Life-cycle greenhouse gas emissions and economic analysis of alternative treatments of solid waste from city markets in Vietnam

We utilize life cycle assessment to trace conversion of degradable organic carbon (DOC) contained in organic waste from city markets in Da Nang, Vietnam. Our methodology makes explicit the process of conversion of DOC under aerobic and anaerobic conditions, as well as the balance of nutrients. Greenhouse gas emissions were calculated for six alternative scenarios: (i) anaerobic landfilling (current situation); (ii) semi-aerobic landfilling; (iii) landfill gas capture; (iv) composting; (v) pre-composting before landfill; and (vi) biogas production. We calculate that 1 t of waste in anaerobic landfilling emits 1.70 t CO₂-eq. with life-cycle perspective. Lowest emission occurs in biogas scenario with 0.26 t CO₂-eq./t. Composting occupies an intermediate position with 0.39 t CO₂-eq./t. Likewise, we estimate that cost of emission reduction in solid waste sector of Vietnam is 15.13 US$/t CO₂-eq., given by alternative of composting and taking anaerobic landfilling as reference. On the other hand, if social cost of carbon (SCC) is incorporated lowest cost to treat 1 t of waste is given by composting and semi-aerobic landfilling at discount rate of 5 %. However, using lower discount rates, and consequently higher values of SCC, composting and biogas production become the alternatives with lowest treatment costs.     

The Market for Waste Vitrification Technology

Waste vitrification technology has largely been developed by the United States Department of Energy (DOE). Numerous vendors offer vitrification units, and a number of commercial and large pilot applications have been made. Nevertheless, the industry is still in its infancy and does not dominate any waste treatment niche. DOE funding of vitrification technology development is nearing an end, and DOE waste treatment is being privatized, with private bidders selecting the technologies and offering to treat wastes for a per-unit fee. Thus, the DOE market is shifting from a cost-plus, largely R&D environment to a fixed-fee environment in which vendors and waste treatment contractors must accept technological risks. Significant quantities of DOE waste are still uncommitted, but the number of vendors is larger than the market can possibly sustain. Domestic private sector opportunities are limited and vendors are looking to foreign markets with less mature treatment capacity and growing demand.     

A survey on municipal solid waste and residents’ awareness in Da Nang city, Vietnam

A survey on solid waste generation and residents’ awareness was conducted in Da Nang city, Vietnam in 2010. We took samples from residents, hotels, restaurants, and city markets. Data reveals that each resident generates on average 0.71 kg/capita/day (3 kg/household/day). Regarding the composition, organic waste (food, flowers, leaves, grass) accounts for about 70 % of residents’ waste followed by plastics. Likewise, about 14 % of residents’ waste can be recycled. Furthermore, we find that middle income households in the suburbs have the largest waste generation with 4.9 kg/household/day. We consider that this finding is explained by their dedication to agricultural activities, such as planting fruit trees and vegetables, and gardening. Finally, we find that only about 60 % of interviewees have knowledge of how to segregate waste, however more than 90 % of them are willing to cooperate with the introduction of a waste segregation program in the city.     

Municipal solid waste generation in municipalities: quantifying impacts of household structure, commercial waste and domestic fuel

Waste management planning requires reliable data concerning waste generation, influencing factors on waste generation and forecasts of waste quantities based on facts. This paper aims at identifying and quantifying differences between different municipalities' municipal solid waste (MSW) collection quantities based on data from waste management and on socio-economic indicators. A large set of 116 indicators from 542 municipalities in the Province of Styria was investigated. The resulting regression model included municipal tax revenue per capita, household size and the percentage of buildings with solid fuel heating systems. The model explains 74.3% of the MSW variation and the model assumptions are met. Other factors such as tourism, home composting or age distribution of the population did not significantly improve the model. According to the model, 21% of MSW collected in Styria was commercial waste and 18% of the generated MSW was burned in domestic heating systems. While the percentage of commercial waste is consistent with literature data, practically no literature data are available for the quantity of MSW burned, which seems to be overestimated by the model. The resulting regression model was used as basis for a waste prognosis model (Beigl and Lebersorger, in preparation).     

Critical Review of Norms and Standards for Biodegradable Agricultural Plastics Part II: Composting

The critical review of norms and standards and corresponding tests to determine the compostability of biodegradable plastics, possibly applicable also to biodegradable agricultural plastics, shows that many norms concerning testing and labelling of compostable plastics have been established at the international level. Some of them are about plastic materials, some others are about products like packaging. The media and conditions of testing cover mainly the conditions designed for industrial composting facilities, and only a few concern home composting conditions. Considering that the end of life management of biodegradable agricultural plastic products will be done at the farm to reduce the management of the waste and also its cost, only a few of these norms are considered to be suitable for adaptation to cover also biodegradable agricultural plastic products. The biodegradability validation criteria under composting conditions, such as the threshold percentage of biodegradation and disintegration, the time and temperature, and the ecotoxicity, are presented for the main norms and standard testing methods. Based on these different norms and their content, a list of specs and technical requirements that could be adapted to meet farm composting conditions for agricultural compostable plastics is proposed. These requirements may be used as criteria for the establishment of a new integrative norm for agricultural compostable plastics.     

Comparison of compostable bags and aerated bins with conventional storage systems to collect the organic fraction of municipal solid waste from homes. A Catalonia case study

The separation of biowaste at home is key to improving, facilitating and reducing the operational costs of the treatment of organic municipal waste. The conventional method of collecting such waste and separating it at home is usually done by using a sealed bin with a plastic bag. The use of modern compostable bags is starting to be implemented in some European countries. These compostable bags are made of biodegradable polymers, often from renewable sources. In addition to compostable bags, a new model of bin is also promoted that has a perforated surface that, together with the compostable bag, makes the so-called “aerated system”. In this study, different combinations of home collection systems have been systematically studied in the laboratory and at home. The results obtained quantitatively demonstrate that the aerated bin and compostable bag system combination is effective at improving the collection of biowaste without significant gaseous emissions and preparing the organic waste for further composting as concluded from the respiration indices. In terms of weight loss, temperature, gas emissions, respiration index and organic matter reduction, the best results were achieved with the aerated system. At the same time, a qualitative study of bin and bag combinations was carried in 100 homes in which more than 80% of the families participating preferred the aerated system.     

Performance of compostable baby used diapers in the composting process with the organic fraction of municipal solid waste

In modern societies, disposable diapers constitute a significant percentage of municipal solid wastes. They have been traditionally landfilled or incinerated as only limited recycling processes are being implemented in some parts of Europe. With the implementation of separated collection systems for the organic fraction of municipal solid wastes (OFMSWs) and the need to preserve the environment, compostable diapers have appeared in the market to avoid the main environmental impacts associated to non-biodegradable disposable diapers. In this study, a full-scale composting of door-to-door collected OFMSW with a 3% (w/w) of compostable diapers has also been carried out. Previously, lab-scale experiments confirmed that almost 50% of carbon of compostable diapers is emitted as CO₂ under aerobic controlled conditions. The results obtained at full-scale demonstrate that both the composting process and the final end product (compost) are not altered by the presence of compostable diapers in crucial aspects such as pathogenic content, stability and elemental composition (including nutrients and heavy metals). The main conclusion of this study is that the collection of the OFMSW with compostable diapers can be a new way to transform this waste into high-quality compost.     

Compostable cutlery and waste management: an LCA approach

The use of disposable cutlery in fast food restaurants and canteens in the current management scenario generates mixed heterogeneous waste (containing food waste and non-compostable plastic cutlery). The waste is not recyclable and is disposed of in landfills or incinerated with or without energy recovery. Using biodegradable and compostable (B&C) plastic cutlery, an alternative management scenario is possible. The resulting mixed homogeneous waste (containing food waste and compostable plastic cutlery) can be recycled through organic recovery, i.e., composting. This LCA study, whose functional unit is "serving 1000 meals", shows that remarkable improvements can be obtained by shifting from the current scenario to the alternative scenario (based on B&C cutlery and final organic recovery of the total waste). The non-renewable energy consumption changes from 1490 to 128MJ (an overall 10-fold energy savings) and the CO(2) equivalents emission changes from 64 to 22 CO(2) eq. (an overall 3-fold GHG savings).     

A progress indicator-based assessment guide for integrated municipal solid-waste management systems

Managing municipal solid waste is a major concern for cities around the world. Particularly urban communities with developing economies are urged to improve their waste management practices, and set up appropriate waste management systems. Waste management is a city-specific topic; there is no ideal solution that can be operationalized everywhere. In developing cities, municipalities and decision makers need simple and effective indicators to assess the sustainability of their current waste management systems, and set a performance reference point. The current study investigates available literature and suggests a list of measurable sustainability indicators which are specific to solid-waste management. The list encompasses 27 indicators that cover the building blocks of an integrated solid-waste management system, i.e., collection and sorting, recycling, composting, energy recovery, and landfilling. An assessment tool is developed through a five-point Likert scale, evaluating these indicators. Case studies of Cairo and Brussels were analyzed. The outcomes of this analysis can be used as a benchmark on a local level in planning, clarifying policy objectives, and setting priorities.     

Prioritising objectives for waste reprocessing: a case study in secondary lead refining

Secondary lead refining produces a sulphidic slag that also contains varying quantities of lead. Initially, the objectives of this project were to treat the slag in order to recover the valuable lead as well as to render the slag environmentally benign. However, in keeping with the principles of clean technology and, specifically, the approach of clean production, the project was redefined with the following priorities: waste characterisation; waste minimisation through process improvement; waste modification; identification of slag treatment methods. Characterisation of the waste facilitated an overall process understanding and aided in identifying process deficiencies. Process improvement was aimed at reducing both the quantity of slag produced as well as the lead loss to the slag. Waste characterisation combined with local hazardous waste regulations enabled desirable waste modifications to be identified. These waste adaptations were implemented through process modification. Lastly, treatment methods for the slag were identified.     

Hazardous industrial waste management in Vietnam: current status and future direction

This article concentrates on the existing situation of hazardous industrial waste management in Vietnam. To realize the importance of the development of a Vietnam national strategy based on the reduce, reuse, recycle (3R) concept to the year 2020, the author summarizes the practice of recycling activities of hazardous industrial waste and discusses the challenges arising from increases in the quantity and types of waste and the level of hazard of the waste generated considering that the technical infrastructure for handling and managing the waste is inadequate and the legal system on environmental protection is lacking. In order to improve the existing situation of hazardous industrial waste management, the Vietnamese Government recently has played an increasing role in promoting regional and international cooperation on environmental protection through ratifying the international conventions on the environment including the Basel Convention on the Control of Trans-boundary Movements of Hazardous Waste and their Disposal and the International Labor Organization Convention on Safety in the Use of Chemicals at Work and by adhering to the concept of the material-cycle society. These steps are key opportunities for applying the principles of 3R to the recovery of value from hazardous waste in the future.     

Carbon dioxide and ammonia emissions during composting of mixed paper, yard waste and food waste

The objective of the work was to provide a method to predict CO2 and NH3 yields during composting of the biodegradable fraction of municipal solid wastes (MSW). The compostable portion of MSW was simulated using three principal biodegradable components, namely mixed paper wastes, yard wastes and food wastes. Twelve laboratory runs were carried out at thermophilic temperatures based on the principles of mixture experimental and full factorial designs. Seeded mixed paper (MXP), seeded yard waste (YW) and seeded food waste (FW), each composted individually, produced 150, 220 and 370 g CO2-C, and 2.0, 4.4 and 34 g NH3-N per dry kg of initial substrate, respectively. Several experimental runs were also carried out with different mixtures of these three substrates. The effect of seeding was insignificant during composting of food wastes and yard wastes, while seeding was necessary for composting of mixed paper. Polynomial equations were developed to predict CO2 and NH3 (in amounts of mass per dry kg of MSW) from mixtures of MSW. No interactions among components were found to be significant when predicting CO2 yields, while the interaction of food wastes and mixed paper was found to be significant when predicting NH3 yields.     

Report: Healthcare waste characterization in Chittagong Medical College Hospital, Bangladesh

Healthcare waste management (HCWM) options are inconsistent in Bangladesh. One of the first critical steps in the process of developing a reliable waste management plan requires a comprehensive understanding of the quantities and characteristics of the waste that needs to be managed. This study took into consideration both the quantity and quality of the generated waste to determine the generation rates and physical properties of healthcare waste (HCW) in Chittagong Medical College Hospital (CMCH) and also to estimate the amount of infectious and non-infectious waste generated in different wards. CMCH, the second largest hospital in Bangladesh, comprises 34 wards, 12 of which were selected randomly. Waste materials were collected from these wards and then segregated and weighed. Waste generation per day was found to be 73.22 kg/ward, 1.28 kg/bed and 0.57 kg/patient. A total of 2490 kg of HCW was produced each day in CMCH (37% being infectious and the rest being non-infectious waste). Infectious waste was 27.07 kg per ward, 0.47 kg per bed and 0.21 kg per patient and the non-infectious waste was 46.15 kg per ward, 0.81 kg per bed and 0.36 kg per patient per day. HCW comprised eight categories of waste materials with vegetable/food waste being the largest component (50.21%) and varied significantly (P < 0.05) among the 12 different wards studied. The greatest amount of HCW was recorded (154 kg) in Orthopaedics followed by 96.66 kg in the Medicine Unit-3 and the smallest amount was recorded in Casualty (8.79 kg). The amount of HCW was positively correlated with the number of occupied beds (rxy = 0.79, P < 0.01). There is no structured form of medical waste treatment in CMCH and most waste materials are dumped in open areas for natural degradation or re-sold by scavengers. It is essential to develop a national policy and implement a comprehensive action plan for HCWM that will provide environmentally sound technological measures to improve HCWM in Bangladesh.     

Does industrial waste taxation contribute to reduction of landfilled waste? Dynamic panel analysis considering industrial waste category in Japan

Waste taxes, such as landfill and incineration taxes, have emerged as a popular option in developed countries to promote the 3Rs (reduce, reuse, and recycle). However, few studies have examined the effectiveness of waste taxes. In addition, quite a few studies have considered both dynamic relationships among dependent variables and unobserved individual heterogeneity among the jurisdictions. If dependent variables are persistent, omitted variables cause a bias, or common characteristics exist across the jurisdictions that have introduced waste taxes, the standard fixed effects model may lead to biased estimation results and misunderstood causal relationships. In addition, most existing studies have examined waste in terms of total amounts rather than by categories. Even if significant reductions in total waste amounts are not observed, some reduction within each category may, nevertheless, become evident.Therefore, this study analyzes the effects of industrial waste taxation on quantities of waste in landfill in Japan by applying the bias-corrected least-squares dummy variable (LSDVC) estimators; the general method of moments (difference GMM); and the system GMM. In addition, the study investigates effect differences attributable to industrial waste categories and taxation types. This paper shows that industrial waste taxes in Japan have minimal, significant effects on the reduction of final disposal amounts thus far, considering dynamic relationships and waste categories.     

Capacity assessment to secure COVID-19 waste treatment in Vietnam

Journal of Material Cycles and Waste Management - The accelerated generation of COVID-19 waste under the Delta-fuelled outbreak placed a sudden burden on waste disposal in Vietnam. To secure the...     

Determinants of sustainability in solid waste management - The Gianyar Waste Recovery Project in Indonesia

According to most experts, integrated and sustainable solid waste management should not only be given top priority, but must go beyond technical aspects to include various key elements of sustainability to ensure success of any solid waste project. Aside from project sustainable impacts, the overall enabling environment is the key feature determining performance and success of an integrated and affordable solid waste system. This paper describes a project-specific approach to assess typical success or failure factors. A questionnaire-based assessment method covers issues of: (i) social mobilisation and acceptance (social element), (ii) stakeholder, legal and institutional arrangements comprising roles, responsibilities and management functions (institutional element); (iii) financial and operational requirements, as well as cost recovery mechanisms (economic element). The Gianyar Waste Recovery Project in Bali, Indonesia was analysed using this integrated assessment method. The results clearly identified chief characteristics, key factors to consider when planning country wide replication but also major barriers and obstacles which must be overcome to ensure project sustainability. The Gianyar project consists of a composting unit processing 60tons of municipal waste per day from 500,000 inhabitants, including manual waste segregation and subsequent composting of the biodegradable organic fraction.     

Household solid waste characteristics and management in Chittagong, Bangladesh

Solid waste management (SWM) is a multidimensional challenge faced by urban authorities, especially in developing countries like Bangladesh. We investigated per capita waste generation by residents, its composition, and the households' attitudes towards waste management at Rahman Nagar Residential Area, Chittagong, Bangladesh. The study involved a structured questionnaire and encompassed 75 households from five different socioeconomic groups (SEGs): low (LSEG), lower middle (LMSEG), middle (MSEG), upper middle (UMSEG) and high (HSEG). Wastes, collected from all of the groups of households, were segregated and weighed. Waste generation was 1.3kg/household/day and 0.25kg/person/day. Household solid waste (HSW) was comprised of nine categories of wastes with vegetable/food waste being the largest component (62%). Vegetable/food waste generation increased from the HSEG (47%) to the LSEG (88%). By weight, 66% of the waste was compostable in nature. The generation of HSW was positively correlated with family size (r(xy)=0.236, p<0.05), education level (r(xy)=0.244, p<0.05) and monthly income (r(xy)=0.671, p<0.01) of the households. Municipal authorities are usually the responsible agencies for solid waste collection and disposal, but the magnitude of the problem is well beyond the ability of any municipal government to tackle. Hence dwellers were found to take the service from the local waste management initiative. Of the respondents, an impressive 44% were willing to pay US$0.3 to US$0.4 per month to waste collectors and it is recommended that service charge be based on the volume of waste generated by households. Almost a quarter (22.7%) of the respondents preferred 12-1pm as the time period for their waste to be collected. This study adequately shows that household solid waste can be converted from burden to resource through segregation at the source, since people are aware of their role in this direction provided a mechanism to assist them in this pursuit exists and the burden is distributed according to the amount of waste generated.     

Sources and factors controlling the disposal of biodegradable municipal solid waste in urban and rural areas of Cyprus

An inventory of sources of biodegradable municipal soil waste (BMSW) was constructed for urban and rural areas in the EU accession region of Cyprus. Composition analysis was performed on source-separated BMSW collected from households in the rural Ergates Community and an urban area within the Agglanjia Municipality. The data were statistically scrutinized to identify the main factors influencing the quantities of BMSW disposed by urban and rural communities in Cyprus. The results were extrapolated to predict the quantities and types of BMSW disposed by the entire communities. Significantly more BMSW was disposed in the urban area compared to the rural community due to lower diversion rates for green waste and the disposal of food waste from commercial sources. The quantity of food waste collected from households was influenced by socio-economic (household size, income, percentage of children) and behavioural (feeding of food waste to domestic animals, consuming processed 'ready' food) factors, whereas garden size, the type of vegetation, the reuse of trimmings and home composting were the main factors controlling the disposal of green waste.     

Waste incineration—An important element of the integrated waste management system in Germany

This paper describes the present situation of waste incineration in Europe and discusses the problems faced in the future when the Directives of the European Community will be implemented on waste management. As an example, the status of thermal waste treatment in Germany is dealt with in detail. A point addressed is that public acceptance of incineration can only be increased if the public is aware of the conditions governing waste avoidance and recycling and if these conditions are actually realized. This means, prior to incineration, recyclable or compostable materials should be separated, and only then can the remaining amounts of wastes be treated before being deposited. The main aim of the treatment process is to reduce the hazard potential posed by waste and to meet the landfill requirements laid down in the German Technical Instructions for Municipal Waste.