聚合氯化铝铁絮凝剂的性能研究

煤矸石是采煤过程之废料。本文利用煤矸石制备出了聚合氯化铝铁（ＰＡＦＣ）：一种新型无机高分子絮凝剂，探讨了Ｆｅ＾３＋的稳定性与溶液离子强度之间的关系，发现溶液的离子强度越大，则产生Ｆｅ（ＯＨ）３沉淀时的ＰＨ越高。研究了ＰＡＦＣ水解产物的ζ电位及絮凝效果随ＰＨ的变化情况，比较了ＰＡＦＣ、ＰＡＣ和ＰＦＳ的除浊性能，ＰＡＦＣ在ＰＨ为７．０－８．２范围内除浊效果最佳，ＰＡＦＣ的除浊效果优于ＰＡＣ。     

聚合氯化铝与有机机高分子复合絮凝剂的电荷特性及其絮凝作用

用流动电流技术研究了聚合氯化铝与不同类型有机高分子复合絮凝剂的电荷特性。并用ζ电位分析仪结合混凝烧杯实验研究了不同碱化度（Ｂ）的ＰＡＣ与阳离子型有机高分子Ｃ１０９Ｐ复合絮凝剂的电中和水体颗粒物的能力与絮凝效能的关系。     

淀粉改性絮凝剂与PAC复合絮凝发制品废水性能研究:小试和中试

发制品在生产过程中产生大量废水,一般首先通过混凝/絮凝预处理去除废水中大部分悬浮胶体颗粒及少量可溶性物质.本研究中,设计并合成了两种含有强阳离子季铵盐基团的淀粉改性絮凝剂,分别是基团位于主链的3-氯-2-羟丙基三甲基氯化铵改性淀粉(St-CTA-DQ)和基团位于侧链的淀粉接枝聚甲基丙烯酰氧乙基三甲基氯化铵(St-g-PDMC-DQ).将它们分别在小试和中试规模下与聚合氯化铝(PAC)复合絮凝发制品废水,重点考察了复合絮凝中无机混凝剂与高分子絮凝剂的投加顺序与投加量等因素影响.实验室小试结果表明,先加PAC再加改性淀粉絮凝剂的絮凝工艺效果明显优于先加高分子絮凝剂再加PAC及两者同时加入的絮凝工艺;当与两种淀粉改性絮凝剂分别复合使用时,St-CTA-DQ与St-g-PDMC-DQ投加量分别为:10 mg·L~(-1)和20 mg·L~(-1),PAC的最佳投加量(90 mg·L~(-1))相比其单独使用(190 mg·L~(-1))下降一半以上;且复合絮凝对于浊度和UV_(254)的去除效果明显增强;形成的絮体尺寸更大,结构也更为密实;中试实验结果基本与小试一致.这是因为除了PAC电中和作用外,加入的阳离子高分子絮凝剂同时具有混凝和絮凝双重功能,能够进一步通过电中和与黏结架桥作用去除废水中污染物与初级絮体.同时还比较了上述两种阳离子淀粉改性絮凝剂不同结构对其絮凝性能影响,阳离子基团位于主链的St-CTA-DQ具有更佳的絮凝性能.淀粉改性絮凝剂与PAC复合使用在发制品废水处理中拥有良好的应用前景.     

聚合硅酸铝铁絮凝剂的制备及其水解和絮凝特性

聚合硅酸铝铁(PAFSC)作为一种新型絮凝剂,它保留了铝铁各自均聚物的优点,克服了聚合氯化铝(PAC)处理水样时残余铝含量较高和聚合氯化铁(PFC)稳定性较差的缺点．本文利用共聚和复合两种工艺制备PAFSC,研究Al／Fe／Si摩尔比和碱化度(B)对絮凝效果的影响．     

聚合氯化铝-壳聚糖复合絮凝剂的合成及在蓝藻沼液预处理中的应用

以聚合氯化铝(PACl)和壳聚糖(CTS)为主要原料合成了聚合氯化铝-壳聚糖(PACl-CTS)复合絮凝剂,考察了PACl与CTS的质量比、反应温度、反应液pH和反应时间等因素对PACl-CTS絮凝性能的影响,优化出PACl-CTS合成最佳工艺条件为:温度控制在70℃,m(PACl)∶m(CTS)=4∶1,反应时间1 h,pH值为4.通过红外图谱(IR)和扫描电镜(SEM)对PACl-CTS的微观结构进行了表征,表明PACl以一定的晶体结构镶嵌在CTS中,PACl和CTS之间存在一定的相互作用,而不是简单的复配.将合成的PACl-CTS应用于蓝藻沼液废水处理,结果表明,PACl-CTS对浊度、COD、TP具有良好的絮凝性能,当投加量为21.0 mg.L-1时,浊度、COD、TP的去除率分别达到了98.15%、67.78%和84.05%,可作为新型高效絮凝剂应用于蓝藻沼液废水预处理.     

Al13去除水中腐殖酸的混凝作用机理

研究对比了Al13、不同碱化度的聚合氯化铝(PACl)及工业聚合氯化铝等去除水中腐殖酸的絮凝特征,从Zeta电位、RT(余浊)、UV254等角度分别考察了pH值和投药量的影响,对不同形态组成絮凝剂的混凝效能有了进一步明确的认识,并且对Al13的絮凝机理进行了有益的探索．结果表明,Al13是混凝过程中的优势形态,决定着混凝剂的电中和能力．     

"类龟式"Al13盐酸盐的制备及絮凝性能

采用氯化铝溶液电解法、氯化铝溶液溶铝法、稀盐酸溶铝法、氯化铝溶液碱性阴离子树脂交换法、氯化铝溶液补水蒸馏法、氯化铝溶液压溶氢氧化铝或氧化铝法等促使氯化铝水解-聚合的方法,通过控制起始溶液的浓度、水解-聚合的程度和体系的温度,制成"类龟式"Al13含量超过96.5%的聚合氯化铝结晶,其中电解法制备的产物纯度达99.9%,盐基度61.48%,总铝(Al2O3)33.75%,水不溶物0.01%,Alb达97%.化学分析、X-射线粉末衍射和X-射线单晶结构解析结果表明,产物是一种由十三个铝氧八面体连接组成的Al13(OH)24Cl15·37H2O化合物.高岭土模拟水样和黄河水样絮凝试验表明,絮凝效果优于市售固体聚合氯化铝、氯化铝和硫酸铝,经絮凝处理的黄河水主要水质质量指标达到国家生活饮用水标准GB5749-85的要求.     

聚合氯化铝与有机高分子复合絮凝剂的电荷特性及其絮凝作用

用流动电流技术研究了聚合氯化铝(PAC)与不同类型有机高分子复合絮凝剂的电荷特性,并用ζ电位分析仪结合混凝烧杯实验研究了不同碱化度(B)的PAC与阳离子型有机高分子C109P复合絮凝剂的电中和水体颗粒物的能力与絮凝效能的关系,对无机-有机复合型絮凝剂中有机高分子在凝聚絮凝过程中所起的作用进行了讨论.     

聚合氯化铝对水中微量铬（Ⅳ）的富集

本文研究了聚合氯化铝作为一种新的无机吸附共沉淀剂对水中微量铬（Ⅵ）的富集和测定，实验表明，它能有效地富集水中微量铬（Ⅵ），１．５ｇ聚合氯化铝在１０００ｍｌ溶液中（ｐＨ７－８，铬（Ⅵ）浓度０－５００μｇ／ｌ），搅拌速度在３００ｒ／ｍｉｎ左右，搅拌时间１０ｍｉｎ时，铬（Ⅵ）的吸附率在９５％以上，用分光光度法满意地实现了对河水中微量铬（Ⅵ）的测定。结果表明：铬（Ⅵ）的加入回收率≥９４％，测定的相对标准偏     

聚氯硫酸铝铁的制备及絮凝性能研究

以粉煤灰为主要原料制备聚氯硫酸铝铁(PAFCS)新型无机高分子絮凝剂,并对该絮凝剂的X-射线衍射图和透射电镜照片进行了分析;同时比较了该絮凝剂和聚合氯化铝(PAC)絮凝剂对模拟水样的净水效果,结果表明：该絮凝剂的除浊效果和沉降效果要优于聚合氯化铝(PAC)．     

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.     

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.     

Parasitic wasps orient to green leaf volatiles

Summary Undamaged plants emit low levels of green leaf volatiles (GLVs), while caterpillar-damaged and artificially damaged plants emit relatively higher levels of certain GLVs. Female braconid parasitoids,Microplitis croceipes, oriented to both damaged plants and to individual GLVs in no-choice tests in a wind tunnel, but seldom oriented to undamaged plants. Female ichneumonid parasitoids,Netelia heroica, also oriented to individual GLVs in a wind tunnel. Males of both wasp species failed to orient to the GLVs. These data show that leaf-feeding caterpillars can cause the release of GLVs, and that parasitic wasps can respond to these odors by flying upwind (chemoanemotactic response), which brings the wasps to their caterpillar hosts. This supports the hypothesis that plants communicate with members of the third trophic level,i.e., plants under herbivore attack emit chemical signals that guide natural enemies of herbivores to sites of plant damage. In this interaction, the GLVs serve as tritrophic plant-to-parasitoid synomones. That parasitoids from two different wasp families oriented to GLVs suggests that the response may be widespread among the Hymenoptera.Mention of a commercial or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture     

Potential for Electropositive Metal to Reduce the Interactions of Atlantic Sturgeon with Fishing Gear

Atlantic sturgeon (Acipenser oxyrhynchus) populations have been declared either endangered or threatened under the U.S. Endangered Species Act. Effective measures to repel sturgeon from fishing gear would be beneficial to both fish and fishers because they could reduce both fishery‐associated mortality and the need for seasonal and area closures of specific fisheries. Some chondrostean fishes (e.g., sturgeons and paddlefishes) can detect weak electric field gradients (possibly as low as 5 Μv/cm) due to arrays of electroreceptors (ampullae of Lorenzini) on their snout and gill covers. Weak electric fields, such as those produced by electropositive metals (typically mixtures of the lanthanide elements), could therefore potentially be used as a deterrent. To test this idea, we recorded the behavioral responses of juvenile Atlantic sturgeon (31–43 cm fork length) to electropositive metal (primarily a mixture of the lanthanide elements neodymium and praseodymium) both in the presence and absence of food stimuli. Trials were conducted in an approximately 2.5 m diameter × 0.3 m deep tank, and fish behaviors were recorded with an overhead digital video camera. Video records were subsequently digitized (x, y coordinate system), the distance between the fish and the electropositive metal calculated, and data summarized by compiling frequency distributions with 5‐cm bins. Juvenile sturgeon showed clear avoidance of electropositive metal but only when food was present. On the basis of our results, we conclude that the electropositive metals, or other sources of weak electric fields, may eventually be used to reduce the interactions of Atlantic sturgeon with fishing gear, but further investigation is needed. El Potencial del Metal Electropositivo para Reducir las Interacciones del Esturión Atlántico con Instrumentos de Pesca Bouyoucos, Bushnell & Brill 13–003     

The role of time and species identities in spatial patterns of species richness and conservation

Many conservation actions are justified on the basis of managing biodiversity. Biodiversity, in terms of species richness, is largely the product of rare species. This is problematic because the intensity of sampling needed to characterize communities and patterns of rarity or to justify the use of surrogates has biased sampling in favor of space over time. However, environmental fluctuations interacting with community dynamics lead to temporal variations in where and when species occur, potentially affecting conservation planning by generating uncertainty about results of species distribution modeling (including range determinations), selection of surrogates for biodiversity, and the proportion of biodiversity composed of rare species. To have confidence in the evidence base for conservation actions, one must consider whether temporal replication is necessary to produce broad inferences. Using approximately 20 years of macrofaunal data from tidal flats in 2 harbors, we explored variation in the identity of rare, common, restricted range, and widespread species over time and space. Over time, rare taxa were more likely to increase in abundance or occurrence than to remain rare or disappear and to exhibit temporal patterns in their occurrence. Space–time congruency in ranges (i.e., spatially widespread taxa were also temporally widespread) was observed only where samples were collected across an environmental gradient. Fifteen percent of the taxa in both harbors changed over time from having spatially restricted ranges to having widespread ranges. Our findings suggest that rare species can provide stability against environmental change, because the majority of species were not random transients, but that selection of biodiversity surrogates requires temporal validation. Rarity needs to be considered both spatially and temporally, as species that occur randomly over time are likely to play a different role in ecosystem functioning than those exhibiting temporal structure (e.g., seasonality). Moreover, temporal structure offers the opportunity to place management and conservation activities within windows of maximum opportunity.     

Main nutrient compounds in food bodies of Mexican <Emphasis Type="Italic">Acacia</Emphasis> ant-plants

Summary. Myrmecophytic plants use obligate ant mutualists as a constitutive indirect defence mechanism. These plants often produce cellular food bodies (FBs) to nourish their resident ants. Lipids, proteins, and even highly specialised compounds such as glycogen have been reported from FBs, but detailed chemical analyses of FB composition have so far been presented only for Southeast Asian Macaranga and Central American Piper myrmecophytes. Here we report the chemical composition of FBs of five myrmecophytic Acacia (Fabaceae) species from Mexico using HPLC (carbohydrates and proteins) and GC-MS (lipids). Feeding experiments revealed no hints on any use of external food sources by the inhabiting Pseudomyrmex ants. These ants obviously rely completely on FBs and extrafloral nectar provided by their hosts. The total content of nutrients in Acacia FBs was 15-25% of FB dry mass, being much lower than in Macaranga or Piper FBs. Proteins were dominating (8-14 % dm) in Acacia FBs and thus were present in higher amounts than in Macaranga FBs, yet in lower amounts than in Piper. Lipids contributed 1-9 % of dry mass, showing a lower proportion than in FBs of Macaranga or Piper. Carbohydrates made up 3-11 % dm, reaching in most Acacia species the same range as observed in Macaranga and in Piper FBs. Water content was 18-24 % of FB fresh mass, and structural tissue obviously made up a much higher proportion in Acacia FBs than in Macaranga or Piper FBs. Both characters might represent an adaptation to producing FBs unprotected at the leaf tips under dry conditions. Acacia FBs contain all amino acids and all fatty acids that are considered essential for insects, and their contents of lipids and proteins are higher than in the leaves from which they are ontogenetically derived. This indicates a putatively adaptive enrichment of nutritionally valuable compounds in structures functioning as ant-food.     

Examining the uncertain origin and management role of martens on Prince of Wales Island,Alaska

Conservation biologists are generally united in efforts to curtail the spread of non‐native species globally. However, the colonization history of a species is not always certain, and whether a species is considered non‐native or native depends on the conservation benchmark. Such ambiguities have led to inconsistent management. Within the Tongass National Forest of Alaska, the status of American marten (Martes americana) on the largest, most biologically diverse and deforested island, Prince of Wales (POW), is unclear. Ten martens were released to POW in the early 1930s, and it was generally believed to be the founding event, although this has been questioned. The uncertainty surrounding when and how martens colonized POW complicates management, especially because martens were selected as a design species for the Tongass. To explore the history of martens of POW we reviewed other plausible routes of colonization; genetically and isotopically analyzed putative marten fossils deposited in the late Pleistocene and early Holocene to verify marten occupancy of POW; and used contemporary genetic data from martens on POW and the mainland in coalescent simulations to identify the probable source of the present‐day marten population on POW. We found evidence for multiple routes of colonization by forest‐associated mammals beginning in the Holocene, which were likely used by American martens to naturally colonize POW. Although we cannot rule out human‐assisted movement of martens by Alaskan Natives or fur trappers, we suggest that martens be managed for persistence on POW. More generally, our findings illustrate the difficulty of labeling species as non‐native or native, even when genetic and paleo‐ecological data are available, and support the notion that community resilience or species invasiveness should be prioritized when making management decisions rather than more subjective and less certain conservation benchmarks.