3种镉超富集植物毛状根体系对镉胁迫响应的比较

近年来,转基因毛状根组织被越来越多地应用于重金属和有机污染物的植物修复技术研究中,已成为进行污染物毒性响应机制研究的便捷的实验室工具。为了探究龙葵、油菜、芥菜3种镉(cadmium,Cd)超富集植物对Cd毒性胁迫响应的差异,以诱导出的3种植物毛状根为研究材料,从毛状根的生长状态、富集Cd的能力、根组织细胞的凋亡程度和抗氧化酶活性等方面进行了探讨。结果表明:Cd浓度为0~50μmol·L-1时,龙葵、油菜、芥菜毛状根受Cd毒害的影响都不明显;Cd浓度为75~100μmol·L-1时,龙葵、油菜、芥菜毛状根均表现出对Cd胁迫的防御响应。在较高的Cd浓度(100μmol·L-1)下,龙葵毛状根的生物量受Cd毒害的影响最小,芥菜次之,油菜受影响最大;同时龙葵毛状根富集的Cd含量最高(745.0μg·g-1),芥菜次之(681.4μg·g-1),油菜最差(505.2μg·g-1)。龙葵、油菜、芥菜毛状根在Cd胁迫下的细胞凋亡水平均随Cd浓度的升高而升高,当Cd浓度为100μmol·L-1时,龙葵毛状根比油菜和芥菜毛状根的细胞凋亡程度均低。同时3种植物毛状根在不同浓度Cd处理下抗氧化酶活性的变化有一定差异。从上述结果综合来看,龙葵毛状根受Cd毒害的影响最小、富集Cd的能力最好,是进一步开展Cd超富集植物转基因改造研究的较好的实验室载体。     

Application of treated wastewater and digested sewage sludge to obtain biodiesel from Helianthus annuus L. seeds oil

Waste from wastewater treatment plants (WWTP) for Helianthus annuus L. production may be a viable solution to obtain biodiesel. This study achieved two objectives: assess the agronomical viability of waste (wastewater and sludge) from the Alcázar de San Juan WWTP in central Spain for H. annuus L. production; use H. annuus L. seeds grown in this way to obtain biodiesel. Five study plots, each measuring 6 m × 6 m (36 m²), were set up on the agricultural land near the Alcázar de San Juan WWTP. Five fertilizer treatment types were considered: drinking water, as the control; treated wastewater; 10 t ha^?1 of air-dried sewage sludge; 20 t ha^?1 of air-dried sewage sludge; 0.6 t ha^?1 of commercial inorganic fertilizer. Soil, irrigation water, sewage sludge, crop development and fatty acid composition in achenes oil were monitored. The 20 t ha^–1 dose of sewage sludge proved effective to grow H. annuus L. with similar results to those grown with a commercial fertilizer. However, precautions should be taken when irrigating with wastewater because of high salinity and nutrient deficiency. Sunflower oil was composed mostly of linoleic and oleic acid. The remaining fatty acids were linolenic, estearic, nervonic, palmitoleic, and palmitic.     

污水处理厂剩余污泥对凤仙花和万寿菊生长的影响

采用盆栽方式,通过对花卉植物生长状况和各项生理指标的考察,研究了不同污泥施用比对凤仙花(Impatiens balsamina)和万寿菊(Tagetes erecta L.)生长的影响。结果表明,污泥施用比不高于5%(质量分数)时对两种花卉植物发芽有促进作用。在前期,对照组凤仙花和万寿菊生长较好,其株高、叶绿素和可溶性糖含量高于污泥施用组,丙二醛(MDA)含量低于污泥施用组。而在后期,污泥的施用对两种花卉生长促进作用明显,污泥施用组的两种花卉植物株高和各项生理指标优于对照组,尤其是开花状况显著好于对照组。凤仙花和万寿菊较优的污泥施用比分别为3%~5%和1%~5%。     

The effects of residual tetracycline on soil enzymatic activities and plant growth

A pot trial was carried out to investigate the adverse effects of tetracycline (TC) on soil microbial communities, microbial activities, and the growth of ryegrass (Lolium perenne L). The results showed that the presence of TC significantly disturbed the structure of microbial communities and inhibited soil microbial activities in terms of urease, acid phosphatase and dehydrogenase (p < 0.05). Plant biomass was adversely influenced by TC, especially the roots with a reduction of 40% when compared with the control. Furthermore, TC decreased the assimilation of phosphorus by the plant although the concentration of phosphorus was increased by 20% due to decreased plant biomass. TC seemed to increase the concentration of dissolved organic carbon (by 20%) in soil. The findings implied that the agricultural use of animal manure or fishpond sediment containing considerable amounts of antibiotics may give rise to ecological risks.     

Is corporate social responsibility possible in the mining sector? Evidence from Catalan companies

This paper examines the role and diffusion of corporate social responsibility (CSR) management, especially in relation with the adoption of other management systems, in small and medium sized companies in the surface mining industry in Catalonia (Spain). Specifically, it identifies the most salient CSR practices, procedures and metrics and the profiles of companies more prone to adopt them. To fulfill this aim, a survey has been conducted. Results show that mining companies are familiar with CSR practices, but there is not much formalization of procedures and measurement systems of CSR yet. Results show that the majority of socially responsible practices are related to environmental issues and therefore there is a relation between CSR and the application of environmental management systems. The analysis reveals that the management of CSR activities improves with the diffusion of knowledge on CSR practices. A second survey collected the opinion of professional associations in the sector. Respondents indicate that an improvement in CSR management will lead to a better global competitive position.     

Some observations on copper yields and ore grades

The paper examines trends in the average copper content of mined ores over the years. It has tended to decline over the long term, but by no means evenly. US averages are not typical of global averages, at least in the past four decades. Those have been both higher, and less volatile than in the US. One reason for falling averages is a change in the type of deposit mined, with a rise in the share of relatively low grade porphyry deposits. The different nature of their deposits is reflected in marked differences in grades between the different continents. African and Australian average grades are higher than the global average, and changes in the share of Central Africa in global output have affected the global average grade. Yields are have been consistently lower in North America than elsewhere, and Latin American average grades have trended downwards, reflecting both the ageing of mines and the rising share of production from porphyry deposits. Typically the yield of mines declines over time as mining proceeds. The average copper content of ore deposits is usually below the average yield of the ore accessed in the early years of production. The initial grades of new mines have not declined over the past forty years, and there has been no perceptible tendency for the average grade of porphyry deposits brought into production to decline over time. There is no apparent correlation between average grade and deposit size, but mine operators tend to exploit economies of scale to offset low grades. The relationship between the annual percentage yields (the head grade) and the reserve grades of deposits is not static. In recent years head grades have fallen closer to reserve grades. The relationship may be affected by movements in metal prices. Although the evidence about the influence of prices is not clear-cut, it does suggest that prices and cut-off grades may be inversely related. As many ores contain other valuable metals besides copper, copper yields will sometimes be subordinated to the extraction of these other metals. Copper equivalent grades have not moved in the same way as copper grades alone.     

Enclave development and ‘offshore corporate social responsibility’: Implications for oil-rich sub-Saharan Africa

This paper critically reflects on the challenges of engaging, proactively, in Corporate Social Responsibility (CSR) in oil-rich sub-Saharan Africa. Most of the region's oil production takes place in enclave-type environments offshore and in countries ruled by autocratic governments which generally exert minimal pressure on companies to embrace CSR. With companies having little sense of who to target in their local economic development policies and programs, there is always a possibility of ‘offshore CSR’ – recognized here as potentially-effective ideas for improving social welfare that linger within the enclave and never fully materialize – surfacing. The aim is to conceptualize and broaden understanding of the challenge of developing CSR programs in these settings, where there are no clear linkages to communities or local economies more generally.     

Corporate Social Responsibility in the extractive industries: Experiences from developing countries

This paper introduces a special issue on ‘Corporate Social Responsibility in the extractive industries: experiences from developing countries’. Drawing upon case study analysis from Latin America, sub-Saharan Africa and Asia, the papers in this issue broaden understanding of how multinational mining and oil and gas companies have embraced the CSR challenge and responded to criticisms of their performance in developing countries. This paper provides an introduction to the debate on CSR in the extractive industries in developing countries, reviewing the key issues examined on this subject to date.     

微量元素对牛粪低温厌氧发酵的影响

为考察较低温度(<17℃)条件下添加微量金属元素对厌氧发酵产气量的影响,在发酵底物TS(含固率)为10%下采用10 L玻璃瓶作反应器,以牛粪为原料,向厌氧生物反应器中分别添加MnSO4、FeSO4·7H2O、电解锰渣,分析了厌氧消化系统运行过程中的产气量、COD(化学需氧量)和pH的变化。结果表明,锰元素能促进低温下牛粪的厌氧发酵,加速反应启动。当添加6 g MnSO4、100 g电解锰渣时,单位质量VS产气率分别为0.26 mL/g和0.64 mL/g,添加6 g FeSO4·7H2O与空白对照组均未见明显产气。