唐家河自然保护区植被景观梯度变化及其成因

以ETM 影像数据为基础,利用景观分析软件Fragstats对唐家河自然保护区植被景观分别从东西、南北、西北至东南3个方向进行空间梯度分析.结果表明,沿东西方向,景观多样性呈现"升-降-升"的波动变化趋势,破碎化程度与复杂度降低;沿北南方向,景观多样性、复杂度以及连接度逐渐下降,但破碎度增加,形状趋于复杂;沿西北至东南方向,景观多样性与复杂度均表现出"降-升-降-升"的波动变化趋势;在西北部至中部斑块邻近度相对较高,变化较为明显;而东南部相对较低,变化幅度小.唐家河自然保护区所处的自然条件是其景观格局梯度变化形成的主要原因和先决条件,植物群落的空间格局明显受水文地貌特征的控制.     

C4植物甜高梁和玉米幼苗对Zn胁迫的响应差异

实验采用营养液培养法,设置2,50,100,500和1000μmol-L-1浓度ZnSO4处理,比较C4植物甜高粱(Sorghum bicolor(L.)Moench.)和玉米(Zeamays.L)幼苗对zn胁迫的响应差异.结果表明,甜高粱对重金属zn胁迫的敏感性强于玉米,随着zn处理浓度加大,前者幼苗苗高、根长、单株干物质量、叶绿素含量和根系活力的下降幅度及丙二醛含量的上升幅度皆大于后者,玉米对Zn胁迫的耐受性强于甜高粱.在处理浓度达到500 μmol-L-1之前,甜高粱和玉米体内吸收的Zn随处理浓度加大显著递增,达500μmol-L-1之后,玉米根系积累的Zn不再明显增加.在处理浓度达到和高于100μmol·L-1时,甜高粱由根系向地上部转运的Zn显著高于玉米.甜高粱和玉米对Zn胁迫的敏感性差异可能缘于它们的吸收和转运差异.     

生活垃圾焚烧厂贮坑沥滤液的负压蒸发预处理研究

采用负压蒸发法处理上海市某大型生活垃圾焚烧发电厂贮坑沥滤液,实验研究了沥滤液蒸发过程中冷凝液组分的变化特征.结果表明:生活垃圾焚烧厂贮坑沥滤液中含有高质量浓度的挥发性污染物,低碳醇和碳原子数不大于7的挥发性有机酸(VFA)约占沥滤液中有机碳质量浓度的50%;沥滤液直接蒸发可将原液转化为原液量的84%,不含氨氮,有机物质量浓度为原液的21%,且90%以上为VFA及低碳醇的冷凝液,以及有机物质量浓度浓缩了4.4倍,适于焚烧处理的浓缩液;通过蒸发处理,沥滤液的处理难度大大降低,蒸发用能可取自焚烧热能回收后的低温位热能,降低了蒸发处理的费用.      

催化湿式氧化法处理糖蜜酒精废液的研究

以非贵金属Cu、Fe、Mn和Ce为主要活性成分和TiO2、-γA l2O3为载体,制备了10种用于催化湿式氧化法处理糖蜜酒精废液的催化剂。考察了载体、焙烧温度、成分配比对催化剂催化活性与稳定性的影响,研究了氧气分压、催化剂投加量、反应温度和反应时间对催化湿式氧化过程的影响规律。结果表明:(1)Fe-Mn/-γA l2O3(3∶1∶1)催化剂是催化湿式氧化法处理糖蜜酒精废液的可选催化剂;(2)适宜的氧气供应量为理论需氧量的3.4~4.6倍,催化剂的投加量以10 g/L为佳;在300℃下反应30 m in或在280℃下反应60 m in,处理水可达到污水综合排放标准GB9878-1996的三级标准。     

降酚菌株的固定化细胞处理含酚废水的性能研究

用海藻酸钠作为载体将一株降酚菌株进行固定化包埋。利用正交实验确定了该菌株固定化细胞制备的最优条件。研究表明,该降酚菌株的固定化细胞对苯酚的降解能力和耐受能力均大于游离细胞。降酚菌株固定化细胞降解苯酚的最适温度范围是30~35℃,最适pH值范围为6~8。该菌株的固定化细胞对废水中的COD也具有良好的降解效果。     

铁屑吸附-微波辐照-内电解协同处理结晶紫染料废水

以结晶紫为模型化合物,提出了一种新的“铁屑吸附—微波辐照—内电解”协同处理染料废水的方法。试验结果表明,吸附在铁屑表面的染料通过微波催化裂解和内电解协同作用迅速降解,染料溶液的脱色率和COD去除率分别达到99％和95％以上。废铁屑经8次使用后仍有良好的处理效果。研究了各种相关因素对染料废水脱色的影响。     

Adsorption-desorption characteristics of mercury in paddy soils of China

Mercury (Hg) has received considerable attention because of its association with various human health problems. Adsorption-desorption behavior of Hg at contaminated levels in two paddy soils was investigated. The two representative soils for rice production in China, locally referred to as a yellowish red soil (YRS) and silty loam soil (SLS) and classified as Gleyi-Stagnic Anthrosols in FAO/UNESCO nomenclature, were respectively collected from Jiaxin County and Xiasha District of Hangzhou City, Zhejiang Province. The YRS adsorbed more Hg(2+) than the SLS. The characteristics of Hg adsorption could be described by the simple Langmuir adsorption equation (r2 = 0.999 and 0.999, P < 0.01, respectively, for the SLS and YRS). The maximum adsorption values (Xm) that were obtained from the simple Langmuir model were 111 and 213 mg Hg(2+) kg(-1) soil, respectively, for the SLS and YRS. Adsorption of Hg(2+) decreased soil pH by 0.75 unit for the SLS soil and 0.91 unit for the YRS soil at the highest loading. The distribution coefficient (kd) of Hg in the soil decreased exponentially with increasing Hg(2+) loading. After five successive desorptions with 0.01 mol L(-1) KCl solution (pH 5.4), 0 to 24.4% of the total adsorbed Hg(2+) in the SLS soil was desorbed and the corresponding value of the YRS soil was 0 to 14.4%, indicating that the SLS soil had a lower affinity for Hg(2+) than the YRS soil at the same Hg(2+) loading. Different mechanisms are likely involved in Hg(2+) adsorption-desorption at different levels of Hg(2+) loading and between the two soils.     

秦皇岛港建设绿色企业文化探析

建设绿色企业文化是秦皇岛港实现绿色发展的前提,对港口的发展有深远的意义和重要作用.秦皇岛港应从强化领导意识、提高职工素质、完善绿色制度体系、构建绿色企业形象等方面入手建设港口绿色企业文化.     

图书馆书库清点方法初探

图书馆藏书大多存在实物与财产登记不符的状况,如情况较为严重则会影响到图书馆流通、采访等项工作的开展,因此适时进行书库清点具有重要意义。本文以中国环境管理干部学院图书馆的清点为实例,初步探讨了将条码作为清点切入点的书库清点工作的方法、步骤和注意事项。     

Water level response to hydropower development in the upper Mekong River

Environmental changes and their transboundary influences on the Mekong watercourse system have been an international research focus in recent years, but the opinions and results related to the impacts of upper Mekong River dams are quite different. In this paper, based on the records of water levels from 1960 to 2003 at three mainstream sites in the upper Mekong River, a quantitative examination has been undertaken into characteristics of the mainstream water-level process at multiple timescales and its response to cascade development. The major results are: i) Annual mean, wet period mean, and the mean water levels during the period between March and April (PBMA period) exhibit a significant increasing trend at Jiuzhou and Yunjinghong sites, which are influenced by large-scale factors such as climate change and solar activity. ii) The interdecadal and interannual variations of annual mean, annual maximum, and wet period mean water levels at three sites show similar features during the dam construction period. iii) The interdecadal variations of PBMA period water level show a gradual increase at Gajiu and Yunjinghong sites but a falling trend at Jiuzhou; these trends confirm that there is some regulation on the flow in the dry season caused by the two existing dams. iv) The downstream effects of the present dams on water levels are very limited at the annual mean and wet season mean levels, not apparent at the monthly and yearly timescales, and relatively significant at daily and hourly timescales.