Effects of Climate Change,Invasive Species,and Disease on the Distribution of Native European Crayfishes

Climate change will require species to adapt to new conditions or follow preferred climates to higher latitudes or elevations, but many dispersal‐limited freshwater species may be unable to move due to barriers imposed by watershed boundaries. In addition, invasive nonnative species may expand into new regions under future climate conditions and contribute to the decline of native species. We evaluated future distributions for the threatened European crayfish fauna in response to climate change, watershed boundaries, and the spread of invasive crayfishes, which transmit the crayfish plague, a lethal disease for native European crayfishes. We used climate projections from general circulation models and statistical models based on Mahalanobis distance to predict climate‐suitable regions for native and invasive crayfishes in the middle and at the end of the 21st century. We identified these suitable regions as accessible or inaccessible on the basis of major watershed boundaries and present occurrences and evaluated potential future overlap with 3 invasive North American crayfishes. Climate‐suitable areas decreased for native crayfishes by 19% to 72%, and the majority of future suitable areas for most of these species were inaccessible relative to native and current distributions. Overlap with invasive crayfish plague‐transmitting species was predicted to increase. Some native crayfish species (e.g., noble crayfish [Astacus astacus]) had no future refugia that were unsuitable for the modeled nonnative species. Our results emphasize the importance of preventing additional introductions and spread of invasive crayfishes in Europe to minimize interactions between the multiple stressors of climate change and invasive species, while suggesting candidate regions for the debatable management option of assisted colonization. Efectos del Cambio Climático, Especies Invasoras y Enfermedades sobre la Distribución de Cangrejos de Río Europeos Nativos     

Ultrasonically enhanced anaerobic digestion of waste activated sludge

Anaerobic digestion is increasingly applied to stabilise sludge and to reduce operating costs of the wastewater treatment plant by generating biogas, considered as a sustainable energy source. The process suffers from many drawbacks such as slow and incomplete degradation rates, the result of the slow and rate‐limiting sludge hydrolysis step, due to the low biodegradability of the cell walls and the presence of extra‐cellular biopolymers.

Methods to enhance the biogas formation should hence make the substrate more accessible to the anaerobic micro‐organisms. Research on increasing the biogas production is extensive, with low‐frequency ultrasound treatment emerging as the technical and economic most appropriate technology. Although ultrasound is now widely applied in practice, underlying phenomena and optimum operating conditions are still open to debate. Laboratory ultrasound treatment was coupled with digestion experiments (at 37°C) using 12 parallel digesters, two of them being used as control digesters with untreated sludge.

The present paper demonstrates that ultrasound treatment can – within specific ranges of energy‐input – achieve (i) an increased disintegration of the sludge, as witnessed by an increasing soluble COD‐fraction accompanied by an increasing presence of BOD; (ii) an increased release of volatile fatty acids as a result of the oxidising radicals being formed through cavitation; and (iii) a slightly reduced dewaterability of the residual sludge, needing an increased dosage of poly‐electrolyte to obtain a high degree of cake dryness.

As pre‐treatment to digestion, ultrasound enhances the biogas production by more than 40% at low specific energy‐inputs (SE), and approximately 15% at higher SE‐values.     

转基因棉花基因花粉散布频率及距离的研究

选用从国外引进的和我国自己培育的Ｂｔ基因抗虫棉和转ｔｆｄ Ａ基因抗除草剂棉花,研究了外源Ｂｔ基因和ｔｆｄ Ａ基因向周围环境遗传漂流的频率和距离。结果表明：无论是我国自行培育的转基因棉花,还是从国外引进的转基因棉花;无论是转Ｂｔ基因棉花,还是转ｔｆｄ Ａ基因棉花,导入到棉株体内的外源基因均可向周围环境漂流,其最高漂流频率为１０．４８％,最远漂流距离可达５０ｍ。防止外源基因向周围环境扩散的最有效方法是     

Modeling of the EMRAS urban working group hypothetical scenario using the RESRAD-RDD methodology

The RESRAD-RDD methodology was applied to model the short- and long-term radiation exposures after a hypothetical radiological dispersal device (RDD) event in an urban environment. It was assumed that an RDD event would result in outside surface contamination of the exterior walls and roofs of surrounding buildings, as well as associated paved areas and lawns. The contaminants also might move inside the buildings and deposit on floors and interior walls. Some important input parameters include occupancy factors, building characteristics, and weathering of surface contamination. The modeling results include predicted external dose rates, relative contributions from important surfaces, annual and cumulative doses, and radionuclide concentrations. Potential countermeasures evaluated include grass removal, soil removal, and washing of paved areas.     

超声与碱预处理低有机质剩余污泥特性分析

以某城市污水处理厂低有机质剩余污泥（VSS/SS为0.42）为对象,通过实验研究了超声与碱（NaOH和CaO）预处理对其特性的影响,分析了加碱和未加碱时污泥上清液中pH值、ORP（氧化还原电位）、SCOD、TP和NH₃-N等随超声处理时间的变化规律。结果表明,在超声处理30～120 min范围内,超声加碱处理可使污泥上清液中ORP明显下降;超声加碱处理可明显提高污泥上清液中的SCOD释放量,且加NaOH比加CaO更为明显;NaOH加超声处理可促进污泥中TP的释放,但CaO加超声处理则与此相反;无论是否加碱,超声处理对污泥上清液中NH₃-N释放影响较小;超声加碱处理剩余污泥可明显改善污泥絮体,使其更为紧密。     

超声、臭氧处理石化污水厂剩余活性污泥研究

采用超声波和臭氧处理石化污水处理厂的剩余活性污泥,促进其脱水和破解。实验结果表明,小功率超声对污泥脱水效果较好,最佳超声条件为：输出电压70 V,超声时间2 min;污泥抽滤后的含水率在试验范围内随臭氧量的增加而降低,最佳臭氧剂量为0.05 g O³/g SS。经超声处理过的臭氧化污泥要比没经超声处理过的含水率低约1%。在传统的絮凝方法下,加上超声和臭氧可以使污泥含水率再降低2%以上,减少絮凝剂用量近40%;臭氧和超声联合比单独臭氧对污泥破解效果更显著,污泥可减量约25%。臭氧投量较少时,超声破解效果更明显。     

Testing the capacity of clothing to act as a vector for non-native seed in protected areas

Although humans are a major mechanism for short and long distance seed dispersal, there is limited research testing clothing as a vector. The effect of different types of material (sports vs hiking socks), or different items of clothing (boots, socks, laces vs legs) or the same item (socks) worn in different places on seed composition were assessed in Kosciuszko National Park, Australia. Data was analyzed using Repeated Measures ANOVA, independent and paired t-tests, Multi-dimensional Scaling Ordinations and Analysis of Similarity. A total of 24,776 seeds from 70 taxa were collected from the 207 pieces of clothing sampled, with seed identified from 31 native and 19 non-native species. Socks worn off-track collected more native seeds while those worn on roadsides collected more non-native seeds. Sports socks collected a greater diversity of seeds and more native seeds than hiking socks. Boots, uncovered socks and laces collect more seeds than covered socks and laces, resulting in 17% fewer seeds collected when wearing trousers. With seeds from over 179 species (134 recognized weeds) collected on clothing in this, and nine other studies, it is clear that clothing contributes to unintended human mediated seed dispersal, including for many invasive species.     

超声/臭氧组合工艺降解乐果农药废水的实验研究

采用超声波(US)/臭氧(O3)组合工艺降解乐果农药废水,考察了pH值、O3流量、反应时间、COD浓度对处理效果的影响。结果表明,采用变频、低功率(40 W)的US设备与O3组合使用,其处理效果比单独US和O3的处理效果好,二者具有明显的协同作用;通过模拟乐果农药废水确定实验参数,考察组合工艺对实际废水的处理效果,优化工艺参数并得出最佳的实验条件:处理水量为5 L、pH3、O3流量5.20 mg/L、反应时间150 min、废水初始COD浓度4 000 mg/L,COD去除率为29.06%,B/C比由0.20提高至0.35。这表明:在较低能耗和较短时间内,该组合工艺对农药废水具有良好的预处理效果,利于后续好氧生化处理。     

利用超声波辅助提取苦杏仁精油的工艺研究

在超声波作用下,通过使用不同溶剂,研究了苦杏仁中精油的提取方法。结果表明,超声处理有利于提高苦杏仁精油的提取率。通过正交实验确定影响其收率的因素,从大到小依次为料液比、提取温度和提取时间,确定最优工艺为:乙酸乙酯和四氢呋喃的混合溶剂(1∶1,V/V)为提取剂,料液比1∶20,提取温度20°C,提取时间30min,此条件下提取率为16.20%。本研究结果为纯天然苦杏仁精油的提取工艺提供了技术参数。     

超声波强化γ-Al_2O_3催化臭氧氧化法降解2,4-二硝基苯酚

采用超声波强化γ-Al_2O_3催化臭氧氧化法降解模拟废水中的2,4-二硝基苯酚,考察了超声波对降解反应的强化作用及γ-Al_2O_3加入量、臭氧流量、超声波功率等对2,4-二硝基苯酚降解的影响.实验结果表明:2,4-二硝基苯酚在超声波强化γ-Al_2O_3催化臭氧氧化作用下的降解过程符合一级表观动力学;在2,4-二硝基苯酚质量浓度为20.00 mg/L、γ-Al_2O_3催化剂加入量为1.5g/L、臭氧流量为61 mg/min、超声波功率为300 W、反应时间为60 min时,2,4-二硝基苯酚的降解率达96.4%.