人工湿地净化污水机制及发展方向探讨

指出了人工湿地作为一项污水生态处理技术,因其投资低、效率高、操作简单、具有生态效益等优点而受到许多国家的青睐.分析了人工湿地污水处理系统的构成、处理工艺的类型和净化污水的机制.同时对人工湿地污水处理技术的发展方向进行了探讨.     

人工湿地在景观设计工程中的应用

人工湿地是一种新型生态水处理技术，这种处理方法是可靠有效的，在实际应用中取得了快速发展。通过结合具体工程。介绍了人工湿地污水处理的工艺流程、工艺设计数据。实践表明这种处理方法适用于自然湿地的维持并运用于污水处理设计，达到污水净化和美化环境的双重作用。     

人工湿地在农村生活污水处理中的应用分析

为了解人工湿地处理污水的效果,分析表面流人工湿地、垂直流人工湿地、水平潜流人工湿地在处理污水过程中的优缺点。基于农村污水来源以及特点,分析了人工湿地处理技术,探究了人工湿地在农村生活污水处理中的应用。以人工湿地对TN、TP去除率为例,结果表明:人工湿地对污水中TN的去除率可达90.7%,TP的去除率可达86.39%。从处理效果、建设费用和运维费用等方面看,人工湿地污水处理技术适合应用在经济条件和技术水平有限的我国农村地区。     

固定水力负荷下人工湿地各单元净化污水效果研究

以东莞生态产业园内的人工湿地污水处理系统为研究对象,对比分析了系统内反硝化池、垂直流人工湿地、表面流人工湿地单元在高温期和低温期的污水净化能力,探讨了系统建成运行3年后,2013—2015年在固定水力负荷下的污水处理效果。结果表明,该人工湿地污水处理系统运行3年,净化能力保持稳定;相对于低温期,系统在高温期的污水处理效果不明显;反硝化池、垂直流人工湿地、表面流人工湿地各单元的污水处理能力不同,垂直流人工湿地对总磷、总氮的去除效果明显,反硝化池对氨氮的去除效果明显;表面流人工湿地相对于垂直流人工湿地,对各项水质指标值的去除效果不明显。作为人工湿地污水处理系统,应当重视表面流人工湿地对污水净化效果的影响。     

高效污水处理促进剂

随着社会的发展和人口的增长,污水处理问题日益突出,目前,在污水生态处理工程中,主要采用地下渗透和人工湿地技术,缺陷是土壤中微生物种群单一,工艺启动周期漫长,处理负荷和去除率较低.     

南方农村生活污水处理技术

农村生活污水所引起的面源污染日益严重,找到适合在农村地区应用的污水处理技术势在必行.介绍了人工湿地污水处理工艺,并对人工湿地的适用于广东气候的类型、特点、技术指标、管网设计特点进行探讨.     

人工湿地在污水处理中的作用

指出了人工湿地是一种正在不断进行研究、应用的污水处理技术,在国际上已经得到了广泛的应用。探讨了人工湿地对水污染物的净化作用,研究表明：人工湿地用于污水的处理．对化学需氧量（COD）、五日生化需氧量（BOD5）、固体悬浮物（SS）等的去除率均可以达到90％,对总氮（TN）也能达到很好的去除效果,在发展中国家发展人工湿地处理污水技术的前景十分广阔。     

洞庭湖周边乡村生活污水处理技术系统研究——以君山区为例

以君山区为例,分析了洞庭湖区乡村生活污水的类型、分布和特点,在此基础上,有针对性地提出了包括分散处理模式、集中处理模式、组合处理模式在内的三种乡村生活污水处理模式,以及家庭一体化污水处理设备技术、人工湿地污水处理系统、中小型生活污水生态处理系统、小城镇污水处理厂等四种具体的处理技术体系,以期为洞庭湖区乡村生活污水的处理提供参考。     

西北地区人工湿地组合工艺处理农村生活污水技术研究

针对西北地区农村生活污水的水质水量特点及经济运行维护等的限制,综述因地制宜地选择和推广合理的人工湿地及其组合工艺来适应我国西北地区农村生活污水处理的研究和应用方法。主要阐述了两大类技术研究:三种人工湿地的复合组合应用和预处理+人工湿地的组合应用。     

人工湿地基质处理效果分析及发展趋势研究

人工湿地作为一种新型的且行之有效的污水处理兼具生态效应的环境治理手段越来越受到重视,其中湿地基质作为湿地系统的关键是当下研究的重点.在国内外研究的基础上,对人工湿地基质的分类及各种基质对各类污染物的去除效果进行了具体的分析,以此作为湿地基质选择的参考.通过分析当前人工湿地在发展过程中存在的问题,如地域差别、处理对象、研...     

Agroforestry research and practice in Sri Lanka

A review of agroforestry research and practice in Sri Lanka is provided with emphasis on traditional systems, plantation intercropping, silvopastoral systems, fertility improvement and community approaches. Comments are presented on the potentials and difficulties of each technology along with recommendations for further research and training. Some information on components of a number of agroforestry systems has been collected during the last 8 years. A brief account of the results is presented together with comments on current agroforestry practices.     

Assessment for Improvement: Harvesting Operations in Small-Scale Forest on Thai Steep Terrain

Timber harvesting on steep terrain is always a challenge in terms of safety, operating costs, and environmental impact. The motor-manual, cut-to-length method is the most common in harvesting operations in the mountainous areas of Thailand. The motor-manual operations are characterized by various negative features such as high fatality rates, expensive operating costs, and low productivity. The aims of this study were to evaluate the prevailing harvesting operations, to propose new working methods and systems, and to suggest work safety improvement measures. The results indicated an extremely high fatality rate in Thailand compared to the average in other countries. Possible reasons for this may include ineffective safety regulations, inadequate worker training programs, seasonal forestry workers, and a lack of personal protective equipment. Consequently, alternative working methods have been suggested as a system. The proposed working method was intended to improve work safety, enhance productivity and reduce operating costs using by simulation to find best solution. Shifting from a cut-to-length to tree-length processing and moving forward to mechanization was introduced as alternative harvesting systems. The results showed that partly-mechanized systems would significantly improve the productivity. Potential work safety improvement measures may consist of adequate training, personal protective equipment, and technological improvement. Obstacle for implementation is the high investment for forest machines and silvicultural practices.     

Nitrogen-Fixing Trees in Small-Scale Agriculture of Mountainous Southeast Guatemala

Abstract

Intensive, subsistence agriculture on hillsides of southeast Guatemala has caused extensive soil degradation. This retrospective study evaluated the success of an agroforestry treatment in improving the sustainability of mountainous agricultural systems in terms of soil nutrient status and erosion control. Three years after maize (Zea mays) and pasture fields were alley-cropped with N-fixing Gliricidia sepium trees, soil nutrient levels were examined and compared to nonalley-cropped controls. Agroforestry treatment showed significantly higher soil organic matter (SOM) over paired plots with no alley-cropping (mean 4.3% vs. 3.2% C, p < 0.05). Mean total N was also higher, with 0.12% in the nonagro-forestry control plots compared to 0.16% underthe agroforestry treatment (p <0.05). Some improvement in soil water-holding capacity(WHC) was also observed in the agroforestry systems. Differences in soil levels of available P, ranging from 8.0 to 64.4 μg/g, were not significant and correlated more with site than with agroforestry treatment versus control. Specific soil and site properties such as texture and slope as well as land use and ground cover management largely influenced improvements in soil nutrient status under the agroforestry treatment at each site. Despite increases in soil nutrients, maize plant productivity showed no response to the agroforestry treatment in terms of leaf chlorophyll index or maize plant height. Three years after the initiation of agroforestry, soil erosion rates showed no difference from paired controls; rates were correlated with ground cover and soil characteristics such as texture and surface rockiness rather than with agroforestry treatment. While soil nutrient status had not reached levels optimum for maize growth after three years, the positive trajectory of change in soil nutrients suggests the potential for using agroforestry systems in mountainous regions of Guatemala to increase the sustainability of agricultural production.     

Organizational dynamics of an information system： case study from the forestry sector

The Forest Department in the State of Uttar Pradesh, India developed Forest Management Information System （FMIS） for achieving organizational goals of improved financial and human resource management, improvement in the management of forests and wildlife, and for achieving responsive administration. This paper, based on field research, presents an assessment of the dynamics of FMIS in organizational context for a better understanding of such systems in forestry organizations. The paper also investigates the success of FMIS in assisting decision makers in achieving organizational goals. Based on the knowledge developed during the course of the study, key learning elements have been highlighted for the benefit of the stakeholders in information systems in forest sector.     

Oxidative activation of wood surfaces by flame treatment

Summary The effects of an oxidative activation of some different wood surfaces by flame treatment has been studied. Flame treatment markedly increased the wettability and decreased the microbiological activity. No improvement in glue adhesion was discerned for a water-borne PVAc-glue. ESCA measurements showed a considerable increase in oxidation level as a result of the flame treatment. The duration of the activation varied between different wood species.Appreciation is expressed to Prof. E. Back for valuable discussions and to Mr. G. Carlsson, Institute for Surface Chemistry, Stockholm, for ESCA measurements. Financial support from the Swedish Council for Building Research is kindly acknowledged     

SBR处理生活污水工艺中填料性能研究

指出了随着国家对污水排放标准的要求不断提高,许多采用SBR工艺进行污水处理的水厂需要进行提标改造。投加填料作为一种SBR工艺改造途径已经得到越来越多的研究与应用。针对填料选择时性能要求不明确的问题,结合填料在水处理中的作用,对SBR处理生活污水工艺中所用填料的性能要求进行了总结,为实际工程中填料的选择提供依据,为SBR污水处理工艺中新型填料的开发提供理论基础。     

Incorporation of stable glycerol-borate complex into phenolic resin as a glue line treatment in engineered wood products

ABSTRACT

A glycerol-borate complex has been developed and demonstrated as a new glue line treatment for engineered wood products such as laminated veneer lumber (LVL) and plywood. This allows the entire billet or panel to be evenly penetrated with boron to elevated levels, which increases the level in the central ninth and ensures the panel is significantly higher in boron throughout the panel compared with traditional envelope treatments. These external treatment systems often result in envelope treatments as it is difficult to get the treatment chemical evenly into the central ninth of the panel. The glycerol-borate complex reported herein is compatible with phenol formaldehyde resins typically used for plywood and LVL. These resins systems are not typically compatible with boron as the boron binds to the phenolic hydroxyl groups resulting in a range of undesirable side effects, such as premature gelation of the resin system. Boron is less toxic than alternative treatment chemicals and is very effective due to its broad spectrum of fungicidal and insecticidal activity. Boron does not break down into ineffective compounds and thus does not require high treatment dose levels. Additionally, the amount added can be directly measured using ICP-MS to ensure a suitable level of treatment chemical has been added.     

吉林省民营企业融资困境及对策研究

本文介绍了吉林省民营企业的融资现状,重点分析了吉林省民营企业所面临的融资困境及其产生的原因,从提高民营企业自身的素质、发挥银行对民营企业融资的主渠道功能、完善信用评估和信用担保体系等方面提出了解决民营企业融资困境的对策和建议.     

Research opportunities to improve the production of homegardens

The management of home gardens on a widescale basis is reviewed and examples of specific systems are presented. Opportunities for improvement are presented and recommendations for research are given. Because of the contribution to supply food and goods to millions of people, the home gardens should play a more important role in development programs and more organized and directed research should be provided. This should contribute greatly to the yield from these land use systems.     

Vegetative propagation of Inga feuillei from shoot cuttings and air layering

Cuttage and air layering were evaluated as means of vegetative propagation of the tropical woody tree, Inga feuillei. Effects of moisture management systems, leafiness, auxin application, and stem diameter on rooting of semihardwood cuttings were investigated. Cuttings were taken from 2-year-old seed-propagated, greenhouse-grown stock plants. Compound leaves were either reduced in area or removed entirely before auxin pretreatment with 0, 0.3, or 0.8% indolebutyric acid (IBA) followed by sticking under mist or in a polyethylene enclosure. Leafless cuttings did not root regardless of moisture management system or auxin pretreatment, whereas 55% rooting of leafy cuttings was observed. Leafy cuttings rooted significantly better under mist than in a polyethylene enclosure. Auxin treatment at the higher level increased rooting percentage approximately two fold for larger diameter cuttings (8.1 to 20 mm), but had no effect on the smaller cuttings (2 to 8 mm), and resulted in an approximately three fold increase in the number of roots/rooted cutting for both stem diameter classes. Auxin treatment did not affect rooting percentage of leafy softwood cuttings under fog, however it did increase the number of roots per rooted cutting. One hundred percent of air layered shoots rooted within 5 weeks with or without auxin pretreatment, and all rooted layers survived transplanting to soil. Possible implications of this research on agroforestry, selection, genetic improvement, and conservation are discussed.