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NaCl和KCl盐度对厌氧污泥的驯化及对比产甲烷活性的影响 总被引：2，自引：0，他引：2
研究了NaCl和KCl盐度对厌氧污泥的驯化及盐度对厌氧污泥比产甲烷活性的影响.试验表明,当NaCl和KCl盐度为0～10 g·L-1时,絮状污泥A,B的COD去除率均达到87%以上;当NaCl和KCl盐度为20g·L-1时,絮状污泥A,B的COD去除率分别为84%和74.6%;当NaCl和KCl盐度为30 g·L-1时,絮状污泥A和B均有较差的COD降解效果,且KCl对COD降解的抑制影响大于NaCl.经过驯化后的污泥,10 g·L-1 NaCl或KCl都会对颗粒污泥产生SMA促进作用;10 g·L-1 NaCl对絮状污泥SMA产生轻微抑制,而10 g·L-1 KCl对絮状污泥SMA不会产生抑制影响.20 g·L-1 NaCl或KCl会对颗粒污泥SMA产生轻微抑制,而20 g·L-1 NaCl或KCl都对絮状污泥SMA产生中度抑制.30 g·L-1 NaCl或KCl对颗粒污泥和絮状污泥SMA均产生强烈抑制. 相似文献
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厌氧污泥颗粒化对乙酸盐代谢的影响 总被引：1，自引：0，他引：1
本文报道了厌氧污泥颗粒化对乙酸盐裂解产甲烷的影响。研究指出,当乙酸盐浓度在2400—3600mg/1时,颗粒污泥的乙酸盐分解反应为零级反应,其最佳负荷为4～7gNaAc/g·vss·d,乙酸盐的抑制浓度为4000mg/1。厌氧污泥颗粒化提高了污泥的耐乙酸能力,拓宽了呈零级反应的乙酸盐浓度范围。同分解乙酸盐的产甲烷纯培养物相比,颗粒污泥的 Ks 升高。 相似文献
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在中温(35℃±1℃)厌氧条件下,以葡萄糖为有机碳源,采用间歇实验方法,研究了不同Fe3 ,Cu2 浓度对厌氧颗粒污泥比产甲烷活性及COD去除率的影响。结果表明,当Fe3 浓度为1 mg.L-1~25 mg.L-1时,其比产甲烷活性(SMA)在162.1~254.4 mL.g-1d-1之间,COD去除率最高可达92%,Fe3 起促进作用的最佳浓度为22 mg.L-1。当Cu2 浓度为1~25 mg.L-1时,其SMA在153.6~266.4 mL.g-1d-1之间,COD去除率最高可达92.8%。Cu2 起促进作用的最大浓度为20 mg.L-1,其中最佳促进浓度为10 mg.L-1。 相似文献
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UASB工艺处理高浓度Vc生产废水的试验研究 总被引：5，自引：0，他引：5
采用UASB反应器对高浓度Vc生产废水进行了实验室处理研究。试验结果表明:Vc废水的厌氧处理运行性能因水质不同而存在很大差异。转化母液的容积负荷在8kg COD.m-3d-1以下时,去除率基本稳定在65%以上。当负荷继续提高时,去除率会急剧下降并保持在50%左右。精制母液和提取母液的容积负荷在10kgCOD.m-3d-1时去除率仍能稳定在70%以上。这些表明当两套反应系统的容积负荷控制在一定范围时,UASB反应器可以有效去除大部分的有机污染物。同时也说明转化母液废水中存在相当数量的难生物降解化合物。GC/MS水质分析结果表明,其中含有大量10C以上的长直链或双苯环等结构的难生物降解物。系统中厌氧颗粒污泥的产甲烷活性随着反应器中污泥驯化的进行和负荷的增加而上升。 相似文献
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为加快颗粒污泥的形成速率,解决颗粒污泥培养时间长、污泥活性差的问题,通过向厌氧池中加入人工污泥床层快速培养厌氧颗粒污泥,实现厌氧颗粒污泥培养的可控性。采用电子扫描电镜对培养好的厌氧颗粒污泥微观形态进行观察,通过电子显微镜观察颗粒污泥形态变化,确定颗粒污泥分形维数。以颗粒污泥的数量分布、平均粒径、含水率为表征参数,建立厌氧颗粒污泥的吸附动力学模型。结果表明,厌氧颗粒污泥附着在人工污泥床层上,由于人工污泥床层均匀分布使得形成粒径为4~5 mm的厌氧颗粒污泥质量占总污泥质量的80%,分形维数在2.68~2.83之间,颗粒轮廓清晰,颗粒污泥在水力负荷达到5 kg/(L·d)时,人工污泥床层上形成的颗粒污泥质量浓度仍保持在5.84 kg/m3,颗粒污泥耐冲击能力强;针对吸附在人工污泥床层上的厌氧颗粒污泥建立吸附动力学模型,发现反应池中污泥的内循环可以促进厌氧颗粒污泥的形成,当厌氧反应池任意断面颗粒污泥向上和向下的污泥浓度之比为0.8~0.9时,形成的厌氧颗粒污泥吸附性能最强。 相似文献
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采用规模为240 m3.d-1的厌氧颗粒污泥膨胀床(EGSB)反应器对生活污水进行研究。试验结果表明:采用此系统处理生活污水,出水水质良好。COD的去除率在73%~90%之间,出水的COD值小于70 mg.L-1,SS的去除率在70%~95%之间,停留时间为2 h的产气率在1.26 m3.m-3d-1,出水的氨氮、乙酸值比进水的高;硝酸根离子出水值比进水值低。 相似文献
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为增强产氢颗粒污泥性能,通过UASB反应器进行中温连续产氢试验,探索有机负荷对产氢颗粒污泥性能的影响。结果表明:随着有机负荷的逐渐增加,产氢速率、颗粒污泥粒径、胞外聚合物(EPS)含量逐渐增加,颗粒污泥沉降性能和强度明显提高。在有机负荷为80gCOD/(L.d)时,产氢速率达到最大值8.6L/(L.d);当有机负荷进一步增加至90gCOD/(L.d)时,紧密结合的胞外聚合物(TB-EPS)的含量减少,松散附着的胞外聚合物(LB-EPS)的含量增加,导致颗粒污泥沉降性能和强度变差,产氢速率降低。因此,适度增加有机负荷可增强产氢颗粒污泥的强度及沉降性能,进而提高其产氢效率。 相似文献
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Overland water and salt flows in a set of rice paddies 总被引：1，自引：0，他引：1
E. Playn O. Prez-Coveta A. Martínez-Cob J. Herrero P. García-Navarro B. Latorre P. Brufau J. Garcs 《Agricultural Water Management》2008,95(6):645-658
Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m−1) and an infiltration rate of 5.8 mm day−1. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day−1), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day−1 was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration. 相似文献
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瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。 相似文献
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对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。 相似文献
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对《种子法》存在问题的探讨 总被引：1，自引：0，他引：1
李鹏 《农业机械化与电气化》2011,(6):129-130
《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。 相似文献
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About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered. 相似文献
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在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。 相似文献
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Gunter Wriedt Marijn van der Velde Alberto Aloe Fayçal Bouraoui 《Agricultural Water Management》2009,96(5):771-789
We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications. 相似文献
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在介绍粉质仪和拉伸仪结构和原理的基础上,探讨了粉质曲线中吸水率、形成时间、稳定时间、弱化度和评价值等指标与面粉品质的关系,以及如何根据拉伸曲线中面团最大拉伸阻力、延伸度和拉伸曲线面积等指标来评价面团品质,并结合生产实际,概述了粉质仪和拉伸仪在面粉生产中的作用。 相似文献
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车辆ABS控制算法的研究及探讨 总被引：1，自引：0，他引：1
对现代汽车的ABS控制算法作了一些简单的介绍,同时指出了它们的一些缺陷,相应地提出了几种对ABS的其它控制方法并加以探讨,其中着重论述了ABS门限值控制算法中参考车速的确定方法和基于附着系数的控制算法。 相似文献