超声波/Fenton试剂联用降解水中的吡啶

采用超声波/Fenton联用技术降解水中的吡啶,探讨了吡啶初始浓度、反应温度、pH值、H2O2浓度、超声波声能密度和超声波频率对降解效果的影响及规律,实验发现,在所研究的吡啶初始浓度范围内,随着吡啶初始浓度的增大,其降解率减小;同时,随着反应温度、pH值、H2O2浓度和超声波声能密度的增大,吡啶的降解率增大;对于24.55kHz和30.19kHz两种频率而言,超声波频率愈高吡啶的去除率愈大,而对于30.19kHz和34.19kHz两种频率而言,吡啶去除率随频率的变化关系不明显,超声波和Fenton联用对吡啶进行降解比二者单独降解吡啶有更好的处理效果,另外,对于不同初始浓度的吡啶溶液来说,在所研究的浓度范围内,超声波/Fenton试剂联用降解吡啶的反应属于一级动力学反应,     

H2O2-Fe^2＋氧化法处理重油裂解制气废水

利用H2O2-Fe^2 氧化法处理经过生化系统处理过的重油裂解制气废水，对各种影响H2O2-Fe^2 氧化法对废水COD去除的因素进行了研究，结果显示其合适的处理条件是：废水的COD浓度为197．20～334．7lmg／L、27.5％过氧化氢加量为0．75mL／L、反应初始pH值为5．0、反应时间3h、Fe^2 加量为25mg／L、30℃反应温度。经过处理后，其COD值低于150mg／L，达到国家Ⅱ级排放标准，效果良好。     

水体中微污染磺胺嘧啶药物的氧化降解

环境中残留的微量抗生素药物对生态环境的危害和修复越来越受到人们的重视.对广泛使用的广谱抗菌素磺胺嘧啶(SD)微污染水体的Fenton氧化降解进行了研究,探讨了SD、H2O2、Fe2+质量浓度、pH和反应时间对SD降解率的影响.研究结果表明,当SD初始质量浓度为2.0 mg·L-1,水体中添加H2O2、Fe2+至质量浓度分别为30 mg·L-1和1.25 mg·L-1,反应时间为60 min时,降解率可以达到99.8%,说明Fenton法是一种有效的处理微量磺胺嘧啶带来的水体污染的修复方法.     

在烷基聚葡糖苷W/O微乳液中Novozym 435脂肪酶催化酯合成反应动力学的研究

研究了Novozym435脂肪酶在烷基聚葡糖苷形成的W／O微乳液体系中,催化正丁醇与正己酸合成酯的反应动力学．反应初始速率V0与正丁醇（ROH）和正己酸（HA）摩尔浓度的比值（CROH^0／CHA^0）有关,在CROH^0／CHA^0=0．2-17范围内,随CROH^0／CHA^0比值减小,初始速率V0增大,尤其是当CROH^0／CHA^0〈3时,V0迅速增大．其原因可能是醇浓度较高时,醇与酶结合形成的死端复合物在较高浓度酸的作用下分解,重新析出游离态酶所致．脂肪酶加入量、水相介质组成和醇的种类等对反应速率有重要影响．     

Fenton试剂氧化降解微囊藻毒素-LR

研究了Fenton试剂氧化降解微污染水体中微囊藻毒素MC-LR的效果,在H2O2浓度1.5mmol·l-1,Fe2 浓度0.10 mmol·l-1,反应温度为25±1℃,pH值为4.18及反应时间为30min的条件下,浓度为0.41mg·l-1的MC-LR去除率可以达到92.4%,降解过程符合准一级反应动力学.Fenton试剂氧化体系能有效地降解MC-LR,特别是在紫外光的照射下,MC-LR的降解速率得到大幅度提高.紫外光能促进Fe3 还原为Fe2 ,所以光助Fenton试剂氧化反应中可以使用Fe3 代替Fe2 .     

三硝基甲苯的γ-辐照降解实验研究

基于三硝基甲苯(TNT)溶液采用常规处理方法难以降解,采用60Co-γ射线对三硝基甲苯溶液进行辐照降解,研究了吸收剂量、初始浓度、溶液初始pH值、双氧水(H2O2)等因素对辐照降解效果的影响.实验结果表明,60Co-γ射线辐照能够有效地降解三硝基甲苯.三硝基甲苯溶液初始浓度为5—50 mg.L-1,当接受不超过15 kGy剂量时,三硝基甲苯的降解率可达100%,化学需氧量(COD)去除率可达55%;弱酸性和碱性环境更有利于三硝基甲苯的降解和COD的去除;加入少量H2O2时,三硝基甲苯降解率和COD去除速率均随之增加,但过高的H2O2加入量将会抑制三硝基甲苯的去除,并且加入H2O2的量愈大其抑制作用愈明显.     

激光光散射技术用于Fenton反应中Fe(Ⅲ)水解过程的研究

利用激光光散射技术，研究了不同条件下Ferton反应中Fe(Ⅲ)水解过程的粒径变化，并和一般铁盐体系中Fe(Ⅲ)水解过程进行了比较，结果表明，Fe(Ⅲ)的水解过程中，粒径变化受水解度B^*和铁盐浓度的影响，即B^*值愈大，浓度愈高，体系粒径愈大．并且在相同浓度和水解度B^*的条件下，Fenton反应生成的Fe(Ⅲ)比一般铁盐的水解聚合迅速，形成的粒径大，对采油废水进行处理的实验结果表明，Fenton体系对有机物的吸附去除效果明显优于常规铁盐体系，这可能与Fenton体系的高水解速率有关。     

206nm紫外光降解水相中的氯化三苯基锡

研究了氯化三苯基锡不同初始浓度、光照时间、初始pH值和添加H2O2等因素对光降解效果的影响.结果表明,弱酸条件更有利于氯化i苯基锡的降解;当pH=2.0时,120mg·1-1氯化三苯基锡溶液光照75min后,其降解率约为89.4%;氯化三苯基锡浓度愈低,其光降解效果愈好.在氯化三苯基锡水溶液中加入双氧水后,光照75min后光降解率基本能达到100%.根据产物GC-MS分析结果,初步探讨了氯化三苯基锡光降解的机理.     

催化氧化法预处理苯胺类废水

用Fenton试剂催化氧化法预处理染化厂含苯胺类物质的废水。对影响废水中苯胺类物质去除率的各种因素进行了考察，结果表明，在常温下当废水中苯胺类物质的含量为800mg/L时，在pH为3．5、H2O2和Fe^2 用量分别为28mmol/L和2.8mmol/L的条件下，苯胺类物质的去除率可达98.0%，COD去除率达到76％，废水的BOD5／BODcr值由0提高到0.32，显著地提高了废水的可生化性。     

Fenton试剂预处理H酸废水的影响因素及其可生化性

采用Fenton度剂预处理低浓度难降解的H酸废水,探讨了pH,Fe^2 ,H2O2,反应时间和H酸浓度对废水CODcr去除效果的影响,结果表明,各因素对废水CODcr去除效果影响较大,对CODcr为810mg.l^-1的H酸废水,Fenton试剂预处理的最佳条件;pH为5.5,3%H2O2的观加量为5%,10g.l^-1FeSO4的投加量为7%,反应时间为90min,此条件下CODcr去除率为55.3%-58.7%,可生化值CODB/CODcr从6.3%-6.7%上升到62.2%-68.4%。     

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.     

Threats to intact tropical peatlands and opportunities for their conservation

Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza‐Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land‐use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon‐dense (domed pole forest) areas. New carbon‐based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development.     

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.