Multiple biomarker responses in caged benthic gastropods <Emphasis Type="Italic">Bellamya aeruginosa</Emphasis> after in situ exposure to Taihu Lake in China

Background

Freshwater sediments have been recognized as a long-term sink and potential source for environmental pollutants released into the aquatic ecosystems. In this study, the sediment quality of Taihu Lake, which is susceptible to anthropogenic contamination, was assessed by a combination of chemical analytical and biological end points. Specifically, the snail Bellamya aeruginosa was caged in situ at two locations representing different pollution levels for different exposure times (7, 14 and 21 days). At each of these time points, biochemical parameters, i.e., phase I biotransformation enzymes ethoxyresorufin-O-deethylase (EROD), the antioxidant enzymes superoxide dismutase and catalase, reactive oxygen species, protein carbonyl content and lipid peroxidation, were evaluated in the hepatopancreas of snails. In addition, surface sediments were collected for analysis of contaminants of concern, including inorganic pollutants, organochlorine pesticides, polychlorinated biphenyls and polybrominated diphenyl ethers.

Results

Chemical analyses revealed that sediments from Taihu Lake were contaminated with trace elements and organic pollutants. Concentrations of trace elements (Cu, Ni and As) and organochlorinated pesticides (4,4′-DDE) exceeded their corresponding threshold effect level according to the sediment quality assessment values for freshwater ecosystems in Canada, indicating that adverse biological effects may occur. All biomarkers, except EROD activity, were induced in snails during all exposure times. The integrated biomarker response index (IBR) indicated that during the initial exposure phase (7 days), B. aeruginosa were subjected to significant environmental stress, which diminished during later sampling time points.

Conclusions

Results showed that IBR correlated well with the levels of environmental contaminants, demonstrating the applicability of this biomonitoring approach to complex environmental exposure scenarios.

     

遥控器在桥式起重机上的应用

在桥式起重机上加装遥控装置,既解决了操作者的上下车之苦,又确保了安全生产。     

大气中氯氟烃类物质浓度变化的研究

通过低温脱水和低温浓缩,建立了用气相色谱测定大气中超痕量氯氟烃类物质的分析。方法,对上海市清洁大气中ＣＦＣｓ本底浓度进行了监测,并与日本东京大学的数据进行了比较。     

风雪千里松花江--国家环保总局局长周生贤在松花江污染防控一线工作纪实

面对松花江水污染事件,党中央、国务院及时做出了重要部署,国家环境总局局长周生贤履新伊始,就以对党和人民高度负责的精神直接奔赴松花江污染防控最前线．于冰天雪地里辗转上千公里,现场指导这场罕见的污染防控大战役。本刊特约记者段松君跟随周局长一行,真实记录了周局长与一线环保工作者并肩战斗,共同为保障松花江两岸人民的生产生活安全艰苦奋斗的日日夜夜,刊发这篇独家报道,是想以展现防控前线将士的精神风貌,激发全国环保工作者保障国家环境安全的责任感和使命感;还想以记录审慎决策下的防控工作进展,让党和国家放心,让全国人民放心！[编者按]     

阻尼式脉动气流分选装置处理电子废弃物的基础研究

采用机械物理回收方法对电子废弃物进行资源化利用具有巨大的经济效益和社会效益。针对电子废弃物的特点,作者采用阻尼式脉动气流分选装置对电子废弃物中有价组分的分选进行了研究。研究表明,与传统气流分选装置相比,阻尼式脉动气流分选装置可获得更高的分选效率和更宽范围的操作条件。     

PROTECTING BEIJLNG'S MUNICIPAL WATER SUPPLY THROUGH WATERSHED MANAGEMEN AN ECONOMIC ASSESSMENT1

ABSTRACT: Watersheds above the Miyun reservoir, a principal source of surface water for Beijing, are designated to be managed for water production, but under the principle of multiple use. Because of the scarcity of arable land, these watersheds cannot be managed only for drinking water. Efforts are under way to reduce sediment delivery, improve the quality of water entering Miyun reservoir, and improve the welfare of watershed inhabitants. An economic appraisal of a watershed management project for the 3,298‐ha Shixia watershed above the Miyun reservoir, indicates a 24 percent economic rate of return on the investment made in the project. The net present value (NPV) of the project, calculated at a discount rate of 10 percent, is approximately US$3.49 million. Sensitivity analyses indicate that a doubling of labor costs lowers the NPV to US$2.07 million and a 10 percent decrease in benefits lowered the NPV to US$2.87. It is concluded that the implementation of conservation practices on the Shixia Demonstration Watershed represent an economically efficient use of resources.     

水质管理规划中BOD5响应矩阵的一种改型模式

本文推导对水质管理规划中经典BOD5响应矩阵的一种改型模式,并对数值例加以阐述.该模式以BOD5总量为控制对象,任一河流断面的BOD5输入量在此响应矩阵中仅出现一次,从而使响应关系由下三角矩阵改变为每一行均含三个变量的稀疏矩阵。这一改型不仅提高了计算速度,更重要的是,由于改型模式具有运输问题类型良好的特殊结构,可以方便地判断一个水质管理规划问题是否可行和给出可行的充分必要条件,这一特性具有较大的实际经济意义.改型模式与经典模式所需数据完全相同。      

沥青混凝土装车烟气的除尘净化和余热回收

针对沥青混凝土装车时冲击车厢产生的大量烟尘和有毒气体治理的这一难题 ,设计了一套环保装置。该装置及其工艺过程包括集气罩、喷射器、燃烧室、废气余热回收 4个部分 ,先后将沥青混凝土装车时冲击产生的大量烟尘全部密封在车厢里 ,并利用引风机喷射造成的负压将烟尘抽出并引射到高温燃烧室中 ,使沥青烟气和空气中的氧气发生裂解、燃烧高温反应 ,保证烟气中的烷烃类化合物以及微粒碳粉完全转化为氧化物 ;从燃烧室出来的废气温度高达70 0～ 80 0℃ ,通过热风管道引入到干燥筒 ,在沙石干燥过程中回收废气中的余热 ,并利用原有除尘装置实现了环保达标、投资回报效益高的双重目标。     

海洋赤潮藻球形棕囊藻在氮磷富营养下的细胞增殖

利用常见海洋赤潮微藻球形棕囊藻(Phaeocystis globosa)为试验研究材料,以舵海洋微藻营养液为对照(1P1N:磷质量浓度为5×10-3g·L-1.氮质量浓度为75×10-3g·L-1),设置3组富磷和富氮营养处理(3P1N:磷质量浓度为15×10-3 g·L-1,氮质量浓度为75×10-3 g·L-1;1P3N:磷质量浓度为5××10-3 g·L-1,氮质量浓度为225×10-3 g·L-1;3P3N:磷质量浓度为15××10-3 g·L-1,氮质量浓度为225×10-3 g·L-1),利用细胞记数和叶绿素荧光测定等方法研究了藻细胞在不同富磷和富氮条件的增殖情况.结果显示,不同浓度磷和氮营养下的藻体荧光值变化在试验周期内均呈现"S"型曲线,表明藻细胞的生长经历缓慢期,快速期和平缓期3个阶段;同时,不同的富磷和富氮营养条件对球形棕囊藻的叶绿素荧光值有一定的影响,其中在对照1P1N下的藻体荧光值最低,在试验结束时(第10天)只有850 μg·L-1,而在3P1N,1P3N和3P3N条件下的藻体荧光值均达到900 μg·L-1以上,显著高于1P1N下的藻体荧光值,表明富磷和富氮营养可以促进藻细胞的生长增殖,但在试验设置的不同富磷和富氮营养下的藻体荧光值之间没有显著的差异.就不同磷和氮营养条件下的藻最大比生长速率而言,3P3N和3P1N条件下的最大,均达到0.77 d-1,明显高于1P1N和1P3N条件下的藻最大比生长速率(分别只有0.70 d-1和0.69 d-1).此外,试验结束时细胞密度的变化趋势与藻体荧光值相似,富磷和富氮营养条件下的细胞密度显著高于1P1N下的细胞密度,而富磷和富氮营养条件下的细胞密度间也不存在显著的差异.研究结果揭示,水体中的高磷和高氮营养浓度是导致藻细胞大量快速增殖的一个主要因素,而利用叶绿素荧光来测定藻细胞增殖是一种快速、简便,灵敏和可靠的方法,可在今后赤潮监测过程中多加利用,以能及时、准确地预测预报赤潮爆发.从而减少其对环境和经济的影响.     

煤矸石堆放场周围玉米作物中苯并(a)芘污染特征

以焦作矿区演马矿煤矸石堆放场周围农田玉米为研究对象,对玉米中苯并(a)芘污染特征进行了分析研究.在矸石堆周围布设三条采样线采集玉米样品,玉米样品经提取、浓缩、净化处理后采用高效液相色谱(HPLc)法对其中苯并(a)芘含量进行检测分析.结果表明,研究区玉米作物叶子中苯并(a)芘污染水平较高,达46.7%,茎和籽均未出现苯并(a)芘污染现象,且玉米各部位苯并(a)芘含量与距矸石堆距离呈反比.进一步指出矿区企业应加强对周围环境生态的预防保护,以确保企业的可持续发展.