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1.
集约化蛋鸡场鸡粪混合液资源化无害化处理   总被引:3,自引:0,他引:3  
本研究采用离心分离法、高温好氧发酵法和中温厌氧发酵对鸡粪混合液进行资源化、无害化综合处理。实验结果:鸡粪回收率53.0%~91.8%;发酵后,鸡粪含水率31%~44%;废水厌氧处理的体积负荷12.14kg·COD_(cr)/m~3·d;产沼比0.52m~3/kg·COD_(cr);甲烷含量>70%。通过综合处理,COD_cr)、BOD_5的总去除率均大于90%。实验表明,本工艺具有投资少、能耗低、费用省和效益比较明显等优点。  相似文献   

2.
UASB反应器处理味精生产废水的研究   总被引:5,自引:0,他引:5  
曹业始  张辉 《环境化学》1991,10(4):19-25
用厌氧颗粒污泥接种的UASB反应器经驯化后,仅一个月处理味精生产废水容积负荷,由1.87kg COD/m~3·d提高到18.9kg COD/m~3·d,进料浓度COD4500—5000mg/L,去除率约80%,产气正常,抗负荷变化性能良好。 反应器工艺设计参数:进料浓度COD 5000mg/L,容积负荷10—15kg COD/m~3·d,去除率80%,操作温度38±1℃。提出了处理味精生产废水的整个工艺流程和有待进一步试验解决的问题。  相似文献   

3.
本试验利用未沉淀的生活污水(COD在432mg/L左右)在7℃~22℃温度下自接种启动容积为5L的升流式厌氧污泥层反应器.初始有机容积负荷为1.75kgCOD/m~3·d,水力停留时间为5.9h.运行57天时出现了颗粒污泥,此时污泥负荷为0.33kgCOD/kgVSS·d.106天后反应器达到稳定的处理效果.当温度在20℃左右,HRT为6h,COD去除率达81.2%,出水COD低于100mg/L.培养出的颗粒污泥呈黑色,粒径在0.5mm~3mm之间,比重为1.04, SVI在15左右,有较好的沉降性和产甲烷活性.污泥中产甲烷菌主要是素氏甲烷丝菌.  相似文献   

4.
UASB反应器处理COD/SO4^2—=0.5有机废水试验   总被引:1,自引:0,他引:1  
本文对使用UASB反应器处理COD/SO42-=0.5有机废水(温度为35±1℃)进行了较系统的研究。试验结果表明:(1)UASB反应器可以较好地处理COD/SO42-=0.5的有机废水,COD去除负荷与SO42-去除负荷之比(ΔCOD/ΔSO42-)在1.0左右。当COD和SO42-的进水负荷分别为1.036g/L/d和2.086g/L/d时,其去除率可达70%和30%以上;而当COD和SO42-的进水负荷分别为2.489g/L/d和4.977g/L/d时,去除率仍可达50%和30%。(2)反应器中的细菌主要是硫酸盐还原菌和发酵性细菌,而产甲烷菌含量很少。(3)反应器中硫化物的抑制浓度为300mg/L,相应的硫化氢浓度为129mg/L。  相似文献   

5.
厌氧-好氧一体式折流板反应器处理淀粉废水的启动运行   总被引:1,自引:0,他引:1  
采用厌氧-好氧一体式折流板反应器,处理马铃薯淀粉废水,以淀粉废水排放口底泥作为接种污泥,可以实现快速启动。启动过程的结果表明:在温度为2 5℃~35℃,总水力停留时间(HRT)为5 4h ,容积负荷从0 .5kg/ (m3 ·d)逐渐升高到3.0 8kg/ (m3 ·d)时,第11d就将反应器启动成功,前3级厌氧反应器总的去除率达到75 % ,厌氧-好氧一体式折流板反应器总的去除率达到96 %。而后逐渐提高容积负荷,当容积负荷为10 .0kg/ (m3 ·d)时,COD去除率最高为96 % ,出水水质达到或接近国家污水排放二级标准(GB 8978- 96 )。  相似文献   

6.
工(产)业园区内企业在紧急情况下排放的污水中,有毒物质会影响污水处理厂活性污泥微生物的活性,甚至导致微生物的死亡.基于此,利用CASS工艺的特点检验微生物系统抗冲击毒性的能力,通过不同的配比浓度调整试验水样中Cu~(2+)、Ni~(2+)的质量浓度,监测CASS系统进出水的Cu~(2+)、Ni~(2+)、COD_(cr)指标,用以判断微生物系统是否受到影响,进而确定CASS微生物系统抗毒性冲击的临界点.结果表明:Cu~(2+)质量浓度小于3.0 mg·L~(-1),Ni~(2+)质量浓度小于5.0 mg·L~(-1),时,CASS 工艺微生物抵抗含Cu~(2+)、Ni~(2+)锻造添加剂废水的毒性能力较强,对Cu~(2+)、Ni~(2+)、COD_(cr)的去除率均可以达到80%;当Cu~(2+)质量浓度大于3.0 mg·L~(-1),Ni~(2+)质量浓度大于5.0mg·L~(-1)时,CASS工艺微生物对毒性抵抗能力显著降低,活性受到严重破坏,对CU~(2+)、Ni~(2+)、COD_(cr)去除率下降至60%以下.所以可以确定CASS工艺微生物抵抗含Cu~(2+)、Ni~(2+)锻造添加剂废水毒性的最高质量浓度限值,Cu~(2+)为3.0 mg·L~(-1),Ni~(2+)为5.0mg·L~(-1).为污水处理厂实际运行工程中避免活性污泥微生物系统受毒性冲击而导致运行瘫痪提供参考依据.  相似文献   

7.
针对印染废水中COD_(cr)值日渐增高,BOD_5/COD_(cr)值日渐降低的趋势,为改善生化法处理印染废水水质条件,降低生化处理负荷,提高水质可生化性能,本文以不同水质编制试验方案,以探求最佳工艺特点,COD_(cr)值与投药量关系,絮凝前后水质可生化性能变化趋势。试验结果证实:化学絮凝法处理中长纤维染色废水,对降低水质COD_(cr)值、脱色、改善水质可生化性能是行之有效的。  相似文献   

8.
沸石对污水中BOD5和CODcr净化效果的研究   总被引:6,自引:0,他引:6  
研究了天然沸石和活化沸石对污水中BOD_5和COD_(cr)净化效果的影响。结果表明,天然沸石对BOD_5的净化效果较好,而对COD_(cr)的效果较差,沸石适宜的用量和粒径为2.5g/L和80目。活化沸石对污水中的净化效果显著优于天然沸石,而且在处理24h后就能达到较好的净化效果。  相似文献   

9.
COD对颗粒污泥厌氧氨氧化反应性能的影响   总被引:8,自引:1,他引:8  
研究了COD对颗粒污泥厌氧氨氧化反应的影响,并对颗粒污泥的厌氧氨氧化脱氮性能进行了分析.厌氧颗粒污泥取自实验室长期运行的EGSB生物脱氮反应器,实验用水为人工配水,以葡萄糖为有机碳源;主要考察了COD对NH4 -N、NO2--N、NO3--N和TN去除的影响.结果表明:当进水不含COD时,反应器对NH4 -N、NO2--N和NO3--N和TN的去除率分别为12.5%、29.1%、16.1%和16.3%;当COD浓度分别为200mg/L、350mg/L和550mg/L时,反应器对NH4 -N的去除率分别为14.2%、14.2%和23.7%,对NO2--N的去除率均接近100%,对NO3--N的去除率分别为94.5%、86.6%和84.2%,对TN的去除率分别为50.7%、46.9%和50.4%,COD去除率分别为85%、66%和60%.分析发现,在反应初期,氨氮的去除主要通过厌氧氨氧化过程实现,随着反应的进行,反硝化菌活性逐渐提高,传统的反硝化过程占优势.同时还观察到,在反应初期COD对氨氮去除的抑制作用非常明显.图2参21  相似文献   

10.
味精浓废水生物处理优化工艺   总被引:4,自引:0,他引:4  
本文阐述两相厌氧消化法与缺氧—厌氧消化法处理味精浓废水的比较试验.进水为6×10~4mg/L~8×10~4mg/L时,两相厌氧消化法COD去除率为78%,产气率为0.15m~3/kgCOD,CH_4含量为50%.缺氧—厌氧消化法COD去除率为82.2%,产气率为0.23m~3/kgCOD,CH.含量达65%.两种方法均可使出水pH值由3.2上升至7.0以上.氯离子和氨氮的去除不明显.综合上述结果与运行管理的稳定程度均是缺氧——厌氧消化法优于两相厌氧消化法.  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.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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   

17.
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.  相似文献   

18.
Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.  相似文献   

19.
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.  相似文献   

20.
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   

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