大中型生活垃圾转运站技术监管要点研究

大中型生活垃圾转运设施作为城镇环境基础设施的重要组成部分,设施的环保、安全运行和高效监督监管是改善城镇生态环境的有效举措。文章通过分析国内外大中型生活垃圾转运站的处置形式和工艺布置方案,特别是“平进低出”工艺转运站,探讨环保关键环节分析及治理措施,并提出监管工作主要安全控制要素,以有效确保生活垃圾转运设施规范运行、达标排放和安全生产,实现生活垃圾转运站的高效运营和环保达标。

Variation of Coenzyme F_(420) Activity and Methane Yield in Landfill Simulation of Organic Waste

A simulated landfill anaerobic bioreactor was used to characterize the anaerobic biodegradation and biogas generation of organic waste which was mainly composed of residuals of vegetables and foods. We investigated the dynamics of the coenzyme F420 activity and determined correlations between biogas yields, methane yields, methane concentration and coenzyme F420 activity. The experiment was carded out under different conditions from control without any treatment, addition of Fe^3＋, microorganism inoculation to a combination of Fe3＋ addition and inoculation at a temperature of 36±2℃. The experiment was lasted 120 d and coenzyme F420 activity was analyzed using ultraviolet spectrophotornetry. Experimental results indicated that activity of the coenzyme F420 treated by Fe and microorganism inoculation increased substantially. The waste treated by inoculation had the greatest increase. When the waste was treated by Fe^3＋, inoculation and the combination of Fe^3＋ and inoculation, biogas yields increased by 46.9%, 132.6% and 153.1%, respectively; while the methane yields increased 4, 97 and 98 times. Methane concentration varied between 0 and 6% in the control reactor, from 0 to 14% for waste treated by the addition of Fe^3＋, from 0 to 59% for waste treated by inoculation and from 0 to 63% for waste treated by Fe^3＋ addition and inoculation. Correlations between coenzyme F420 activity and biogas production, methane production and methane concentration proved to be positively significant （p〈0.05）, except for the control. Consequently, coenzyme F420 activity could be used as an index for monitoring the activity of methanogens during anaerobic biodegradation of the organic fraction of municipal solid waste.

Application of Grey Situation Decision-Making Theory in Site Selection of a Waste Sanitary Landfill

An application of an unequal-weighted multi-objective decision making method in site selection of a waste sanitary landfill is discussed. The eight factors, which affected possible options, were: size and capacity of the landfill, permeability of the stratum, the average difference in elevation between the groundwater level and the bottom of the landfill pit, quality and source of clay, the quality grade of the landfill site, the effect of landfill engineering on nearby residents, distance to the water supply and the water source as well as the cost of construction and waste transport. These are determined, given the conditions of the geological environment, the need for environmental protection and landfill site construction and transportation related to the design and operation of a sanitary landfill. The weights of the eight factors were further investigated based on the difference in their relevance. Combined with practical experience from Xuzhou city (Jiangsu province, China), the objectives, effects and weights of grey decision-making were deter- mined and the process and outcome of the landfill site selection are stated in detail. The decision-making results have been proven to be acceptable and correct. As we show, unequal-weighted multi-objective grey situation decision-mak- ing is characterized by easy calculations and good maneuverability when used in landfill site selection. The number of factors (objectives) affecting the outcome and the quantitative method of qualitative indices can be adjusted on the basis of concrete conditions in landfill site selection. Therefore, unequal-weighted multi-objective grey situation decision making is a feasible method in selecting landfill sites which offers a reference method for landfill site selection else- where. It is a useful, rational and scientific exploration in the choice of`a landfill site.

Laboratory testing of a densified municipal solid waste in Beijing

Municipal solid waste （MSW） and its disposal are gaining significant importance in geotechnical and geoenvironmental engineering. However, conventional research is primarily focused on fresh MSW or MSW that is compacted under its own weight in the landfill. In this work, a series of tests to study the properties of a densified MSW after ground treatment were presented. The tests involved oedometer test, simple shear test, triaxial shear test, and permeability test, which were conducted to investigate the compressibility, shear strength, creep behavior and permeability of the MSW. The results show that the compressibility modulus of the MSW increases as the dry density increases. However, the influence of density on modulus decreases once the density reaches a certain value. Like most soils, the stress-strain curve of the densified MSW can be approximated by a hyperbola in the triaxial shear test. Fibrous components provide additional cohesion for MSW, but have a relatively smaller effect on friction angle. Permeability is also found to be closely related to the dry density of the MSW, i.e., MSW with a higher dry density has a smaller permeability. The permeability coefficient may be less than 10 7 cm/s if the density is high enough.

Effect of Moisture on Partitioning of Heavy Metals in Incineration of Municipal Solid Waste

The effect of moisture in municipal solid waste (MSW) on partitioning of lead (Pb), zinc (Zn), copper (Cu) and cadmium (Cd) was studied in a laboratory tubular furnace by using simulated MSW. The moisture in MSW influences heavy metals in following ways, to increase the moisture in flue gas and decrease the combustion temperature, to prolong the combustion time, and to prolong the releasing time of volatiles with the furnace temperature decreased by increasing the moisture. The volatilization of Pb, Zn and Cd was enhanced by increasing the moisture in MSW because of the prolonged combustion time. For Pb and Zn, the combustion time was important at higher temperature, while for Cd, it was important at low temperature. The moisture content showed slight effect on Cu partitioning. When extra chlorine was added to MSW, such as 1%PVC + 0.5%NaCl, the volatilization of Pb, Zn and Cu was enhanced by increasing the moisture because water evaporation reduced the temperature and increased devolatilization time. At higher temperature, NaCl tends to decompose and generates more free chlorine, producing more metal chlorides. Since Cd is a strong volatile heavy metal in MSW, the effect of moisture content on its volatilization is less than that of Pb, Zn or Cu during the MSW incineration.

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.

Perspectives for Energetic Destination of MSW （Municipal Solid Waste）

The correct individuation of the best final destination for MSW cannot ignore the option of thermal treatment, taking into account both the possibility of energy recovery and the capacity of the thermal process to destroy an important part of the pollutants that are originally present in the waste itself. In order to realize this operation, it is possible to use conventional incineration systems, but also to consider new innovative processes and technologies; among them, production of RDF （refuse derived fuel） is quite often used in process plants, and gasification of waste seems to be a promising solution. The aim of the present paper is a critical analysis of the above-mentioned solutions, not only from the operational point of view but also on the basis of the status of the art of practical applications and in consideration of the most significant results for the Italian and European situation. For the application of these technologies a specific Italian case has been considered： it consists of the correct individuation of waste management modality for final destination of wastes produced in a city located in Piedmont （north of Italy）. The results of the analysis highlight the environmental and economic convenience, for the specific considered case, of the direct combustion in incineration plant of the all amount of the wastes produced. From the considered specific example some more general conclusions can be drawn.

Preparation and Characterization of Refuse Derived Fuel for Pyrolysis and Gasification by Bindless High Pressure Briquetting Technology

A new type of refuse derived fuel (RDF) for pyrolysis and gasification was prepared from municipal solid waste (MSW) in the presence of a small quantity of coal by bindless high pressure technology at room temperature. The physicochemical property of RDF was tested. Orthogonal experiment method was used to optimize the process parameters using dropping strength (mechanical strength) and thermal stability of the RDF as indices for quality of RDF. The result shows that the mixture of MSW and coal with a total moisture ranging from 5% to 17% can be easily compressed into RDF briquettes at a pressure above 70 MPa. When the briquetting pressure is higher than 100 kN and moisture content is about 10%, the qualified RDF can be obtained. The orthogonal experiment shows that the moisture can greatly affect the mechanical strength of RDF, while all the technique parameters have no obvious influence on thermal stability of RDF. The optimal parameters are a shaping pressure of 106 MPa, a moisture content of 10%, and a coal content of 20%.

Gasification of Municipal Solid Waste for Power Generation in Brazil, a Review of Available Technologies and Their Environmental Benefits

This article reviews the literature on thermochemical processing of municipal solid waste as the final disposal in Brazil, explores recent publications in the field of solid waste generated, its origin, characteristics and removal mechanisms currently employed, in the same way, available technologies for the thermochemical treatment of MSW with an emphasis on gasification and clean technology are evaluated, highlighting the current technical and reported in the literature in order to identify indicators of efficiency and flexibility of the technology. From the review it is concluded that gasification is a technically feasible option for the thermochemical conversion of municipal solid waste and subsequent power generation, besides being a technology that meets the applicable emission limits. Some of the main advantages of gasification of municipal solid waste are： （a） the sharp reduction in the waste mass （about 70-80%） and volume （approximately 80-90%）; （b） the drastic reduction in land use, 1：3000; （c） destruction of organic pollutants and other halogenated hydrocarbons; （d） concentration and immobilisation of inorganic contaminants so that they can be used effectively and safely removed; （e） use recyclables, such as ferrous metals, ferrous ash and slag materials; （f） reducing emissions of greenhouse gases by anaerobic decomposition of organic waste and （g） power generation.

Plate Load Tests on Municipal Solid Waste Dump Site to Assess Ground Improvement Alternatives

Urbanization is the physical growth of urban areas as a result of global change. As the land cost is increasing tremendously and decreasing availability of good construction site is building up pressure on the engineers to utilize even the poorest site either by providing special type of foundation or by improving ground in urban centres. In this context literature is reviewed for use of landfill site for housing. The site exploration for old dump site was carried out to assess subsoil characteristics. The objective was to evolve strategy for economical feasible ground improvement technique to obtain permissible bearing capacity of 150 kPa and total settlement not more than 50 mm. The tests carried out are load tests with geotextile mat and stone filled wire mess matress. The analysis was attempted to evaluate the soil response and bearing capacity. The site can be used for construction of low rise housing for rehabilitation of displaced persons under TP scheme within city area utilizing old landfill sites.

Environment in Tirana and Its Pollution as a Result of Urban Development after 90 Years

Developments of these last two decades in Albania after the fall of communism are associated with major changes both in terms of socio-economic and environmental simultaneously. In the context as for environmental change, Albania is one of the countries with a wide range of problems that have been and are constantly in the focus of attention not only state institutions but also non-governmental organizations operating in authors＇ country. In this city that appears to approach a problem from the stand point of the environment is Tirana. Tirana as the capital of this country has experienced two decades such an extra ordinary transformation that has not been without its environmental costs. Human activities have transformed the environment in Tirana. Greater quantities of waste generated especially solid waste are those caused by major construction boom in Tirana performed. Considerable amount of clinical waste involved in urban waste, in places where hospital, sand clinics, and though a part of Tirana clinical waste burned in special places. With the economy in this city, this volume will increase. In this context, authors＇ theme will focus on a more extensive treatment of these problem, sand forecasts above are provided in the future as well as measures to reduce them to levels required by the EU and to have a quality of life good.

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.

Phytoextraction of Nickel and Chrome in Paddy Soil Amended With Municipal Solid Waste and Sewage Sludge

A field study was conducted in the paddy soil amended with municipal solid waste （MSW） and sewage sludge （SS） to find out total, DTPA extractable nickel （Ni） and chrome （Cr） in soil and their uptake by rice plant as split-plot arrangement based on randomized complete block design with three replications. The results indicated that the most available Ni （2.10 ppm） measured under 3 years application of 40 ton.ha~ MSW＋I/2 chemical fertilizer （CF）. Also, with 3 application of 40 ton-ha＂l MSW concluded the highest available Cr. The most accumulation of Ni in root （14.51 ppm） and grain （8.89 ppm） happened under 3 years application of 40 ton.ha-1 SS and 20 ton ha-1 MSW＋I/2 CF, respectively. With application of 40 ton.ha-1 SS and 40 ton SS＋1/2 CF, respectively happened the maximum Cr uptake by root and grain （12.43 and 3.65 ppm, respectively）.

Analysis of the Per Capita Generation of Municipal Solid Waste by Socioeconomic Strata in Veracruz, Mexico, Using a Statistical Experimental Design

The management of municipal solid waste （MSW） is currently one of the major environmental concerns in Mexico. Therefore, municipalities must develop local programs for prevention and integrated management of MSW based on the data of MSW generation; however, these are scarce and diffuse. It is known that the MSW generation is affected by many factors, including life level. Given the importance of having reliable data, the objective of this study was to determine the per capita MSW generation of a small urban locality in the state of Veracruz and test whether there were significant statistic differences of per capita M SW generation among the life levels. The households were randomly sampled according to the Mexican standard of reference and were classified as popular, middle and residential. The per capita MSW generation determined was 0.355 kg·inhab^-1.day^-1. This value was lower than the value estimated by the national reference, suggesting that it might be overestimated and consequently lead to errors in estimating installations costs for the MSW treatment. The result of the experimental design revealed that there were significant statistic differences in the per capita MSW generation among the three socioeconomic strata. This study will allow the municipality to establish better strategies within the municipal program and differential rate for the provision of public clean service and it also provides a solid basis for future research under similar conditions.

Assessment of the Social, Economic and Environmental Aspects of Solid Waste Management in Selected Open Dumpsites in Kenya

The most prevalent way of disposing solid waste in most of the developing countries is open dumping which is the easiest and considered to be the cheapest method of removing waste from the immediate environment. The increasing awareness on public health and environment quality concerns are expected to provide the impetus that is needed to develop and implement a sustainable approach to manage solids. An inventory of these locations, the types of waste handled and management processes for waste products will aid in the assessment of the polluting capability of such sites. This paper discusses research experiences gathered during a study that was undertaken in three Kenya dumpsites to explore the potential for utilising the waste for energy generation in a low-income economy and at the same time, address worsening disposal challenges.

Geo-information Technologies for Decision Issues of Municipal Solid Waste

The article reveals the potential of information technology in decision issues of municipal solid waste. The technique proposed for definition of ecological and technical potential for ecological optimization of the territory for the purpose of efficient decision-making in the environmental field. Studies are based on the information capacity usage and implementation of geographic information technologies in combination with the methods of remote sensing of the earth. On this basis, the authors have developed mechanisms that will overcome the existing environmental and technical challenges--economic, political and human capital.

Health Risks Assessment Due to Exposure to Vinyl Chloride in Groundwater from a Closed Landfill： A Case Study as a Contaminant of Concern and Effect of Subsurface Characteristics

The purpose of this study was to analyze the migration pathways of contaminants from closed landfills and to estimate health risks based on soil characteristics. The health risks were estimated using Framework for Risk Analysis Multimedia Environmental Systems （FRAMES） software. The sensitivity of human health risks and hazard indices due to vinyl chloride contamination in groundwater were performed in relation to soil characteristics such as Darcy velocity, thickness of soil layer, mass of contaminant present in the aquifer. Based on the analysis, Darcy velocity showed no effect on estimated risks. Since soil layer thickness had a significant effect on the estimated health risks, effects of different soil types on estimated risks were analyzed. The results showed that soils from the least appropriate to the most appropriate for risk management due to groundwater contamination were sand, sandy clay, sandy loam, loam and clay loam. FRAMES model was suitable for assessing the health risks due to vinyl chloride contamination in groundwater originating from a municipal solid waste landfill. The model showed the changes in both carcinogenic and non carcinogenic risks over time. The estimated health risks were directly correlated with the levels of vinyl chloride detected in groundwater.

GHG Emissions Estimation from Household Solid Waste Management in Jakarta, Indonesia

This study defines and compares four scenarios for MSW （municipal solid waste） management： Scenario 1, unsorted waste taken to a landfill （baseline scenario）; Scenario 2, sorted waste used for home or communal composting; Scenario 3, sorted waste used for anaerobic digestion; and Scenario 4, sorted waste taken to a composting centre. The results of this study suggest that Scenario 1 would emit the highest levels of GHG （greenhouse gas） emissions, 692 x 103 tonnes CO2eq per year. Scenario 3 would have the lowest levels of GHG emissions, 195 x 103 tonnes CO2eq per year. Compared with the baseline scenario, it yields a 72% reduction of GHG emissions with a total savings of 498 ~ 103 tonnes CO2eq per year. The second-best option is Scenario 2, followed closely by Scenario 4, both yield 66.6% reductions with deviation by 0.03%. The deviation is due to transportation, which emission is negligibly small. The amounts of GHG savings for Scenario 2 and 4 are 461.3 ×10^3 tonnes CO2eq per year and 461×10^3 tonnes CO2eq per year, respectively It is evident from these results that anaerobic digestion has the highest potential for reducing GHG emissions.

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.

Model for Evaluating the Ecological Health of Municipal Solid Waste Treatment System

Ecological municipal solid waste (MSW) treatment systems are complex systems engineering concerning with multiple objectives and hierarchical levels. By combining an extension method with fuzzy logic theory, this paper investigated key technologies required by the comprehensive evaluation of ecological health. The method includes the construction of an evaluation system, quantification of evaluation indices, development of a matter-element model, development of an extension evaluation method, and assignment of a blended weight that combines subjectively and objectively estimated weights. This approach was used to develop a comprehensive model for evaluating the ecological health of an ecological treatment system for MSW. The model was then applied to a case study, and the results demonstrated that the model is a reasonable and effective.