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921.
付鹏艳  童华  杨迪 《环境工程学报》2016,10(8):4424-4428
实验研究了在鼓泡反应器中硫化钠溶液吸收低浓度NOx的吸收特性,分析了NOx、O2、Na2S和NaOH浓度对吸收过程的影响,以及被吸收NO2的形态。结果显示,Na2S浓度在15.8和47.5 mmol·L-1时,气相中NO2浓度变化对吸收率影响不明显,但在0.30~3.25 mmol·L-1时,NO2浓度变化对吸收率有较大影响。气相中的O2会加速吸收反应,但同时也引起吸收剂的额外消耗。当Na2S溶液中加入NaOH,浓度达到0.1%时,可强化NO2的吸收。NOx中NO含量增加会导致吸收率下降,即使有NaOH的条件下,也未观察到NOx氧化度为0.5时NO与NO2的协同吸收效应。Na2S溶液将被吸收的NO2一部分还原为N2,一部分还原为NO2-。  相似文献   
922.
唐婧  范开敏 《环境工程学报》2016,10(8):4201-4205
采用环氧氯丙烷和二乙烯三胺对花生壳中纤维素进行改性,制备了二乙烯三胺花生壳纤维素(DMPSC),运用红外光谱(FTIR)进行表征,并探究了DMPSC对刚果红的吸附性能和机理。结果表明,DMPSC的吸附率明显高于其他吸附剂。在原始pH,吸附剂用量为1 g·L-1,吸附时间为180 min,温度为8、30和50℃时,100 mg·L-1的刚果红溶液吸附量分别达到83.24、99.04和99.78 mg·g-1。吸附过程符合Langmuir等温线模型,在8℃时饱和吸附量(qm)为111.86 mg·g-1。准二级动力学方程能更好地描述吸附动力学过程,表观活化能Ea为56.88 kJ·mol-1,升高温度有利于DMPSC对刚果红的吸附,该过程属于化学吸附。  相似文献   
923.
The effect of long-term exposure to high frequency electromagnetic field (HF EMF) on some somatic and neural characteristics was studied in neurodefective Lurcher mutant (+/Lc) and normal wild type mice (+/+). Both newborn and young adult (3 months) animals derived from two strains (C3H, B6CBA) were exposed to HF EMF (870 MHz) from 1st to 21st day or from 91st to 120th day respectively. In animals of both groups and controls we observed the development of body weight. Moreover, in the HF EMF exposed adult B6CBA animals we studied spatial learning ability, motor functions and the CNS excitability. To investigate specific energy absorption rate (SAR) in experimental animals we have done the basic 3D calculations of the electromagnetic energy distribution in the simplified model of the mouse. The HF EMF exposed animals exhibited mild differences of body weight between them and unexposed controls. The long-term exposure to HF EMF did not significantly influence the ability to learn in the Morris water maze. However, significant lower swimming speed was found in the irradiated +/Lc as well as lower motor activity of +/+ in the open field when compared to controls. No significant differences were found between HF EMF irradiated animals and controls in examination of the CNS excitability and motor functions.  相似文献   
924.
Management of waste electrical and electronic equipment (WEEE) or e-waste is becoming a major issue as around 20–50 million tons of such waste is generated worldwide and increasing at a higher rate than other solid waste streams. Electrical and electronic equipment (EEE) contains over 1,000 materials of which brominated flame retardants (BFRs) such as polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) have been the target of the regulators forcing manufacturers to adopt halogen-free flame retardants. As far as these alternatives are concerned, key consideration should be its performance during the whole life cycle through design, use and end-of-life management. The global halogen-free flame retardant movement has reached a point of no return. The most important issue as far as the environment is concerned, for which the transformation to halogen-free retardants was initially targeted, is to make sure that life span of the EEE using the alternatives to BFRs is not shortened thereby resulting in unforeseen increases in e-waste to deal with. The aim of this article is to investigate the environmental issues and current developments related to the use of BFRs in EEE manufacture. It describes the sources, toxicity and human exposure of BFRs, EOL management such as recycling and thermal treatments, exposure of BFRs from e-waste processing facilities and the environment around them and examines the developments and feasibility of the alternatives to BFR in EEE manufacture.  相似文献   
925.
微波消解-原子荧光法测定土壤中锑与铋   总被引:1,自引:0,他引:1  
采用微波消解和原子荧光技术测定土壤中锑、铋,预处理样品方便快捷,对环境污染小。方法的线性好,检出限、精密度和准确度符合测试要求,经国家有证标准物质验证,该法适用于土壤环境样品中锑和铋的监测。  相似文献   
926.
采用氢化物一原子荧光法,应用AFS-2202a型双道原子荧光仪联合测定水中的硒和汞,方法的检出限为:Se0.31μg/L、Hg0.01μg/L,线性范围为:Se0-20.0μg/L、Hg0~2.00μg/L。  相似文献   
927.
Tian H 《Chemosphere》2011,83(3):349-355
A sensitive method for determination of chloramphenicol, enrofloxacin and 29 pesticides residues in bovine milk by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed. Residues of the targets were extracted from milk with acetonitrile, cleaned up by C18-SPE cartridge, and then determined by HPLC-MS/MS. The MS detection was operated in positive or negative ionization mode, depending on the compounds. For confirmation of each target compound, two precursor ion > product ion transitions were selected by multi-reaction monitoring mode (MRM). The method showed good linearity for all the tested compounds over the studied concentration range with correlation coefficient higher than 0.9910. Recoveries for the studied compounds at three spiked levels (0.05, 0.10, 0.19 mg kg−1) in bovine milk were in the range of 71-107% with RSDs not larger than 13.7%, except that recoveries of trifluralin ranged between 62% and 70% at the spiked levels. Limits of quantitation for the analytes were estimated to range between 0.03 × 10−3 and 14.5 × 10−3 mg kg−1. The proposed method was applied for the determination of the analytes residues in real samples. The found levels of the analytes in milk samples were lower than maximum residues levels (MRL).  相似文献   
928.
利用爆破法处理废旧轮胎,通过观察测量废旧轮胎爆破后的橡胶碎片量,考察了不同炸药对轮胎回收效果的影响。通过测量加入不同比例消焰剂的TNT爆破回收量,确定了最佳配比范围。研究表明,在TNT中加入消焰剂可有效提高轮胎爆破回收效果,消焰剂加入量10%~15%时效果最佳。  相似文献   
929.
天然气管道时常受到破坏,并诱发巨大的射流火焰,可能引燃周围建构物体。系统地分析了管道压力对天然气射流火热辐射灾害的影响,以建立天然气射流火热辐射灾害的系统定量分析方法。基于压力管道小孔泄漏模型和权重-多点源热辐射计算模型,建立了目标物体最大入射热辐射通量、管道压力和目标物与泄漏小孔水平距离的定量关系式。进而选定10 k W/m~2和31.5 k W/m~2作为城镇建筑物遭受引燃和机械破坏的热辐射通量阈值,得到了不同管道压力下天然气射流火热辐射灾害范围。计算结果表明,GB 50028—2006《城镇燃气设计规范》依据管道压力所规定的燃气管道与建筑物的安全间距不能完全满足天然气管道破坏时射流火焰的安全要求,与某武汉天然气管道射流火事故后果一致。  相似文献   
930.
根据容积式受限空间油气爆燃火焰特征实验研究的需要,设计了实验系统,进行了不同油气体积分数下的油气爆燃模拟实验。基于实验所得的瞬时火焰信号数据与火焰图像,分析了不同油气体积分数下容积式受限空间内油气爆燃的火焰形态结构、传播速度、强度与持续时间等主要行为特征,所得结果对探索油气爆燃机理与基本规律具有重要参考意义。  相似文献   
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