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1.
采用上流式厌氧污泥床(UASB)与膜生物反应器(MBR)组合工艺对城市垃圾填埋场渗滤液进行处理试验研究。当渗滤液CODCr为1491~2965mg/L,该组合工艺对CODCr、BOD5、NH3-N的平均去除率分别达到73%、98.3%和61.7%。文中还对渗滤液CODCr的降解性能、厌氧-好氧工艺的合理组合等问题进行了讨论分析。  相似文献   

2.
固定化微生物厌氧移动床——好氧法处理偶氮染料废水   总被引:9,自引:0,他引:9  
在分离获得的三株高效脱色菌组成的混合脱色菌种基础上,利用固定化微生物 氧移动床与好氧生物氧化法结合的工艺处理人工配制的偶氮染料废水,在15-18℃的条件下,当原水COD浓度为1500mg/L=1580mg/L,色度400倍,厌氧水为停留时间8h,好氧容积负荷率4.0kgCOD/m^3(填料),d时,色度及COD的去除率分别为96.9%及93.4%。  相似文献   

3.
采用15种不同的微生物菌剂,以葡萄糖配水、中药提取废水、啤酒废水、氨氮配水等为基质,分别测定了微生物菌剂的耗氧速率和厌氧比产甲烷速率,以单位菌剂对不同基质的耗氧速率和厌氧比产甲烷活性为指标,比较了各菌剂对废水的适配性.根据测定结果选择活性高的菌剂,在试验室进行了菌剂对废水的连续处理试验.结果表明,不同菌剂对同一种废水的好氧或厌氧活性不同,同种菌剂对不同废水的好氧和厌氧活性不同.废水的连续处理试验取得良好的处理效果.No.8菌剂处理葡萄糖配水,系统有机负荷最高可达(COD)10.8 g L-1d-1,COD去除率可达90%以上;采用No.10菌剂处理氨氮配水,好氧氨氮负荷可达(NH4-N )1.42 g L-1d-1,厌氧氨氮负荷可达(NH4-N )0.3 gL-1d-1,系统NH4-N 去除率可达90%以上.图2表3参8  相似文献   

4.
采用固液分离—改良型UASB(上流式厌氧污泥床反应器)厌氧消化—SBBR(序批式生物膜反应器)好氧生化—高效复合絮凝组合工艺处理甘薯燃料乙醇糟液,处理出水各项敏感环境因子均达到国家《污水综合排放标准》(GB8978-1996)一级标准.在改良型UASB进水COD36720~43890mgL-1、SS8370~11400mgL-1条件下,维持反应温度(35±3)℃,其容积负荷可达到28.86~34.5g(COD)L-1d-1,对COD、SS、VFA去除率分别为92%~93%、89%~91.5%、96%~98%.在12~30℃时,厌氧消化液SS360~530mgL-1,BOD400~530mgL-1,NH3-N120~163mgL-1,S2-40~50mgL-1,经两级SBBR好氧生化处理后,分别降低到40~60mgL-1、250~310mgL-1、7.2~13.8mgL-1、低于0.5mgL-1.考察3种絮凝剂的混凝效果,以高效复合絮凝剂效果最好,生化处理出水经该絮凝剂混凝处理后,COD、TP和色度分别降低到低于100mgL-1、0.5mgL-1和40倍.  相似文献   

5.
造纸黑液的微生物酸化和两相厌氧消化处理的研究   总被引:5,自引:0,他引:5  
本文研究了造纸黑液的微生物酸化和厌氧消化处理过程。利用厌氧微生物的产酸过程预处理黑液,降低其pH值,使之适合于厌氧处理,是一种简便可行的预处理手段;用两相厌氧系统处理黑液,在水力停留时间.2~2.7天,进水浓度为20890~32144mg/L;有机负荷为7.65~13.46kgCOD/m~3·d时,COD去除率为61.7~69.7%,BOD_5去除率为88.9%~91.0%;每去除1gCOD产气率为0.39~0.55L;沼气中甲烷的含量为61.5%~66.6%,出水pH为7.0~7.4。处理过程运行稳定,受进水的影响小,废水不需要进行中间调节,为造纸黑液的厌氧处理提供了一种新的工艺。文中还研究了厌氧处理过程中有机酸的积累问题。  相似文献   

6.
林亲铁  张淑娟 《生态环境》2007,16(5):1382-1385
为了降低生活垃圾压滤液污染负荷,为后续生化处理的正常运行创造良好条件,针对垃圾压滤液污染特性,以CODCr去除率为指标,通过正交实验和单因素实验研究了Fenton—聚硅铝铁混凝法处理城市生活垃圾压滤液的最优反应条件和处理效果。结果表明:采用该工艺处理垃圾压滤液时,pH值对CODCr去除率影响最大,其次是PSAF,再次是H2O2和FeSO4,在最优反应条件下,浊度去除率达到95.3%,CODCr去除率达到86.7%,BOD5去除率达到81.6%,浊度、CODCr、BOD5分别下降到86NTU、4201 mg.L-1、855 mg.L-1。  相似文献   

7.
褚兆晶  徐婷  郭景  安娟  刘俊琢  胡清静 《生态环境》2010,19(8):1956-1959
以丙烯腈废水为研究对象,进行废水预处理对提高废水的可生化性和后续好氧生物处理效率的研究。实验采用电化学氧化法对难降解丙烯腈废水处理效果进行了单因子试验,分析了电压、电解时间、氯离子质量浓度对废水色度及CODcr的去除效果,以及对废水可生化性的影响。实验结果显示,电化学氧化法在电压5V,pH为3.00,反应时间6h,搅拌速率为250r·min^-1,氯离子质量浓度为5000mg·L^-1的条件下,对CODCr1156mg·L^-1,色度512倍的丙烯腈废水中CODcr去除率达到60%,色度的去除率达到90%,并使废水的可生化性明显提高。CODCr去除率和色度去除率随电解时间、电压增加而增大,电解时间达5h、电压大于5V以后使水电解副反应更容易发生,对有机物的降解速率减小,同时随电解时间延长,能耗逐渐增大,处理成本增大;氯离子质量浓度对电解效果影响较大,适量增大氯离子质量浓度,可以提高CODCr的去除率。  相似文献   

8.
移动床生物膜反应器在污水处理中的应用研究   总被引:24,自引:0,他引:24  
应用好氧移动床生物膜反应器处理生活污水,厌氧复合生物反应器处理高浓度有机废水,厌氧-好氧移动床生物膜工艺处理食品废水的试验均取得良好的效果。试验结果表明,该工艺具有处理效率高,出水水质稳定,耐冲击负荷能力强,占地少,结构紧凑,维护管理简单的特点。  相似文献   

9.
硝基苯废水的厌氧-好氧基本实验与工艺理论分析   总被引:12,自引:0,他引:12  
根据含硝基苯( N B) 废水的水质特性,利用自然驯化和诱变驯化得到的两株厌氧菌 Bacteroides distasonis( 吉氏拟杆菌) 和 Bacteroides merdae( 屎拟杆菌) ,采用厌氧填充床- 好氧污泥床相结合的 A/ O 工艺使 N B 得到彻底降解.研究表明:利用吸附能力强的活性炭作为厌氧填充床的载体,可以在短期内使高效菌挂膜;在影响填充床厌氧处理效果中,t H R和进水p H 值是主要影响因素,而 N B 质量浓度ρ( N B) 和θ/ ℃次之.实验结果表明:进水ρ( N B) 为300 ~800 mg/ L, C O D Cr 值为1 500 ~3 500 mg/ L,色度为100 ~250 倍,经过厌氧填充床控制t H R= 24 h ,硝基苯转化率大于90 % , C O D 去除率为20 % ~30 % ;在好氧污泥床中继续曝气12 h ,则总 C O D 去除率为60 % ~70 % ,色度去除率大于70 % .连续90 d 用氯霉素制药厂实际废水处理运行结果亦显示本工艺的可行性.  相似文献   

10.
人工增氧型复合湿地污染物净化效果   总被引:2,自引:0,他引:2  
针对传统人工湿地负荷低、硝化能力弱和易堵塞的缺点,结合曝气生物滤池与人工湿地强化理论的研究成果,自主开发了人工增氧型复合湿地工艺,即生物接触氧化预处理+微曝气垂直流湿地+水平潜流湿地。通过对滇池北岸城郊混合制污水处理的模型试验,分析该工艺流程各净化单元的污染物去除效果。结果显示,人工增氧型复合湿地对不同水力负荷和污染负荷都体现了较强的缓冲调节能力和较高的净化效果。对污染物的总去除率分别为SS 94.5%、CODCr71.3%、氨氮72.3%,在进水总氮10.0 mg.L-1条件下实现了41.9%的总氮去除率,出水总氮均值为5.8 mg.L-1。  相似文献   

11.
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  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
Abstract: The last century has seen the ascendance of a core economic model, which we will refer to as Walrasian economics. This model is driven by the psychological assumptions that humans act only in a self‐referential and narrowly rational way and that production can be described as a self‐contained circular flow between firms and households. These assumptions have critical implications for the way economics is used to inform conservation biology. Yet the Walrasian model is inconsistent with a large body of empirical evidence about actual human behavior, and it violates a number of basic physical laws. Research in behavioral science and neuroscience shows that humans are uniquely social animals and not self‐centered rational economic beings. Economic production is subject to physical laws including the laws of thermodynamics and mass balance. In addition, some contemporary economic theory, spurred by exciting new research in human behavior and a wealth of data about the negative global impact of the human economy on natural systems, is moving toward a world view that places consumption and production squarely in its behavioral and biophysical context. We argue that abandoning the straightjacket of the Walrasian core is essential to further progress in understanding the complex, coupled interactions between the human economy and the natural world. We call for a new framework for economic theory and policy that is consistent with observed human behavior, recognizes the complex and frequently irreversible interaction between human and natural systems, and directly confronts the cumulative negative effects of the human economy on the Earth's life support systems. Biophysical economics and ecological economics are two emerging economic frameworks in this movement.  相似文献   

16.
Effects of Coffee Management on Deforestation Rates and Forest Integrity   总被引:1,自引:0,他引:1  
Knowledge about how forest margins are utilized can be crucial for a general understanding of changes in forest cover, forest structure, and biodiversity across landscapes. We studied forest‐agriculture transitions in southwestern Ethiopia and hypothesized that the presence of coffee (Coffea arabica)decreases deforestation rates because of coffee's importance to local economies and its widespread occurrence in forests and forest margins. Using satellite images and elevation data, we compared changes in forest cover over 37 years (1973–2010) across elevations in 2 forest‐agriculture mosaic landscapes (1100 km2 around Bonga and 3000 km2 in Goma‐Gera). In the field in the Bonga area, we determined coffee cover and forest structure in 40 forest margins that differed in time since deforestation. Both the absolute and relative deforestation rates were lower at coffee‐growing elevations compared with at higher elevations (?10/20% vs. ?40/50% comparing relative rates at 1800 m asl and 2300–2500 m asl, respectively). Within the coffee‐growing elevation, the proportion of sites with high coffee cover (>20%) was significantly higher in stable margins (42% of sites that had been in the same location for the entire period) than in recently changed margins (0% of sites where expansion of annual crops had changed the margin). Disturbance level and forest structure did not differ between sites with 30% or 3% coffee. However, a growing body of literature on gradients of coffee management in Ethiopia reports coffee's negative effects on abundances of forest‐specialist species. Even if the presence of coffee slows down the conversion of forest to annual‐crop agriculture, there is a risk that an intensification of coffee management will still threaten forest biodiversity, including the genetic diversity of wild coffee. Conservation policy for Ethiopian forests thus needs to develop strategies that acknowledge that forests without coffee production may have higher deforestation risks than forests with coffee production and that forests with coffee production often have lower biodiversity value. Efectos de la Administración Cafetalera sobre las Tasas de Deforestación y la Integridad de los Bosques  相似文献   

17.
As drivers of terrestrial ecosystems, humans have replaced large carnivores in most areas, and human influence not only exerts striking ecological pressures on biodiversity at local scales but also has indirect effects in distant corners of the world. We suggest that the multibillion dollar cashmere industry creates economic motivations that link western fashion preferences for cashmere to land use in Central Asia. This penchant for stylish clothing, in turn, encourages herders to increase livestock production which affects persistence of over 6 endangered large mammals in these remote, arid ecosystems. We hypothesized that global trade in cashmere has strong negative effects on native large mammals of deserts and grassland where cashmere‐producing goats are raised. We used time series data, ecological snapshots of the biomass of native and domestic ungulates, and ecologically and behaviorally based fieldwork to test our hypothesis. In Mongolia increases in domestic goat production were associated with a 3‐fold increase in local profits for herders coexisting with endangered saiga (Saiga tatarica).That increasing domestic grazing pressure carries fitness consequences was inferred on the basis of an approximately 4‐fold difference in juvenile recruitment among blue sheep (Pseudois nayaur)in trans‐Himalayan India. Across 7 study areas in Mongolia, India, and China's Tibetan Plateau, native ungulate biomass is now <5% that of domestic species. Such trends suggest ecosystem degradation and decreased capacity for the persistence of native species, including at least 8 Asian endemic species: saiga, chiru (Pantholops hodgsoni), Bactrian camel (Camelus bactrianus), snow leopard(Panthera uncia), khulan(Equus hemionus), kiang (E. kiang), takhi (E. przewalski), and wild yak (Bos mutus). Our results suggest striking yet indirect and unintended actions that link trophic‐level effects to markets induced by the trade for cashmere. Globalización del Mercado de Cachemira y la Declinación de Mamíferos Mayores en Asia Central  相似文献   

18.
The high conservational value of the lichen-rich vegetation and landscape of the marine foreland Ørkenen on the isle of Anholt is treated from a Danish as well as a European perspective. The sensitivity of the lichen-rich vegetation to physical disturbance is emphasized. The impact of invasive species such asPinus mugo as well as the effect of atmospheric deposition of nutrients on the heaths at Anholt is described. Considerations related to the development of a management plan for Ørkenen are presented.  相似文献   

19.
Summary The attraction of Old World leaf beetles in the genusAulacophora to kairomones and parakairomones which are effective lures for New WorldDiabrotica andAcalymma were investigated. Beetles captured on sticky traps baited with single and multicomponent lures were no different from the control traps for two species ofAulacophora. Yellow colored traps and squash blossoms are attractive toAulacophora beetles which detect sub-microgram quantities of cucurbitacins on silica gel. Leaf feeding behavior and flight activity data are correlated with varietal preference of threeAulacophora species. The common response byDiabrotica andAulacophora to cucurbitacins reinforces the two groups' coevolutionary association with the Cucurbitaceae. The apparent lack of a common response toCucurbita blossom volatiles suggests recent evolutionary pathways are substantially different for these two groups of beetles.  相似文献   

20.
Assessing causes of population decline is critically important to management of threatened species. Stochastic patch occupancy models (SPOMs) are popular tools for examining spatial and temporal dynamics of populations when presence–absence data in multiple habitat patches are available. We developed a Bayesian Markov chain method that extends existing SPOMs by focusing on past environmental changes that may have altered occupancy patterns prior to the beginning of data collection. Using occupancy data from 3 creeks, we applied the method to assess 2 hypothesized causes of population decline—in situ die-off and residual impact of past source population loss—in the California red-legged frog. Despite having no data for the 20–30 years between the hypothetical event leading to population decline and the first data collected, we were able to discriminate among hypotheses, finding evidence that in situ die-off increased in 2 of the creeks. Although the creeks had comparable numbers of occupied segments, owing to different extinction–colonization dynamics, our model predicted an 8-fold difference in persistence probabilities of their populations to 2030. Adding a source population led to a greater predicted persistence probability than did decreasing the in situ die-off, emphasizing that reversing the deleterious impacts of a disturbance may not be the most efficient management strategy. We expect our method will be useful for studying dynamics and evaluating management strategies of many species.  相似文献   

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