硫杆菌浸出废旧MH/Ni电池中重金属研究

生物淋滤法具有对环境友好、反应温和、运行成本低等优点,近年来主要用于回收难浸提矿石中有用金属及城市污泥有毒重金属脱除。应用氧化硫硫杆菌和氧化亚铁硫杆菌对废旧MH/Ni电池电极材料中重金属进行了生物淋滤处理可行性及工艺技术研究,考查了初始pH值、电极材料投加量、温度及底物单质硫添加量对金属Ni、Co浸出率的影响。试验结果表明:硫杆菌可以浸出电极材料中的重金属Ni和Co,初始pH值及温度对生物淋滤过程金属Ni、Co浸出率影响显著。在初始pH值1.0、电极材料质量分数为1.0%、温度30℃、底物单质硫质量浓度为4.0g·L-1条件下,经过20d生物淋滤,废旧MH/Ni电池中金属Ni和Co浸出率分别为95.7%和72.4%。     

环境条件对采矿废石中重金属溶出特性的影响

采矿废石中的重金属元素会由于废石长时间的露天堆放,受到风化、雨水侵蚀等的作用而释放出来,从而对环境产生一定的危害.以广西某锡钽铌多金属矿区采矿废石为研究对象,对采矿废石样品进行了性质鉴别,并考察了pH、温度和离子强度等环境条件对采矿废石中铅、砷、镉等重金属溶出的影响.结果表明:实验所选取的废石样品为第I类的一般工业固体废物.采矿废石中的铜、铅、镍在pH=4,镉和锌在pH=5,而砷在pH=6的条件下溶出较为明显;重金属元素砷,锌,铜,铅在离子强度为1 ms?cm-1时,浸出浓度最大,而镍和镉元素则是在0.1 ms?cm-1时出较多;砷,镉和铜在温度为35℃,镍元素在30℃,铅元素在25℃的条件下溶出质量浓度达到最大值,而锌元素的浸出质量浓度受温度的影响较小.     

镍钴采选行业废石和尾矿中重金属淋溶释放规律研究

镍钴采选废石和尾矿中重金属的溶出释放规律对矿区的重金属污染防治具有重要意义。但目前,国内还没有对镍钴行业采选产生的尾矿和废石中重金属的溶出规律开展研究。本文以镍钴采选企业的尾矿和废石作为样本,开展了毒性浸出实验。研究了不同pH值、离子强度、温度等实验条件对重金属溶出的影响,探讨了镍钴采选过程中所产生的尾矿和废石中重金属的溶出特性和释放规律。实验结果表明,尾矿样品中Ni的浸出浓度为42.28 mg·L^-1,是最大允许排放浓度的8.86倍,为具有浸出毒性特征的危险废物;废石样品中重金属Ni和Cu的溶出浓度分别为4.72 mg·L^-1和26.2 mg·L^-1,超过最大允许排放浓度,属于第Ⅱ类一般工业固体废物。pH对样品中Ni、Cr、Pb、Co和As的溶出量影响较大,其中尾矿中Ni和Cu在pH较低的条件下,可达到44.28 mg·L^-1和53 mg·L^-1,远高于最大允许排放浓度,而Hg、Cd和Cu的溶出量随pH值的变化不大。除As以外,样品中大多数重金属的溶出质量浓度在酸性条件下比在中性条件下高,这表明在酸性环境条件下,这些重金属对周围生态环境的潜在风险更大。离子强度的变化对Cd和Co的溶出量的变化并不明显,而当离子强度变化时,Ni、Cr、Pb、Hg、Cu和As的溶出量可能达到最大,使周围环境的潜在生态风险增大。当温度达到35~40℃时,部分重金属如Co、Pb、Cd 等,溶出量将达到最大;当温度低于25℃时,除 Ni 以外,大部分重金属溶出量很低。而温度变化对重金属Cu、As、Cr和Hg的溶出量的影响不明显,波动范围较小,对周围生态环境产生的潜在生态风险较小。     

炼油行业废催化剂中重金属源释放特征及其影响因素

采用连续分批浸出和柱淋溶方法研究废催化剂中重金属在环境暴露下的源释放特征,其中连续分批浸出实验设置液固比为5∶1、10∶1和20∶1,浸提液pH值为4.5,柱淋溶实验浸提液为pH 4.5、pH 7.0及pH 7.0的浓度20 mg·L-1的DOM溶液.结果表明,连续分批浸出中,酸性条件下废催化剂中重金属浸出率随液固比增...     

活性炭吸附富集-火焰原子吸收分光光度法测定河水中微量铅、锌、镉、铜、镍的探讨

水中微量铅、锌、镉、铜、镍的测定,一般采用萃取法、加热浓缩法等。本文是利用活性炭在大体积水相中有吸附微量重金属的能力,富集河水中微量铅、锌、镉、铜、镍。探讨了吸附时pH条件、活性炭用量、洗脱条件及共存离子的影响,研究结果表明:镉、铅的富集浓度为0.002mg/L;锌、铜、镍的富集浓度为0.005mg/L。     

浸提剂pH值对污泥中重金属浸出的影响

为了探讨浸提剂的pH对污泥中重金属释放的影响,采集了我国四个典型城市污水厂的剩余污泥,应用固体废物浸出毒性的浸出方法(GB5086.2-1997),以不同pH值的浸提剂对污泥中重金属的浸出特性进行了实验研究.实验结果表明,污泥中的Cr和Fe的最大浸出质量浓度分别出现在6.5～7.0和5.0左右的pH值范围;Mo和Ni的浸出质量浓度则随着浸提剂pH值的升高而升高;而Zn和Mn的浸出质量浓度则随着浸提剂pH的升高而降低.这表明,浸提剂的pH 值对污泥中重金属的浸出具有显著的影响,而且pH 值对污泥中重金属浸出的影响因重金属的不同而存在较大的差异.     

火焰原子吸收光谱法测定大气降尘中的几种重金属

本文介绍了大气降尘中铜、铅、锌、镉、铁、锰、镍、钴八种重金属的分析方法，以及共存离子对上述重金属测试时的干扰及其抑制干扰的方法。并提出了表示大气降尘中重金属量的三种浓度概念即容量浓度、重量浓度及降金属量的不同物理意义。     

火焰原子吸收光谱法测定大气降尘中的几种重要金属

本文介绍了大气降尘中铜、铅、锌、镉、铁、锰、镍、钴八种重要金属的分析方法，以及共存离子对上述重金属测试时的干扰及其抑制干扰的方法，并提出了表示大气降尘中重金属量的三种浓度概念即容量浓度、重量浓度及降金属量的不同物理意义。     

间歇反应器内污泥衍生吸附剂去除水溶液中镉、镍离子

利用城市污水厂的污泥化学活化法热解产生的吸附剂 ,在间歇反应器内对水溶液中Cd2 和Ni2 离子进行吸附性能的研究 .考察了溶液的pH值、接触时间、吸附剂的投加量及吸附质初始浓度对吸附效果的影响 ,结果表明 ,Cd2 ,Ni2 离子吸附达到平衡时的接触时间为 60min,pH值为 5 5— 6 0 ,溶液的初始浓度为 40mg·l- 1 和 30mg·l- 1 ,吸附剂的投加量不少于 1 0g·l- 1 和 2 0g·l- 1 .     

NDA-105树脂对对苯二甲酸生产废水中锰的吸附

使用NDA-105大孔树脂对对苯二甲酸生产废水中锰的吸附进行研究,结果表明,当pH值为5、流量为10BV(床体积)·h-1、温度为25℃时,NDA-105树脂对废水中锰离子的吸附效果最好、对锰离子的交换容量为0.5mmol·g-1、对浓度为15mg·l-1锰离子的吸附体积为1000BV,使用2BV 10%硫酸 2BV水作为洗脱剂、温度为80℃、洗脱剂流量为2BV·h-1,累积脱附率达到99%以上.     

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.     

Representation of the world's biophysical conditions by the global protected area network

Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.     

Quantitative composition of the defensive secretion ofBledius species (Coleoptera: Staphylinidae: Oxytelinae) is adapted to naturally occurring predators

Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.     

Democracy versus development: New urban debates

The politics of development includes subtexts of choice, as underpinned by community consensus (or lack of it), against the larger backdrop of a liberal democracy, with its intricate power structures that influence the choice of concepts and often lead to complicity rather than consent. A dilemma exists between the understanding of field-level practitioners and that of academics, whose understandings of progress differ. Progress can (and often does) imply long-term change across generations whereas development is often more a matter of crisis management and delivering tangible results to end-users. This makes it a bone of contention across political systems, irrespective of local or global dynamics. Development can emerge as a tool to be wielded for power and further political mileage at the expense of progress. Progress cannot be studied as a counterpoint to development as the sense of history is often missing in development interventions. Development tends to be piecemeal as its very logic often stems from the rationale of power. This is not to suggest, however, that development is only about politics; it is definitely more than the politics of everyday life and involves all of civil society that requires its critical and immediate attention. In this sense, it has become a priority for politicians with an underlying agenda designed to out-manouevre dissent and all statements of protest.     

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.     

A framework to measure the wildness of managed large vertebrate populations

As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.     

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.     

Sexual Predators,Energy Development,and Conservation in Greater Yellowstone

Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.     

Comparison of the insecticidal effects of water extracted and intact aromatic plants onAcanthoscelides obtectus,a bruchid beetle pest of kidney beans

Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.