共查询到20条相似文献，搜索用时 296 毫秒
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利用微生物处理技术对经聚丙烯酰胺脱水后的污泥进行不同方式微生物预处理,研究进料总固体(TS)质量分数为3%、发酵温度为35℃时厌氧消化过程中累积产气量与产甲烷含量、p H值、氨氮和化学需氧量(TCOD)等参数的变化趋势,探索真菌宛氏拟青霉不同预处理方式对脱水污泥厌氧消化过程特性的影响。试验结果表明:微生物预处理脱水污泥厌氧消化技术具有较好的可行性。直接添加宛氏拟青霉和添加宛氏拟青霉预处理2 d的污泥进行厌氧消化反应能够有效提高产气量和产甲烷量,加快水解速率,促进污泥中有机物的有效降解,使产甲烷过程顺利进行。直接添加宛氏拟青霉处理的产甲烷效果最优,其净累积产气量和产甲烷量较纯污泥分别提高85.79%和42.76%,且1 kg污泥可产甲烷12.69 L,较纯污泥提高42.74%。 相似文献
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文章考察了污泥与麦秸共厌氧消化的性能,以初沉污泥、剩余污泥和脱水污泥为原料,用麦秸作为碳源调节污泥C/N为15~25∶1,并进行混合物料的厌氧消化。结果表明:以麦秸作为碳源,与污泥根据不同C/N进行混合,可以提高污泥的厌氧消化性能。当C/N为25∶1时,不同污泥累积产甲烷量最大。初沉污泥、剩余污泥和脱水污泥分别为19670 m L,18790 m L,16300 m L,比单一污泥的累积产气量分别高出43.4%,49.4%,54.4%;并且单位TS与VS产气量比相应单一污泥的分别提高了76.6%,95.4%,322.2%和48.3%,76.0%,250.4%。协同作用结果显示C/N为25∶1时,混合物料产气增加值最大,协同作用贡献率为51.9%~117%。 相似文献
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《中国沼气》2017,(2)
文章以小麦秸秆为原料,研究了不同接种量对产气肠杆菌同步糖化发酵产氢的影响,以期寻求最佳的接种量条件。试验以累积产氢量、产氢速率等指标来分析产气肠杆菌利用小麦秸秆进行同步糖化发酵产氢的潜力及其可行性。结果表明:在以反应液体积为200 mL,底物为5 g小麦秸秆,酶负荷为150 mg·g~(-1)秸秆、初始pH值为6.5,温度为35℃的条件下,接种量为30%时产氢效果最好,此时的累积产气量达到737 mL,累积产氢量达到293mL,最大产氢速率为35.42 mL·h~(-1)L~(-1)。该实验研究为秸秆类生物质同步糖化厌氧暗发酵产氢的进一步研究奠定了基础并提供了科学参考。 相似文献
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文章以茶树叶为发酵原料,厌氧活性污泥为接种物,在接种量为25%,配料TS浓度为7%和恒温35℃下,研究了纤维素酶预处理、高温蒸煮处理与Na OH预处理3种预处理方法对茶树叶厌氧发酵产气性能的影响。试验数据经过改Modified Gompertz模型处理,获得相应的厌氧消化动力学参数(最大累积产气量、最大产气速率和滞留时间),并计算出TS和VS评价指标。分析结果表明:经纤维素酶与Na OH预处理可以不同程度提高产气能力,并缩短发酵启动时间。Modified Gompertz模型拟合不同预处理茶树叶厌氧发酵累积产气量随时间变化具有较好相关性,拟合结果中质量分数4%的Na OH预处理茶树叶产气效果最好,发酵累积产气量2860 m L,最大产气速率127.9m L·d-1,总固体产气率、挥发性固体产气率分别为109.58 m L·g-1,116.73 m L·g-1,优于其他实验组与对照。因此,碱处理可能成为今后茶树叶沼气工程较理想的预处理方法。 相似文献
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生物炭添加对鸡粪厌氧消化产气特性的影响 总被引：2，自引：0，他引：2
在(35±1)℃条件下,采用序批式厌氧消化工艺进行了L9(33)正交试验,以生物炭添加量、生物炭粒径和接种量为因素探索生物炭添加对鸡粪厌氧消化产气特性影响,得出了鸡粪添加生物炭厌氧消化产气的最佳工艺组合。结果表明,各因素对鸡粪厌氧消化产沼气特性的影响从大到小依次为:生物炭添加量(极显著)、生物炭粒径(不显著)、接种量(不显著)。最佳处理组合总固体产气率为345.96 m L/g,挥发性固体产气率为420.62 m L/g,比对照组提高了45.24%。生物炭粒径对甲烷体积分数有极显著影响。 相似文献
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《中国沼气》2016,(5)
文章考察了醋渣和芦苇的混合厌氧消化产气潜力,以4%NaOH预处理前后醋渣、芦苇、两者混合物料进行厌氧消化实验,并对实验结果进行了方差分析和修正Gompertz方程曲线拟合。结果表明:醋渣和芦苇有较好产气潜力,日产甲烷含量均可达58%,单位VS产沼气量为286 m L·g~(-1)VS和331 m L·g~(-1)VS,二者的混合发酵TS和VS去除率可达45.9%和48.9%;与未预处理的醋渣厌氧消化相比,用4%Na OH预处理醋渣,或将醋渣与芦苇混合,或醋渣-芦苇混合后再用4%Na OH处理,其厌氧消化均能明显提升产气性能。可使T90分别缩短4天,6天和10天,单位VS产甲烷量提高30.6%,29.0%和53.2%,TS(VS)去除率提高18.7%(25.0%),38.4%(15.3%)和56.0%(32.2%)。 相似文献
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保障饮水安全是国际社会和中国政府共同关注的问题.滨州市高度重视农村饮水安全保障工作,在对全市农村饮水安全状况调查、监测、评价基础上,找出了存在的主要问题,探索、实践、总结出了全市农村饮水安全工程建设的措施、经验以及管理的成功模式,较好地解决了全市农村饮水安全问题,为不同类型区农村饮水安全工作提供了有益的借鉴. 相似文献
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本文以滨州市2009-2020年间的统计数据为研究样本,构建农业投入产出评价指标体系,采用BCC模型对其农业投入产出效率进行分析。BCC模型分析表明,滨州市农业投入产出的综合效率（TE）较高,且纯技术效率（PTE）高于规模效率（SE）,滨州市农业投入产出的综合效率（TE）对于纯技术效率（PTE）具有较强的依赖性。总体分析,滨州市农业投入产出效率较高,受规模化影响较大,存在一定程度的投资冗余和管理问题。应加大农业科技投入,扩大农业生产规模。 相似文献
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以滨州市2009－2020年的统计数据为研究样本,构建农业投入产出评价指标体系,采用BCC模型分析农业投入产出效率。结果表明,滨州市农业投入产出的综合效率较高,并且纯技术效率高于规模效率,滨州市农业投入产出的综合效率对于纯技术效率具有较强的依赖性。总体上,滨州市农业投入产出效率较高,受规模化影响较大,存在一定程度的投资冗余和管理问题。今后,应加大农业科技投入,扩大农业生产规模。 相似文献
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基于GIS/RS的不同土地利用类型重金属面源污染比较 总被引：1，自引：0，他引：1
针对不同土地利用类型,采样测定土壤重金属质量比背景值;基于DEM数据和遥感影像数据,结合空间信息技术（GIS/RS）,利用RUSLE模型和SCS-CN模型分别核算流域内不同土地利用类型的土壤流失量和地表径流量,在验证模型准确性的基础上,估算重金属非点源污染负荷。研究结果表明：研究区域不同土地利用类型的重金属质量比背景值差异较大,重金属Cu和Pb在工矿用地、草地和住宅用地的背景值较高,在有林地的背景值较低。综合估算随2种主要迁移途径输出的重金属面源污染负荷,重金属Cu总污染负荷量大约为651913kg/a,重金属Pb总污染负荷量大约为268004kg/a。不同土地利用类型中,随土壤侵蚀输出的重金属污染负荷,以疏林地和草地的贡献率最大,有林地和水浇地最小;随地表径流输出的重金属污染负荷,以草地和疏林地的贡献率最大,有林地和旱地最小。 相似文献
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为了探明盐渍土水盐分布和土壤蒸发特性对掺沙的响应特征,以山东省滨州市无棣县"渤海粮仓"科技示范区土壤为研究对象,分析了不同掺沙量(沙-土质量比为0,10％,30％,50％和70％,分别以处理CK,T1,T2,T3和T4表示)对盐渍土水盐运移特征和土壤蒸发的影响.结果表明,0～5000 min,处理T1和T2表层0～1 ... 相似文献
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Production of halophytes using saline waters and soils and feeding them to livestock is one of the most sustainable methods of conservation in desert ecosystems, in addition to accomplishing food production for the people living in these areas. Therefore, to study the possibility of irrigating Kochia (Kochia scoparia L. Schrad) with minimum quantities of highly saline water for use as a fodder crop in arid environments stretching across saline waters, two experiments were carried out in the Research Farm of the Ferdowsi University of Mashhad, Iran. In the salinity experiments, two populations of Kochia, including the Sabzevar and Indian genotypes, were irrigated with ground water having electrical conductivity (EC) of 5, 15, and 20 dS m−1. In the irrigation-treatment experiments, two local populations of Kochia, including Sabzevar and Borujerd, were subjected to four irrigation regimes as follows: complete irrigation (100%), 80%, 60%, and 40% of the water requirements using a saline ground water with EC = 5 dS m−1. Because, the Indian genotype is preferred as an ornamental plant, it is not suitable for increased dry-matter production under high-salinity irrigation water compared to the local genotype (Sabzevar), which is suitable for forage. The Sabzevar genotype produced a large amount of dry matter (7530 kg ha−1), even when irrigated with 20 dS m−1 saline water. The best time for harvesting Kochia for fresh feeding is at the end of flowering (88 days after sowing or DAS), when the biomass is relatively high (6500 kg ha−1) and the leaf-to-shoot ratio, as a quality index, is approximately 50%. The highest green-area index was observed at 15 dS m−1 and decreased at high levels of salinity. Photosynthesis and transpiration rate did not decline significantly with increasing external salinity four weeks after salinization, but increased in both genotypes at 15 dS m−1, indicating that the salinity-tolerance threshold of Kochia for both photosynthesis and transpiration reduction is above this salinity level. The Indian genotype also showed a very low seed yield (210 kg ha−1) at low levels of salinity, whereas Sabzevar produced 1120 kg ha−1 seed under the same conditions. Different irrigation regimes had a significant effect on the biomass and seed production of Kochia. The highest forage yield was obtained from complete irrigation, with 11.1 Mg ha−1 dry material. Sabzevar local population represented a better performance in terms of all characteristics, except accumulation of inflorescence dry matter, and no significant effects were recorded. In conclusion, Kochia's high foliage production capacity in the presence of salinity and limited irrigation make this plant suitable for use as an alternative forage crop in harsh environmental conditions. There is a wide range of intraspecific variation in K. scoparia, but more investigation is needed to introduce it as a cash crop. 相似文献
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Pierre-Olivier Malaterre 《Irrigation and Drainage Systems》1995,9(4):297-327
This article suggests and defines a characterisation of irrigation canal regulation methods, based on four criteria: considered variables (controlled, measured, and control action variables), logic of control, design method (structure and technique) and field implementation (configuration and device). Depending on the chosen criterion and partition rule, different classifications can be built from this characterisation. In conclusion, a structured characterisation table of the main published canal regulation methods is presented.Abbreviations ASCE
American Society of Civil Engineers
- CACG
Compagnie d'Aménagement des Coteaux de Gascogne
- CARA
Compagnie d'Aménagement Rural d'Aquitaine
- CARDD
Canal Automation for Rapid Demand Deliveries
- CEMAGREF
Centre National du Machinisme Agricole, du Génie Rural, des Eaux et des Forêts
- CNABRL
Compagnie Nationale d'Aménagement du Bas — Rhône Languedoc
- ELFLO
Electronic Filter and Level Offset
- FB
Feedback or closed — loop control
- FB
dn
Feedback or closed-loop downstream control
- FB
mi
Feedback or closed-loop mixed control
- FB
up
Feedback or closed-loop upstream control
- FF
Feedforward or open-loop control
- GPC
Generalised Predictive Control
- LQR
Linear Quadratic Regulator
- MIMO
Multiple Inputs, Multiple Outputs
- nI mO
n Inputs, m Outputs
- P
Perturbation
- P
Estimation of perturbations
- PID
Proportional, Integral, Derivative Controller
- PIR
Contrôleur Proportionnel, Intégral, Retard (PI Delay controller)
- Q
Discharge in the canal
- Q
dn
Downstream discharge in the canal
- Q
in
Intermediate discharge in the canal
- Q
up
Upstream discharge in the canal
- SCP
Société du Canal de Provence
- SISO
Single Input, Single Output
- U
Control action variable
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V
Volume in a canal pool
- V
Elementary control action variable
- w
Regulator gate opening
- Y
Controlled variable
- Y
c
Target controlled variable
- y
Water elevation
- y
dn
Downstream water elevation of the pool (therefore upstream of a regulator)
- y
in
Intermediate water elevation in the pool
- y
up
Upstream water elevation of the pool (therefore downstream of a regulator)
- Z
Measured variable 相似文献
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Shortage of organic matter hinders agricultural production in the Sahel, and this lack of enough organic matter is more severe for peri-urban horticulture, which depends heavily on it. Alternative sources of organic matter that offer new options for peri-urban horticulture can help reduce the potential for conflict over finite resources between traditional crop production and peri-urban horticulture. Both agronomic and economic evaluations of an organic amendment called heated sewage sludge (HSS) were conducted in the research station of International Crops Research Institute for the Semi-Arid Tropics (ICRISAT)-Niamey, Niger, West Africa. For this study, HSS, a material imported from Japan, applied at a dosage application equivalent to 20.0 kg 100 m−2 on lettuce fields led to production levels as high as those of conventional methods, and the yield became even higher than those of conventional methods when the dosage was increased to 50.0 kg 100 m−2 and 100.0 kg 100 m−2. Even though HSS was imported, its benefits outweighed its cost, as evidenced by the positive net returns. Since profitability in peri-urban horticulture is much higher than that of traditional crop production, the results of this study imply that if adopted, the use of HSS can lead to increased availability of organic matter for traditional cropping systems. 相似文献