A sandy loam soil as a natural control for Pb contamination

The Pb (II) adsorption/desorption mechanism onto a natural sandy loam soil was studied by batch experiments at different pHs (3.0, 4.5, 6.0), at different ionic strength (0, 0.02 and 0.1 M) and with different electrolytes solutions of NaCl, NaAcO and NaNO₃. Pb was strongly adsorbed onto the soil due to the formation of a mix of inner-sphere and outer-sphere complexes. Experimental adsorption data fitted Freundlich and Langmuir isotherms. The desorption results with 0.1 M Mg (NO₃)₂ and 0.1 M NaAcO solutions corroborated the mechanisms proposed. The strong binding of Pb (II) to high affinity sites on soil minerals seems to be responsible for the extent of hysteresis. The sandy loam soil under study thus constitutes a natural control for Pb contamination.     

粮食筒仓粉尘爆炸的安全措施

介绍了粮食筒仓粉尘爆炸的条件及爆炸的主要地点。提出了从设计、管理等方面采取的主要安全措施。     

Assessment of tomato Mediterranean production in open-field and standard multi-tunnel greenhouse,with compost or mineral fertilizers,from an agricultural and environmental standpoint

This study presents detailed and comprehensive inventories on the horticultural production of tomato using compost (CM) or mineral fertilizers (M), in both open-fields (OF) and greenhouses (GH), providing information on the environmental impacts and assessing the agronomic viability of the four cultivation options. Life cycle assessment (LCA) was used to calculate the potential environmental impacts of the tomato production cycle per ton of product. The stages in the assessment included: mineral and organic fertilizers production, fertilizers transport, cultivation stage and greenhouse stage. The data were obtained experimentally in pilot fields and in an industrial composting facility using municipal organic waste, both located in the Mediterranean area. The results indicate that replacing a fraction of the mineral fertilizers dosage with compost is a good option, as this did not alter yield or fruit size parameters. Greenhouse protection increased infrastructure materials requirements but enhanced harvest by almost 50% and reduced the water and pesticides requirement. Compost production and greenhouse stages were the most impacting stages. Without subtracting the avoided burdens by composting and not dumping organic waste, the cultivation option OF_M had the lowest and OF_CM the highest impact. When avoided burdens were taken into consideration, the environmental impacts of the four cultivation options varied, depending on the impact category, with bigger differences due to fertilization as a variable rather than the production system.     

Differential activity of non-fluorinated and fluorinated analogues of the European corn borer pheromone

Summary.  The differing antagonist activity of (Z)-13-hexadecen-2-one (Z11 – 14 :MK, 1) and its 1,1,1-trifluoro derivative (Z11 –14 :TFMK, 2), two closely related analogues of the European corn borer pheromone Ostrinia nubilalis (Z strain), and their rationale is reported. Both chemicals exhibited some electrophysiological activity, and topical application of 10 pg of pheromone analogue on male antennae was sufficient to induce significantly lower depolarization responses to the pheromone versus untreated insects. In a wind tunnel, the number of European corn borer males attracted to sources containing mixtures of 1 + pheromone in ratios ≥ 1 :1 was significantly lower than the number attracted to a source containing pheromone alone. Source contact behaviour was dramatically impaired when the 1 + pheromone blend reached a ratio of 10 :1, in which only 2% of males displayed source contact in the presence of antagonist. When compound 1 was present at the source, males usually flew upwind with occasional downwind reversals; when compound 2 was present at the lure, males performed wider crosswind reversals, with little progress toward the source. In the field, traps baited with mixtures of both compounds with the pheromone in ratios of 5 :1 and 10 :1 elicited a significantly decreased number of male catches. In esterase inhibition assays, compound 2 was a potent inhibitor (IC₅₀ = 70 nM), whereas the non-fluorinated compound 1 was not. The different activity of both compounds is presumed to be due to different mechanisms of action; considerations for using methyl ketone analogues as new behavioural antagonists of the pheromone are outlined.     

资源综合利用与环保和经济的协调发展

保护环境究其实质意义上来讲就是保护生产力,保护资源,保护发展,实现经济及社会可持续发展,这是一种全新的发展观念。本文从此出发,说明了要搞好资源优化配置和综合作用,以促进环保和经济建设协调发展。     

菲、3-甲基菲和菲醌对河鲀(Takifugu rubripes)幼鱼肝组织损伤的比较研究

原油毒性主要源于多环芳烃(PAHs),而烷基化多环芳烃是PAHs的主要组分,氧化衍生物是PAHs降解和代谢过程所产生的重要产物。为评估比较烷基PAHs和氧化PAHs与其母体化合物对海洋生物的毒性,本研究以菲、3-甲基菲和菲醌为研究对象,对海洋经济鱼种——红鳍东方鲀(Takifugu rubripes)幼鱼进行了肝损伤评价。结果显示,线粒体、内质网是对上述3种化合物最为敏感的细胞器;3种化合物对肝损伤的表现形式不同:1.菲导致线粒体数量增加形态改变、内质网减少纹理模糊、出现脂滴、细胞空泡化、出血,2.3-甲基菲导致内质网减少、出现脂滴、细胞空泡化、出血,3.菲醌导致线粒体和内质网水肿、出现脂滴及细胞空泡化;随化合物浓度升高,肝损伤程度加重;同一浓度下,不同化合物损伤程度也有差异,总体趋势为菲醌3-甲基菲菲。上述结果表明,PAHs衍生物的毒性可能强于其母体化合物;除浓度外,化合物的结构可能对其毒性有重要影响。     

Sociality, exotic ectoparasites, and fitness in the plural breeding rodent Octodon degus

Social animals are susceptible to high infection levels by contact-transmitted parasites due to increased conspecific interaction. Exotic parasites are known to have adverse consequences on native hosts. We examined the relationship between social group size and exotic ectoparasite loads, and adult infection levels with per capita fitness and offspring survival in the plural breeding rodent Octodon degus in central Chile. Degus at our site were almost entirely infected by two exotic ectoparasites: the fleas Leptopsylla segnis and Xenopsylla cheopis. Neither group size nor number of females per group predicted the abundance of either exotic flea species. The per capita number of pups (per capita fitness) that emerged from burrow systems used by known social groups was negatively correlated with abundance of L. segnis but not X. cheopis. On adults, X. cheopis abundance was three times greater than L. segnis but was not significantly correlated with per capita fitness. In females, L. segnis abundance was negatively correlated with peak body mass during pregnancy. Adult ectoparasite load was not correlated with offspring survival. Based on these results, we hypothesize that high infection levels of L. segnis result in decreased reproductive fitness of adult female degus but are not a cost of sociality because parasite loads are not predicted by social group size. Further work is needed to experimentally test this hypothesis and to determine if L. segnis serves as a vector for a deleterious pathogen. Lastly, the lack of native ectoparasites may explain why a previous study at our site determined that behavioral adaptations needed to cope with high ectoparasite burdens (e.g., grooming) are not extensive in degus; they simply have not had the coevolutionary time needed for selection of these behaviors.     

印染废水生化出水中有机污染物特性及在硫酸镁混凝过程中的去除行为

以某印染废水二级生化出水为研究对象,考察了生化出水中有机污染物中各组分含量、分子量分布特点等特性,以及各类有机物在硫酸镁混凝处理过程中的去除行为.实验结果表明,该印染废水的生化出水溶解性有机物的主要成分是疏水性物质,以溶解性有机碳（DOC）表征时占总DOC的78%,其中非酸疏水物质约占46%,而以UV254表征时约占总55%,以美国染料生产协会色度值（ADMI7.6）表征时为97%,其中以非酸疏水物质的贡献最大,达到66%,并且非酸疏水物质中不饱和双键或芳香环有机物的含量较高.生化出水中的DOC主要集中在小于1000 D的有机物上,占37%.在硫酸镁的最佳混凝条件下,可以有效地去除由大分子量的非酸疏水物质引起的色度,而对小分子量的有机物也有一定的去除效果.     

Atmospheric deposition of 137Cs between 1994 and 2002 at Cienfuegos, Cuba

Levels of 137Cs in total atmospheric deposition have been measured in the Cienfuegos region (Cuba) between 1994 and 2002. Samples were collected every three months, evaporated to dryness to obtain residual samples, and measured by gamma spectrometry. The 137Cs mean concentration in total deposition was 0.24 Bq m(-2) and data ranged between < 0.05 and 0.62 Bq m(-2). Precipitation rates and raintime have proved to be the most important factors controlling the concentration and depositional flux of 137Cs in the atmosphere over Cienfuegos, showing a high correlation coefficient (R = 0.93).     

Kinetics of acetyl CoA: Arylamine N‐acetyltransferase from rapid and slow acetylator fish tissues

N‐acetyltransferase (NAT) activity was determined in 100 fish (Oreochromis mossambicus) livers using 2‐aminofluorene and p‐aminobenzoic acid as substrates. Overall, the liver NAT activity of the 50 females was higher than the liver NAT activity of the 50 males. The activities (mean ± SD) of NAT from kidney, blood, intestine, and liver of males was 0.42 ± 0.11, 0.12 ± 0.03, 0.12 ± 0.08, and 1.56 ± 0.54 nmol/min/mg protein for the acetylation of 2‐aminofluorene and 0.36 ± 0.09, 0.09 ± 0.01, 0.11 ± 0.04, and 0.46 ± 0.15 nmol/min/mg protein for the acetylation of p‐aminobenzoic acid. In kidney, blood, intestine, and liver from female fish, the activities obtained were 1.60 ± 0.12, 0.35 ± 0.07, 0.15 ± 0.09, and 1.89 ± 0.50 nmol/min/mg protein for 2‐aminofluorene and 0.95 ± 0.11, 0.27 ± 0.03, 0.13 ± 0.09, and 0.57 ± 0.12nmol/min/mg protein for p‐aminobenzoic acid. Kinetic constants for arylamine N‐acetyltransferase activity in kidney, blood, intestine, and liver from fish with rapid, intermediate, and slow acetylator activity were determined. Apparent K _m and V _max values for 2‐aminofluorene were 5.5 and 7‐fold higher for liver than for the other tissues. Apparent K _m and V _max values for p‐aminobenzoic acid were 3.5 and 4.7‐fold higher for liver than for the other tissues. Based on the 2‐aminofluorene NAT activity of liver, there appears to be a polymorphism in NAT activity with 16 rapid, 28 intermediate, and 56 slow acetylators among the 100 fish assayed. This is the first demonstration of acetyl CoA: arylamine N‐acetyltransferase activity in fresh water fish and could lead to the development of a fish model for monitoring the effect of pollution of water environments on native species.