DO对好氧颗粒污泥短程同步硝化反硝化脱氮的影响

以模拟城市污水为处理对象,研究了不同溶解氧下序批式活性污泥反应器（SBR）的短程同步硝化反硝化过程特征及处理效果。试验结果表明,溶解氧浓度是实现短程同步硝化反硝化的一个重要控制参数。在亚氮积累阶段,控制温度为28～32℃,pH值为7.5～7.8,当进水NH⁺₄-N为30 mg/L左右,COD为250 mg/L左右时,亚硝酸盐氮的积累率达到96%～98%。在试验阶段,常温下控制溶解氧在0.5～1.0 mg/L,可保证氨氮的去除率达到95%～97%,总氮的去除率达到82%～85%。     

复合沸石滤床修复北方景观水体的实验研究

以天然矿物质沸石、细砂及煤渣取代传统滤料构建复合基质生态床,表面种植景观植物,采用下向流-上向流运行方式修复北方景观水体。分别进行静态实验及不同循环速率下的动态实验,考察对水体污染物去除过程。结果表明,2种运行方式下对水体NH⁺₄-N去除率都在85%以上,其中以1 h为循环周期的运行方式去除率达97%,较静态提高12.8%;TN去除率最高为84%;TP去除不稳定,过程缓慢。煤渣层对NH⁺₄-N的去除效果差,硝化作用不彻底与反硝化作用的加强使下层出水NH⁺₄-N 、NO^-₂-N及NO^-₃-N浓度均高于上层。提高循环速率有利于对氮的去除。     

浸提分离法提取皂素清洁工艺研究

提出一种通过溶剂提取将游离皂苷与淀粉、纤维等成分分离,从源头上减少用水量、耗酸量和污染物排放量的皂素清洁生产工艺。首先对溶剂提取条件进行优化,得出最佳工艺条件为：90%（体积比）乙醇溶液,料液比1∶7,沸腾回流提取3 h,重复提取3次。然后通过气质联用（GC/MS）分析了皂素废水的有机物组成。研究结果表明,清洁工艺皂素产率为1.51%（降低3.82%）,用酸量比传统工艺减少了71%,头道液COD浓度降低了46%,每100 g原料排放的COD总量下降了84%;皂素废水的有机物污染物主要为糠醛及其衍生物,清洁工艺废水的有机物含量更低,更易降解。     

脂肪酰基氨基酸对矿物润滑油生物降解性的影响研究

通过生物降解试验研究了N-月桂酰基谷氨酸、N-月桂酰基甘氨酸、N-月桂酰基丙氨酸和N-油酰基甘氨酸4种脂肪酰基氨基酸对HVI 350矿物润滑油生物降解性的影响,采用高倍电子显微镜分析了生物降解过程中微生物数量和形态变化。结果表明,在矿物润滑油中添加少量脂肪酰基氨基酸后,矿物润滑油的生物降解性能明显改善,且生物降解过程中微生物数量增多、形态发生变化,这可能是脂肪酰基氨基酸增加了微生物的营养,且具有表面活性,有利于细胞的吸收,从而促进了矿物润滑油生物降解。     

铈改性Al_2O_3担载Pd催化剂的CO氧化性能研究

浸渍法制备了Al2O3+CeO2为载体的Pd催化剂,对制备中各因素对催化剂效果的影响作了初步研究.考察了活性组分含量与催化荆性能的关系以及焙烧温度、水蒸气对催化剂活性的影响.结果表明,稀土Ce元素的存在使催化剂的性能得到明显改善.制备过程中焙烧步骤对催化剂的活性影响很大,催化剂制备必须高于600 ℃焙烧.     

基于生态安全的DAT-IAT城市污水处理工艺改进研究

通过正交试验,得到了DAT-IAT工艺和A/DAT-IAT工艺处理城市污水的常规指标去除和生态毒理指标削减的最优运行条件。结果表明,在正交试验的同一工艺中,COD去除最优运行条件的出水COD值优于生态毒性削减最优运行条件的出水COD值,但前者出水的生态毒性较大。由于厌氧池的水解酸化作用,A/DAT-IAT工艺对COD和生态毒性的处理效果均优于DAT-IAT工艺,并且回流总能耗低于DAT-IAT工艺,但是出水COD仍不达标。为了降低进入工艺的COD的总量,以絮凝沉淀做为预处理工艺,并采用Al残留量最小的絮凝剂投药量以降低出水中残留Al带来的生态风险。结果表明,在COD去除最优运行条件下,具有絮凝预处理的工艺对COD的去除效果优于没有絮凝预处理的工艺。絮凝-A/DAT-IAT工艺在COD去除最优运行条件下出水COD为104.46 mg/L,满足排放标准。在毒性削减最优运行条件下,具有絮凝预处理的工艺的出水生态毒性有所上升,但是污染物的总量得到了大幅削减。絮凝-A/DAT-IAT工艺与DAT-IAT工艺相比,在污染物去除效率得到大幅增加的同时,生态毒性得到有效控制,生态安全得到了有效的保障。     

六自由度气锤振动技术与电磁斜面振动技术比较

六自由度气锤振动与电磁斜面振动是两种模拟产品三轴振动的振动技术。由于两种振动技术的机理不同,其对样品的振动影响也会有区别。本文研究讨论两种不同振动技术的不同特点,以及对不同产品的振动效果别,我们可以根据样品特点和测试需求,选择更合适的震动技术。     

Profile of Methane Concentrations in Soil and Atmosphere in Alpine Steppe Ecosystem on Tibetan Plateau

The methane concentration profile from -1.5m depth in soil to 32m height in air was measured in alpine steppe located in the permafrost area. Methane concentrations showed widely variations both in air and in soil during the study period. The mean concentrations in atmosphere were all higher than those in soil, and the highest methane concentration was found in air at the height of 16m with the lowest concentration occurring at the depth of 1.5m in soil. The variations of atmospheric methane concentrations did not show any clear pattern both temporally and spatially, although they exhibited a more steadystable state than those in soil. During the seasonal variations, the methane concentrations at different depths in soil were significantly correlated （R^2〉0.6） with each other comparing to the weak correlations （R^2〈0.2） between the atmospheric concentra- tions at different heights. Mean methane concentrations in soil significantly decreased with depth. This was the compositive influence of the decreasing production rates and the increasing methane oxidation rates, which was caused by the descent soil moisture with depth. Although the methane concentrations at all depths varied widely during the growing season, they showed very distinct temporal variations in the non-growing season. It was indicated from the literatures that methane oxidation rates were positively correlated with soil temperature. The higher methane concentrations in soil during the winter were determined by the lower methane oxidation rates with decreasing soil temperatures, whereas methane production rates had no reaction to the lower temperature. Relations between methane contribution and other environmental factors were not discussed in this paper for lacking of data, which impulse us to carry out further and more detailed studies in this unique area.     

Analysis of the Energy Embodied in Foreign Goods Trade of China

In recent years, scientists have been increasingly interested in the energy embodied in traded goods among countries. In this article, the direct energy intensities in various economic sectors of China were calculated with the data of energy consumption and output value of each sector, and the input-output table was used to estimate the external energy consumption. The total energy intensity of all sectors was then obtained. From the data of international trade, the energy embodied in goods trade of China was estimated for the period of 1994-2001. During this period, the average energy intensity of imported goods was always higher than that of exported ones. As a country with a surplus in international goods trade, China actually imported net embodied energy in the past few years. The net embodied energy imported was at the same magnitude of the imported energy in the form of fossil fuels.     

A Review of Environmental Sociology and the Sociology of Natural Resources： Insights for the Development of Environmental Sociology in China

Environmental sociology and the sociology of natural resources are two key subdisciplines of the sociological study on the interactions between nature and human society. Previous discussion on the relationships of these two fields has largely focused on their distinctions and synthesis in western （particularly American） academia. Environmental sociology emerged as an important sociological subdiscipline in China in the early 1990s and is under vigorous disciplinary construction at present. By contrast, the sociology of natural resources is still a novel term for most Chinese researchers. This article provides a systematic review of recent literature on the relationships between environmental and natural resource sociologies, which should provide important implications for the further development of environmental sociology in China.