过渡金属Fe、Co、Ni介孔分子筛MCM-41催化剂的制备及其氧化性能

本研究用直接法和后处理法合成了不同过渡金属(Fe、Co、Ni)负载的介孔分子筛载体材料MCM-41,并利用Al对分子筛进行了改性,制备了Fe/Al复合催化剂,对上述材料进行了表征.研究了这些非均相催化剂对染料活性艳蓝KN-R的催化氧化脱色,分别研究了催化剂制备方法、过渡金属种类及负载量对KN-R脱色效率的影响,并考察了所制得催化剂的稳定性和重复利用性.结果表明,直接法合成的催化剂具有较高的催化性能及较低的金属溶出量,负载铁(Ⅱ)的催化剂对染料的催化降解性能要远高于钴(Ⅱ)和镍(Ⅱ)负载型催化剂,催化氧化活性随金属负载量的提高而显著升高.Al改性进一步提高了催化剂的活性,在pH=2.5,氧化剂H_2O_2投加剂量为50.0 mmol·L~(-1),催化剂剂量为4.0 g·L~(-1)的条件下,反应30 min,对初始浓度为250 mg·L~(-1)的KN-R染料的脱色率均可达95%以上,矿化率达60%以上.当Al/Si为0.21,Fe负载量为23.6 mg·g~(-1)时,在10 min内可将250 mg·L-1的KN-R完全脱色.经过3次循环使用后,上述催化剂仍能表现出良好的性能,但进一步循环使用,催化活性下降.     

多针-水电极直流电晕放电染料废水脱色

采用多针-水电极反应器,研究了直流电晕放电对活性艳蓝KN-R染料废水的脱色,考察了放电电压、初始pH值和初始浓度对活性艳蓝脱色的影响,通过对液相活性物质(O3和.OH)浓度的考察探讨了脱色机理.结果表明,多针-水电极直流电晕放电对活性艳蓝脱色效果明显;放电电压、溶液初始pH值对活性艳蓝脱色效果的影响与其对液相O和.OH浓度的影响一致;.OH和O是促使RBB脱色的主要因素.     

低传质阻力渗流式纳米电极电化学反应器处理活性艳蓝X-BR

采用渗流式电化学反应器,以碳纳米管和活性碳纤维作为反应器的阳极.选取活性艳蓝X-BR模拟废水作为实验对象,计算电化学过程的传质系数,考察电压、pH值和电解质对活性艳蓝脱色的影响,在优化条件下(电压为8V,pH=2,电解质浓度为1g·l-1),对浓度为200mg·l-1活性艳蓝X-BR的脱色率可达90%以上.     

固定化无花果曲霉对活性艳蓝KN-R的脱色

采用海藻酸钙法固定不同状态无花果曲霉，形成活菌固定化小球和死菌固定化小球。同时考察了不同因素如培养时间、温度、pH、染料浓度对活性艳蓝KN-R的脱色影响。试验结果表明：在33℃、pH为5．0、150r／min的振荡条件下，经66h它对活性艳蓝KN-R的脱色达到最佳效果。两种不同状态固定化小球的脱色率有较大的差别，其中活菌固定化小球的脱色率明显高于死菌固定化小球。其中活菌固定化小球经3次脱色后能重复使用，脱色率仍达79．8％。     

微米气泡强化臭氧氧化的作用机理研究

采用微米气泡系统(平均粒径约为58 μm)和普通的鼓泡系统进行对比研究微米气泡对臭氧氧化的强化作用机理.在相同的进气流率下,采用微米气泡体系臭氧在水中的传质系数和利用率是鼓泡系统的1.6-2.7倍和2.3-3.2倍.利用臭氧氧化模拟活性艳蓝KN-R废水(100 mg·l-1)的实验结果表明,染料在微米气泡体系中的脱色速率高于鼓泡系统,二者达到99%脱色效率所需的时间分别为30 min和60 min.在同样的脱色速率下,染料在微米气泡系统中的TOC去除率较大,说明微米气泡不仅能够提高臭氧的传质速度,而且可以强化臭氧的氧化能力.     

UV-vis/草酸铁/Fenton体系降解蒽醌染料

以活性艳蓝KN—R作为研究对象,考察了处理活性艳蓝KN-R的主要影响因素。在固定染料浓度为100 mg/L时,得到氧化体系的最佳用量比值为ρ(Fe2+):ρ(H2O2):ρ(H2C2O4)为1:15:1.5。在最佳条件下,脱色率达到95%以上,COD和TOC去除率分别达到87.7%和66.8%。活性艳蓝KN-R脱色的动力学模型为拟一级反应模型。     

纳米TiO_2多孔微粒阳光催化降解活性艳蓝染料

首次利用高分子悬浮聚合与溶胶-凝胶法相结合的技术,成功地制备不同孔结构的TiO2多孔微粒,并对其光催化降解活性艳蓝KN-R的染料溶液pH、无机阴离子、光强、通空气等影响因素进行了系统研究。结果表明:强酸性条件有利于染料在催化剂表面的吸附,而强碱性条件有利于催化反应的进行;常见无机阴离子Cl-、SO42-,对染料降解有不同程度的抑制作用;染料降解效率随光强增加而提高;光降解动力学结果表明:TiO2多孔微粒对活性艳蓝KN-R染料的光催化降解反应符合一级反应动力学;降解时持续通空气有利于降解效率的提高。实验证明所制得的微粒具有良好的光催化降解效果和重复使用性能。     

微电解对不同结构染料脱色效果的研究

采用微电解法研究了染料脱色效率与染料结构的关系.结果表明,脱色的难易程度从染料结构看,依次为偶氮型、蒽醌型＞金属络合型＞半菁阳型.在pH值为5.7-6.0,铁炭比为2:1时,处理效果最好,对100mg·l-1的摸拟染料废水处理1h后,脱色率达到90%以上.     

多孔陶瓷球负载纳米晶粒二氧化钛光催化剂的制备及光催化活性

以多孔陶瓷球为载体,采用溶胶-凝胶法在其表面进行纳米TiO2薄膜负载,制备了多孔陶瓷球负载纳米晶粒二氧化钛光催化剂,经X射线衍射法(XRD)等手段对其表征结果表明,复合载体经500℃焙烧后,TiO2以锐钛矿晶型存在。对催化剂降解活性艳蓝溶液的催化活性进行研究表明,催化剂在5 h内可完全降解活性艳蓝染料。     

合成锰钾矿型化合物对偶氮染料的脱色研究

利用合成锰钾矿型化合物对酸性橙Ⅱ染料废水进行了脱色研究,讨论了初始溶液酸度、样品投加量、样品粒径大小、反应时间、反应温度等实验条件对脱色率的影响;在最佳脱色条件为:25℃条件下,pH值为2.9,粒径160-200目,锰钾矿投加量0.10g,反应2h,对50ml浓度为400mg·l-1酸性橙Ⅱ模拟废水的脱色率可达到95%以上,处理后废水色度为25倍,完全达到了<纺织染整工业污染物排放标准>(GB4287-1992)中的一级标准.通过反应前后锰钾矿比表面积的测定及Mn(Ⅱ)溶出试验研究结果表明,染料与锰钾矿颗粒物的界面发生了氧化还原反应,使染料的发色基团破坏而导致其脱色;另外锰钾矿会吸附小分子物质.据此推断染料废水的脱色是锰钾矿型化合物的吸附性和氧化性共同作用的结果.     

Achieving Open Access to Conservation Science

Conservation science is a crisis discipline in which the results of scientific enquiry must be made available quickly to those implementing management. We assessed the extent to which scientific research published since the year 2000 in 20 conservation science journals is publicly available. Of the 19,207 papers published, 1,667 (8.68%) are freely downloadable from an official repository. Moreover, only 938 papers (4.88%) meet the standard definition of open access in which material can be freely reused providing attribution to the authors is given. This compares poorly with a comparable set of 20 evolutionary biology journals, where 31.93% of papers are freely downloadable and 7.49% are open access. Seventeen of the 20 conservation journals offer an open access option, but fewer than 5% of the papers are available through open access. The cost of accessing the full body of conservation science runs into tens of thousands of dollars per year for institutional subscribers, and many conservation practitioners cannot access pay‐per‐view science through their workplace. However, important initiatives such as Research4Life are making science available to organizations in developing countries. We urge authors of conservation science to pay for open access on a per‐article basis or to choose publication in open access journals, taking care to ensure the license allows reuse for any purpose providing attribution is given. Currently, it would cost $51 million to make all conservation science published since 2000 freely available by paying the open access fees currently levied to authors. Publishers of conservation journals might consider more cost effective models for open access and conservation‐oriented organizations running journals could consider a broader range of options for open access to nonmembers such as sponsorship of open access via membership fees. Obtención de Acceso Abierto a la Ciencia de la Conservación     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.     

Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters

Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.     

Some polyphagous Homoptera gain protection from their natural enemies by feeding on the toxic plantsSpartium junceum andErythrina corallodendrum (Leguminosae)

Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.     

A palaeo-hydrogeological model for arsenic contamination in southern and south-east Asia

An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.     

Sequestration of cucurbitacin analogs by New and Old World chrysomelid leaf beetles in the tribe Luperini

Summary Two South American polyphagous leaf beetles,Diabrotica speciosa andCerotoma arcuata, selectively accumulated the bitter tasting compound 23,24-dihydrocucurbitacin D in their body after ingesting root tissues of cucurbit plants. Similarly, three Asian Cucurbitaceae-feeding specialists in the genusAulacophora were found to sequester the same compound. Cucurbitacin analogs were shown to deter feeding by a bird predator, indicating an allomonal role for these compounds in cucurbitacin-associated chrysomelid leaf beetles both of New and Old Worlds. The strong affinity to cucurbitacins, selective sequestration of the analogs and consequent protection from predators suggested an ecological adaptation mechanism developed in common among these two geographically isolated subtribes in the Luperini.     

Effects of Controlled Fire and Livestock Grazing on Bird Communities in East African Savannas

Abstract: In East Africa fire and grazing by wild and domestic ungulates maintain savannas, and pastoralists historically set fires and herded livestock through the use of temporary corrals called bomas. In recent decades traditional pastoral practices have declined, and this may be affecting biodiversity. We investigated the effects of prescribed fires and bomas on savanna bird communities in East Africa during the first and second dry seasons of the year (respectively before and after the rains that mark the onset of breeding for most birds). We compared abundance, richness, and community composition on 9‐ha burned plots, recently abandoned bomas, and control plots in the undisturbed matrix habitat over a 3‐year period. Generally, recently burned areas and abandoned bomas attracted greater densities of birds and had different community assemblages than the surrounding matrix. The effects of disturbances were influenced by interactions between primary productivity, represented by the normalized difference vegetation index, and time. Bird densities were highest and a greater proportion of species was observed on burned plots in the months following the fires. Drought conditions equalized bird densities across treatments within 1 year, and individuals from a greater proportion of species were more commonly observed on abandoned bomas. Yearly fluctuations in abundance were less pronounced on bomas than on burns, which indicate that although fire may benefit birds in the short term, bomas may have a more‐lasting positive effect and provide resources during droughts. Several Palearctic migrants were attracted to burned plots regardless of rainfall, which indicates continued fire suppression may threaten their already‐declining populations. Most notably, the paucity of birds observed on the controls suggests that the current structure of the matrix developed as a result of fire suppression. Traditional pastoralism appears critical to the maintenance of avian diversity in these savannas.     

Cost‐effective conservation of an endangered frog under uncertainty

How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.     

What Every Conservation Biologist Should Know about Economic Theory

Abstract: The last century has seen the ascendance of a core economic model, which we will refer to as Walrasian economics. This model is driven by the psychological assumptions that humans act only in a self‐referential and narrowly rational way and that production can be described as a self‐contained circular flow between firms and households. These assumptions have critical implications for the way economics is used to inform conservation biology. Yet the Walrasian model is inconsistent with a large body of empirical evidence about actual human behavior, and it violates a number of basic physical laws. Research in behavioral science and neuroscience shows that humans are uniquely social animals and not self‐centered rational economic beings. Economic production is subject to physical laws including the laws of thermodynamics and mass balance. In addition, some contemporary economic theory, spurred by exciting new research in human behavior and a wealth of data about the negative global impact of the human economy on natural systems, is moving toward a world view that places consumption and production squarely in its behavioral and biophysical context. We argue that abandoning the straightjacket of the Walrasian core is essential to further progress in understanding the complex, coupled interactions between the human economy and the natural world. We call for a new framework for economic theory and policy that is consistent with observed human behavior, recognizes the complex and frequently irreversible interaction between human and natural systems, and directly confronts the cumulative negative effects of the human economy on the Earth's life support systems. Biophysical economics and ecological economics are two emerging economic frameworks in this movement.     

Effects of Coffee Management on Deforestation Rates and Forest Integrity

Knowledge about how forest margins are utilized can be crucial for a general understanding of changes in forest cover, forest structure, and biodiversity across landscapes. We studied forest‐agriculture transitions in southwestern Ethiopia and hypothesized that the presence of coffee (Coffea arabica)decreases deforestation rates because of coffee's importance to local economies and its widespread occurrence in forests and forest margins. Using satellite images and elevation data, we compared changes in forest cover over 37 years (1973–2010) across elevations in 2 forest‐agriculture mosaic landscapes (1100 km² around Bonga and 3000 km² in Goma‐Gera). In the field in the Bonga area, we determined coffee cover and forest structure in 40 forest margins that differed in time since deforestation. Both the absolute and relative deforestation rates were lower at coffee‐growing elevations compared with at higher elevations (?10/20% vs. ?40/50% comparing relative rates at 1800 m asl and 2300–2500 m asl, respectively). Within the coffee‐growing elevation, the proportion of sites with high coffee cover (>20%) was significantly higher in stable margins (42% of sites that had been in the same location for the entire period) than in recently changed margins (0% of sites where expansion of annual crops had changed the margin). Disturbance level and forest structure did not differ between sites with 30% or 3% coffee. However, a growing body of literature on gradients of coffee management in Ethiopia reports coffee's negative effects on abundances of forest‐specialist species. Even if the presence of coffee slows down the conversion of forest to annual‐crop agriculture, there is a risk that an intensification of coffee management will still threaten forest biodiversity, including the genetic diversity of wild coffee. Conservation policy for Ethiopian forests thus needs to develop strategies that acknowledge that forests without coffee production may have higher deforestation risks than forests with coffee production and that forests with coffee production often have lower biodiversity value. Efectos de la Administración Cafetalera sobre las Tasas de Deforestación y la Integridad de los Bosques