Municipal solid waste management in Thailand and disposal emission inventory

The increasing municipal solid waste (MSW) generation along with the high fraction of organic waste and a common disposal of open dumping is the current scenario in many areas in Thailand. As a response to this problem, the country’s Pollution Control Department (PCD) aims to reduce the MSW generation rate to less than 1 kg/capita/day, increase the collection efficiency, and improve the recovery of recyclables. For many years, more than 60% of the solid waste disposal system in Thailand has been carried out by open dumping. According to the survey conducted by this study, in 2004 there were 425 disposal sites (95 landfills; 330 open dumps) in Thailand and an estimated methane emission of 115.4 Gg/year was generated based on this practice. It has been estimated that the anticipated methane emission in Thailand will rise from 115.4 Gg/year to 118.5 Gg/year if the largest open dumpsites in provinces with no existing landfill are upgraded to sanitary landfill; and it will increase to 193.5 Gg/year if the existing sanitary landfill is upgraded to integrated waste management facilities. Moreover, Bangkok metropolitan have the highest methane emission (54.83 Gg/year) among all the regions in Thailand. The methane emission forecast of 339 Gg/year by 2020 (based on LandGEM methodology) provides a stimulus to create a comprehensive plan to capture and utilize methane as an energy source.     

Monitoring quantity and characteristics of municipal solid waste in Dhaka City

A reliable estimate of the quantity of solid waste generation in the city is very important for proper solid waste planning and management. However, reported estimates of solid waste generation vary widely and lead to questionability. The reported values have been derived on the assumption of demography, standard rate of waste generation by households, density values, number of trucks engaged for waste transportation and monitoring of truck movement at dump sites, etc. This diverse nature of the available data and the question of accuracy necessitate a rigorous study that has tried to document the waste quantity in the recently formulated master plan of Dhaka City. The socio-economic parameters, behavioral characteristics, generation sources, seasonality, and per capita growth rate are considered in estimating the waste quantity along with its future projections. The findings from the estimation of waste quantities state that seasonal differences in the municipal solid waste stream are not substantial. The most seasonably variable material in the municipal solid waste stream is food waste. Residential waste is relatively homogeneous. Although there are some differences in waste generation depending on demographic and other local factors, most households dispose of essentially similar types of wastes. Variation occurs in waste composition dependent upon income levels and category of sources. Variation also occurs based upon the extent of source reduction and recycling opportunities. As opportunities exist to recycle wastes, the recycling facilities might have to grow at a similar pace to the generation of waste. Physical and chemical characteristics of solid waste are important to implement the waste disposal and management plan for the selection of resource and energy recovery potentials. A number of studies have been conducted to determine the composition of wastes including moisture content and calorific value. The data show that the moisture content in city waste is significantly higher and the calorific value is much lower, which determines the viability of composting or anaerobic digestions rather than waste combustion.     

Distribution and availability of trace elements in municipal solid waste composts

Trace element contamination is one of the main problems linked to the quality of compost, especially when it is produced from urban wastes, which can lead to high levels of some potentially toxic elements such as Cu, Pb or Zn. In this work, the distribution and bioavailability of five elements (Cu, Zn, Pb, Cr and Ni) were studied in five Spanish composts obtained from different feedstocks (municipal solid waste, garden trimmings, sewage sludge and mixed manure). The five composts showed high total concentrations of these elements, which in some cases limited their commercialization due to legal imperatives. First, a physical fractionation of the composts was performed, and the five elements were determined in each size fraction. Their availability was assessed by several methods of extraction (water, CaCl(2)-DTPA, the PBET extract, the TCLP extract, and sodium pyrophosphate), and their chemical distribution was assessed using the BCR sequential extraction procedure. The results showed that the finer fractions were enriched with the elements studied, and that Cu, Pb and Zn were the most potentially problematic ones, due to both their high total concentrations and availability. The partition into the BCR fractions was different for each element, but the differences between composts were scarce. Pb was evenly distributed among the four fractions defined in the BCR (soluble, oxidizable, reducible and residual); Cu was mainly found in the oxidizable fraction, linked to organic matter, and Zn was mainly associated to the reducible fraction (iron oxides), while Ni and Cr were mainly present almost exclusively in the residual fraction. It was not possible to establish a univocal relation between trace elements availability and their BCR fractionation. Given the differences existing for the availability and distribution of these elements, which not always were related to their total concentrations, we think that legal limits should consider availability, in order to achieve a more realistic assessment of the risks linked to compost use.     

Impact of poor solid waste management on ground water

Eight sediment cores recovered from Tamaki Estuary were analysed for Cu, Pb, Zn, and Cd using downward cored sub-samples. The results indicate a significant upward enrichment in heavy metals with the highest concentrations found in the uppermost 0–10 cm layer. Assessment of heavy metal pollution in marine sediments requires knowledge of pre-anthropogenic metal concentrations to act as a reference against which measured values can be compared. Pristine values for the cored sediments were determined from flat “base-line” metal trends evident in lower core samples. Various methods for calculating metal enrichment and contamination factors are reviewed in detail and a modified and more robust version of the procedure for calculating the degree of contamination is proposed. The revised procedure allows the incorporation of a flexible range of pollutants, including various organic species, and the degree of contamination is expressed as an average ratio rather than an absolute summation number. Comparative data for normalized enrichment factors and the modified degree of contamination show that Tamaki Estuary sediments have suffered significant systematic heavy metal contamination following catchment urbanization. Compared to baseline values the uppermost sediment layers show four-fold enrichment averaged across eight cores and four analysed metals.     

The composition, trend and impact of urban solid waste in Beijing

This paper provides an overview of the trend of generation, composition, and management of municipal solid waste, and estimates the carbon emissions arising from municipal solid waste management in Beijing. The correlation analysis conducted shows that the generation of municipal solid waste in Beijing has been growing steadily, showing high correlations (r > 0.9) to the total GDP, per capita income, and the population. Food waste showed an increasing trend since 1990. Compared with the results of an investigation in 1990, ash and woodchips content in 2003 declined from 56% to 17%, while the percentage of paper and plastic increased from 10% to 29% over the same period. The calorific value of the municipal waste also increased, from 2,686 kJ/kg in 1990 to 4,667 kJ/kg in 2003, indicating that the waste is suitable for incineration. Currently, the source separation ratio of municipal waste is approximately 15%. About 94% of all the collected solid waste goes to the landfill while 4% is composted and 2% is incinerated. A moderate garbage collection fee is applied to both permanent and temporary residents in Beijing, but the willingness to pay for solid waste collection and treatment is still low. Under current treatment mode, the total amounts of carbon emission from waste disposal sites and incineration increased with the increase of municipal solid waste, from 29.8 Gg in 1990 to 84.5 Gg in 2003, including 83.3 Gg of CH₄ and 22.0 Gg of CO₂. The data availability and methodological challenges in monitoring the quantity and characteristics of municipal solid waste are discussed.     

Assessment of plastic waste generation and its potential recycling of household solid waste in Can Tho City, Vietnam

Plastic solid waste has become a serious problem when considering the disposal alternatives following the sequential hierarchy of sound solid waste management. This study was undertaken to assess the quantity and composition of household solid waste, especially plastic waste to identify opportunities for waste recycling. A 1-month survey of 130 households was carried out in Can Tho City, the capital city of the Mekong Delta region in southern Vietnam. Household solid waste was collected from each household and classified into ten physical categories; especially plastic waste was sorted into 22 subcategories. The average household solid waste generation rate was 281.27 g/cap/day. The compostable and recyclable shares respectively accounted for high percentage as 80.74% and 11%. Regarding plastic waste, the average plastic waste generation rate was 17.24 g/cap/day; plastic packaging and plastic containers dominated with the high percentage, 95.64% of plastic waste. Plastic shopping bags were especially identified as the major component, accounting for 45.72% of total plastic waste. Relevant factors such as household income and household size were found to have an existing correlation to plastic waste generation in detailed composition. The household habits and behaviors of plastic waste discharge and the aspects of environmental impacts and resource consumption for plastic waste disposal alternatives were also evaluated.     

北京市生活垃圾中重金属元素污染特性调查

采用现场调研取样和理化分析检测的方法对北京市城区垃圾中重金属含量水平、主要污染元素和主要污染物进行测定,并在调查基础上提出北京市城区垃圾重金属污染的防治对策,为废弃物减量化、无害化与资源化提供依据。     

炉排型城市生活垃圾焚烧炉排气中二(口恶)(口英)污染状况及存在问题

选择四种规模不同的炉排型生活垃圾焚烧炉,分别对其排放烟气中的二(口恶)(口英)进行测定,从不同炉排型垃圾焚烧炉二(口恶)(口英)的排放现状并结合实际调查结果表明,不同炉型的生活垃圾焚烧炉存在一些共性问题,尚需加强垃圾焚烧的炉前、炉中及烟气处理各个环节的运行管理.     

Study on the law of heavy metal leaching in municipal solid waste landfill

Comparative leaching experiments were carried out using leaching medium with different pH to municipal solid waste in the landfill columns in order to investigate the mobility of heavy metals. The leachate pH and oxidation–reduction potential were measured by oxidation–reduction potential analyzer; the contents of heavy metals were measured by inductively coupled plasma mass spectrometry. It is very different in leaching concentrations of heavy metals; the dynamic leaching of heavy metals decreased with the rise of the leaching amount on the whole. Acid leaching medium had definite influence on the leaching of heavy metals in the early landfill, but it had the obvious inhibition effect on the leaching in the middle and late period of landfill; the neutral and alkaline leaching medium are more beneficial to the leaching of heavy metals. Due to the influence of the environment of landfill, the differences of the results in cumulative leaching amount, leaching rate, and leaching intensity of heavy metals are very big. The calculation results of the release rates of heavy metals prove that the orders of the release rates are not identical under different leaching conditions. Acid rain made heavy metals migrate from municipal solid waste to soil and detain in soil more easily; approached neutral and alkaline leaching mediums are more beneficial to leaching of heavy metals in the municipal solid waste and soil with leachate. The field verification of experimental data showed that the law of heavy metal leaching in municipal solid waste revealed by the experiment has a good consistency with the data obtained by municipal solid waste landfill.     

炉排型城市生活垃圾焚烧炉排气中二

选择四种规模不同的炉排型生活垃圾焚烧炉,分别对其排放烟气中的二     

The potential of biogas production from municipal solid waste in a tropical climate

The objective of this study was to estimate the potential of organic municipal solid waste generated in an urban setting in a tropical climate to produce biogas. Five different categories of wastes were considered: fruit waste, food waste, yard waste, paper waste, and mixed waste. These fractions were assessed for their efficiency for biogas production in a laboratory-scale batch digester for a total period of 8 weeks at a temperature of 15–30 °C. During this period, fruit waste, food waste, yard waste, paper waste, and mixed waste were observed to produce 0.15, 0.17, 0.10, 0.08, and 0.15 m³ of biogas per kilogram of volatile solids, respectively. The biogas produced and caloric value of each feedstock was in the range of 1.25?×?10^?3 m³ (17 kWh)/cap/day (paper waste) to 15?×?10^?3 m³ (170 kWh)/cap/day (mixed waste). Paper waste produced the least (<1×10^?3(<17.8 kWh)/cap/day), and mixed waste produced the highest methane yield (10?×?10^?3 m³ (178 kWh)/cap/day). Thus, mixed waste was found to be more efficient than other feedstocks for biogas and methane production; this was mainly related to the better C/N ratio in mixed waste. Taking the total waste production in Jimma into account, the total mixed organic solid waste could produce 865?×?10³ m³ (5.4 m³/capita) of biogas or 537?×?10³ m³ (3.4 m³/capita) of methane per year. The total caloric value of methane production potential from mixed organic municipal solid waste was many times higher than the total energy requirement of the area.     

城市垃圾焚烧残渣中阴离子的溶解性研究

通过笔者在日本研修期间所作的城市垃圾焚烧残渣中阴离子的溶解性实验,研究其在城市垃圾填埋场堆存期间无机盐类对自然环境可能产生的影响。指出要重视固体废物污染的研究和控制。     

A new method for environmental site assessment of urban solid waste landfills

Regarding various types of pollutant, waste management requires high attention. Environmental site selection study, prior to landfill operation, and subsequently, monitoring and maintaining of the location, are of foremost points in landfill site selection process. By means of these studies, it is possible to control the undesirable impacts caused by landfills. Study ahead aims at examination of effectiveness of a new method called Monavari 95–2 in landfill site assessment. For this purpose, two landfills Rasht and Andisheh, which are, respectively, located on humid and arid areas, were selected as case studies. Then, the results obtained from both sites were compared with each other to find out the weaknesses and strengths of each site. Compared with others similar methods, much more criteria (53 parameters) can be considered within this method, so the results will be more calculable. According to this method, Rasht landfill (site H) is classified as unacceptable landfill site i.e. there is an urgent need for a new suitable site for landfill, while Andishe Landfill (site D) is ranked as acceptable landfill site but needs environmental management program to handle the existing weaknesses.     

Contribution of a municipal solid waste incinerator to the trace metals in the surrounding soil

This study analyses the pedological environment of the area near a municipal waste incinerator that has been operating in the south-east district of Pisa for approximately 20?years. There are many other industrial activities in the area besides the incinerator, which represent possible sources of pollution, as well as heavy road traffic. The study area was defined by a 0-4-km zone around the site with a population of approximately 12,000 residents. The study included the physical and chemical characterisation of 100 samples of soil and an analysis of trace metals such as Cr, Ni, Pb, Zn, Hg, As and Cd. The samples were grouped into soil use categories. The results showed Zn, Pb and Hg correlated with their potentially mobile fractions, and suggested an anthropic contribution to their presence in the soil. Ni, Cr and As showed values attributable to a lithological origin. This was consistent with the PCA results. The aim was to define the environmental state of the soil of the area in order to create a reference for future research and to verify the possible presence of pollution from other sources (local industrial activities and traffic).     

Geospatial strategy for sustainable management of municipal solid waste for growing urban environment

This paper presents the implementation of a Geospatial approach for improving the Municipal Solid Waste (MSW) disposal suitability site assessment in growing urban environment. The increasing trend of population growth and the absolute amounts of waste disposed of worldwide have increased substantially reflecting changes in consumption patterns, consequently worldwide. MSW is now a bigger problem than ever. Despite an increase in alternative techniques for disposing of waste, land-filling remains the primary means. In this context, the pressures and requirements placed on decision makers dealing with land-filling by government and society have increased, as they now have to make decisions taking into considerations environmental safety and economic practicality. The waste disposed by the municipal corporation in the Bhagalpur City (India) is thought to be different from the landfill waste where clearly scientific criterion for locating suitable disposal sites does not seem to exist. The location of disposal sites of Bhagalpur City represents the unconsciousness about the environmental and public health hazards arising from disposing of waste in improper location. Concerning about urban environment and health aspects of people, a good method of waste management and appropriate technologies needed for urban area of Bhagalpur city to improve this trend using Multi Criteria Geographical Information System and Remote Sensing for selection of suitable disposal sites. The purpose of GIS was to perform process to part restricted to highly suitable land followed by using chosen criteria. GIS modeling with overlay operation has been used to find the suitability site for MSW.     

Renewable energy from solid waste: life cycle analysis and social welfare

In this study, municipal solid waste (MSW) composition in distinct world locations is compared and a case study is assessed. Three waste-to-energy (WtE) techniques are employed within the framework of an industrial partnership. Life cycle assessment (LCA) and a brief social contextualization including the production of renewable energy from the waste generated worldwide were held to attain a holistic view and attract the interest of multiple stakeholders.Incineration depicted a sustainable profile with improved results for global warming potential and terrestrial ecotoxicity potential. Regular gasification revealed the best results for eutrophication, acidification, marine aquatic ecotoxicity and human toxicity potential. Two-stage plasma gasification showed negative values for all impact categories i.e. achieving environmental credits. The estimate of the electricity produced from the waste generated per capita showed a fair coverage of the electrical demand in distinct world areas.To the best of the authors' knowledge, there are no reports connecting the electricity use, the waste production and the renewable energy achieved from WtE for different world regions. Therefore, this study supports the replacement of fossil fuels with renewable alternatives, reducing greenhouse gas emissions while maintaining the comfort and commodities suitable for a comfortable quality of life.     

Application of processed organic municipal solid waste on agricultural land – a scenario analysis

Source separation, composting and anaerobic digestion, with associated land application, are increasingly being considered as alternative waste management strategies to landfilling and incineration of municipal solid waste (MSW). Environmental life cycle assessments are a useful tool in political decision-making about waste management strategies. However, due to the diversity of processed organic MSW and the situations in which it can be applied, the environmental impacts of land application are very hard to determine by experimental means. In the current study, we used the agroecosystem model Daisy to simulate a range of different scenarios representing different geographical areas, farm and soil types under Danish conditions and legislation. Generally, the application of processed organic MSW resulted in increased emissions compared with the corresponding standard scenarios, but with large differences between scenarios. Emission coefficients for nitrogen leaching to the groundwater ranged from 0.03 to 0.87, while those for nitrogen lost to surface waters through tile drains ranged from 0 to 0.30. Emission coefficients for N₂O formation ranged from 0.013 to 0.022 and for ammonia volatilization from 0.016 to 0.11. These estimates are within reasonable range of observed values under similar conditions. Furthermore, a sensitivity analysis showed that the estimates were not very sensitive to the mineralization dynamics of the processed organic MSW. The results show that agroecosystem models can be powerful tools to estimate the environmental impacts of land application of processed MSW under different conditions. Despite this, agroecosystem models have only been used to a very limited degree for this purpose.     

Feature extraction using Hough transform for solid waste bin level detection and classification

This paper deals with the solid waste image detection and classification to detect and classify the solid waste bin level. To do so, Hough transform techniques is used for feature extraction to identify the line detection based on image’s gradient field. The feedforward neural network (FFNN) model is used to classify the level content of solid waste based on learning concept. Numbers of training have been performed using FFNN to learn and match the targets of the testing images to compute the sum squared error with the performance goal met. The images for each class are used as input samples for classification. Result from the neural network and the rules decision are used to build the receiver operating characteristic (ROC) graph. Decision graph shows the performance of the system waste system based on area under curve (AUC), WS-class reached 0.9875 for excellent result and WS-grade reached 0.8293 for good result. The system has been successfully designated with the motivation of solid waste bin monitoring system that can applied to a wide variety of local municipal authorities system.     

Enhanced uptake of heavy metals in municipal solid waste compost by turfgrass following the application of EDTA

Enhancement of multiple heavy metal uptake from municipal solid waste (MSW) compost by Lolium perenne L. in a field experiment was investigated with application of EDTA. EDTA was added in solution at six rates (0–30 mmol kg^???1) after 50 days of plant growth. Two weeks later, plants were harvested for the first crop and then all the turfgrasses were mowed. After another 30 days of growth, EDTA was added again at above six rates to the corresponding sites and the second crop was harvested 2 weeks later. The results showed that EDTA significantly increased heavy metal accumulation in both crops of L. perenne. For the first crop, the concentrations of Mn, Ni, Cd, and Pb in the shoots increased remarkably with increasing EDTA supply, peaked at 25 mmol kg^???1 EDTA, and shoots of 0–5 cm height (shoots from medium surface to 5 cm height) had higher metal concentrations than 5–10 cm and >10 cm shoots. The highest concentration of Mn, Ni, Cd, and Pb was 2.3-, 2.3-, 2.6-, and 3.2-fold, respectively, in 0–5 cm shoots higher than control. For the second crop, the concentrations of Mn, Cu, and Pb in shoots were, in general, less than those in the first crop. However, the second crop was significantly higher (P?< 0.05) than the first crop in dry biomass, so the total amount of metals removed by the second crop was more than the first crop. In addition, EDTA significantly increased the translocation ratios of most heavy metals from roots to shoots. For the first crop, 38% of the total Zn, 51% of Cd, 49% of Pb, 60% Mn, 55% Ni, and 45% Cu taken up by the plant was translocated in the shoots of 0–5 cm height. Turfgrass would have potential for use in remediation of heavy metals in MSW compost or contaminated soils.     

Application of ANP and DEMATEL to evaluate the decision-making of municipal solid waste management in Metro Manila

A municipal solid waste management (MSW) expert group was consulted in order to mirror how government officials might reach an effective solution regarding municipal solid waste management in Metro Manila. A critical issue regarding this is how the expert group can better evaluate and select a favorable MSW management solution using a series of criteria. MSW management solution selection is a multiple criteria decision-making (MCDM) problem, which requires the consideration of a large number of complex criteria. A robust MCDM method should consider the interactions among these criteria. The analytic network process (ANP) is a relatively new MCDM method which can deal with all kinds of interactions systematically. The Decision Making Trial and Evaluation Laboratory (DEMATEL) not only can convert the relations between cause and effect of criteria into a structural model, but also can be used as a way to handle the inner dependences within a set of criteria. Hence, this paper applies an effective solution based on a combined ANP and DEMATEL method to assist the expert group evaluating different MSW management solutions. According to the results, the best solution is for each city to have its own type of thermal process technology and resource recovery facility before landfill rather than entering a joint venture with enterprises or going into build-operate-transfer projects in order to be able to construct thermal process technologies and resource recovery facilities.