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651.
考察了处理效果良好的循序间歇式废水生物除磷试验装置内活性污泥的微生物组成及其优势菌的磷代谢特性。试验结果表明,活性污泥混合液中的优势菌为假单胞菌属,其次是气单胞菌属和棒杆菌属,仅发现少量的不动杆菌属。当以乙酸钠为基质时,假单胞菌属于好氧培养过程中能明显除磷,其效果与厌氧/好氧培养过程的相近。另外,在好氧条件下,以乙酸钠为基质培养时,向培养基内滴加H2SO4可导致假单胞菌产生磷释放现象,滴加NaOH或NaHCO3时,则发生过量摄磷现象,并且加NaOH所引起的磷摄取量较NaHCO3的大。 相似文献
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654.
Fernanda Silva dos Santos Raquel A.F. Neves Mirian Araújo Carlos Crapez Valéria Laneuville Teixeir Natascha Krepsky 《环境科学学报(英文版)》2022,34(1):412-428
The brown mussel Perna perna (Linnaeus, 1758) is a valuable resource for aquaculture in tropical and subtropical coastal regions. It presents desirable characteristics for biomonitoring, including being sessile, widely distributed and abundant, and is a filter-feeder able to accumulate several classes of pollutants (e.g., metals, hydrocarbons, among others). Mussels’ biological responses to pollution exposure can be measured as biomarkers, which include alterations ranging from molecular to physiological levels, to estimate the degree of environmental contamination and its effects on biota. This full review compiles two decades (2000–2020) of literature concerning biological effects on P. perna mussel caused by environmental pollutants (i.e., metals, hydrocarbons, and emerging pollutants), considering environmental and farm-based biomonitoring. Biochemical markers related to mussels’ oxidative status were efficient for the biomonitoring of metals (i.e., antioxidant enzymes associated with oxidative damage in biomolecules). Genotoxicity and cytotoxicity indicators (i.e., comet, micronucleus, and neutral red assays) provided a depiction of hydrocarbon contamination. The neutral red assay gave a time-concentration cytotoxic response to a wide range of pollutants, including emerging pollutants (e.g., pharmaceuticals and biocides) and hydrocarbons. Perna perna hemocyte parameters provided a useful approach for biocide biomonitoring. This paper summarizes useful biomarkers from molecular to physiological levels in this mussel species used to identify and quantify the degree of coastal pollution. An integrated biomarker analysis may provide a way to overcome possible biomarker variations and assess multi-polluted sites. Nevertheless, it is necessary to investigate biomarker variations according to natural factors (e.g., season and gonad maturation stage) to standardize them for trustworthy biomonitoring. 相似文献
655.
Carlos Carroll Reed F. Noss Lindsay M. Dreiss Healy Hamilton Bruce A. Stein 《Conservation biology》2023,37(5):e14075
Comprehensive biodiversity assessments play an essential role in strengthening global and national conservation strategies. The recently announced first U.S. National Nature Assessment (NNA) provides an unparalleled opportunity to comprehensively review status and trends of biodiversity at all levels. This broad context can help in the coordination of actions to conserve individual species and ecosystems. The scientific assessments that informed the Kunming–Montreal Global Biodiversity Framework adopted at the 2022 Convention on Biological Diversity (CBD) conference of parties provide models for synthesizing information on trends at multiple levels of biodiversity, including decline in abundance and distribution of species, loss of populations and genetic diversity, and degradation and loss of ecosystems and their services. The assessments then relate these trends to data on drivers of biodiversity loss and pathways to their mitigation. The U.S. NNA can augment such global analyses and avoid the pitfalls encountered by previous U.S. efforts by ensuring policy-relevant design, data accessibility, and inclusivity in process and product and by incorporating spatial data relevant to national and subnational audiences. Although the United States is not formally a CBD party, an effective NNA should take full advantage of the global context by including indicators adopted at the 2022 meeting and incorporating an independent review mechanism that supports periodic stocktaking and ratcheting up of ambition in response to identified shortfalls in stemming biodiversity loss. The challenges to design of an effective U.S. assessment are relevant globally as nations develop assessments and reporting to support the new global biodiversity framework's targets. By considering and incorporating the diverse ways in which society values and benefits from nature, such assessments can help bridge the gap between research and conservation practice and communicate the extent of the biodiversity crisis to the public, fostering broad-based support for transformative change in humanity's relationship to the natural world. 相似文献
656.
Restoring riparian ecosystems in human-dominated landscapes requires attention to complexity, and consideration of diverse drivers, social actors, and contexts. Addressing a Global North bias, this case study uses a mixed-method approach, integrating historical data, remote sensing techniques and stakeholder perceptions to guide restoration of a river in the Western Cape, South Africa. An analysis of aerial photographs of the riparian zone from 1953 to 2016 revealed that although anthropogenic land conversion happened primarily before the 1950s, several land use and land cover classes showed marked increases in area, including: waterbodies (+ 1074%), urban areas (+ 316%), alien weeds (+ 311%) and terrestrial alien trees (+ 79%). These changes have likely been driven by land fragmentation, disturbance, and agricultural intensification. Stakeholder interviews revealed that despite the clear need for restoration, several barriers exist to successful implementation; these stem from inadequate financial resources, inappropriate funding models, institutional challenges, and a lack of techno-scientific knowledge. We give several recommendations to overcome these barriers.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01691-y. 相似文献
657.
介绍了C语言格式式化输出类操作函数,对该类函数的实现方式和C语言可变参数的工作原理进行了较为详细的阐述,同时,构造了一个方便通用的格式化输出函数,为数据数据格式化操作提供了一条灵活便捷有效的处理途径. 相似文献
658.
Xingyu Liu Bowei Chen Jinghe Chen Laichang Zou Jiankang Wen 《Chemistry and Ecology》2016,32(5):419-431
The Zijin heap bioleaching plant started operation by the end of 2005; due to the proximity of the Ting River, concerns rose about the migration of acidophiles outside of the heap. In this study, 53 soil samples and 51 liquid samples were collected, and the biogeographical distribution of acidophiles was investigated using clone libraries and real-time polymerase chain reaction (PCR), the physicochemical characteristics were analysed by Inductively Coupled Plasma Optical Emission Spectrometry (ICP). The results indicated the bioleaching system had some influence on the surrounding environment. Both microbial community and physiochemical index emerged correlation with distance of sampling sites from bioleaching system, mainly limited in the zone 30?m outside bioleaching system. Correlation analysis indicated the migration of different acidophiles was influenced by different factors. Leptospirillum had higher migration capability than the other acidophiles, and such migration capability was one of the important influence factors for its distribution. Environment factors and survival ability were the key influence factors for Acidithiobacillus, Sulfobacillus and Ferroplasma to survive in the surrounding environment. 相似文献
659.
复合碳源填料反硝化脱氮及微生物群落特性 总被引:4,自引:0,他引:4
为探讨低碳氮比污水厂尾水的深度脱氮技术,以碱处理玉米芯、零价铁和活性炭组成的复合碳源作为填料,考察反硝化生物脱氮滤柱的运行效果,并借助Miseq高通量测序技术对滤柱生物膜的微生物群落组成和结构进行解析.结果表明,复合碳源填料进行反硝化脱氮时,能有效的被微生物利用并获得较高的TN去除率.在温度为28℃左右,反硝化滤柱进水NO3--N浓度为20~30mg/L、HRT=7.7h时,TN去除率可达到95%以上,出水TOC在15mg/L左右;微生物在属水平进行聚类分析结果表明,生物膜中与反硝化作用有关的菌属和与纤维素降解有关的菌属分别占已知菌属的40.35%和29.04%.因此,污泥中反硝化作用菌属和纤维素降解有关的菌属的大量存在,为复合碳源填料高效反硝化作用提供了可能. 相似文献
660.
应用SMT法研究了洋河水库流域土壤、河道及库区沉积物中总磷(TP)、无机磷(IP)、有机磷(OP)、铁/铝磷(Fe/Al-P)、钙磷(Ca-P)等5种形态,分析了不同区域各形态磷的分布特征.结果表明,洋河水库流域土壤、沉积物中TP、总氮(TN)和有机质(OM)的均值含量总体变化趋势为河道>库区>土壤,其中TP含量变化不大,这说明营养盐不仅通过土壤径流、河道迁移进入库区,而且库区沉积物的释放作用同样明显.库区柱状沉积物有明显的“表层富积”现象,随着沉积物深度的增加,TP、TN和OM含量逐渐减少,在0~16cm下降趋势明显,16cm以下基本保持不变,说明库区沉积物主要以表层污染为主.土壤、沉积物中的磷以IP为主,大约占TP的46%~79%之间,且研究区各磷形态中以Ca-P为主,大约占TP的22%~68%,这与库区地质—地球化学特征有关.土壤中TP的增加主要来自于Ca-P,与该地区土壤的地质背景有关,河道沉积物中TP的增加主要来自于Fe/Al-P,即河道受到人类活动污染的影响较大,而库区TP的增加主要来自于OP,说明洋河水库的富营养化与流域的工业、生活污染以及农业面源污染有关. 相似文献