加油站地下储油罐压力管理系统的相关研究

在当前普遍采用的加油站真空辅助式第二阶段油气回收系统中,为了避免回收到地下储油罐中的油气再次通过P/V阀排空,必须对其中气相空间的压力实施有效控制。从国外的发展情况来看,地下储油罐的压力管理系统主要分为基于膜分离技术、基于弹性气囊和基于活性炭吸附三大类,其中膜法油气回收装置在国内已经得到了较多关注。首次系统介绍了气囊式压力管理系统的工作原理及其主要结构设计,具体包括管线布局、钢制压力容器壳体、位于容器顶部封头上的接口组件和全部位于容器内的气囊等;同时对另外一种可行方案进行了分析。     

粉状活性焦在双层滤料颗粒床中的脱硫试验研究

在双层滤料颗粒床模型试验台上对粒径为300～400目的粉状活性焦进行了脱硫试验,研究了温度、O2和水蒸气体积分数、气体流速、再生次数对脱硫效果的影响.试验结果表明.温度为120℃、O2体积分数为8%、水蒸气体积分数为10%条件下,脱硫效果最好;粉状活性焦在双层滤料颗粒床中经过7次重复吸附.达到硫饱和吸附量为66.2 mg/g.粉状活性焦再生试验表明,随着再生次数的增加.粉状活性焦的脱硫性能呈下降趋势.     

矸石基X型分子筛对水中Co2+、Cu2+、Cd2+和Cr3+的去除

以煤矸石为原料,采用碱熔后水热合成法制备X型分子筛并进行XRD、SEM、BET和Zeta电位分析。研究其对水中Co2+、Cu2+、Cd2+和Cr3+4种离子的吸附性能,包括吸附等温线、吸附动力学以及初始金属离子浓度、pH值对吸附性能的影响。所合成的矸石基X型分子筛的BET比表面积为676.02 m2/g,微孔孔容为0.263 cm3/g。吸附实验表明,矸石基X型分子筛能有效去除上述4种离子,同时实现煤矸石的资源化和金属离子的去除。4种离子的平衡吸附量均随初始浓度的增大而增大,相同条件下平衡吸附量的大小顺序为Cd2+>Cr3+>Cu2+>Co2+。准二级动力学模型能很好地描述4种离子的吸附动力行为。Langmuir模型对Co2+、Cu2+和Cd2+吸附的拟合较Freundlich模型高,说明其主要表现为物理吸附过程。4种离子的吸附速率均由液膜扩散和颗粒内扩散共同控制。     

Polycyclic aromatic hydrocarbon (PAH) deposition to and exchange at the air-water interface of Luhu, an urban lake in Guangzhou, China

Urban lakes are vulnerable to the accumulation of semivolatile organic compounds, such as PAHs from wet and dry atmospheric deposition. Little was reported on the seasonal patterns of atmospheric deposition of PAHs under Asian monsoon climate. Bulk (dry + wet) particle deposition, air-water diffusion exchange, and vapour wet deposition of PAHs in a small urban lake in Guangzhou were estimated based on a year-round monitoring. The total PAH particle deposition fluxes observed were 0.44-3.46 μg m⁻² day⁻¹. The mean air-water diffusive exchange flux was 20.7 μg m⁻² day⁻¹. The vapour deposition fluxes of PAHs ranged 0.15-8.26 μg m⁻² day⁻¹. Remarkable seasonal variations of particulate PAH deposition, air-water exchange fluxes and vapour wet deposition were influenced by seasonal changes in meteorological parameters. The deposition fluxes were predominantly controlled by the precipitation intensity in wet season whereas by atmospheric concentration in dry season.     

饮用水生物处理中微生物量和活性的测定方法

微生物量和微生物活性是饮用水生物处理工艺设计与运行的重要参数。总结论述了适用于表示饮用水生物处理过程生物膜中微生物数量和活性的几种主要指标的测定方法。     

竹炭-微生物联合法对沼液中氨氮的去除

采用竹炭-微生物联合法,考察了竹炭用量、菌液用量、进水氨氮浓度、pH、DO、HRT等因素对氨氮废水处理效果的影响;同时采用对比实验,初步探讨了竹炭-微生物联合法处理沼液的作用机理。结果表明,竹炭-微生物法去除沼液氨氮的最优条件推荐为:竹炭用量30 g/L,微生物活性液用量3%,pH 7.0～8.0,DO为2 mg/L,HRT为48 h。竹炭-微生物法对沼液氨氮的去除过程可用一级反应动力学模型C=272.56e-0.0148描述,其去除效果来源于竹炭吸附和生物降解的协同作用,协同程度为48.45%。     

土壤-纳滤系统处理再生水补充地下水的研究

为充分保障再生水回灌地下时的水质安全、提供高质量地下水资源,在土壤处理系统中嵌入纳滤技术强化对再生水的处理效果,并初步探讨土壤系统作为前处理对纳滤膜污染的控制机理.结果表明,未采用臭氧氧化预处理前,土壤处理对再生水DOC和UV254的平均去除率分别为22%和20%.臭氧氧化对UV254的平均去除率为51%,并将土壤对D...     

不同曝气方式下SBR亚硝化的实现及NO2--N积累效果

研究不同曝气方式下亚硝化的实现以及基质浓度、曝气频率和温度对NO-2-N积累效果的影响。以实际污泥脱水液为研究对象,控制进水NH+4-N浓度在50~80 mg/L范围内,温度为27℃,pH值为7.8~8.2,DO浓度为0.5~1.0mg/L,分别采用连续曝气和间歇曝气2种方式启动SBR亚硝化反应器,并考察了在不同基质浓度、曝气频率和温度条件下NO-2-N累积情况。实验研究结果表明,经过40 d左右的运行,在2种不同曝气方式下SBR均成功实现了亚硝化,稳定运行阶段,NO-2-N积累率分别达到95%和85%。经SEM扫描电镜观察发现,在驯化成熟的活性污泥中,亚硝化细菌多呈球状和杆状,大小不同,外形饱满。当进水氨氮浓度小于200 mg/L,曝气频率为曝气15 min/停曝15 min,温度为27℃时,NO-2-N积累效果最佳,平均积累率可达90%以上。间歇曝气可以有效促进亚硝化细菌富集,有利于实现较高浓度的NO-2-N积累。基质浓度、曝气频率和温度对NO-2-N积累效果的影响显著。     

Cytotoxicity and DNA damage of five organophosphorus pesticides mediated by oxidative stress in PC12 cells and protection by vitamin E

Previous studies have demonstrated that pesticides could induce cytotoxicity and genotoxicity in vivo and in vitro, and that oxidative stress may be an important factor involved. However, investigations comparing the capability of different organophosphorous (OP) compounds to induce cytotoxicity, genotoxicity and oxidative stress are limited. Hence, the aim of this paper was to access the cytotoxic and genotoxic effects of five OPs or metabolites, Acephate (ACE), Methamidophos (MET), Chloramidophos (CHL), Malathion (MAT) and Malaoxon (MAO), and to clarify the role of oxidative stress, using PC12 cells. The results demonstrated that MET, MAT and MAO caused significant inhibition of cell viability and increased DNA damage in PC12 cells at 40 mg L^?1. MAO was more toxic than the other OPs. ACE, MET, MAT and MAO increased the levels of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA), and decreased the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) at 20 mg L^?1 and 40 mg L^?1 to different degrees. Pre-treatment with vitamin E(600 μM)caused a significant attenuation in the cytotoxic and genotoxic effect; pre-treatment reversed subsequent OP-induced elevation of peroxidation products and the decline of anti-oxidant enzyme activities. These results indicate that oxidative damage is likely to be an initiating event that contributes to the OP-induced cytotoxicity.     

液化石油气轿车实际道路污染物排放特征

利用PEMS对国2技术LPG出租轿车和汽油轿车的实际道路排放进行测试,基于测试数据对LPG轿车排放特征进行解析,并与汽油轿车的排放因子进行对比分析.结果显示:速度和行驶模式对LPG轿车污染物排放影响明显;LPG轿车CO 2、CO、HC和NOx污染物的实测排放因子分别为(169.5±22.2)、(2.18±2.38)、(...