应用酵母菌处理木薯酒精废液的试验研究

应用酵母菌对木薯酒精废液进行了小型批量的处理试验研究.结果表明,该菌种对于高浓度有机废水具有很强的适应能力,能迅速形成优势菌群,分解有机物.在进水pH 5.0～5.5、温度30℃、曝气时间72 h、接种量1‰(v/v,活菌数为4.1×106个/mL)、溶解氧2～3 mg/L、BOD5∶N∶P为400∶2∶1条件下,COD和BOD5去除率可分别达85%和92%.该技术操作简单,可作为木薯酒精废液的一级生物处理,并可回收利用酵母蛋白.     

地质滑坡条件下不同因素对油气管道危险性影响分析

地质滑坡对油气管道的安全运行危害很大。建立横向滑坡管道有限元模型,分析管道的力学行为和极限状态,研究了滑坡位移、滑坡规模、埋深和土质等因素对管道变形和应力的影响,为可能滑坡地区管道的设计、施工和维护提供理论依据和技术参考。     

Application of an integrated biomarker response index to assess ground water contamination in the vicinity of a rare earth mine tailings site

We utilized a multi-biomarker approach (Integrated Biomarker Response version 2, IBRv2) to investigate the scope and dispersion of groundwater contamination surrounding a rare earth mine tailings impoundment. Parameters of SD rat included in our IBRv2 analyses were glutathione levels, superoxide dismutase, catalase, and glutathione peroxidase activities, total anti-oxidative capacity, chromosome aberration, and micronucleus formation. The concentration of 20 pollutants including Cl^?, SO₄ ^2?, Na⁺, K⁺, Mg²⁺, Ca²⁺, TH, COD_Mn, As, Se, TDS, Be, Mn, Co, Ni, Cu, Zn, Mo, Cd, and Pb in the groundwater were also analyzed. The results of this study indicated that groundwater polluted by tailings impoundment leakage exhibited significant ecotoxicological effects. The selected biomarkers responded sensitively to groundwater pollution. Analyses showed a significant relationship between IBRv2 values and the Nemerow composite index. IBRv2 could serve as a sensitive ecotoxicological diagnosis method for assessing groundwater contamination in the vicinity of rare earth mine tailings. According to the trend of IBRv2 value and Nemerow composite index, the maximum diffusion distance of groundwater pollutants from rare earth mine tailings was approximately 5.7 km.

     

南亚热带常绿阔叶林林冠层附生植物及其宿主叶片的形态解剖特征

选择南亚热带常绿阔叶林中具有代表性的4种林冠层附生植物：白背瓜馥木（Fissistigma glaucescens）、瓜子金（Dischidia chinensis）、蔓九节（Psychotria serpens）、山蒌（Piper hancei）及其主要宿主植物：厚壳桂（Cryptocaryachinensis）、荷木（Schimasuperba）、华润楠（Machilus chinensis）、锥栗（Castanopsis chinensis）为研究对象,对其叶片形态结构和解剖结构特征进行比较。研究结果表明：宿主植物与附生植物的叶片形态结构差异显著。相对于4种宿主植物,4种附生植物叶片无蜡被,比叶面积大,且具有含水量高,上下表皮厚度增加,气孔密度、气孔面积减少等特征,有利于叶片对水分和养分的吸收、贮存和利用。着生在林冠层不同部位的附生植物的叶片形态结构特征随着光合有效辐射、温度、湿度等微环境因子的变化表现出显著的差异：位于冠层顶部的瓜子金和蔓九节叶片小而厚,含水量高,气孔密度低且覆盖角质膜,更适应冠层顶部高温、低湿、高光照的环境;位于冠层下部的白背瓜馥木和山蒌叶片相对较薄,气孔面积较大,叶肉细胞分化明显,海绵组织排列松散,更适应冠层中下部低温、高湿、弱光照环境。变化的叶片结构是植物适应环境条件的重要表现。     

Online monitoring of water-soluble ionic composition of PM10 during early summer over Lanzhou City

Lanzhou is one of the most aerosol-polluted cities in China. In this study, an online analyzer for Monitoring for AeRosols and GAses was deployed to measure major water-soluble inorganic ions in PM10 at 1-hour time resolution, and 923 samples were obtained from Apr 1 to May 24, 2011. During the field campaign, air pollution days were encountered with Air Quality Index more than 100 and daily average concentration of PM10 exceeding 150 μg/m3. Based on the variation of water-soluble ions and results of Positive Matrix Factorization 3.0 model execution, the air pollution days were classified as crustal species- or secondary aerosol-induced, and the different formation mechanisms of these two air pollution types were studied. During the crustal species pollution days, the content of Ca2+increased and was about 2.3 times higher than the average on clear days, and the air parcel back trajectory was used to analyze the sources of crustal species. Data on sulfate, trace gases and meteorological factors were used to reveal the formation mechanism of secondary aerosol pollution. The sulfur oxidation ratio(SOR) was derived from the 923 samples, and the SOR had high positive correlation with relative humidity in early summer in Lanzhou.     

尾矿库周边地下水对SD大鼠的毒性效应研究

金属冶选尾矿库渗漏对其周边区域地下水环境造成的复合污染是一个普通存在的问题。为了明确某尾矿库周边地下水污染对生物的影响状况,以该尾矿库周边地下水为实验用水,以SD大鼠为实验动物,进行尾矿库周边地下水污染对SD大鼠的毒性效应研究。实验中尾矿库周边地下水中污染物监测采用电感耦合等离子体质谱技术(ICP-MS)、分光光度法和滴定法;SD大鼠的饮食行为和体重测定采用称量法和统计法;SD大鼠肝、肾细胞DNA的损伤检测采用单细胞凝胶电泳法。结果显示,尾矿库周边地下水中的硫酸盐、硝酸盐氮、Zn等污染物均有不同程度的超标现象。尾矿库周边地下水污染对SD大鼠的生长性能有抑制作用。尾矿库周边地下水污染对SD大鼠肝、肾细胞的DNA损伤作用显著(p0.05),受损程度随着与尾矿库距离的减少而增加;尾矿库周边地下水中硝酸盐氮、Zn污染与肝、肾细胞DNA损伤之间具有相关性(p0.05)。结果表明尾矿库渗漏水对周边地下水造成了不同程度的污染,受污染的周边地下水对SD大鼠具有较强的毒性效应。     

不同碳氮比下污水反硝化过程中亚硝氮积累的特性研究

以乙酸钠为碳源,在不同的碳氮比(COD/NO_3~--N)条件下,通过控制反应器中反硝化时间,将NO_3~--N仅还原至NO_2~--N,实现NO_2~--N的稳定积累.结果表明,反硝化时间从60 min缩短至20 min,NO_3~--N还原速率和NO_2~--N积累速率分别增大至0.417 g·g~(-1)·h~(-1)(以VSS计,下同)和0.402g·g~(-1)·h~(-1).经过108 d的培养,NO_2~--N的积累率为95%.反硝化活性随碳氮比的增大而增大,而较低碳氮比更有利于NO_2~--N的稳定积累.在反硝化亚硝氮积累过程中,当碳源充足时,由于电子受体NO_3~--N和NO_2~--N相互竞争碳源,NO_3~--N的存在会抑制NO_2~--N的还原,从而导致NO_2~--N积累;而当碳源不足时,基质限制使NO_3~--N优先还原,导致NO_2~--N的积累.微生物宏基因组测序结果表明,培养污泥中的优势菌群为Thauera(71.85%),该菌仅能将NO_3~--N还原为NO_2~--N,从而导致NO_2~--N的积累.     

Optimization of the T3-induced Xenopus metamorphosis assay for detecting thyroid hormone signaling disruption of chemicals

T3-induced Xenopus metamorphosis is an ideal model for detecting thyroid hormone(TH)signaling disruption of chemicals. To optimize the T3-induced Xenopus assay and improve its sensitivity and reproducibility, we intend to develop quantitatively morphological endpoints and choose appropriate concentrations and exposure durations for T3 induction.Xenopus laevis at stage 52 were exposed to series of concentrations of T3(0.31–2.5 nmol/L)for 6 days. By comparing morphological changes induced by T3, we propose head area,mouth width, unilateral brain width/brain length, and hindlimb length/snout-vent length as quantitative parameters for characterizing T3-induced morphological changes, with body weight as a parameter for indicating integrated changes. By analyzing time-response curves, we found that following 4-day exposure, T3-induced grossly morphological changes displayed linear concentration–response curves, with moderate morphological changes resulting from 1.25 nmol/L T3 exposure. When using grossly morphological endpoints to detect TH signaling disruption, we propose 4 days as exposure duration of T3, with concentrations close to 1.25 nmol/L as induction concentrations. However, it is appropriate to examine morphological and molecular changes of the intestine on day 2 due to their early response to T3. The quantitative endpoints and T3 induction concentrations and durations we determined would improve the sensitivity and the reproducibility of the T3-induced Xenopus metamorphosis assay.     

兴安盟地表水污染分析及保护对策

通过对兴安盟境内8个水质检测采样点的水污染现状监测数据的分析,掌握全盟境内地表水质现状和存在的问题,并提出了相应的对策。     

镜泊湖浮游植物群落结构组成及多样性研究

镜泊湖是中国最大的高山堰塞湖,是中国27个火山地质公园之一,分别于2014年和2015年在镜泊湖入水、中心区、出水区进行浮游植物定性样品和定量样品的采集.结果表明,镜泊湖浮游植物种类很多,组成复杂.经初步鉴定,2014年共发现浮游植物210个分类单位,分别隶属于8门,11纲,22目,44科,94属,210种.2015年共发现浮游植物222个分类单位,分别隶属于8门,11纲,23目,36科,111属,222种.对镜泊湖浮游植物多样性分析显示以标准清洁水平为主.