Song Toan Pham Phu

Plastic pollution is becoming urgent all over the world, which linear economy has also exacerbated plastic issues. Transition from traditional economic models to circular economy — where material is circulated within processes such as maintenance, reuse, refurbishment, remanufacture, recycling, and composting — is expected as solution for not only plastic pollution but also issues of linear economy. Municipal solid waste management system plays an essential role in this transition, particularly practices for management of material flows and enhancement of material circulation. This study applied waste flow diagram (WFD) and material flow analysis (MFA) to clarify municipal solid waste flow, recyclable waste flow, and mechanism of plastic leakage in a tourism destination of a developing country in Southeast Asia — Hoi An city, Vietnam. With support of geographic information system and remote sensing techniques, popular methods in ‘small q’ qualitative research — interview and observation — were applied to collect data for WFD and MFA. Results denoted that average amount of municipal solid waste generation (MSWG) was around 1.19 kg/cap/day (436 kg/cap/year), being between those of upper middle income countries and high income countries. Majority of municipal solid waste was collected by formal environmental service, capturing approximately 39,743 tonnes/year of MSWG (90.62% of total MSWG), however, 27 tonnes/year of plastic was leaked from collection services. Importantly, largest proportions of unmanaged plastic waste sources were from uncollected plastic waste (77.48%) and collection service (18.38%). Reversed logistic system was predominantly operated by informal sectors, where itinerant buyers and waste pickers contributed considerably by collecting 1,727 tonnes/year (59.45% of total recovered recyclable waste) of recyclable waste. Due to severe weather conditions and natural disasters, Cam Ha treatment facility was responsible for 4 tonnes/year of plastic leakage. Promoting waste separation at source with strict inspection, upgrading collection and transportation system, integration of informal sector, and regional planning for municipal solid waste management were proposed for controlling plastic leakage and heading to circular economy.

This study aimed to assess the impact of material recovery facility (MRF) in dealing with problems of solid waste management systems, reducing solid waste generation, and raising awareness among residents in Cu Lao Cham island (CLC). Additionally, perception of islanders toward operation and development of MRF was also assessed. Literature review was conducted to have general understanding on status of MRF operation. Waste flow analysis was performed to illustrate waste flow of MRF by scenarios. In-depth interviews, observation, and questionnaire survey were applied to gain deep social insights into operation and potential for expansion of MRF. The results denoted that MRF recovered 51.41 kg of solid waste per day, accounting for 1.75% of the total MSW generated from households in CLC. Products from MRF, environmental effectiveness, the effectiveness of education and information publicity, and social cooperation had statistically significant effects on the participation of habitants in the operation and development of MRF. The MRFs will reduce 5.5% and 16% of the total domestic waste to Eo Gio in 2025 and 2028. The MRF was expected to attain financial independence from around 2025. Results from this study were scientific bases for managers, planners, policy-makers and other stakeholders for management and development of MRF not only in CLC but also other islands in developing countries.

Integration of extended theory of planned behaviour (TPB) and norm activation model (NAM) was applied to examine psychological mechanism of single-use plastic reduction intention (SUPRI) of citizens in Danang city, Vietnam. The partial least squares structural equation modelling algorithms were applied to assess measurement model, structural model, explanatory power, and predictive power of model. Personal norm, attitude, subjective norm, perceived behaviour control, and policy intervention had significant influence on SUPRI. Attitude was the most important factor affecting SUPRI. Regarding integrated model, awareness of consequence and ascription of responsibility were positively associated with attitude toward SUPRI while subjective norm had significant relationship toward personal norm. Association of policy intervention toward SUPRI was confirmed through direct and indirect relationships. Integration of TPB and NAM was effective in explaining SUPRI. Planning and strategy for single-use plastic reduction should be designed to comprehensively cover human self-interests, take advantage of social moral values, and promote policy enactment and enforcement with prioritisation of action on raising citizens’ attitude toward single-use plastic reduction. Utilisation of geographic information system and remote sensing was effective in supporting random sampling. This study offered practical and scientific base for planners and policymakers in combating environmental issues from plastic waste.

Recently, the transition to the circular economy has become environmentally and economically urgent for every single nation in the world. Closing the loops of material is one of the key ideas behind the foundation of a circular economy (CE). The informal recyclable stations (IRSs) within the solid waste management (SWM) system play an important role as the reversed logistic system, being in charge of collecting and trading recyclable solid waste. This study aimed to comprehend the spatial nature of the system of IRSs in Danang city, Hue city, and Hoi An city as representative sites for the whole of central Vietnam and the nation. The integration of geographic information system (GIS), remote sensing, and statistical learning was performed to clarify spatial characteristics and dynamics of the system of IRSs as well as combat status of limitations of available data in developing countries. Results denoted that the system of IRSs was distributed in close proximity to transportation systems and residential areas with low vegetation coverage. Coverage ratios of the system of IRSs did not strongly fluctuate in case the number of IRSs decreased by 80% regarding the 3500 m distance covered. Negative binomial regression proved to be the most congruent model for understanding the prevalence of IRSs in central Vietnam. Population and normalized difference vegetation index were statistically related to prevalence of IRS. While linear regression depicted balance between variance and bias, support vector machine would be applied if prioritized aim is model performance. The results of this study are a scientific base for the management of the IRS system and the integration of this system into a formal SWM system as well as the transition to a CE.

This study extended the theory of planned behaviour (TPB) and applied it to analyse influencing factors of food waste separation intention (FSI) among households in central Vietnam. Partial least squares structural equation modelling (PLS-SEM) was employed to analyse the data. The heterogeneity of factors contributing to FSI in cities of three levels was examined using multi-group analysis (MGA). The results indicate that attitudes, subjective norms (SN), perceived behavioural control (PBC), awareness of benefit (AB), information publicity (IP), facility availability (FA), and trust significantly affected FSI of households. MGA results indicated the heterogeneity of impacts of PBC and attitude on FSI of households among three municipal levels. The results will serve as basic data for waste officers, solid-waste management project leaders, non-governmental organisations (NGOs), and other related stakeholders to lay the foundation of food waste management planning in terms of regional scale and local scale. This study will also aid the creation of a circular economy by providing a scientific base for enhancing food waste separation at source in central Vietnam.

A study was undertaken to develop options for sustainable integrated solid waste management for a tourist city in Vietnam. The generation and characterisation of tourism waste were based on a sampling survey of Hoi An city (HAC). Problems and challenges of a tourism waste management system were indicated using material flow analysis. Five scenarios were developed for the tourism sector of the city based on current solid waste management practice (SWMP), a consensus of stakeholders, the suitability of waste management systems and the contribution of the government. In two of the scenarios, waste reduction was 6.5 times higher and recyclables recovered was 3.3–4.2 times greater than that in two of the minimalist scenarios. Furthermore, the former scenarios showed more efficiency in treatment, optimal economy and minimum greenhouse gas emissions. The study indicated the advantages and challenges of each scenario and identified an optimal model for SWMP for the tourism industry of HAC. A framework for gradually developing a sustainable tourism waste management system was proposed, potentially applicable to any tourist city in a developing country.

This study evaluates the gaps between urban and rural linkages within the corridor of Hoi An city and suggests potential solutions utilizing the circulating and ecological sphere principles for further strengthening these linkages and gradually promoting sustainable development of the city and surrounding area. A face-to-face interview method and an Origin 2018-based analysis were utilized to analyse the gaps between urban and rural linkages. Results were represented by ArcGIS 10.3 with a line diagram. The identified obstacles were (a) unequal distribution of human resources and income gaps, (b) poor basic and economic infrastructures, (c) a lack of interest in the agricultural sector and (d) the absence of corresponding policies. The suggested solutions were effective decentralization, raising investment for basic and economic infrastructures and sustainable agricultural systems, including tourism, value-added chain of network building and more focused and effective corresponding policies. This study also recommends optimizing synergies as well as reducing trade-offs between the proposed approach and the Sustainable Development Goals.

Domestic solid waste management (DSWM) in Vung Tau City (VTC) is emerging as an envi-ronmental problem behind rapid urban development. The amount of DSW increased rapidly, leading to a disturbance in the collection, transportation, and challenges in the implementation of DSWM at the source. This study aims to assess the situation and develop and analyze the scenarios of the DSWM system for VTC, thereby proposing strategies to improve the DSWM system for the city in 2024 - 2033. The scenarios of the DSWM system were built based on the situation analysis, the national and regional SWM regulations, and scientific assumptions that have been studied in Viet Nam. This study showed that the amount of DSW in VTC has in-creased rapidly at the rate of 7,4%/year over the past decade and reached 457.9 tons in 2022. About 80% of the DSW is collected by 500 informal collectors, who work spontaneously and are unmanaged. The minimalist and optimal DSWM models have been built and evaluated. The results showed that these two models of the DSWM should be applied in two phases, 2024-2028 and 2029-2033, respectively. According to this roadmap, the amount of DSW to the land-fill was estimated to reduce 26% of the total waste generation. The amount of recovered recy-clable waste is also estimated to be increased five times compared to 2023. Furthermore, the quality of DSW in the treatment area is suitable for composting and handling by waste-to-energy solutions.