十二烷基苯磺酸钠(SDBS)-氢氧化钠耦合污泥脱水技术研究

研究了十二烷基苯磺酸钠(SDBS)-氢氧化钠(NaOH)耦合预处理对污泥特性的影响,分析了不同预处理条件下污泥溶解性化学需氧量(SCOD)、挥发性悬浮物(VSS)、总悬浮物(TSS)和有机酸溶出率随时间的变化规律,并进一步探讨了其对污泥脱水性能的影响.结果表明,SDBS-NaOH耦合作用时能有效地加速VSS和TSS的溶解,提高污泥水解相SCOD的浓度,当SDBS和NaOH的投加量分别为0.02g·g-1污泥(污泥干基,下同)和0.1g·g-1污泥时,VSS溶解效率高达64.0%,此时TSS含量最低,仅为23.2mg·l-1;另外,当SDBS和NaOH添加量分别为0.02和0.25g·g-1时,污泥的脱水性能良好,脱水后污泥的含水率可降到72%左右,而未预处理的污泥其含水率高达84%。     

阳离子表面活性剂对污泥脱水性能的影响和作用机理

采用实验室模拟的方法研究了十六烷基三甲基溴化铵(CTMAB)和四甲基溴化铵(TMAB)对活性污泥脱水性能的影响.结果表明,相比污泥原样,经两种表面活性剂调理的污泥脱水性能均有一定程度的改善;在同样的投加量下,CTMAB比TMAB能更有效地改善污泥的脱水性能.实验数据显示:与TMAB相比,投加约为泥样干重25%的CTMAB可以释放出更多污泥胞外聚合物总量,其值约为231mg·l-1;污泥毛细吸水时间(CST)可缩短为73s左右;当TMAB和CTMAB的投加量大于泥样干重的15%时,真空抽滤后,污泥比阻达到易脱水范围;CTMAB和TMAB对污泥沉降性能的改善不是非常明显.     

利用酱油酿造废水生产微生物絮凝剂及其性能研究

土壤杆菌(Agrobacteriumsp.)LG5-1能够利用酱油酿造废水作为替代培养基生产微生物絮凝剂.在温度为30℃的条件下,研究了碳源、氮源、初始pH及培养时间等条件对絮凝剂的产量及絮凝剂活性的影响,得到了以酱油酿造废水为培养基生产微生物絮凝剂GIL-1的最佳条件:100mL酱油酿造废水中加入2mL乙醇(75%)作为补充碳源,不需添加氮源,调节pH值至8.0左右,培养时间约为48h.获得的絮凝剂GIL-1具有较高的絮凝率和较好的稳定性能,低温储存200d,絮凝率仍可达76.3%.图5参19     

不同深度脱水污泥的热解特性及动力学分析

选用4种利于深度脱水的复合调理剂(FeCl3/CaO、FeCl3/CaO/煤粉、芬顿试剂(Fe2+和H2O2组成体系)/CaO、芬顿试剂CaO/煤粉)来改善污泥的脱水性能,所得泥饼的含水率为43.7%—56.1%,满足深度脱水的要求.CaO和煤粉的添加能改变污泥的灰分和挥发分含量.与传统聚丙烯酰胺(PAM)脱水污泥的热重分析对比结果表明,由于复合调理剂对EPS的破坏溶解作用,因此对污泥热解性质有较大影响,不仅能前移水分失重峰,还使得热重主要反应阶段峰个数变少.热解动力学计算表明,反应级数在1—2范围内.表观活化能差异表明4种复合调理剂处理后脱水污泥更容易发生热解反应.     

超声波对剩余污泥化学调理的影响

以污泥脱水性能与沉降性能为指标,研究了超声波预处理对剩余污泥经阳离子聚丙烯酰胺（CPAM）进行化学调理时污泥减量效果的影响。试验结果表明,单独采用CPAM对剩余污泥进行化学调理时的ρ（最佳添加量）为120 mg.L-1,污泥滤饼含水率为81.2%;单独采用超声波处理剩余污泥时的最佳声能密度为0.04 W.mL-1,此时的滤饼含水率为80.4%。而当在采用CPAM对剩余污泥进行化学调理前先进行超声波预处理后,污泥滤饼含水率降至72.2%。试验结果表明这种联合处理方式不仅使剩余污泥的脱水性能大为改善,并且最佳CPAM投加量降低至60 mg.L-1,最佳超声声能密度降至0.03 W.mL-1,这表明联合处理方法降低了污泥处理成本。     

臭氧对活性污泥性状的影响

分别在臭氧浓度为31.50,31.96,32.23,33.89,36.65,39.33和40.25mg·l-1下,考察污泥混合液MLSS,MLVSS和pH值及上清液SCOD,TN,NH3-N和,TP等随臭氧作用时间的变化.结果表明:臭氧对污泥混合液中的溶解性同体(DS)具有氧化作用,能有效破解微生物絮体、细胞壁和细胞膜等,使微生物体内有机质溶出,溶出物能被微生物作为底物重新利用,本实验中,MLSS和MLVSS降低最大量分别为1250 mg·l-1和465 Mg·l-1,SCOD增加最大量为250.3 mg·l-1.另外,根据混合液各性状的变化规律分析了臭氧氧化污泥的机理.     

聚合氯化铝/壳聚糖复合絮凝剂在活性污泥中的调理作用

考察了聚合氯化铝、壳聚糖以及复合絮凝剂对活性污泥的调理作用,结果表明,它们都有助于改善活性污泥的脱水,通过比较污泥比阻的变化,观察试验中的矾花生成现象,表明聚合氯化铝/壳聚糖复合絮凝剂在污泥调理中不仅效果明显,污泥比阻最先达到低点3×1012m·kg-1,滤速较快,而且有助于减少金属污泥的生成,是较佳的调理剂.     

水体/沉积物中蒽的生物降解

对水体/沉积物中蒽的降解情况进行了研究,结果表明,往天然水体中添加沉积物对蒽的生物降解有较明显的促进作用,沉积物能够吸附一定量的蒽,从而抑制其自然挥发,体系中沉积物含量为15g·l-1时,吸附效果最为明显,在蒽初始浓度为10mg·l-1的情况下,5d后残留率达100.00%,沉积物本身存在的土著微生物对蒽有一定的降解能力,沉积物含量为15g·l-1时,5d后蒽降解率最高,为49.29%,往15g·l-1沉积物中接种蒽高效降解菌烟曲霉A10后,蒽降解率达88.92%,表明往污染环境中外加微生物能够明显改善污染物的降解情况.     

污泥中水分布形式划分及脱水性能研究

为解决污泥脱水难问题,考虑有机质膜对污泥脱水的影响,重新对水分布形式进行了划分,将其分为重力水、封闭水、包裹水和结合水4种类型。通过自重沉降、离心脱水和盐溶液渗析试验,测定以上4种水分含量,计算污泥中各形式水分占总水分的比例;并与前人研究数据进行对比分析,对污水处理厂处理污泥的方法和技术提出改进建议。研究结果表明,(1)重力水、封闭水、包裹水、结合水占总水分的比例分别为47.6%、31.7%、17.5%和3.2%。(2)自重脱水试验得到的污泥含水率为90%左右,而国内污水处理厂经重力浓缩后污泥含水率仍旧高达98%,说明污水厂在进行浓缩处理后污泥仍保留相当多一部分水分,可以通过自重沉降的方式脱除,因此建议在今后的重力浓缩过程中,适当延长沉降时间,有利于提高排水量,减轻后续脱水处理的机械工作量和能耗。(3)盐溶液渗析法利用渗透压差值,能够脱除污泥中的大量水分。当溶液渗透压超过0.1 MPa,含水率可降低至60%以下,实现污泥深度脱水。利用盐溶液渗析的方式处理污泥,可以免去污泥预处理过程,避免环境的二次污染;稀释后的盐溶液可以浓缩后循环使用,利于降低污泥脱水处理总成本和能耗。该研究解决了现有水分定量手段无法与水分布理论结合的问题,可为今后污泥的脱水研究提供新的方法和思路。     

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 .     

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.     

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.     

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.     

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.     

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.     

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.     

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.