The effects of socioeconomic parameters on household solid-waste generation and composition in developing countries (a case study: Ahvaz,Iran)

Environment problems associated with the generation of waste are part of societal changes where households play an important role. These societal changes influence the size, structure and characteristic of given households. For the effective planning of solid-waste handling infrastructure, it is essential to know the quantity of waste generation and its composition. This paper presents the findings of a study carried out in an urban municipal area in Iran to determine the household solid-waste generation rate and waste composition based on field surveys and to determine the related socioeconomic parameters. The dependent variables were waste generation and composition, and independent variables were family size, family employment, age, number of room and education. Over 400 sample households were selected for the study using a stratified random sampling methodology and from five different socioeconomic groups. Waste collected from all groups of households were segregated and weighted. Waste generation rate was 5.4 kg/household/day. Household solid waste comprised of ten categories of wastes and with the largest component (76.9%). The generation and composition of household solid waste were correlated with family size, education level and households income. This paper adequately suggests new insights concerning the role of socioeconomic parameters in affecting the generation of household waste.     

A comprehensive physico-chemical, mineralogical and morphological characterization of Indian mineral wastes

This paper provides a comprehensive characterization of mineral waste such as fly ash, bottom ash, slag and construction demolition (C&D) collected from four different thermal power plants, three steel plants and three C&D waste generation sites in India. To determine utilisation potential and environmental concerns, as received fly ash, bottom ash, slag and C&D waste were analysed for physico-chemical, mineralogical and morphological properties. The physico-chemical properties analysed include pH, moisture content, acid insoluble residue, loss on ignition(LOI), carbon content, fineness, chloride content, sulphate content, reactive silica content, XRF and heavy metal analysis. Morphological and mineralogical characteristics were investigated using scanning electron microscopy–energy dispersive X-ray. Particle size distribution was obtained using particle size analyser. The material analysed has different compositions and were selected with a view to determine their suitability for different applications in cement and concrete industry and for further research studies.     

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.     

Relation of waste generation and composition to socio-economic factors: a case study

To develop an effective waste management strategy for a given region, it is important to know the amount of waste generated and the composition of the waste stream. Past research has shown that the amount of waste generated is proportional to the population and the average mean living standards or the average income of the people. In addition, other factors may affect the amount and composition of waste. These are climate, living habits, level of education, religious and cultural beliefs, and social and public attitudes. This paper presents the findings of a study carried out in a suburban municipal area in Sri Lanka to determine the solid waste generation rate and waste composition based on field surveys and to determine the related socio-economic factors. A database was developed that included information on the quantity and composition of waste generated in a sample of households in the study area over a time period. The collected data was analysed to relate waste generation and composition data to various socio-economic factors. Over 400 sample households were selected for the study using a stratified random sampling methodology based on municipal wards and property values. A technique that considers both the number of households in a particular income group (property value range) and the standard deviation of property values within a given income group was used to determine the appropriate sample size for each municipal ward. Through category and regression analyses, the quantities of waste and waste composition were related to several socio-economic factors. The paper describes the basis for the sample selection, the methodology adopted for data collection, the socio-economic parameters used for the analysis, and the relationships developed from the analysis.     

Modeling the environmental sustainability of timber structures: A case study

A revival in timber buildings and the appreciation of their positive physical and mechanical properties can be explained by the unique environmental credentials of timber products and their versatility. Heightened public awareness of sustainability in the construction sector places timber among the most preferential sustainable materials. There is plenty of previous research on sustainability assessments for complete buildings, although far less on the sustainability assessment of specific parts of the buildings, such as the case of timber structures. The objective of this study is to present an evaluation model, based on MIVES methodology, specifically designed for timber structures, which can be used to enhance the environmental sustainability and to reduce the impacts that are generated, in those areas where it has been awarded a lower score. The application of the model to the largest multi-storey residential timber building in south-western Europe clearly shows that changes to the material, such as its background and environmental certification, generate significant changes to the overall results of the assessment. A sensitivity analysis is then used to verify the analysis of the results and both the validity and the stability of the proposed model.     

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.     

Assessment of potential impacts of municipal solid waste treatment alternatives by using life cycle approach: a case study in Vietnam

In Vietnam, most of municipal solid waste (MSW) is disposed of at open dumping and landfill sites, and the methane gas from waste is the un-ignorable source of greenhouse gas (GHG) emission. It is indispensable to explore the possibility for GHG mitigation in MSW management. The objective of this study was to estimate alternative waste treatment practices towards the GHG emission mitigation, energy consumption and generation, reduction of landfill volume, and various benefits for proposing the appropriate selection by scenario analyses for representative Vietnam’s cities. Impacts were calculated by utilizing life cycle assessment (LCA) method. A literature review survey on the current applicability of LCA database for assessing impacts from waste sector in developing countries, especially for Vietnam, was carried out. This study assessed the contribution of alternative solid waste treatment practices. The result showed that, except investment and operation costs, incineration with energy recovery seems the suitable alternative for treating waste from representative cities of Vietnam according to reduction of GHG emission and waste burden to landfill sites and energy recovery and generation. Besides, MSW composition was identified as an important factor directly influencing to impacts as well as other products and benefits of waste treatment alternatives. Reliable data on waste composition are indispensable for assessing to choose, improve, or plan the waste treatment practices towards sustainable development.     

Metal Levels in Raccoon Tissues: Differences On and Off the Department of Energy's Savannah River Site in South Carolina

Levels of arsenic, cadmium, chromium, copper, lead, manganese, selenium, and strontium⁸⁸ were examined in heart, kidney, muscle, spleen and liver of raccoons (Procyon lotor) from four areas on the Department of Energy's Savannah River Site (SRS), including near a former reactor cooling reservoir and a coal ash basin, and from public hunting areas within 15 km of the site. Mercury is mentioned briefly because it is discussed more fully in another paper. We test the hypotheses that there are no differences in metal levels between raccoons on SRS and off the SRS (off-site), and among different locations on the SRS. Although raccoons collected off-site had significantly lower levels of mercury and selenium in both the liver and kidney, there were few consistencies otherwise. There were significantly higher levels of cadmium in liver of on-site compared to off-site raccoons, and significantly higher levels of chromium and strontium⁸⁸ in kidney of on-site compared to off-site raccoons. Copper and manganese were highest in the liver; cadmium, lead, mercury and selenium were highest in the liver and kidney; chromium was highest in the spleen and muscle; arsenic was highest in the heart, and strontium⁸⁸ was slightly higher in the kidney than other organs. Where there were significant differences on site, chromium, manganese were highest in raccoon tissues from Steel Creek; arsenic, lead and selenium were highest in the Ash Basin; cadmium was highest at Upper Three Runs; and strontium⁸⁸ was highest at Upper Three Runs and Steel Creek. The patterns were far from consistent.     

Evolutionary game analysis of stakeholders' decision-making behaviours in construction and demolition waste management

Continuing industrial development has created large quantities of construction and demolition (C&D) waste, which has led to severe environmental and social problems. The aim of this study was to investigate the decision-making behaviours of stakeholders involved in C&D waste management. Based on evolutionary game theory, stakeholder decision-making behaviours in C&D waste management were analysed, and their influencing factors were identified, including government supervision costs, public participation costs, government penalties, government incentives, government supervisory intensity, probability of contractors conducting illegal dumping, probability of public participation, and probability of illegal dumping being detected. The results also revealed how government penalties and incentives impacted the decision-making behaviours of the contractors and public. Penalties and incentives can effectively reduce illegal C&D waste dumping behaviours, while excessive penalties and incentives have limitations in controlling illegal dumping. The model proposed in this research provides an experimental simulation platform to determine the appropriate values for government penalties and incentives for C&D waste management based on stakeholder decision-making behaviours. In addition, the research results for the stable strategy point of a three-party evolutionary game model demonstrated the importance of public participation in C&D waste management. These results may inform research hypotheses for future empirical studies and provide a simple model for developing appropriate government penalties and incentives in practice.     

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.     

Desertification control: A framework for action

Desertification is a little-understood term that aggregates several land degradation processes occurring in the arid regions of the world. The major processes are vegetation degradation, water erosion, wind erosion, salinization, and soil compaction. Water erosion is the principal threat to environmental stability in both arid and humid climatic zones. Land degradation is generally reversible unless damage is very severe or soils are shallow. Practices to control land degradation are widely available but are not put to use for many reasons. Absence of a food crisis in developed countries is one of the important reasons. A related reason is the perception that no real problem exists. A third reason is that degradation control is not cost effective, except for controlling salinity and compaction. It is time to change emphasis from reducing on-site damage to reducing off-site damage.     

Dynamic game strategies for construction and demolition waste recycling with learning and reference effects

Construction and demolition waste (C&DW) recycling can effectively reduce the environmental impacts caused by the massive amounts of untreated C&DW, and can promote the sustainable development of the construction industry. This study aims to provide relevant insights for the implementation of C&DW recycling, and can be practically used to guide participants' dynamic strategies in the presence of both the reference price effect and cost learning effect. Based on game theory, a static model is developed as a benchmark, including a construction materials manufacturer and a C&DW recycler under a government subsidy. Then, a dual-period dynamic model combining the learning and reference effects is established to broaden the understanding of C&DW recycling management. On this basis, the decisions and revenues of players are compared and analysed, and managerial insights are obtained through numerical analysis. It is found that both the learning and reference effects affect the manufacturer's decisions and revenues, and that the reference effect has a much greater impact on profit than the learning effect. In addition, only the learning effect has a positive influence on the recycler's recycling efforts and profits, thereby promoting C&DW recycling and reducing environmental impacts. Moreover, government subsidies always benefit the environment and recycler, and as the learning ability becomes stronger, the subsidy becomes more efficient in reducing the environmental impacts and improving the recycler's profit. Comparatively, the impact of subsidy on the manufacturer's profits depends on the learning ability. When the learning ability is relatively high, a higher subsidy is detrimental to the manufacturer in the short term but benefits it in the long term.     

Environmental planning based on reduce,reuse, recycle and recover using artificial intelligence

Waste disposal was a significant challenge faced by the community and government. Customers buy and use goods that produce a considerable amount of waste. Waste management is a major problem since the number of consumers increased due to high waste generation. This has resulted in a huge amount of waste, which calls for enormous waste-management policies. Reduce; Reuse, Recycle, and Recover are the tools to reduce the adverse implications of retailing and manufacturing on the environment. In this paper, Artificial Intelligence based Hybridized Intelligent Framework (AIHIF) has been proposed for automated recycling to optimizing the waste management process. The system will optimize waste collection with a short distance by utilizing machine learning and graph theory. AI design technology, which helps different approaches adapted to interest groups, collecting their specific information and greatly improving environmental planning and urban management performance, accuracy, and efficiency. The experimental results show that the proposed method enhances performance and accuracy when compared to other existing methods.     

涪陵页岩气田一期工程环境影响调查

采用现场调研与实地监测相结合的方法对涪陵页岩气田一期工程污染源和区域环境质量现状进行深入调查研究,剖析涪陵页岩气开发对环境产生的影响。结果表明,涪陵页岩气田开发过程中废水实行循环利用,钻屑固体废物固化填埋,企业环保措施基本落实,短期内页岩气开发未对区域环境产生明显不良影响。指出修建井场、池体、道路等设施对生态环境具有一定影响,且随着时间推移,钻屑固化填埋对周围土壤及水环境也具有潜在影响。     

A habitat-based microscale forest classification system for zoning wood production areas to conserve a rare species threatened by logging operations in south-eastern Australia

The production of timber from native forests is presently one of the most controversial land management issues in Australia. Part of this controversy results from the potential impacts of forestry practices on forest-dependent fauna, particularly those that are rare and endangered, such as Leadbeater's Possum Gymnobelideus leadbeateri McCoy, in the forests of central Victoria, south-eastern Australia. A significant proportion of the highly limited distribution of this species overlaps with some of the most valuable wood production forests in Australia within which extensive clearfelling operations are employed to produce timber and pulpwood. These operations can destroy the habitat of G. leadbeateri. The Victoria government agency that is responsible for forest and wildlife management has devised a forest zoning system as part of the management strategies to conserve G. leadbeateri within timber production areas. This is designed to partition the forest into three types of areas: (1) where the conservation of G. leadbeateri is a priority, (2) where wood production is a priority, and, (3) where both land uses are a joint priority. The classification of areas of forest where the conservation of G. leadbeateri is the primary land use is based on an understanding of the habitat requirements of the species. The results of recent field studies, where statistical models of the habitat requirements of G. leadbeateri have been developed and their performance subsequently tested using a new dataset, highlights the need for a new basis to guide the classification of areas for the conservation of the species within wood production forests. We describe a method for devising a forest management zoning system that is based on a statistical model of the habitat requirements of G. leadbeateri and which will better integrate wood production and the conservation of the species. This procedure accounts for the uncertainty in the statistical model and, in turn, reduces the risk that areas where G. leadbeateri occurs are logged, whilst ensuring that other areas are not unnecessarily excluded from timber harvesting.     

Classification and mapping forest sites using geographic information system (GIS): a case study in Artvin Province

The productivity of forest sites has been indirectly determined with solo wood production objective in forest management. Forest site productivity should, however, be determined directly in order to implement ecosystem based multipurpose forest management philosophy. This article tackles the problem in distinguishing and mapping forest sites using both direct method and indirect method in Genya Mountain located in central of Artvin State Forest Enterprise. About 112 sample plots were designed and distributed over the area. In each sample plot, soil samples were collected and the classical timber inventory measurements were taken. According to direct method, Soil Moisture Regime (SMR) method is preferred due to a water deficiency in the study area. Water holding capacity was used as an essential criterion for the classification of the forest site. Forest site classifications were assigned regarding the physiographic factors such as landform, aspect, and slope. Five different forest sites classes; dry, moderate fresh, fresh, humid and hygric were determined. According to direct method, the guiding curve was used to generate anamorphic site index (SI) equations and three site index classes; good (SI=I–II), medium (SI=III) and low (SI=IV–V) were determined. Some important differences between the methods were realized. The forest sites determined with site index estimation method indicate that site index I and II is 505.99 ha, III 1095.79 ha and IV and V 992.95 ha, whereas forest sites determined with direct method related to dry site of 937.58 ha, moderate fresh site of 931.90 ha, fresh site of 1,797.71 ha, humid site of 80.48 ha and hygric site of 356.55 ha. The forest site maps of both methods were created using GIS functions. The forest sites of open and degraded areas should be determined according to direct method.     

Strategic Management Decision Support System: An Analysis of the Environmental Policy Issues

In this paper we present a new approach for modeling environmental problem as a bilevel programming problem. To the authors best knowledge, this is the first attempt to use bilivel techniques to tackle such problems. We derive at solution to help decision makers to cope with environmental policy issues. San Francisco, Bay Area is used as a real world example with the solution to their environmental problem.California is presently faced with a serious deficit of solid waste treatment and disposal facilities. Federal legislation has sought to compel the States to assure the capacity to treat and dispose of their own wastes and the California Legislature has enacted laws requiring the counties to initiate programs so that they can treat and dispose of their own wastes. Neither the federal nor the State programs have met with success in California. California continues to ship greater and greater amounts of waste out-of-state, and the majority of California counties have not instituted plans acceptable to the State government regarding the treatment and disposal of their own wastes.In the few cases where sitting and licensing programs have been proposed, the policy-makers charged with their evaluation have proceeded with largely intuitive, non-quantitative evaluation of policy options, often ignoring most of the financial and environmental implication of their decisions.We have developed a strategic management decision model that can evaluate multiple solid waste management options from both economic and environmental standpoints. Examples of problems a quantitative model might evaluate include the economic and environmental impacts of multiple treatment or disposal facilities as opposed to only one site; the environmental impact of taxing dirty waste streams, thus encouraging waste treatment and/or minimization on-site; and the social risk resulting from transportation risks assuming one or more multiple treatment or disposal sites or the use of alternative transportation routes.Because of extensive information presently available for the San Francisco Bay region, we have investigated the regional waste management problem there under several different treatment and disposal scenarios. As appropriate, results from this regional model and from authors earlier work [1] will be applied to California as a whole.     

A Routing and Scheduling System for Infectious Waste Collection

Most hospitals and clinics in Taiwan do not have on-site treatment facilities for their infectious waste and must rely on outside agencies for their collection and treatment. The problem of optimally routing and scheduling the collection of medical waste from a disperse group of facilities is recognized as a periodic vehicle routing problem. This study develops a computer system to solve the resulting optimization problem based on a two-phased approach proposed earlier. The first phase solves a standard vehicle routing problem to determine a set of individual routes for the collection vehicles. The second phase uses a mixed integer programming method to assign routes to particular days of the week. The computer system is user-friendly and consists of several Visual Basic programs while the geographical information system is incorporated to facilitate input and output interface and database management. An illustrative example for the infectious waste of 348 hospitals in the Tainan City area demonstrates the effectiveness of the system.     

Comparison of static and mineralogical ARD prediction methods in the Nordic environment

Acid rock drainage (ARD) is a major problem related to the management of mining wastes, especially concerning deposits containing sulphide minerals. Commonly used tests for ARD prediction include acid–base accounting (ABA) tests and the net acid generation (NAG) test. Since drainage quality largely depends on the ratio and quality of acid-producing and neutralising minerals, mineralogical calculations could also be used for ARD prediction. In this study, several Finnish waste rock sites were investigated and the performance of different static ARD test methods was evaluated and compared. At the target mine sites, pyrrhotite was the main mineral contributing to acid production (AP). Silicate minerals were the main contributors to the neutralisation potential (NP) at 60% of the investigated mine sites. Since silicate minerals appear to have a significant role in ARD generation at Finnish mine waste sites, the behaviour of these minerals should be more thoroughly investigated, especially in relation to the acid produced by pyrrhotite oxidation. In general, the NP of silicate minerals appears to be underestimated by laboratory measurements. For example, in the NAG test, the slower-reacting NP-contributing minerals might require a longer time to react than is specified in the currently used method. The results suggest that ARD prediction based on SEM mineralogical calculations is at least as accurate as the commonly used static laboratory methods.