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921.
湿法烟气脱硫喷淋塔的阻力特性研究   总被引:1,自引:0,他引:1  
以装配有自行设计的湍流装置的冷态喷淋塔为研究对象,考察了气速、喷淋量、液气比(L/G)、湍流装置垂直和水平间距对其阻力特性的影响。结果表明,当湍流装置结构形式一定时,喷淋塔的湍流层阻力(ΔP)均随气速、喷淋量和L/G的增大而增大;当气速、喷淋量、L/G一定时,湍流层阻力均随湍流装置垂直与水平间距的增大而减小。当气速、喷淋量、L/G、湍流装置垂直与水平间距分别为2.0 m/s、100 m~3/h、10 L/m~3、120 mm、120 mm时,湍流层的最小阻力为0.14 kP a;而当气速、喷淋量、L/G、湍流装置垂直与水平间距分别为3.6 m/s、240 m~3/h、25 L/m~3、90 mm、100 mm时,湍流层的最大阻力为0.62 kP a。对实验数据进行多元线性回归分析,得出该喷淋塔湍流层阻力的经验公式为ΔP=0.000 46V ~(0.724)Q~(0.930)D~(-1.860)f~(-5.480),其拟合优度与显著性良好,对工业应用具有一定的理论指导意义和实际参考价值。  相似文献   
922.
Mercury (Hg) exists in different chemical forms presenting varied toxic potentials. It is necessary to explore an ecological risk assessment method for different mercury species in aquatic environment. The predicted no-effect concentrations (PNECs) for Hg(II) and methyl mercury (MeHg) in the aqueous phase, calculated using the species sensitivity distribution method and the assessment factor method, were 0.39 and 6.5 × 10− 3 μg/L, respectively. The partition theory of Hg between sediment and aqueous phases was considered, along with PNECs for the aqueous phase to conduct an ecological risk assessment for Hg in the sediment phase. Two case studies, one in China and one in the Western Black Sea, were conducted using these PNECs. The toxicity of mercury is heavily dependent on their forms, and their potential ecological risk should be respectively evaluated on the basis of mercury species.  相似文献   
923.
    
Mercury (Hg) exists in different chemical forms presenting varied toxic potentials. It is necessary to explore an ecological risk assessment method for different mercury species in aquatic environment. The predicted no-effect concentrations (PNECs) for Hg(II) and methyl mercury (MeHg) in the aqueous phase, calculated using the species sensitivity distribution method and the assessment factor method, were 0.39 and 6.5 × 10-3 μg/L, respectively. The partition theory of Hg between sediment and aqueous phases was considered, along with PNECs for the aqueous phase to conduct an ecological risk assessment for Hg in the sediment phase. Two case studies, one in China and one in the Western Black Sea, were conducted using these PNECs. The toxicity of mercury is heavily dependent on their forms, and their potential ecological risk should be respectively evaluated on the basis of mercury species.  相似文献   
924.
炼油厂碱渣废水的处理研究   总被引:3,自引:0,他引:3  
本文着重研究大孔吸附树脂对炼油厂碱渣处理后含酚废水的处理情况,实验表明,此种树脂吸附量大,酚去除率达95%以上,COD去除率达60%以上。  相似文献   
925.
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As a frequently used product with antimicrobial activity, consumed allicin might be discharged and concentrated in waste-activated sludge (WAS). However, the influence of allicin (as an exogenous pollutant) on WAS fermentation has not been clearly revealed. This study aimed to disclose the impacts of allicin on volatile fatty acid (VFA) generation during WAS fermentation. The results showed that the appropriate presence of allicin (10 mg/g TSS) significantly enhanced the VFA yield (1894 versus 575 mg COD/L in the control) with increased acetate proportion (24.3%). Further exploration found that allicin promoted WAS solubilization, hydrolysis and acidification simultaneously. Metagenomic analysis revealed that the key genes involved in extracellular hydrolysis metabolism (i.e., CAZymes), membrane transport (i.e., gtsA and ytfT), substrate metabolism (i.e., yhdR and pfkC) and fatty acid synthesis (i.e., accA and accD) were all highly expressed. Allicin also induced the bacteria to produce more signalling molecules and regulate cellular functions, thereby enhancing the microbial adaptive and regulatory capacity to the unfavourable environment. Moreover, the variations in fermentative microbes and their contributions to the upregulation of functional genes (i.e., ytfR, gltL, INV, iolD and pflD) for VFA generation were disclosed. Overall, the simultaneous stimulation of functional microbial abundances and metabolic activities contributed to VFA production in allicin-conditioned reactors.  相似文献   
926.
《混凝土结构》课程教学方法探讨   总被引:1,自引:0,他引:1  
为了提高<混凝土结构>课程教学质量,本文在分析<混凝土结构>课程特点基础上,提出了改进的教学方法,即合理安排教学内容,结合传统和现代教学手段,重视课程设计和实践教学环节.实践证明,这些改进的教学方法对于充分挖掘学生潜力,激发求知欲望,提高教学质量,促进教学改革具有重要意义.  相似文献   
927.
Herein,we developed the invasive plant-derived biochar (IPB) functionalized with CaAl-LDH at five mass ratios using a physical mixture method,assessed their adsorption perform for Eu(Ⅲ),and explored the relative mechanisms.Results show that the IPB successfully loaded CaAl-LDH in five composites and their Eu(Ⅲ) sorption affinities were strongly affected by solution p H,contact time,temperature,and the mass ratio of LDH and IPB.All the sorpiton process for Eu(Ⅲ) occurred on the heterogeneous surf...  相似文献   
928.
应用密闭箱法首次测定了南极菲尔德斯半岛苔藓、地衣植被土壤N2 O的排放通量 ,并估算了该半岛植被区土壤在夏季 2个月内N2 O的排放总量 .结果表明 :在晴天和雨天 ,苔藓土壤N2 O的排放通量与温度有较好的响应关系 ,呈现单峰型变化趋势 ;但在雪天 ,与温度的变化不一致 ;苔藓、地衣这 2种不同的植被土壤N2 O排放通量日变化基本一致 ;温度是影响苔藓土壤N2 O的排放通量季节变化的主要因子 ,同时还受降水的影响 ,干湿交替有利于N2 O的排放 ;苔藓土壤N2 O的排放总量为 3 .71 52kg ;地衣土壤N2 O的排放总量为 2 .53 4 4kg .由此可见 ,南极菲尔德斯半岛苔藓、地衣植被土壤N2 O排放量虽然很小 ,但仍起着大气N2 O源的作用  相似文献   
929.
    
The present work aims to ascertain the mechanisms of surfactant (dodecylbenzene sulfonate; DBS) effects on the aggregation behaviors of TiO2 nanoparticles (TiO2-NPs) in natural water samples. Aggregation experiments were conducted at a TiO2-NPs concentration of 10 mg/L in deionized water and in natural water samples via dynamic light scattering and Zeta potential determination. Average attachment efficiency was calculated to compare the aggregation behaviors of nanoparticles in the two aqueous media. Results showed that the effects of DBS on aggregation could be interpreted by both Derjaguin–Landau–Verwey–Overbeek (DLVO) and non-DLVO mechanisms. In natural water samples, aggregation did not occur rapidly and was able to develop slowly under all conditions, and the roles of DBS were obvious at high DBS concentration owing to the impacts of inherent components of natural water samples, such as colloids and natural organic compounds. Future aggregation studies should concentrate on multi-factor, multi-colloidal and dynamic aspects under similar environmental conditions.  相似文献   
930.
    
Microtopography affects hydrological processes and forms different microhabitats.Our previous study uncovered that riparian zone microtopography created various microhabitats with different soil environments and runoff-infiltration patterns.However,how riparian microtopography and microtopography within the water area(waterfall and tributary) affects downstream water quality remains unclear.Therefore,water samples were taken almost monthly in both the main stream and the tributary,before and aft...  相似文献   
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