市政工程技术在城市垃圾处理与资源回收中的应用研究

本研究以我国当前城市垃圾处理和资源回收情况为出发点,深入研究市政工程技术的适用性以及优势。研究方法主要采用工程案例分析、技术对比和仿真模拟等。研究结果显示,利用市政工程技术实施城市垃圾处理以及资源回收,不仅可以提升垃圾处理效率,减少环境污染,同时还能够大幅度提高资源回收率,为城市可持续发展做出重要贡献。特别是,通过使用先进的市政工程技术,可以实现垃圾分类、垃圾转化以及资源化等多重效益。研究结果为城市垃圾处理和资源回收的实践提供了技术支持,对推动我国城市垃圾处理和资源回收的未来发展具有重要的参考价值。

政府购买农村生活垃圾处理服务:问题、成因与优化路径

政府购买农购买农购买农村生活垃圾处垃圾处垃圾处理服务具有重要意义。当前,这一领域存在的主要问题问题是:政府购买购买“内部化;政策、制度不健全;监管机制不完善;环保产业发产业发产业发展缓慢。这些问题问题的成因主要是:政府服务范围不明确;政府管理体系不完善;农村居民环保观念落后;缺乏有效保障机制。必须通过优化政府指导行为,发挥发挥政府统筹协调筹协调筹协调作用;发挥发挥市场决定作用,凝聚各方环保力量;加强环强环保知识宣传,积极积极推进公众参与;建立评估监管机制,构建长效制度保障体系来加以改善。

德阳市城市生活垃圾处理技术的研究与实践

本文以德阳市城市生活垃圾的研究及垃圾处理工程的建设为主线 ,论述了德阳市在生活垃圾处理实践中不断探索和改造的实情 ;以满足城市发展需要的垃圾处理方式及转运工作为主线 ,介绍了生活垃圾处理场不断进行科研和实践的工作。

城市生活垃圾处理的可持续发展研究

良好的生态环境是发展生产、建设经济、追求美好生活的必要条件。这也是确保人民生活质量的基本环境要求。然而,多年来,中国的生态环境遭到了极大的破坏,环境污染对人们的生产生活造成了重大的负面影响。其中,城市生活垃圾处理方法不当、处理方法不合理、利用效率低下是造成资源浪费和环境污染的重要原因。因此,提高生活垃圾回收利用水平,变废为宝已成为环境保护的重点。城市生活垃圾是一种放错地方的资源,不科学、不合理地处理城市垃圾不仅不能利用这一资源,反而会造成严重的资源浪费,不利于人们满足美好生活的需要,在一定程度上降低了生活质量。生活垃圾的资源化处理和可再生利用为城市居民生活垃圾处理提供了新的方法和处理途径,并找到了有效的处理方法来解决目前垃圾处理中的困难,它对资源的高效利用和生态环境的保护具有重要意义和作用。

“三化”让“三万”迸发无穷力量

"万名干部进万村惠万民"活动开展以来,宜昌以转变干部作风、密切联系群众、全力服务"三农"为目标,以常态化建设、立体化推进、精细化操作为抓手,精心谋划部署,统筹整合资源,健全工作机制,在宣传政策、增进感情、兴办实事、服务"三农"发展中爆发出无穷力量,兴办各类实事1.2万余件。

Contribution of aboveground litter to soil respiration in Populus davidiana Dode plantations at different stand ages

Soil respiration from decomposing aboveground litter is a major component of the terrestrial carbon cycle. However, variations in the contribution of aboveground litter to the total soil respiration for stands of varying ages are poorly understood. To assess soil respiration induced by aboveground litter, treatments of litter and no litter were applied to 5-, l0-, and 20-year-old stands of Populus davidiana Dode in the sandstorm source area of Beijing-Tianjin, equations were applied to China. Optimal nonlinear model the combined effects of soil temperature and soil water content on soil respiration. Results showed that the monthly average contribution of aboveground litter to total soil respiration were 18.46% ± 4.63%, 16.64% ± 9.31%, and 22.37% ± 8.17% for 5-, 10-, and ao-year-old stands, respectively. The relatively high contribution in 5- and 20-year-old stands could be attributed to easily decomposition products and high accumulated litter, resoectivelv. Also. it fluctuated monthly for all stand ages due to substrate availability caused by phenology and environmental factors. Litter removal significantly decreased soil respiration and soil water content for all stand ages （P 〈 0.05） but not soil temperature （P 〉 0.05）. Variations of soil respiration could be explained by soil temperature at 5-cm depth using an exponential equation and by soil water content at lo-cm depth using a quadratic equation, whereas soil respiration was better modeled using the combined parameters of soil temperature and soil water content than with either soil temperature or soil water content alone. Temperature sensitivity （Q10） increased with stand age in both the litter and the no litter treatments. Considering the effects of aboveground litter, this study provides insights for predicting future soil carbon fluxes and for accurately assessing soil carbon budgets.

Influence of temperature on production of lactic acid from kitchen garbage

The production of lactic acid from kitchen garbage, the precursor for production of biodegradable plastics is described in detail. The influence of temperature on the lactic acid concentration, sugar concentration, and decrement of garbage were evaluated through experiments. Fermentation were carried out in an incubator at 5, 25, 37 and 50 ℃. The latic acid produced was maximum at initial pH 6.0 and 37 ℃, i.e. 38 g/L with a yield of 0.23 g/gVS. It is concluded from the experimental results that temperature has quite a considerable effect on the production of lactic acid; lactic acid concentration increases with temperature until 37 ℃, and production rate of lactic acid drops at 50 ℃; the optimal fermentation is 37 ℃. This study shows that production of lactic acid from kitchen garbage is feasible and reduction of garbage can be realized.

市政府、市府办发文目录(8．16—9．15)

宁政发[2008]154关于关闭南京力丰化工有限公司等22家化工生产企业的决定宁政发[2008]155关于进一步强化土地执法监管落实耕地保护责任的通知宁政发[2008]159批转市民政局等部门《关于统一社区专职工作者工资补贴待遇的指导意见(试行)》的通知宁政发[2008]160关于批转市市容局等部门《委托供水企业代收城市生活垃圾处理费实施办法》的通知宁政发[2008]162关于做好2008年中国南京金秋经贸洽谈会。

关于《福建省固体废物污染环境防治若干规定(草案)》修改情况的报告

(2009年7月30日在福建省第十一届人民代表大会常务委员会第十次会议上)主任、各位副主任、秘书长、各位委员:2009年5月20日上午,省十一届人大常委会第九次会议分组审议了《福建省固体废物污染环境防治若干规定(草案)》(以下简称草案)。审议中委员们认为。

Influence of landfill structures on stabilization of fully recycled leachate

The experiment was conducted to treat the leachate from two simulating columns by recycling to the columns themselves without being discharged into the enviroment. The columns were employed to simulate anaerobic and semi-aerobic landfills separately. The influence of landfill structure on stabilization of fully recycled leachate was studied. The results show that semi-aerobic landfill structure accelerates the stabilization of leachate recycled. The full recycle of leachate in semi-aerobic landfill is a very feasible and effective technology for leachate treatment with low cost and energy saving especially in arid and rare rainfall regions. Meanwhile, the environmental impact of landfill can be greatly minimized.

Utilization of fly ash from coal-fired power plants in China

The rapidly increasing demand for energy in China leads to the construction of new power plants all over the country. Coal, as the main fuel resource of those power plants, results in increasing problems with the disposal of solid residues from combustion and off gas cleaning. This investigation describes chances for the utilization of fly ash from coal-fired power plants in China. After briefly comparing the situation in China and Germany, the status of aluminum recycling from fly ash and the ad- vantages for using fly ash in concrete products are introduced. Chemical and physical analyses of Chinese fly ash samples, e.g., X-ray diffraction (XRD), ICP (Inductive Coupled Plasma) and particle size analysis, water requirement, etc. are presented. Rea- sonable amounts of aluminum were detected in the samples under investigation, but for recovery only sophisticated procedures are available up to now. Therefore, simpler techniques are suggested for the first steps in the utilization of Chinese fly ash.

Design concept for the solid waste landfill site:a case study of Chuzhou City,China

This paper introduces landfill site of Chuzhou domestic waste, to which the improved anaerobic hygienic burying technology is applied. Chuzhou City, situated between Yangtze River and Huai River, is a window city in the east of Anhui Province. A landfill site with a capacity of 400 ton per day is to be constructed according to the city development plan and the garbage amount, This paper summarizes the landfill location, landform, groundwater, surface water, landfill stratal configuration, dominant wind, and the major machinery equipment. The projects of anti-percolation, seepage collection, seepage disposal, rainwater discharge, biogas diversion are deeply studied. The advanced design principle of the landfills is summarized, which is environment-friendly, science-oriented and economy-based. Environment-friendly principle is implemented in the selection of landfill location, construction of all projects, sealing up project and perfecting environment monitoring system; science-oriented principle prescribes that the design, construction, and management should be science-oriented; the selection of landfill location, design, plan optimization, resource-saving measures and comprehensive utilization should be economy-based Chuzhou domestic waste landfill site is qualified as a goiden model in this paper.

Comment on the development and policy of the waste incineration power generation industry

Development space of the waste incineration power generation is expanding. According to the technical route of previous planning and related policies, the principles of our garbage disposal are based on sanitary landfill, supplemented by burning. However, with the accelerated process of urbanization, land resources are increasingly strained and most large cities have been unable to find a suitable landfill within the feasible urban extent, the main equipment for the incinerator and the localization of the overall process greatly reduced its capital investment and these factors will promote the rapid development of waste incineration power generation industry. Waste incineration and power generation technology has the dual benefits of environmental protection and energy and it is the development direction of waste disposal in the future. According to the condition that our country＇s waste incineration power generation started from scratch and developed rapidly in recent years ,there is a introduction about the application of the waste incineration and a brief analysis of the its obstacles in the promotion and financing, as well as the potential for future applications.

Experimental research on the compressibility of stale waste

The compressibility of stale waste is studied based on the investigation into the composition and properties of stale waste in the Chongqing City. Stale waste sampled at a landfill closed for over 8 a was analyzed indoors for its natural density, natural water content, relative density, grain size distribution curve, uniformity coefficient and curvature coefficient. Indoor compression tests for the stale waste were performed to find out the void ratio and its dependence upon applied pressure, compressibility coefficient, constrained modulus and volume compressibility coefficient. From the experimental data, the curvature coefficient and the preconsolidation pressure of the stale waste were worked out. The results indicates that the stale waste is of high compressibility, which is different from the other kinds of common soil, and is underconsolidated soil. The measured compressibility parameters are applicable to settlement calculation of closed landfills.

Feasibility analysis of remedial scheme of Qilongcun landfill

Based on hydro-geological of Qilongcun landfill, the transportation mathematical model of leachat was established. The boundaries conditions and replenishment ofmodel were determined. The leachate COD density and the water level were simulated, and the model was identified, and then the right model was defined. The right model was used to simulate leachate COD density in the interior, exterior, and peripheral of landfill. The results show that the COD densities are not high. The pollution is slight in the interior of landfill and is little in the exterior of landfill. They are proving the overburden on top of landfill and drain around the landfill is right. The max. density on the south of landfill shows it is scientific that the cisterns are building on the south of landfill. The paper shows the remediation scheme is feasible.

Geotechnical behavior of the MSW in Tianziling landfill

The valley shaped Tianziling landfill of Hangzhou in China built in 1991 to dispose of municipal solid waste (MSW) was designed for a service life of 13 years. The problem of waste landfill slope stability and expansion must be considered from the geotechnical engineering point of view, for which purpose, it is necessary to understand the geotechnical properties of the MSW in the landfill, some of whose physical properties were measured by common geotechnical tests, such as those on unit weight, water content, organic matter content, specific gravity, coefficient of permeability, compressibility, etc. The mechanical properties were studied by direct shear test, triaxial compression test, and static and dynamic penetration tests. Some strength parameters for engineering analysis were obtained.

An Analysis of Solid Waste Generation and Characterization in Thika Municipality of Kiambu County, Kenya

The rapid increase in population in Thika has led to increase in municipal solid waste generation, which has posed challenges in the waste disposal and management. This study was carried out to quantify and characterize the waste generated within Thika municipality. Six months data （between March 2014 and August 2014） of waste stream at the dumpsite was reviewed and analyzed. The survey indicated that 66.95% ± 0.34% of the total waste dumped originated from the municipal council ofThika （MCT）. It constitutes of domestic, commercial and institutional waste. 33.05% is industrial waste. Sixty eight percent （68%） of the waste consisted primarily of four components： paper, plastic, organics and food. Food accounted for 15.51% ± 0.95%, paper 18.31% ± 1.7%, plastics 17.89% ± 0.81% and organics other than food 16.51% ±1.01%, respectively obtained at 95% confidence level. Each of the components has some level of recovery. Some of the reusable and recyclable materials were being recovered, food waste had the highest recovery rate of 23% ± 1.7% and was used as animal feed, while plastic （soft plastic） 17% ± 0.93% was sold to recyclers. Recovery of materials for recycling and composting was estimated at 10.21 tonnes or 11.35% of daily generation, leaving 76.44 tonnes per day that can be converted into useful energy. The study shows waste in this dumpsite can be exploited to by converting it to energy thus a good solution for waste management.

Waste Management Practices and Profile of Selected Key Green House Gases at Selected Livestock Farms in Ibadan, Nigeria

Livestock farm waste contributes substantially to annual worldwide emissions of GHG （Greenhouse Gases）, including CH4 （Methane） and CO2 （Carbon Dioxide）. However, despite evidence of global climate change and its adverse health effects, studies on anthropogenic contributions to the increasing levels of GHG, particularly from livestock waste management practices, have not been adequately explored, especially in less developed countries. This study determined waste management practices and outdoor levels of CH4 and CO2 at three selected livestock farms （A-C） in Ibadan, Oyo State, Nigeria. Each study farm consisted of poultry, cattle and pig units. A 30-point observational checklist documented adequacy of solid waste management practices. Ambient concentrations of CH4 and CO2 at farm buildings and at waste disposal sites were monitored every other day, twice each day of monitoring （morning and evening hours）, for eight weeks during months of September-November in 2013. Average scores for the waste management practices for Farms A-C were 29.6%, 33.3% and 18.5%, respectively. Morning and evening CH4 concentrations in parts per million （ppm） at main buildings of Farms A-C were 2,538 ± 773 and 1,916 ± 662, 2,325 ± 773 and 1,180 ± 483, and 2,389 ± 687 and 1,854 ± 571, respectively. Morning and evening CO2 concentrations （ppm） at Farms A-C main buildings were 350 ± 130 and 330 ± 110, 470 ± 100 and 440 ± 100, and 430 ± 80 and 400 ± 70, respectively. Morning and evening CH4 concentrations （ppm） at Farms A-C waste disposal sites were 2,452 ± 495 and 1,614 ± 372, 1,527 ± 390 and 1,736 ± 269, and 2,345 ± 615 and 1,690 ± 387, respectively. Morning and evening CO2 concentrations （ppm） at Farms A-C waste disposal sites were 330 ± 90, 370 ± 60 and 350 ± 30, respectively. Waste management practices were inadequate; solid waste management practices like infrequent evacuation of slurry waste and open burning of waste may have contributed to the production of CH4 and CO2. This study suggested proper handling, removal and disposal of farm waste which can reduce production of GHGs like CH4 and CO2.

Sustainable Solutions for Municipal Solid Waste Management in Thailand

General as well as the municipal solid waste （MSW） management in Thailand is reviewed in this paper. Topics include the MSW generation, sources, composition and trends. The review, then, moves to sustainable solutions for MSW management and sustainable alternative approaches with an emphasis on an integrated MSW management. Information of waste in Thailand is also given at the beginning of this paper for better understanding of later contents. It is clear that no one single method of MSW disposal can deal with all materials in an environmentally sustainable way. As such, a suitable approach in MSW management should be an integrated approach that could deliver both environmental and economic sustainability. With increasing environmental concerns, the integrated MSW management system has a potential to maximize the useable waste materials as well as produce energy as a by-product. In Thailand, the compositions of waste （86%） are mainly organic waste, paper, plastic, glass and metal. As a result, the waste in Thailand is suitable for an integrated MSW management. Currently, the Thai national waste management policy starts to encourage the local administrations to gather into clusters, to establish central MSW disposal facilities with suitable technologies and reducing the disposal cost based on the amount of MSW generated.

Optimization on Pretreatment and Enzymatic Hydrolysis of Sugarcane Trash for Ethanol Production

The present study was conducted for the optimization of pretreatment and enzymatic hydrolysis of lignocellulosic biomass （sugarcane trash）, which is a renewable resource for the production of bioethanol. The pretreatment and enzymatic hydrolysis conditions including alkali （NaOH）/dilute acid （H2SO4）, substrate and chemical concentration for pretreatment, enzyme dosage, pH, temperature and substrate concentration for hydrolysis were varied and evaluated for sugar and ethanol production at the end. The optimum condition was accomplished using 15% w/v DS of 0-2 mm sugarcane trash in size of particle. It was pretreated with two steps of 2% w/v NaOH autoclaving followed by 2% w/v H2SO4 autoclaving with washing step after pretreatment. An enzymatic hydrolysis was then performed using 15% w/v DS pretreated substrate, hydrolyzed with cellulase 50 filter paper unit （FPU）/g DS at 50 ℃ and pH 5. After incubating at 160 r for 48 h, 117.16 g/L reducing sugar was obtained. The achieved sugar after enzymatic hydrolysis was finally fermented to ethanol by Saccharomyces cerevisiae TISTR 5596, with concentration of 48.17 g/L ethanol or yield 0.509 g/g reducing sugars which was equal to 99.81% of theoretical yield.