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1.
物化预处理-水解酸化-接触氧化法处理选矿废水   总被引:1,自引:0,他引:1  
对某浮选厂浮选废水进行混凝沉淀+活性碳吸附预处理,然后进入生化系统,厌氧池、好氧池停留时间为10h.结果证明:进水COD为400~700mg/L,出水74~145 mg/L,去除率达75.8%以上,首次成功地将生物法应用到铅锌选矿废水的处理,若对该工艺进行适当调整,完全可以使出水达到排放或回用标准.  相似文献   

2.
采用混凝沉淀-两段接触氧化法处理制革区综合制革废水,经过半年多稳定运行,系统COD去除率达到96%,硫化物去除率达到99.5%,处理后出水的各项指标完全达到了国家《污水综合排放标准》(GB8978-1996)制革行业废水二级标准。对废水处理系统的工艺作了简单介绍,对系统调试、运行结果进行了分析与总结。  相似文献   

3.
为解决低浑浊度煤气化含油废水混凝气浮药剂投加量大、效率低的问题,本文开展混凝剂污泥共投加提高气浮工艺除污染能力的研究.研究表明,剩余污泥的投加明显改善了混凝沉淀对油类污染物的去除,在剩余污泥投加量从0增加到1200 mg·L~(-1)时,含油量去除率由28.1%提升至44.1%.聚合氯化铝(PAC)、聚丙烯酰胺(PAM)和剩余污泥的最适宜投加量分别为150、2、1200 mg·L~(-1).A/O工艺二沉池剩余污泥强化混凝气浮效果最佳,充分气浮反应后对含油量的去除率由46%提升至84%,且气浮池油水分离区微气泡的稳定性得到明显改善.  相似文献   

4.
针对微污染水,就高锰酸钾预氧化技术与与饮用水常规混凝沉淀工艺组合联用开展了一些试验研究。结果表明:高锰酸钾的预氧化作用有助于PAC混凝沉淀工艺对原水中有机污染物的去除;KMnO4和聚合氯化铝(PAC)的投加方式对原水耗氧量的去除率有明显影响;KMnO4预氧化有一个最佳时间;高锰酸钾预氧化-混凝沉淀组合微污染水处理工艺,对原水pH值的波动有比较好的适应性。  相似文献   

5.
在混凝剂筛选、不同水质处理效果比较和生物处理实验的基础上,优化确定出混凝气浮—生物接触氧化组合处理工艺。工程实践证实:将含油乳化液与总排口水混合,混凝气浮的COD去除率可达52.4%;接触氧化的COD去除率为81%;处理出水达到国家排放标准一级指标要求。  相似文献   

6.
分别研究了SBR法,水解酸化预处理及工艺组合对餐饮油脂废水的处理效果,确定了最佳处理工艺.同时,实验考察了曝气时间、污泥沉降比、溶解氧等因素与处理效果的关系,从而确定最佳的反应条件.结果表明,在曝气时间为2 h、SV为30%、DO为3 mg.L-1的条件下,SBR工艺处理餐饮油脂废水中COD、动植物油脂的平均去除率分别达到91.2%、82.5%;经水解酸化预处理,出水COD、动植物油脂平均浓度分别为1062.90 mg.L-1、50.66 mg.L-1,去除率均值分别为36.9%、83.5%;经水解酸化+SBR组合工艺处理后,废水出水COD平均浓度为93.66 mg.L-1,去除率高达94.8%,出水动植物油脂浓度为4.9 mg.L-1,去除率为98.25%.  相似文献   

7.
使用富集、稀释涂平板的方法从制药、染料、化工及精细化工、食品等多家工厂的混合高浓度难降解化工废水中筛选到8株细菌,经16S rDNA鉴定为Bacillus aquimaris、Enterobacter、Pseudomonas putida、Microbacterium、Agrobacterium、Alpha proteobacterium、Planococcus rifietoensis,其中两株细菌为Bacillus aquimaris。对各单一菌种生长条件的研究表明,各菌种生长的最适pH为7,最适接种量为15%(v/v),最适生长温度为37℃,其中Pseudomonas putida的最适生长温度为30℃。在最适生长条件下,研究了各单一菌种及不同组合的混合菌种对废水的降解效果,结果表明在单一菌种中Pseudomonas putida对废水的降解效果最优,混合菌的降解效果优于单一菌种的降解效果,混合菌可将废水COD由1 249 mg/L降至97 mg/L,比普通活性污泥对废水的去除率提高了14.7%。  相似文献   

8.
周汇  买文宁  肖珊 《环境化学》2012,31(10):1631-1636
通过采用负载FeSO4活性炭、CuSO4活性炭和一般活性炭作为微波催化剂处理抗生素废水的对比实验,研究不同负载方法对抗生素制药废水COD去除的差别,结果表明,负载FeSO4的活性炭作为催化剂的微波处理系统对COD的去除率最高.以微波诱导负载FeSO4的活性炭为催化剂对抗生素制药废水进行处理,结果表明,增大负载FeSO4活性炭质量,微波辐射时间和微波功率,均有利于抗生素废水中COD的去除,但各影响因素的取值并不是越大越好.对微波诱导负载FeSO4活性炭催化工艺处理抗生素废水进行反应动力学分析,结果显示,过程近似一级反应,其动力学方程为:lnC0/C=0.1413t+5.4121,r=0.9876.反应动力学常数为0.1413 min-1.  相似文献   

9.
流化床三维电极电催化氧化深度处理焦化废水   总被引:1,自引:0,他引:1  
研究了以焦粒为粒子电极的流化床三维电极反应器对二级生化处理后的焦化废水进行深度处理。结果表明:采用以焦粒为粒子电极的流化床三维电极反应器能有效降解废水中的有机物,COD去除率依赖于粒子投加量、电流密度、电导率、pH值、曝气量等操作参数的影响。在电导率(以S计)为7.1 m.cm-1,曝气量为160 L.h-1,电流密度(以A计)为48 m.cm-2,pH值为5.0,投加量30 g.L-1时,电解30 min,COD的去除率超过60%,表明流化床三维电极反应器在焦化废水深度处理中有很好工程应用前景。  相似文献   

10.
本文研究了一种新型消灭农作物害虫的药物——亚洲玉米螟性信息素在合成过程中排放的废水的处理方法。经混凝沉降—氧化—活性碳吸附三级处理后,废水的COD值下降77.1%、有机磷去除率达90%以上、硫化物去除率达90%以上,恶臭基本消除。  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.
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   

16.
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   

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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