膨胀颗粒污泥床(EGSB)反应器的研究进展

本主要介绍了厌氧膨胀颗粒污泥床（GESB）反应器的特性及研究进展。EGSB反应器是在USAB反应器的基础上发展起来的第三代厌氧生物反应器,与UASB反应器相比,它增加出水再循环部分,使得反应器内的液体上升流速体上升流速远远高于UASB反应器,污水和微生物之间的接触加强了,正是由于这种独特的技术优势,使得它可以用于多种有机污水的处理,并且获得较高的处理效率,本还展望了EGSB反应器今后的发展前景。     

ABR反应器中颗粒污泥的微生态特性

以葡萄糖和生活污水人工配制的废水对ABR反应器中颗粒污泥的微生态特性进行了研究.研究表明,ABR反应器中呈现出明显的相分离特征,颗粒污泥微生物随反应器隔室不同的微生态环境而有不同的优势菌属.高负荷条件下(反应器前端隔室)的产酸颗粒污泥颗粒大、表面粗糙,其优势微生物为产气杆菌属,而位于反应器中部隔室的产甲烷颗粒污泥结构紧密,表面光滑,其优势菌属为甲烷球菌;低负荷条件下(反应器后端隔室)的颗粒污泥颗粒小、结构较松散,其优势菌属为甲烷丝菌属.据此,分析了ABR中颗粒污泥的形成机理.     

高浓度变性淀粉生产废水厌氧生物处理

利用膨胀颗粒污泥床(EGSB)反应器厌氧生物处理高浓度变性淀粉生产废水,通过逐步提高厌氧反应器的有机负荷在65天内完成厌氧反应器的启动,主要标志为颗粒化污泥的出现以及稳定的有机物(以COD表示)去除效果(达到74%),有机负荷达到6kg/m3.d.通过工程实践表明EGSB厌氧反应器可以有效地降解高浓度变性淀粉生产废水中的有机物.     

EGSB反应器的动力学模型研究(1)--模型的建立

本文基于Monod方程，对膨胀颗粒污泥床（EGSB）反应器建立了动力学模型。该模型将厌氧体系中的微生物简化为两大类，即产酸菌和产甲烷菌，并考虑了其生长和衰亡的动力学过程；将厌氧消化过程简化为碳水化合物的发酵产酸、挥发性脂肪酸产甲烷两个子过程；还引入了厌氧缓冲体系中的各类物化平衡；在已知进水水质和有关运行参数的条件下，模型可以预测出EGSB反应器出水COD和VFA浓度、反应器内部pH值和碱度变化、沼气产量及气相组成。     

EGSB反应器内厌氧颗粒污泥性质的研究

本文研究了处理自配有机废水小试EGSB反应器内颗粒污泥的性质。结果表明，随着运行时间和水力上升流速（Vup)的增加，颗粒污泥粒径逐渐增大，且污泥床下部污泥的粒径大于污泥床上部的；颗粒污泥在清水中的静沉速与颗粒粒径成正比，二者之间的关系可用Allen公式来描述；在扫描电镜下观察发现，颗粒污泥表面和内部的细菌均存在着分区生长的现象。     

厌氧悬浮颗粒污泥床同时反硝化产甲烷研究

利用厌氧悬浮颗粒污泥床反应器，以自配水为基质，通过微生物的反硝化作用和产甲烷作用成功实现了在单级反应器中去除硝酸盐和水中有机质的目的。反应器开始接种的污泥是产甲烷颗粒污泥，通过不断提高进水中硝酸盐的浓度，使厌氧颗粒污泥逐渐适应水中的硝酸盐，反硝化剩余的有机碳源转化为甲烷气体。在硝酸盐负荷为0.75kgN03^- -N·m^-3d^-1和COD负荷为14.1kgCOD·m^-3d^-1的稳态下，硝酸盐和有机碳的去除率分别为99.5％和90.1％以上。对反应器产生的气体所进行的气体组成测试表明，加入的硝酸盐全部转化为氮气，这一结果表明发生了真正的反硝化反应。     

利用微电极技术研究厌氧颗粒污泥内部的微环境

文章分别以蔗糖、乙酸和丁酸为进水唯一碳源,运行3个UASB反应器,当反应器稳定运行后,采用自制氢离子选择性液膜微电极对3种厌氧颗粒污泥进行内部pH值梯度分析,并对厌氧颗粒污泥进行了多种测试底物的产甲烷活性分析和16S rDNA测序分析。结果表明,采用微电极技术可以准确测定厌氧颗粒污泥内部的pH值梯度,并推断微生物种群的空间分布,所得结果与产甲烷活性和16S rDNA测序分析结果相一致,说明微电极技术可作为厌氧颗粒污泥内部微环境分析和微生物种群空间分布研究的有力工具。     

厌氧产甲烷颗粒污泥微生态学的研究现状

厌氧颗粒作为一个复杂而完整的微生态系统是厌氧反应器高效稳定运行的基础和关键。其中不同类型的微生物群落之间形成了共生或互生关系,并根据不同的工艺条件和处理功能形成各种合理的空间分布,以利于细菌生长以及不同细菌种群之间基质的传递。借助先进的分子生物学技术对厌氧颗粒污泥中微生物群落结构和原位空间分布的研究,使我们能深入了解不同代谢基质的颗粒污泥的微生物群落结构特点和多样性变化,以及这种特殊活性污泥结构的微观调节过程,并且为提高反应器处理功能提供了微生物学依据。     

土壤腐殖质对重金属离子吸附-解吸作用的研究探讨

从土壤腐殖质对重金属离子的吸附作用、解吸作用和吸附机制三方面,综述了近期的研究状况和最新进展,并对今后的研究方向进行分析,以促进吸附-解吸作用研究的继续深入开展。     

UASB反应器中厌氧污泥颗粒化的微生物学机理

通过对容积为5升的UASB反应器启动试验,研究了反应器内以葡萄糖为基质污泥颗粒化过程中不同类群细菌的消长规律。依据对颗粒化过程中细菌行为的观察,初步提出了厌氧颗粒污泥形成的机理,讨论了细菌种类对颗粒污泥性能的影响。     

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。