Curbside Collection Research Articles

Challenges in Managing Centralized Taxi Dispatching at High-Volume Airports

This paper provides an evaluation of taxi dispatching procedures at New York City's John F. Kennedy International Airport (JFK). Curbside data collection and interviews with airport stakeholders were conducted to describe and quantify conditions for taxi drivers and passengers at JFK. A literature review was performed to identify operational similarities and differences between JFK and other high-volume airports with centralized taxi dispatching and to identify potential solutions for application at JFK. The outcomes of this study include (a) characterization of relationships between airportwide and terminal-level passenger demands and available taxi supply at JFK, (b) identification of sources of inefficiency in existing taxi dispatching procedures and taxi operations, and (c) identification of approaches for addressing supply–demand imbalances and next steps in evaluating those approaches.

Life cycle assessment of integrated recycling schemes for plastic containers and packaging with consideration of resin composition

Many life cycle assessment studies have evaluated and compared the environmental performance of various technologies for recycling plastic containers and packaging in Japan and other countries. However, no studies have evaluated the combination of recycling technologies in consideration of the resin composition in terms of the quantity of each recycled product so as to maximize their environmental potential. In this study, 27 scenarios of recycling schemes for household waste plastic containers and packaging are developed through integrating a conventional recycling scheme with additional recycling schemes. The conventional recycling scheme involves municipal curbside collection and either the material recycling or feedstock recycling of waste plastics. The additional recycling schemes are feedstock recycling in steel works of the residue from conventional material recycling processes, and corporate voluntary collection and independent material recycling of specific types of plastic trays. Life cycle assessment based on the modeling of recycling processes considering the resin composition in terms of the quantity of each recycled product is applied to evaluate and compare these scenarios from the viewpoints of fossil resource consumption and CO2 emission. The results show that the environmental loads are reduced in all scenarios including the additional recycling schemes compared with the conventional recycling scheme. However, the independent plastic tray recycling scheme exhibits lower additional environmental savings when the residue recycling scheme is integrated with the conventional material recycling scheme. This is because both additional recycling schemes aim to utilize polystyrene and polyethylene terephthalate, which would otherwise be incinerated as residue from material recycling processes. The evaluation of the environmental loads of plastic recycling with consideration of the resin composition in terms of the quantity of each recycled product makes it possible to investigate recycling schemes that integrate different technologies to maximize their environmental potential.

The influence of collection facility attributes on household collection rates of electronic waste: The case of televisions and computer monitors

In the US, household electronic waste collected for recycling is primarily by voluntary drop-off at designated collection facilities. This study examines the influence of specific collection facility attributes (recycling fees charged, number of days open, and driving distance) on the household collection rate of e-waste in the US state of Maine. Data were collected for household computer monitor and television collection for 92 municipal waste transfer facilities representing 30% of the state's population for one year. Results suggest that recycling fees are negatively correlated with the number of televisions and computer monitors collected; furthermore, the more frequently facilities were open, the more televisions and computer monitors were collected per capita. The distance from the facility had no correlation, which prompted an analysis of whether the existence of a curbside collection system in the municipality was influential. Results show a negative correlation between computer monitor and television collection and a municipality having recycling (but not e-waste) curbside collection. Based on the results of this study, policymakers may be able to increase the collection rate of household e-waste by eliminating or lowering recycling fees, expanding collection days and hours to increase convenience, and/or considering curbside collection of e-waste.

Identifying the key factors in increasing recycling and reducing residual household waste: A case study of the Flemish region of Belgium

The competent waste authority in the Flemish region of Belgium created the 'Implementation plan household waste 2003-2007' and the 'Implementation plan sustainable management 2010-2015' to comply with EU regulation. It incorporates European and regional requirements and describes strategies, goals, actions and instruments for the collection and treatment of household waste. The central mandatory goal is to reduce and maintain the amount of residual household waste to 150 kg per capita per year between 2010-2015. In literature, a reasonable body of information has been published on the effectiveness and efficiency of a variety of policy instruments, but the information is complex, often contradictory and difficult to interpret. The objective of this paper is to identify, through the development of a binary logistic regression model, those variables of the waste collection scheme that help municipalities to reach the mandatory 150 kg goal. The model covers a number of variables for household characteristics, provision of recycling services, frequency of waste collection and charging for waste services. This paper, however, is not about waste prevention and reuse. The dataset originates from 2003. Four out of 12 variables in the model contributed significantly: income per capita, cost of residual waste collection, collection frequency and separate curbside collection of organic waste.

The impact of attitudes and behavioral costs on environmental behavior: A natural experiment on household waste recycling

Numerous studies have shown the importance of incentives as well as of attitudes in explaining pro-environmental behavior. Reported attitude effects, however, are generally rather small and exhibit considerable variation among studies. Different theoretical perspectives can account for this finding: whereas theories of rational action suggest additive effects of costs and attitudes, the low-cost hypothesis and dual-process theories imply interaction effects – in different directions, resulting from different mechanisms. The present study tries to overcome the shortcomings of past research by using advanced statistical methods to test competitive hypotheses in the context of post-consumer waste recycling. We utilize data from a natural experiment on recycling participation in Cologne/Germany ( n = 1882) in which the incentive structure for recycling changed due to the conversion of the recycling scheme from a drop-off system to curbside collection. In order to avoid self-selection bias, we conducted pre- and post-treatment surveys and applied conditional fixed-effects regression models. We found that curbside collection had a strong impact on recycling participation and attitudes had a moderate effect. The interaction is negative but statistically insignificant. Our findings contradict the low-cost hypothesis and provide some evidence that environmental concerns moderate the effect of the recycling scheme. We cannot, however, reject the rational choice proposition of mere additive effects.

Wasting Time? Recycling Incentives in Urban Taiwan and Japan

What makes recycling work? We study the factors driving household waste disposal and recycling in 18 cities in Taiwan and Japan in order to understand the impact of alternative waste management incentives. We show that this depends on the effect of distinct policies on the relative costs of the main alternative disposal methods: recycling, disposal to landfill and illegal dumping. The willingness both to recycle and to dispose to landfill depends on the relative costs of the waste collection regime, and these are dominated by the time cost of alternative disposal methods. The higher the frequency of waste collection, the less recycling and the more disposal to landfill there will be. This is because frequent collection reduces the marginal time-cost of disposal to landfill. Curbside collection of recyclable material, and the frequency of that collection, has a similar effect on the recycling rate. Although direct incentives, such as unit pricing are important in the waste disposal decision, recycling depends primarily on management of the time-costs it involves.

Choosing a recycling system using ANP and ELECTRE III techniques

The process of coordinating with the European Union forced the Turkish government to set up new obligations and an environmental policy for Turkey. The new regulations are more obligatory and have more district lines than the preceding policies. According to the new regulations, municipalities have to prepare packaging waste management plans. In this manner, choosing a packaging waste management system appears to be an important decision making problem. Hence, economic, social, cultural, and technical factors in choosing packaging waste management systems should be considered together. A system may have several criteria to be evaluated and different alternatives to be chosen. Due to the structure of this type of problem, it is considered as a multicriteria decision making problem. Taking this fact into consideration, within the scope of the present study, which it is hoped will provide alternatives for decision makers, 5 recycling scenarios were presented concerning the composition of municipal solid waste in Eskisehir. Consequently, these scenarios were evaluated according to their benefits, costs, and risk factors, using analytic network process (ANP) and ELECTRE III techniques. The results of both techniques were compared. Scenario 3a [10% curbside collection (commingled recyclables) + 5% recycling containers + 5% material recovery facility] was determined to be the most appropriate recycling system with both techniques.

Optimization of Municipal Solid Waste Collection System: Case Study

Curbside collection of municipal solid waste (MSW) constitutes a substantial portion of waste management cost. The utilization of operations research tools for the reduction of MSW collection costs in the Township of Millburn, N.J., was investigated. This research identified network models, specifically the Chinese postman problem algorithm as one of the approaches that could be used to evaluate the truck routes and the optimum sequence of each of these vehicles needed to collect the generated waste. The Township of Millburn has a population of 20,000 in approximately 7,000 households. The township divides the service area into three sections and collects waste twice a week from curbsides of single-family and two-2 family units using up to four trucks. Additional data, such as the number of houses per street and distances between intersections, were obtained from the Township and from Google Earth. Then with the aid of commercial software, the optimum routes for each of the trucks were obtained. Results from this optimization study were then compared with the current waste collection practice. Based on the case study results improvements to the current MSW collection procedure were proposed to the Township of Millburn, N.J.

Influência do tipo de coleta (comum ou seletiva) na reciclagem de filmes de poliolefinas pós-consumo

Filmes de polipropileno (PP) e de polietilenos de alta (HDPE) e baixa densidades (LDPE) foram estudados avaliando-se a presença de impurezas e o efluente da lavagem de seus resíduos provenientes tanto de coleta comum (resíduos misturados) quanto seletiva (resíduos separados). Os resultados apontam que os filmes estavam impregnados com, no mínimo, 30% de impurezas quando provenientes de coleta comum e com, no máximo, 10% quando de coleta seletiva. Esses resultados, associados aos da turbidez do efluente de lavagem, indicam que dos filmes de coleta seletiva, preferidos pelos recicladores, se obtém pelo menos 20% mais material e tem-se uma lavagem mais fácil, por envolver praticamente só a retirada de sólidos, ao contrário da coleta comum, associada a resíduos úmidos impregnados. Os efluentes foram também avaliados segundo sólidos totais, sólidos sedimentáveis e o teor de nove metais. Os resultados indicaram que os dois tipos de coleta geram efluentes semelhantes e que no máximo duas etapas devem ser suficientes para seus tratamentos: decantação e diluição do efluente no corpo d'água receptor.

Attitudinal and Community Influences on Participation in New Curbside Recycling Initiatives in Northern Ireland

This study compared the influence of individualistic attitudinal factors with more community-level (or ecological) variables on recycling behavior in the context of Belfast, Northern Ireland. Data obtained from a postal questionnaire ( n = 765) were matched with historical recycling participation behavior data collected by the local government authority to examine the effect of general environmental concern, attitudes toward recycling, sense of community, and socioeconomic status of neighborhood on levels of participation in a recently introduced curbside collection program. The influence of cultural differences between Catholic and Protestant communities in Belfast is also considered. Our results suggested that socioeconomic status of area was the strongest predictor of recycling participation, with recycling attitudes and sense of community also having some affect, and general environmental concern being found to have no effect. Results are discussed in terms of their implications for theories of proenvironmental behavior and their application to the promotion of recycling participation within communities.

Modeling Biowaste Flows for Life‐Cycle Assessment: Calculation of the Potential and Collected Weight of Kitchen and Garden Waste

SummaryThis article presents an integrative approach to calculating the weight of potential biowaste and collected biowaste materials, as the basis for a life‐cycle assessment (LCA) of biowaste management. Biowaste contains kitchen and garden (yard) waste of households. This approach could be used for waste management planning and for the implementation of biowaste schemes. Case studies and examples in the literature are analyzed to model the mass of the flow of biowaste. This article defines relevant operands, presents the main assumptions, and describes the calculation principles. Spatial aspects and the uncertainties related to the inclusion of this aspect are explicitly considered in the calculation of the weight of the potential biowaste. We also present the calculation principles for obtaining the weight of (1) biowaste used in home composting, (2) the organic portion of residual waste, (3) biowaste separately collected by a bring system, and (4) biowaste separately collected by curbside collection (known in some areas as kerbside collection). By choosing the biowaste potential in kilograms per capita year (kg/cap yr) as the functional unit, previously ignored options within the biowaste system could be assessed. For example, widening the system boundaries allows LCA studies to assess the contribution of private and public transport of waste to ecological impact categories. It allows examining the effects of supporting home composting through financial incentives and the introduction of a separate collection system. This study focuses on the comparison of different collection types and on the characteristics of the area under investigation. It also incorporates the behavior of the inhabitants of households and includes a sensitivity analysis of relevant operands. This approach is being included in an LCA assessing biowaste management options.

Comparison of different collection systems for sorted household waste in Sweden

Composition and quantity per person of municipal solid waste (MSW) have been analyzed in six municipalities in southern Sweden with similar socio-economic conditions but with different collection systems. Samples of residual waste have been sorted, classified and weighed in 21 categories during 26 analyses that took place from 1998–2004. Collection data of the total waste flow, including source sorted recycling materials, in the same area have been compiled and compared. Multivariate data analyses have been applied. Weight-based billing reduced delivered amounts of residual household waste by 50%, but it is unknown to what extent improper material paths had developed. With curbside collection more metal, plastic and paper packaging was separated and left to recycling. When separate collection of biodegradables was included in the curbside system, the overall sorting of dry recyclables increased. The large uncertainty associated with waste composition analyses makes it difficult to draw strong conclusions regarding the effects on specific recyclables or the changes in the composition of the residual waste.

Truck sizing models for recyclables pick-up

Growing public concerns about the environmental consequences of waste disposal have led to an increase in recycling efforts. In many communities, curbside collection programs have been instituted for collecting recyclables from households for transfer to material recovery facilities. In most programs the cost of collection is the dominant cost. Despite the high cost and environmental importance of collecting recyclables from households, most municipal collection systems are designed and operated without a clear understanding of what factors drive those costs and how they might be reduced. In this paper, models for determining truck configurations, as well as optimal compartment sizes for recyclables collection are developed. Constraints arising from the operation of the trucks are formulated, and solution schemes are presented. In addition, a procedure for optimally partitioning a vehicle used to collect source-separated material is discussed. Several scenario based planning approaches are developed. Use of the truck sizing models as an industry decision tool and the associated benefits of applying the truck sizing models and the solution methodology to a contract based collection program are also discussed.

Household Willingness to Recycle Electronic Waste

Electronic waste (e-waste) has become the main contributor of lead to landfills in the United States. Households also store large volumes of e-waste, yet little is known about their willingness to recycle e-waste. This article starts filling this gap based on a 2004 mail survey of California households. Using multivariate models, the authors find that gender, education, convenience, and environmental beliefs but not income or political affiliation are key factors explaining the willingness to drop off e-waste at recycling centers. A comparison of an ordered probit with a semi-nonparametric extended ordered probit model of the survey responses shows that the latter better predicts less frequent answers. The results suggest targeting public education programs about recycling at teenagers or younger adults and making recycling more convenient for older adults; moreover, e-waste drop-off centers should first be created in communities that already offer curbside collection programs for conventional recyclable products.

Contaminants and their Levels of Retention in Extruded, Recycled Poly(Ethylene Terephthalate) from Curbside Collection. Part 1: Extraction Kinetics and Particle Size Effects

In the first phase of our studies of the contaminants and their levels in curbside-collected poly(ethylene terephthalate) (PET) subjected to a recycling process, we analysed the washed and dried, shredded PET (flake). Of the semi-volatile contaminants found, 26 were below the US FDA threshold of 215 ppb and six were above. Additionally, it was found that surface levels of contaminants far exceeded average concentrations in the bulk of the flake, raising questions about the appropriateness of sampling procedures. In this second phase (again using dichloromethane Soxhlet extractions for the most part), we examined contaminant levels after the flake was subjected to vacuum extrusion, to complete the recycling process. Initially amorphous, extruded pellets were annealed to introduce crystallinity and allow grinding, in order to examine the effect of particle size. Much reduced concentrations of contaminants were found (all <215ppb). There were no significant differences in contaminant levels as a function of particle size, thus indicating a uniform distribution throughout the extruded material and no need for particle size reduction before sampling and analysis. However, whilst 3 h was sufficient to obtain quantitative extractions from the ground, annealed particles in each size range (0-300 μm, >300-425 μm and >425-700 μm), approximately 8 h were required for the unground annealed pellets.

An Economic Assessment of Market-Based Approaches to Regulating the Municipal Solid Waste Stream

In the late 1980s and early 1990s, it was widely reported that the United States faced a solid waste crisis. Existing landfills were reaching capacity or being shut down because of more stringent regulations while waste volumes were continuing to rise. At the time, several market-oriented policy analysts advocated the adoption of variable rate charges for mixed refuse in conjunction with curbside pick-up of recyclables (without charge) as a means of reducing waste volumes and diverting recyclable material to more valuable uses. During the course of the past decade, such policies have been adopted widely throughout the United States - approximately 20 percent of the U.S. population now face variable rate charges for mixed refuse collection. Even more have curbside collection of recyclable materials. This article collects and reviews empirical studies evaluating the effects of variable rate pricing. It finds that these policies have been quite effective as a means of boosting diversion rates beyond the levels that can be achieved through curbside collection of recyclables alone. The overall cost-benefit analysis of such programs is modestly favorable. Since many states and communities have committed to achieving specified waste diversion targets, variable rate policies have been a cost effective policy tool. The experience with variable rate policies represents a promising example of non-coercive, information-oriented government intervention. With a relatively small budget and no authority to impose household solid waste policy on local governments, EPA has been remarkably successful at developing and diffusing effective solid waste management policies. The economic theory underlying variable rate pricing has proven, after some tinkering at the implementation stage, to be quite workable in practice. In fact, the practical realities of implementing charges have shown that theoretical perfection in terms of getting the prices right is less important in the grand scheme than keeping the transaction costs manageable. Looking forward, variable rate pricing can be expected to become even more economically advantageous as recycling markets continue to mature, landfill tipping fees rise, and improved technologies for curbside collection, monitoring, billing, and measuring waste develop.

Comparative LCAs for Curbside Recycling Versus Either Landfilling or Incineration with Energy Recovery (12 pp)

Comparative LCAs for Curbside Recycling Versus Either Landfilling or Incineration with Energy Recovery (12 pp)

Contaminants and levels of occurrence in washed and shredded poly(ethylene terephthalate) from curbside collection. II: Validation of extraction procedures, particle size sampling and crystallinity

Part I of this study showed that washed and dried, shredded poly(ethylene terephthalate) (PET) (flake) obtained from curbside collection when Soxhlet extracted contained 26 semivolatile contaminants below the US FDA threshold of 215 ppb and six above this level. This paper reports the validation of the Soxhlet extraction technique by comparison with total dissolution with trifluoroacetic acid (TFA). The work was carried out for two of the three particle size ranges obtained by grinding the PET flake (300–425 and 425–700 μm) and for the unground flake. Further validation was undertaken by comparison of contaminant levels determined by total dissolution with TFA and sonication with dichloromethane (DCM) using flake ground to the 0–300 μm size range. The levels of contaminants increased with decreasing particle size range, but X-ray diffraction measurements of degrees of crystallinity were similar for each PET particle size range, thus showing that the differences in contaminant levels were not due to variable percentages of the amorphous material from the tops and bottoms of shredded bottles, relative to the amounts of crystalline PET from the mid-sections of the bottles. Hence, it was postulated that the variations in contaminant levels were due to selective grinding of the more highly contaminated surfaces, whilst the larger particles incorporated the less contaminated interior material. The grinding was also strongly selective with respect to the amorphous flake. Analysis of the segregated amorphous and crystalline flake phases indicated that many contaminants were similarly absorbed into both phases, whilst some were preferred by the amorphous PET and others were preferred by the crystalline PET.

Contaminants and levels of occurrence in washed and shredded poly(ethylene terephthalate) from curbside collection. Part 1: Extraction conditions

The aim was to determine which contaminants were present in washed and dried shredded poly(ethylene terephthalate) (PET, flake) obtained from curbside collection and whether the concentrations were above the US FDA threshold of 215 ppb. Thirty-two semivolatile contaminants were extracted from the treated flake by Soxhlet extraction using dichloromethane as a PET swelling solvent and gas chromatography-mass spectrometry (GC-MS) was used for identification and quantification. Soxhlet extraction of flake ground to 0–300 µm was effectively completed in 24 h, whereas sonication reduced the extraction time to 3 h. In contrast, Soxhlet extractions of flake ground to a larger particle size range (300–425 µm) were completed in 4 h, possibly due to less aggregation in the extraction thimble. The levels of 26 contaminants were below 215 ppb, but six were not. Dodecanoic acid was present at about 1200 ppb, 2-butoxyethanol was approximately 1000 ppb, limonene, benzophenone and methyl salicylate were above 800 ppb, and 2-methylnaphthalene near 215 ppb.

Toward Trash That Thinks: Product Tags for Environmental Management

SummaryIn this article, we explore several options for linking information technology to materials and products through the use of bar codes and radio‐frequency identification (RFID) tags, and the implications for product life‐cycle management. We also describe tests with existing and modified tags, both on and inside products, as would be needed for environmental management applications.Bar codes are cheap and have an existing infrastructure; RFID tags are more expensive and less widespread, but they can be read without a line of sight between the tag and the reader. Bar codes and RFID tags carrying basic product information could link to different databases for a range of applications. Product tags could increase recycling efficiency by automating the sorting of recyclables or by linking to product dismantling instructions during the recycling process. Product tags could provide incentives for good waste management, through Universal Product Code (UPC) bar‐code recycling coupons or through RFID tag automatic recycling credits for curbside collection programs. Measures to encourage the development of these types of applications include moves toward competitive, market‐based waste management systems, the encouragement of experimental systems, and coordination between manufacturers and waste management industries.