阿维菌素对意大利蜜蜂(Apis mellifera L.)的毒性影响

通过单次饲喂高浓度阿维菌素药液以及连续饲喂亚致死浓度阿维菌素药液进行意大利蜜蜂的经口染毒,从而探讨阿维菌素对意大利蜜蜂的急性及慢性毒性影响。结果表明,阿维菌素对意大利蜜蜂急性经口毒性48 h半数致死剂量(48 h-LD50)为0.00700μg a.i.·蜂-1,慢性经口毒性240 h每日半数致死剂量(240 h-LDD50)为0.000308μg a.i.·蜂-1·天-1。在亚致死效应方面,0.0233 mg a.i.·L-1和0.0467 mg a.i.·L-1处理组在168 h后摄食量出现明显的减少,说明阿维菌素中毒已经严重影响意大利蜜蜂的觅食和摄食能力。同时,由于摄食量的下降以及阿维菌素的毒性作用,造成了0.0467 mg a.i.·L-1处理组意大利蜜蜂体重的大幅度下降,试验前后的体重变化率达到-54.84%。意大利蜜蜂爬行能力的测定结果显示,各处理组的爬行通过率均低于对照组,特别是0.0117 mg a.i.·L-1处理组、0.0233 mg a.i.·L-1处理组和0.0467 mg a.i.·L-1处理组(P0.05)。综上所述,阿维菌素对意大利蜜蜂的急性经口毒性为高毒,较高剂量染毒会引起意大利蜜蜂的直接死亡;此外,长期接触较低浓度的阿维菌素,一方面会损害意大利蜜蜂的运动能力,如爬行、飞行能力的减弱;另一方面意大利蜜蜂生理方面也会遭到威胁,表现为摄食量下降、体重减轻,甚至死亡。因此,在施用该农药时应尽量避开蜜蜂栖息地,同时避免在蜜源植株花期时施用。     

NO oxidation over Co-La catalysts and NO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> reduction in compact SCR

A series of Co-La catalysts were prepared using the wet impregnation method and the synthesis of catalysts were modified by controlling pH with the addition of ammonium hydroxide or oxalic solution. All the catalysts were systematically investigated for NO oxidation and SO₂ resistance in a fixed bed reactor and were characterized by Brunanuer–Emmett–Teller (BET) method, Fourier Transform infrared spectroscopy (FTIR), X–ray diffraction (XRD), Thermogravimetric (TG) and Ion Chromatography (IC). Among the catalysts, the one synthesized at pH = 1 exhibited the maximum NO conversion of 43% at 180°C. The activity of the catalyst was significantly suppressed by the existence of SO₂ (300 ppm) at 220°C. Deactivation may have been associated with the generation of cobalt sulfate, and the SO₂ adsorption quantity of the catalyst might also have effected sulfur resistance. In the case of the compact selective catalytic reduction (SCR), the activity increased from 74% to 91% at the highest gas hourly space velocity (GHSV) of 300000 h^–1 when the NO catalyst maintained the highest activity, in excess of 50% more than that of the standard SCR.

Open image in new window

     

化学污染物对珊瑚礁生态系统的影响研究进展

化学污染物是影响珊瑚礁生态系统健康的重要因素之一。随着我国社会经济的发展，沿海农业活动、城市工业化以及旅游业的发展导致珊瑚礁生长区的化学污染物浓度越来越高。珊瑚礁生态系统长期在化学污染物的联合胁迫下，生态风险指数日益增加，受到国内外研究者的极大关注。本文综述了国内外该领域的重要研究进展，并从个体、细胞和分子水平重点介绍了化学污染物对珊瑚的影响，主要包括：(1)珊瑚礁对重金属和多环芳烃有明显的富集作用，可以作为该海域化学污染物污染水平的外在反映；(2)化学污染物对珊瑚幼体的影响程度比成体大；(3)抗氧化酶和特定的功能基因可被用作生物标记物来监测珊瑚礁生态系统的健康状况。最后，对我国未来珊瑚礁生态系统的研究方向进行展望，建议在典型珊瑚礁海域进行长期的生态学监测，结合室内胁迫实验，筛选出敏感的生物标志物(biomarker)，为今后珊瑚礁生态系统的保护提供基础信息，并对其可能存在的环境风险进行评价。     

Binding characteristics of Cu2+ to natural humic acid fractions sequentially extracted from the lake sediments

Humic acids (HAs) determine the distribution, toxicity, bioavailability, and ultimate fate of heavy metals in the environment. In this work, ten HA fractions (F1–F10) were used as adsorbent, which were sequentially extracted from natural sediments of Lake Wuliangsuhai, to investigate the binding characteristics of Cu²⁺ to HA. On the basis of the characterization results, differences were found between the ten extracted HA fractions responding to their elemental compositions and acidic functional groups. The characterization results reveal that the responses of ten extracted HA fractions to their elemental compositions and acidic functional groups were different. The O/C and (O + N)/C ratio of F1–F8 approximately ranged from 0.66 to 0.53 and from 0.72 to 0.61, respectively; the measured results showed that the contents of phenolic groups and carboxyl groups decreased from 4.46 to 2.60 mmol/g and 1.60 to 0.58 mmol/g, respectively. The binding characteristics of Cu²⁺ to the ten HA fractions were well modeled by the bi-Langmuir model; the binding behavior of Cu²⁺ to all the ten HA fractions were strongly impacted by pH and ionic strength. The FTIR and SEM-EDX image of HA fractions (pre- and post-adsorption) revealed that carboxyl and phenolic groups were responsible for the Cu²⁺ sorption on the ten sequentially extracted HA fractions process, which is the same with the analysis of the ligand binding and bi-Langmuir models Accordingly, the adsorption capacity of the former HA fractions on Cu²⁺ were higher than the latter ones, which may be attributed to the difference of carboxyl and phenolic group contents between the former and latter extracted HA fractions. Additionally, the functional groups with N and S should not be neglected. This work is hopeful to understand the environmental effect of humic substances, environmental geochemical behavior, and bioavailability of heavy metals in lakes.

     

长庆油田油气泄漏防治体系建设与应用

为防治油气泄漏事件,长庆油田以重点环境保护目标为对象,按照层级防护、标本兼治、数字预警、分级响应、就地控制的原则,建设油气泄漏防治体系,明确和落实油田公司、厂处、作业区、生产岗位四个层级的防治范围和职责,构建系统参数预警报警、阀门截断、基础防护三道防线,全面提升安全环保的防范能力和水平。保证事故状态下,能够在最短时间、最小范围内进行最有效的处置,实现重点环境保护目标的安全。     

Occurrence,fate, and transport of potentially toxic metals (PTMs) in an alkaline rhizosphere soil-plant (Maize,Zea mays L.) system: the role of Bacillus subtilis

Environmental Science and Pollution Research - Utilization of microbes is one of the most promising methods to remediate potentially toxic metals (PTMs) from soil. In this study, a systematic...     

Quantitative Evaluation on Urban Ecosystem Carrying Capacity in Tianjin Binhai New Area

Based on the concept of ecosystem carrying capacity, the indicator system of quantitative assessment was set up, which consisted of support indicator system and pressure indicator system. And the factor analysis method was used to screen the indicator system. Different from the traditional indicator weight determination based on the absolute values of the coefficients of regression equation, the squares of factor loadings in the rotated component matrix were attempted to determine the weights of 40 assessment indicators. The result shows that ecological support system and pressure system in Binhai New Area are relatively balanced among six years, and the developing level of urban ecosystem is basically healthy on the whole. However, due to continuously increasing pressure of the resources consumption caused by the rapid growth of the second industry, which is the Leading Industry of Binhai New Area, the ecosystem carrying capacity reached the minimum in 2005.     

2008年云南滇东北电线覆冰的气象条件

通过对2008年1-2月云南滇东北电线覆冰(雨凇)气象条件的分析,得到:①2008年云南滇东北雨凇持续时间是有气象记录以来最长是的一年,所造成的电线覆冰灾害非常严重的;②雨凇持续时间与ENSO有密切对应关系;③2008年滇东北电线覆冰期间昆明准静止锋异常活跃,是最重要的影响天气系统;④2008年滇东北的电线覆冰是在气温偏低、降水偏小、风速不大(或静风)及空气较为潮湿的气象条件下发生的.电线覆冰的厚度与气温成显著负相关,与风速成显著正相关.     

Early detection and evaluation of waste through sensorized containers for a collection monitoring application

The present study describes a novel application for use in the monitoring of municipal solid waste, based on distributed sensor technology and geographical information systems. Original field testing and evaluation of the application were carried out in Pudong, Shanghai (PR China).The local waste management system in Pudong features particular requirements related to the rapidly increasing rate of waste production. In view of the fact that collected waste is currently deployed to landfills or to incineration plants within the context investigated, the key aspects to be taken into account in waste collection procedures include monitoring of the overall amount of waste produced, quantitative measurement of the waste present at each collection point and identification of classes of material present in the collected waste. The case study described herein focuses particularly on the above mentioned aspects, proposing the implementation of a network of sensorized waste containers linked to a data management system.Containers used were equipped with a set of sensors mounted onto standard waste bins. The design, implementation and validation procedures applied are subsequently described. The main aim to be achieved by data collection and evaluation was to provide for feasibility analysis of the final device. Data pertaining to the content of waste containers, sampled and processed by means of devices validated on two purpose-designed prototypes, were therefore uploaded to a central monitoring server using GPRS connection. The data monitoring and management modules are integrated into an existing application used by local municipal authorities.A field test campaign was performed in the Pudong area. The system was evaluated in terms of real data flow from the network nodes (containers) as well as in terms of optimization functions, such as collection vehicle routing and scheduling. The most important outcomes obtained were related to calculations of waste weight and volume. The latter data were subsequently used as parameters for the routing optimization of collection trucks and material density evaluation.     

不同碳源添加量对垂直流人工湿地污水处理效果的影响

以垂直流人工湿地小试系统为研究对象,采用碱处理过的千屈菜(Lythrum salicaria)作为反硝化碳源补充材料,探讨了不同碳源添加量对系统COD及氮、磷去除效果的影响。结果表明,一定剂量经过碱处理的千屈菜材料可以为人工湿地系统脱氮提供反硝化所需要的碳源,而且具有缓效持续释放的特点。添加此碳源材料可明显提高系统的脱氮效率,最高可提升30.85%,但随着C/N比的增加,硝态氮去除率逐渐降低,C/N比为3、5、8时分别为91.20%、87.72%和84.19%。添加碳源量达到C/N比为3时系统能够发生最大程度反硝化,此时不仅人工湿地系统脱氮效果得到提高,同时人工湿地除磷能力也有所增强。碱处理过的千屈菜材料在本系统中的最适宜添加量为5 g,即100 g/m2(C/N=3),远低于在进水中为满足反硝化所需调控的C/N比(5～8),可以节约外加碳源成本。