四川省卧龙地区土壤中二噁英类化合物和多氯萘的海拔梯度分布及对牦牛的毒性风险评价

初步研究了四川省卧龙地区5个不同海拔高度的表层土壤和2个牦牛样品中二噁英/呋喃(PCDD/Fs)、共平面多氯联苯(co-PCBs)和多氯萘(PCNs)的分布特征、来源、毒性当量以及生态风险状况.土壤样品中总2,3,7,8-PCDD/Fs的含量范围为2.48-4.30 pg·g-1dw,平均3.50 pg·g-1dw,最高含量在海拔3927 m的塘房.co-PCBs的总含量平均为9.14 pg·g-1dw,最高值在海拔4487 m的垭口.总2,3,7,8-PC-DD/Fs和总co-PCBs含量随海拔高度的变化表现出正相关关系.不同海拔高度土壤中的PCDD/Fs和co-PCBs异构体的分布相似,表明具有相同的来源.总PCNs与海拔梯度呈负相关关系,最高含量出现在海拔3345 m的贝母坪,平均21.4 pg·g-1dw,主要以3.氯为主.土壤中PcDD/Fs毒性当量浓度范围为0.29-0.43pg TEQ·g-1dw.牦牛肉和牦牛组织中PcDD,/Fs总浓度分别为27.5和23.6 pg·g-1脂肪,毒性当量浓度为4.04和4.07 pg TEQ·g-1脂肪.结果表明,牦牛中的PCDD/Fg,co-PcBs和PCNs不大可能对卧龙地区人群导致严重的负面效应.     

Behavioral aspects of sperm competition in cuttlefish, Sepia officinalis (Sepioidea: Cephalopoda)

Sexual selection studies in cephalopods indicate that sperm competition is a central feature of their mating systems, yet this has not been studied experimentally in any detail. In 1998 we staged 20 matings of the cuttlefish, Sepia officinalis L., in the laboratory. Males rapidly initiated mating in the “head-to-head” position, with no apparent courtship. Mating lasted an average of 10 min (range 7 to 14 min). For the first 6 min (on average 63% of the mating duration), the male flushed strong jets of water directly at the female's buccal membrane, which sometimes resulted in the expulsion of parts of spermatangia placed there in recent matings. Then, in a single discrete movement that lasted an average of only 14 s, the male's modified fourth left arm – the hectocotylus – wrapped around a single large bundle of spermatophores (ca. 150 to 300) and transferred them to the female's buccal membrane. For the remainder of the mating (average 3 min, range 1.5 to 5.0 min), the hectocotylus repeatedly broke the spermatophores open, and manipulated them, so that sperm were released and many spermatangia were attached along the ventral buccal membrane, near the paired seminal receptacles. Approximately 140 spermatangia were attached in rows 3 to 5 deep around the ventral buccal membrane in a single mating; the rest were usually discarded during mating. Histology revealed that each of the seminal receptacles consists of a series of sperm storage bulbs connected by a central duct, which leads to a single pore at the surface of the buccal membrane. Baseline data on sperm motility were obtained, but the mechanism by which sperm enter the seminal receptacle remains unknown. Females seemed to initiate termination of mating, then males guarded their mates temporarily. These results, combined with other recent laboratory experiments, provide evidence that sperm competition may be a major feature of the mating system of S. officinalis. Received: 4 January 1999 / Accepted: 18 May 1999     

Ammonia emission from grassland and livestock production systems in the UK

Emissions of ammonia were measured from livestock excreta and fertilisers applied to grass swards, from grazed paddocks, from decomposing grass herbage and from an animal house containing dairy cows. Emissions from urine, dung, slurry and fertilisers were determined using a system of wind tunnels with each tunnel covering an area of 1 m(2). Emissions from grazed swards were determined using a micrometeorological mass balance method. From the results of these measurements, together with other published information, an inventory for ammonia emissions has been calculated for grassland and livestock production systems over the UK as a whole. It is estimated that emissions from grassland and cattle and sheep production amount to about 230 kt NH(3)-N annually, while emissions from pig and poultry production amount to about 40 kt and 80 kt NH(3)-N, respectively.     

Distribution of fission products in dust samples from the region of Thessaloniki, Greece, after the Chernobyl nuclear accident

The distribution of the fission products (95)Zr, (95)Nb, (103)Ru, (106)Ru (determined through (106)Rh), (125)Sb, (129m)Te, (134)Cs, (137)Cs, (140)Ba, (140)La, (141)Ce and (144)Ce has been determined in dust samples from the region of Thessaloniki, Greece, after the nuclear accident at Chernobyl. The samples studied also included (110m)Ag, not belonging to the products of (235)U fission. Samples showing higher concentrations of radionuclides also show a higher content in clay minerals, whereas samples having low concentrations of radionuclides usually contain large amounts of quartz and feldspars. Desorption and leaching experiments using solutions of chlorides of sodium, potassium, calcium and magnesium (0.5 N), as well as distilled and tap water, were also performed. Sodium and potassium chloride solutions were found to be efficient in desorbing and/or leaching of caesium and ruthenium isotopes to an extent of about 30%.     

Effects of distillery waste on the performance of Cicer arietinum L

The impact of distillery effluent in various concentrations (1, 2.5, 5, 10, 25, 50, 75 and 100%) on the seed germination, Speed of Germination Index, growth behaviour, leaf area, biomass, net primary productivity, pigment content, reproductive capacity, seed output, seed weight, seed density and the seed protein content of Cicer arietinum L. plants was investigated. The percentage and speed of germination of seeds were increasingly retarded with increase in effluent concentration and at 100% concentration there was no germination. The seedlings exhibited maximum shoot length at 5% concentration and maximum root length at 2.5% concentration. The values of root and shoot lengths, leaf area, biomass, net primary productivity, pigment content, reproductive capacity, seed output, seed weight, seed density and seed protein content in pot plants exhibited a gradual increase from the control up to 5% concentration and decreases at higher concentrations. The very high BOD load and the presence of excessive concentrations of soluble salts could be responsible for the toxicity of the effluent. The effluent at up to 5% concentration was, however, beneficial for the overall growth parameters studied and can thus be used as a liquid fertilizer.     

The sensitivity of surface waters of Great Britain to acidification predicted from catchment characteristics

Using a combination of soil, land use and geological information, a map of Great Britain has been derived which indicates the sensitivity of surface waters to acidification. For the geological information, a slightly modified version of an available map was used which indicated the sensitivity of groundwaters to acidification. For soils, 1-km databases of soil information for England and Wales and for Scotland were employed to map the soil sensitivity as determined by buffering capacity. The derived soils map was modified to take account of agricultural liming in arable and managed grassland areas using the ITE Land Classification. The final map of surface water sensitivity was obtained by using a geographic information system overlay procedure which enabled each combination of soil and geology sensitivity to be uniquely defined. The final sensitivity classification was based upon expert knowledge and the experience of a similar sensitivity mapping exercise for Wales.     

Means to improve the effect of in situ bioremediation of contaminated soil: an overview of novel approaches

Different aspects of bacterial degradation of organic contaminants in soil, and how to improve the efficiency and reproducibility is discussed in this review. Although bioremediation in principle includes the use of any type of organism in improving the condition of a contaminated site, most commonly bacteria are the degraders and other organisms, such as soil animals or plant roots, play a role in dissemination of bacteria and, indirectly, plasmids between bacteria, and in providing nutrients and co-substrates for the bacteria active in the degradation process. There are a number of different procedures that have been tested more-or-less successfully in attempts to improve reliability, cost efficiency and speed of bioremediation. The methods range from minimal intervention, such as mere monitoring of intrinsic bioremediation, through in situ introduction of nutrients and/or bacterial inocula or improvement of physico-chemical conditions, all the way to excavation followed by on site or ex situ composting in its different varieties. In the past the rule has been that more intervention (leading to higher costs) has been more reliable, but novel ideas are continuously tried out, both as a means to come up with new truly functional applications and also as a line of studies in basic soil microbial ecology. Both approaches generate valuable information needed when predicting outcome of remediation activities, evaluating environmental risks, deciding on cleaning-up approaches, etc. The emphasis of this review is to discuss some of the novel methods for which the value has not been clearly shown, but that in our view merit continued studies and efforts to make them work, separately or in combination.     

Development of a new quality fair access best value performance indicator (BVPI) for recycling services

Recycling schemes are being used worldwide to reduce the impact of municipal waste. Those using public funds are usually obliged to set performance indicators by which the standards of such schemes can be measured. In the UK, a set of statutory Best Value Performance Indicators (BVPI) must be reported annually, such as the Quality of Fair Access, which monitors the public's access to recycling facilities within 1000 m (known as BVPI 91). This work shows that BVPI 91, and performance indicators like it, quantify only very basic recycling services. A much more sensitive performance indicator is developed in this paper, labelled as the Maximum Practicable Recycling Rate Provision (MPRRP) achievable by a local authority. It indicates the percentage of local waste that could be reasonably recycled using the services provided, calculated on the basis of the average composition of the local waste, the local population coverage for collection of any materials, and nationally provided information stating how much of each material stream is generally suitable (practical) for recycling. Evidence for the usefulness of this new quantity is presented. Although this paper refers a particular performance indicator in the UK, its findings are applicable to all urban areas worldwide needing to monitor recycling service. Furthermore, the MPRRP could be used for planning purposes, and for determining the level of performance of an existing service, by comparing its predicted recycling rate to that actually obtained. Further work is now being carried out on this.     

Removal of insoluble chloride from bottom ash for recycling

In order to recycle bottom ash and use it as raw material for cement production, the removal of insoluble chloride was investigated by testing various washing techniques. The present work is also focused on investigating the properties of insoluble chlorides and determining the conditions for dissolving these compounds in order to reduce the chlorine content to the required level, i.e., less than 0.1 wt%. Within this framework, the effect of washing with water and CO2 bubbling was investigated, because the main insoluble chloride found in bottom ash, i.e., Friedel's salt, can be dissolved by CO2. Then, in order to better understand the removal of Cl, Friedel's salt was artificially synthesized by hydration and then the effect of CO2 bubbling was investigated. If all chlorides in the ash are converted into Friedel's salt by hydration, all chlorides can then be dissolved by CO2 bubbling. In addition, the effect of pH on removing the remaining insoluble chlorides was investigated by washing the ash with sulfuric acid solution. It was found that the most effective technique to reduce the Cl content to less than 1000 ppm was washing with sulfuric acid solution, while keeping the pH value at less than 4. By using this method, Friedel's salt and other insoluble chlorides were dissolved.