高浓度高氨氮鸡粪沼气工程运行分析

培养驯化耐高氨氮厌氧菌种是解决厌氧消化过程氨抑制的一条非常有效的措施,文章以杭州能源环境工程有效公司已建成并稳定运行多年的工程项目为例,探讨分析鸡粪高浓度高氨氮厌氧消化的工艺流程及运行参数。工程采用耐高氨氮厌氧消化技术,鸡粪厌氧进料TS浓度可达8%~12%,沼液氨氮浓度超过5500 mg·L-1,厌氧产沼气过程不受影响(鸡粪TS产气率仍能超过500 m3·t-1),从而实现鸡场粪污的高效稳定化处理。     

氨水与冻融复合改性玉米秸秆对其高温厌氧消化过程的影响

文章采用CSTR高温反应器进行改性玉米秸秆厌氧消化实验,观察3个有机负荷(1.6,1.8和2.0 g·L^-1d^-1)阶段下高温厌氧消化产甲烷性能变化和过程指标变化。实验结果表明,氨-冻融组玉米秸秆高温厌氧消化产甲烷性能最好,其单位VS产甲烷量在3个有机负荷条件下分别为314,309和306 mL·g■,比未处理组分别提高了16.1%,19.3%和22.6%,比水-冻融提高了8.9%,10.6%和13.8%。且随着有机负荷的提高,3个高温系统厌氧消化过程指标(挥发性脂肪酸、pH值、氨氮、碱度和溶解性COD)值呈现出了一定的规律,且稳定性均良好,其中,氨-冻融组厌氧消化系统过程中氨氮值为658～1148 mg·L^-1,未达到抑制值。因此,对于工程应用来说,氨-冻融复合改性可作为提高玉米秸秆厌氧消化产甲烷量和生物降解性的一种重要方式。     

铜离子对厨余垃圾厌氧消化效率的影响研究

针对厨余垃圾厌氧消化环境脆弱和甲烷产量不高的问题,该试验通过研究铜离子对厨余垃圾厌氧消化的影响来提高甲烷产量.在35℃恒温振荡箱中,添加不同浓度(10,15,30和50 mg·L-1)的铜离子研究其在厨余垃圾厌氧消化过程中的甲烷产量,pH值,氨氮,COD和酶活性.结果表明,铜离子浓度为10～15 mg·L-1时甲烷产量...     

添加猪粪对稻草厌氧消化产气性能的影响

文章以稻草为发酵主原料,考察添加不同猪粪量对稻草厌氧消化产气性能的影响。结果表明,添加适量的猪粪能改善稻草厌氧消化的产气性能,均衡日产气量,避免单一稻草厌氧消化日产气量的大幅度波动;添加大量猪粪不利于混合物料被充分利用产气,而且会造成消化液中氨氮的积累和SCOD值的增加;当添加的猪粪量达到稻草与猪粪的VS比为3∶1时,物料厌氧消化的单位TS总产气量最大,产气量值为310 m L·g-1TS,比单独稻草厌氧消化的单位TS总产气量高4%。     

硫酸盐对厌氧消化的影响

硫酸盐对厌氧消化的影响钱泽澍（浙江农业大学，杭州，３１００２９）在有机物的厌氧消化过程中，硫酸盐对厌氧消化影响的研究在国外已有不少报道。国内有些单位也在从事该项研究。本文对硫酸盐在厌氧消化中的作用作一概述，与有关研究者共同探讨。１硫酸盐还原细菌在厌氧...     

城市垃圾渗滤液厌氧消化试验研究

文章通过试验分析30℃条件下城市垃圾渗滤液的沼气发酵潜力。试验以垃圾渗滤液为发酵原料,实验室长期驯化的秸秆类厌氧活性污泥和猪粪为接种物,在30℃条件下,进行批量式沼气发酵试验。结果表明:接种物的种类和性质影响垃圾渗滤液的厌氧消化过程。以秸秆类厌氧活性污泥作为接种物,城市垃圾渗滤液的原料产气率为0.80 m L·g~(-1)COD,COD降解率为78.83%,氨氮含量提高了1.38倍,总磷含量有所下降,降解率为9.7%。但以长期驯化的猪粪为接种物,垃圾渗滤液厌氧消化过程发生酸化,不能成功启动。     

不同生物预处理方式对污泥厌氧消化过程性能的影响

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%。     

小球藻与小麦秸秆联合厌氧消化产沼气研究

通过分批厌氧消化实验,文章考察了异养小球藻和小麦秸秆的厌氧消化性能。在实验条件下ISR(污泥底物比)=3∶1,TS=6%,异养小球藻和小麦秸秆(C/N=10∶1)的累积沼气产量分别为5515和973 m L;联合厌氧消化(C/N=20∶1)时,获得最高的沼气和甲烷产率,分别为694.4和342.69 m L·g~(-1)。厌氧消化结束后,沼液中的氨氮和COD分别为953 mg·L~(-1)和72000 mg·L~(-1)。结果表明,异养小球藻和小麦秸秆联合厌氧消化可以获得更好的厌氧消化性能。     

硫酸盐还原作用对厌氧消化过程的影响与控制

本文综述和分析了厌氧消化过程中,硫盐酸还原作用的影响及控制方法。对于硫酸盐还原细菌的种类及生长特性进行了归纳,同时指出:硫酸盐还原作用对厌氧消化的抑制影响主要来自二方面:一是基质的竞争性利用;二是还原产物硫化物对细菌生长的抑制作用。根据不同的过程原理,控制硫酸盐还原作用的方法有:物理法—空气或纯O_2充气技术;化学法—投加化学药剂;生物法—二相厌氧消化工艺,其中以生物法最有应用价值。有关二相厌氧消化工艺的运行特性与微生物学基础,处理高浓度硫酸盐废水的可行性等,文章进行了分析探讨。     

水热预处理对不同污泥性质及厌氧消化性能的影响

以不同来源污水处理过程产生的污泥为研究对象,考察了水热预处理对污泥粘度、氨氮质量浓度、pH值、TS(总固体)组分含量及厌氧消化性能的影响,并评估了不同污泥的水热改性效果及其中试条件下厌氧消化增益情况。研究结果表明,同等水热温度处理下,污泥粘度、氨氮质量浓度、pH值受污泥来源的影响较大。水热预处理对不同污泥都具有良好的改性效果,水热温度达到170℃后,污泥性质基本不变。各种污泥挥发性固体(VS)产气率随有机负荷的提高无显著性变化,但运行情况存在差异。不同污泥在水热预处理后厌氧消化产气性能均明显提升,VS产气率增加比例差异较大,北京、上海、山东三地污泥VS产气率增加25. 2%～69. 8%,由于广西污泥为纯剩余污泥,水热处理后VS产气率增加高达101. 6%～133. 8%。VS产气率的增加量相差不大,且随自身产气性能改变的波动较小,增加量为83～218 m~3/t(平均143 m~3/t)。水热预处理后污泥流动性能提高,可实现厌氧消化的高浓度、高负荷进料,反应器减容率可达38%～71%。     

Overland water and salt flows in a set of rice paddies

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.     

瓦房店市水果生产标准化发展研究

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。     

金谷子耐旱TG118引种试种及推广应用

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。     

对《种子法》存在问题的探讨

《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。     

Review of the Egyptian experience in implementing land drainage projects

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.     

和谐社会理论建设的几点哲学思考

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。     

A European irrigation map for spatially distributed agricultural modelling

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.     

粉质仪和拉伸仪在面粉生产中的应用

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。     

农村信息化服务的现状及建设措施

分析当前我国农村信息化服务的现状,提出加强农村信息化服务的新举措。     

车辆ABS控制算法的研究及探讨

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。