Biosorption of mercury by Macrocystis pyrifera and Undaria pinnatifida: Influence of zinc, cadmium and nickel

The article investigated the adsorption of Hg(II) on Macrocystis pyrifera and Undaria pinnatifida in monometallic system and in the presence of Zn(II), Cd(II) and Ni(II).     

Accumulation of some metals in Morinda lucida from Nigeria

Transfer coefficients of the four metals As, Cd, Hg, and Pb were determined in the leaves and barks of Morinda lucida collected in Nigeria, with the view to quantify relative differences in the bioavailability of the metals to these parts of the plant. Samples were acid digested and the levels of the metals in the digestates were determined using an atomic absorption spectrophotometer. Certain properties of the soils, i.e., pH, clay fraction, electrical conductivity, cation exchange capacity, and organic matter, were also determined. The latter influence the bioavailability of the metals. All parameters correlated with the concentrations of the metals in soils. Transfer coefficient values recorded for Cd and Pb in various tissues of M. lucida Benth were within the expected ranges, while those of As and Hg showed elevated topsoil concentrations of metals. The order of bioavailability of the metals and their bioaccumulation in the tissues of M. lucida Benth was Hg > Cd > As > Pb. Stem barks of the plant showed the least bioaccumulation of all four metals and hence are most suitable for therapeutic purposes. Vegetative parts of M. lucida Benth used for therapeutic purposes should be sourced at sites that will give low transfer coefficient in order to reduce human exposure to toxicity associated with ingestion of heavy metals.     

台湾集集7.6级强震前粤东地区的重力中短期异常

基于广东东部地区流动重力观测资料,分析了1999年台湾集集7.6级地震前后重力场的时空动态演化过程,发现1996年起出现的群体性重力测值偏离长趋势的变化,可视为7.6级地震前中期异常的开始,而1998年中出现的反向变化则是中期异常向短期异常的转折。作为强震前的远场重力异常,其时间、空间变化表现出的不一致和非均匀性变化形态,可能主要与测区内不同断层在区域应力场和震源应力场共同作用下产生的局部形变不同有关。     

滇池水华特征及成因分析

滇池水华的规模大,持续时间长。水华的主要种类是蓝藻门的微囊藻属,其中以铜绿微囊藻占绝对优势。每年4～11月为水华发生期,常在外草海南部、海埂、灰湾一带形成大面积水华,盛时可遍及全湖,水体表层藻类叶绿素含量高达5 000 mg/m3。滇池水体中高含量的N和P营养物在水华的形成中起着关键作用,适宜的温度及充足的光照为水华的频发提供了有利条件,并且随着滇池富营养化的加剧及水温逐年升高,将促使水华暴发日趋严重。      

树脂吸附-NaClO曝气氧化法处理促进剂M废水的研究

研究了苯胺法生产促进剂M废水的治理 ,通过采用树脂吸附 NaClO曝气氧化二级处理工艺 ,分步去除有机污染物和硫化物 ,废水出水可达到国家一级排放标准。根据实验确定了适宜的工艺参数 ,氧化阶段的实验结果还证实Na ClO曝气氧化较NaClO搅拌氧化具有更高的去除效率     

PZT的EMI技术在土木工程健康监测中的研究进展

PZT(P iezoe lectric-ceram ic)的EM I(E lectro-m echan ica l im pedance)技术以其适于在线监测的诸多优点受到越来越多的关注。本文系统地阐述了PZT的E/M(电-机)耦合特性、PZT与本体结构的相互作用模型、EM I技术的基本原理及其在土木工程中的研究应用。利用PZT的EM I技术进行健康监测是具有广泛应用前景的一种方法,但由于其研究应用的时间不长,目前仍然处于试验室研究阶段,文中对该项技术中尚需解决的几个问题进行了总结。     

Local and Landscape Correlates of Primate Distribution and Persistence in the Remnant Lowland Rainforests of the Upper Brahmaputra Valley,Northeastern India

Habitat fragmentation affects species distribution and abundance, and drives extinctions. Escalated tropical deforestation and fragmentation have confined many species populations to habitat remnants. How worthwhile is it to invest scarce resources in conserving habitat remnants within densely settled production landscapes? Are these fragments fated to lose species anyway? If not, do other ecological, anthropogenic, and species‐related factors mitigate the effect of fragmentation and offer conservation opportunities? We evaluated, using generalized linear models in an information‐theoretic framework, the effect of local‐ and landscape‐scale factors on the richness, abundance, distribution, and local extinction of 6 primate species in 42 lowland tropical rainforest fragments of the Upper Brahmaputra Valley, northeastern India. On average, the forest fragments lost at least one species in the last 30 years but retained half their original species complement. Species richness declined as proportion of habitat lost increased but was not significantly affected by fragment size and isolation. The occurrence of western hoolock gibbon (Hoolock hoolock) and capped langur (Trachypithecus pileatus) in fragments was inversely related to their isolation and loss of habitat, respectively. Fragment area determined stump‐tailed (Macaca arctoides) and northern pig‐tailed macaque occurrence (Macaca leonina). Assamese macaque (Macaca assamensis) distribution was affected negatively by illegal tree felling, and rhesus macaque (Macaca mulatta) abundance increased as habitat heterogeneity increased. Primate extinction in a fragment was primarily governed by the extent of divergence in its food tree species richness from that in contiguous forests. We suggest the conservation value of these fragments is high because collectively they retained the entire original species pool and individually retained half of it, even a century after fragmentation. Given the extensive habitat and species loss, however, these fragments urgently require protection and active ecological restoration to sustain this rich primate assemblage. Correlaciones Locales y de Paisaje de la Distribución y Persistencia de Primates en los Bosques Lluviosos Remanentes en el Valle del Alto Brahmaputra, Noreste de India     

不同质量浓度黄菖蒲和狭叶香蒲对铜绿微囊藻的化感作用简

分别采用黄菖蒲（Iris pseudacorus L.）、狭叶香蒲（Typha angustifolia L.）和铜绿微囊藻（Microcystis aeruginosa）共生培养的实验方法研究了不同质量浓度黄菖蒲、狭叶香蒲对铜绿微囊藻的化感作用。结果表明，黄菖蒲在质量浓度大于10 g/L时对初始密度为1.0×10⁷ ind/mL的铜绿微囊藻具有较好的抑制作用，表现为黄菖蒲质量浓度为10、20和40 g/L时，第15天对铜绿微囊藻的抑制率分别为30.1%、51.8%和84.0%；狭叶香蒲在质量浓度大于20 g/L时对铜绿微囊藻有明显的抑制作用，表现为狭叶香蒲质量浓度为20 g/L和40 g/L时，第15天对铜绿微囊藻的抑制率分别为34.2%和77.7%，实验过程中，铜绿微囊藻叶绿素a含量逐渐减少，而藻密度、SOD活性及MDA含量先增加后逐渐降低，表明经过一段时间持续地化感胁迫，黄菖蒲和狭叶香蒲可以诱导铜绿微囊藻产生氧化胁迫，导致细胞结构严重损伤和叶绿素大量分解，从而强烈抑制铜绿微囊藻的生长。     

(M)VOC and composting facilities. Part 1: (M)VOC emissions from municipal biowaste and plant refuse

GOAL, SCOPE AND BACKGROUND: Malodorous volatiles derived from the decomposition of biowaste within the process of composting might pose a risk to human health. Different techniques of process engineering have been developed to minimise the burden of malodorous compounds in air possibly affecting compost workers and residents in the vicinity. METHODS: In the present study, three different composting facilities were examined for the emission of volatiles to estimate the impact of process engineering on the dispersal of odorous compounds and to discuss its relevance for human health. RESULTS AND DISCUSSION: Concentrations of single compounds belonging to alcohols, ketones, furanes, sulfur-containing compounds and especially terpenes ranged from 10(2) up to nearly 10(6) ng/m3 depending on the sampling sites and the process engineering. The ratio of MVOC and total VOC measured changed throughout the process of biodegradation. A certain combination of volatile compounds coincided with the occurrence of typical compost odour. CONCLUSION: The type of process engineering seemed to have a major impact on the emission of volatiles, as amounts of (microbial) volatiles emitted were characteristic for the different techniques used. Thus, the MVOC emission basically depends on the degree of biodegradation. It is likely that the concentrations workers are exposed to can have an impact on human health. RECOMMENDATIONS AND OUTLOOK: It is obvious that less sophisticated types of process engineering give rise to greater amounts of bioaerosols and volatiles and, therefore, technical devices have to be improved and controlled regularly to minimise adverse health effects on workers.     

绿色荧光蛋白分子标记在环境微生物学研究中的应用

绿色荧光蛋白(green fluorescent protein,GFP)分子标记是现有遗传标记中最简单方便的一种方法，GFP及GFP突变体在微生物降解污染物、生物膜菌群构架、环境生态学和环境检测生物传感器等研究领域取得了很好的应用效果。