应机理及主要因素对脱硫率的影响,确立了适宜的操作条件.即在空塔气速2.75m/s、L/G=3.0 L/m³、固含量6.7%、气温31℃、进口SO₂初始体积分数1500×10^-6、进塔液pH=8.0并维持不变的条件下,连续运转中的脱硫率可达87%.该法从理论上解释、实践上解决了石灰湿法脱硫过程中设备的结垢问题,其实质是以全钙基物质为脱硫剂的新型间接石灰法.     

硫酸盐在厌氧生物过程中的行为 Ⅱ.硫酸盐还原行为及对体系抑制作用机理

采用半连续实验方法，研究了中温厌氧条件了硫酸盐的还原行为及产生抑制作用的机理。实验结果表明，ＳＯ４＾２－在厌氧体系中被硫酸盐还原菌全部或部分还原为硫化物，其还原率与ＳＯ４＾２－累积加入浓度有关，还原产物的形态与体系中ｐＨ值有关，较高的ｐＨ值（７．６－８．４）使体系中Ｈ３Ｓ含量下降。ＳＯ４＾２－对厌氧体系的抑制与ＳＯ４＾２－还原过程中ＳＲＢ与产甲烷菌的底物竞争及还原产物的毒性相关。前者受ＣＯＤ／ＳＯ