Search Results (10)

In many countries municipal solid waste (MSW) is expected to soon increase beyond the pace of population growth due to urbanization. To minimize its negative impact, MSW management needs to be advanced. We studied administrative awareness-raising projects aimed at reducing household solid waste (HSW), which accounts for a large portion of MSW. An online questionnaire survey was administered to local governments (LGs) in Japan to research the implementation status of the awareness-raising projects and estimate the waste reduction effect of intervention methods within those projects. Regarding social factors, multiple linear regression analysis showed significant negative relationships of HSW generation rate with the household population, total population, and waste charge system. Conversely, positive relationships were identified with age, the number of cars, income, and the frequency of collection. Intervention methods, such as briefing sessions, utilization of resident leaders, and mobile phone apps, were revealed to be effective; in contrast, information dissemination using the traditional intervention method was not. In particular, the utilization of resident leaders may be the most cost-effective, but some LGs seem to have abolished this form of intervention after its introduction 30 years ago due to lack of empirical evidence supporting its effectiveness. Full article

Managing household solid waste (HSW) has gone beyond what the Harare local government can handle. Inadequate knowledge of the interactions existing between issues that affect the efficient running of waste management systems is one of the major hindrances in waste management planning in developing countries like Zimbabwe. The complexity of the waste management system for a given municipal area needs to be identified and understood to generate appropriate and efficient waste management strategies. Network analysis (NA) is a methodology extensively used in research to help reveal a comprehensive picture of the relationships and factors related to a particular phenomenon. The methodology reduces the intricacy of large systems such as waste management to smaller and more understandable structures. In this study, NA, which was done mainly using the R software environment, showed a result of 1.5% for network density, thus signifying that for Harare, waste management strategies need to be ‘seeded’ in various parts of the system. The Pareto principle and the 3Rs (Reduce, Reuse, Recycle) concept were applied to suggest the issues to prioritize and generate strategies that could potentially affect significant change to the city’s waste management system. The key issues identified, in their order of importance, are an increase in uncollected waste, low waste collection efficiency, increase in illegal waste dumping, the deteriorating country’s economy, reduced municipal financial capacity, reduced municipal workforce capacity, inadequate or unreliable waste data, increase in waste volume, increase in the number of street vendors, no waste planning and monitoring unit, no engineered landfills in the city, increase in waste collection pressure, low waste collection frequency, increase in the unemployment rate, reduced municipal technical capacity, few waste collection vehicles, limited vehicles maintenance, distinct socio-economic classes, high vehicles breakdown, and increase in population. Full article

Composting organic waste and human excreta could significantly reduce the amount of waste dumped and increase soil fertility and agricultural yields. However, studies focusing on the replacement of mineral fertilizer with compost from these resources are rare. The presented study quantifies the potential of human excreta and other organic waste for compost production. During wet and dry seasons, the generation and composition of household solid waste (HSW) was measured from three wealth categories: poor, medium, and rich, as well as the organic waste generated from 20 commercial facilities. Furthermore, the amount of human excreta, when converting unimproved into ecological sanitation facilities, was assessed. The HSW generation was significantly higher in the wet (0.77 ± 0.07 kg fresh weight (FW) cap⁻¹ day⁻¹) compared to the dry season (0.54 ± 0.04 kg FW cap⁻¹ day⁻¹). Organic waste was the main component of HSW in the dry and wet seasons, accounting for 84% and 76% of the total HSW, respectively. Annually, about 6824 Mg of organic dry matter could be collected from households, 212 Mg from commercial units, and 12,472 Mg from ecological sanitation. With these resources, 11,732 Mg of compost could be produced annually and used for fertilizing 470 ha of farmland, completely replacing mineral fertilizer. Full article

The accurate and effective classification of household solid waste (HSW) is an indispensable component in the current procedure of waste disposal. In this paper, a novel ensemble learning model called EnCNN-UPMWS, which is based on convolutional neural networks (CNNs) and an unequal precision measurement weighting strategy (UPMWS), is proposed for the classification of HSW via waste images. First, three state-of-the-art CNNs, namely GoogLeNet, ResNet-50, and MobileNetV2, are used as ingredient classifiers to separately predict and obtain three predicted probability vectors, which are significant elements that affect the prediction performance by providing complementary information about the patterns to be classified. Then, the UPMWS is introduced to determine the weight coefficients of the ensemble models. The actual one-hot encoding labels of the validation set and the predicted probability vectors from the CNN ensemble are creatively used to calculate the weights for each classifier during the training phase, which can bring the aggregated prediction vector closer to the target label and improve the performance of the ensemble model. The proposed model was applied to two datasets, namely TrashNet (an open-access dataset) and FourTrash, which was constructed by collecting a total of 47,332 common HSW images containing four types of waste (wet waste, recyclables, harmful waste, and dry waste). The experimental results demonstrate the effectiveness of the proposed method in terms of its accuracy and F1-scores. Moreover, it was found that the UPMWS can simply and effectively enhance the performance of the ensemble learning model, and has potential applications in similar tasks of classification via ensemble learning. Full article

An unprecedented Household Solid Waste (HSW) separation program was launched in 46 cities and some pilot rural areas in China in 2019. This study examines the antecedents of waste separation behavior using the extended theory of planned behavior (TPB) to identify beliefs that are useful targets for interventions, and compares the urban-rural differences. Based on interviews with rural and urban residents, we identified residents’ beliefs influencing waste separation behaviors, including four behavioral, seven normative, and eight control beliefs. Then, we tested the conceptual model with a two-stage questionnaire survey using a sample of 604 residents from urban and rural areas. Evidence from structural equation modeling supports the extended TPB in that it predicts waste separation intention and behavior on the whole. Moral norm and self-identity were found to independently predict intention and may prove a useful addition to the TPB; however, the path from attitude to intention is not supported in both urban and rural models. Moreover, the specific difference of belief between urban and rural residents was examined. The behavioral beliefs associated to money, including earning, free waste bin or bag, and fine, are significant only in the rural group. The normative beliefs of family, Chinese Communist Party (CCP) members, and government can affect residents’ subjective norm in both urban and rural, while the beliefs of relatives, friends, and neighbors are significant only in the rural group. Implications for managers of operating waste separation programs were discussed. Further investigation into the potential of the model to intervene in waste separation behavior is required. Full article

The depletion of natural resources, the useful life of landfill sites, and the amount of garbage accumulating all challenge public policy to manage urban solid waste. We identified the economic potential for unused solid waste (HSW) in São Paulo in 2018 to be USD 637,633,836.04 through descriptive quantitative research and documentary analysis in the collected data. This amount comes from five sources, with the majority coming from internalizing private cost credits (45.58%), followed by recycling (42.21%), carbon credits (5.46%), refuse-derived fuel (3.77%), and organic compounds (2.98%). This potential assumes the implantation of waste sorting plants that generate jobs, reduce public expenses, and provide environmental benefits such as forest protection, water, and minerals. The environmentally adequate final destination of HSW constitutes an economic and socio-environmental measure that enables the reverse logistics of the business sector and urban sustainability. Consequently, the economic potential of HSW, generated from its sorting and marketing, could provide a positive contribution with the mitigation of environmental impacts, in addition to income generation and social inclusion. Full article

Faced with an unprecedented increase in the amount of solid waste, China aims to tighten its waste management regulation. Corresponding local policy experiments are encouraged. This study explores China’s authoritarian environmentalism through an examination of local legislations on Household Solid Waste (HSW) sorting. We present a full picture of relevant local legislation from five key dimensions: local legislative outputs, local standards of HSW classifications, reward and penalty provisions, the use of the social credit system and duties imposed on local governments. We then compare policy-making models based on the experience of Shanghai and Guangzhou. We find China’s HSW sorting policy has been dominated by the central state. The local lawmaking process is generally non-transparent and non-participative. When attempting to mobilize the public, local policymakers emphasize educating the public about “how to” instead of “why to sort wastes”. Also, while the central waste management policies are generally undermined locally, some sub-national governments do demonstrate a strong commitment to push the national policy through. Multiple factors account for this pattern. Though civic engagement did emerge in certain localities where civil society was relatively active, authoritarian environmentalism will continue to prevail in China in the near future. Full article

This study assesses the quantity and composition of household solid waste (HSW) in the City of Da Nang and proposes a transparent and standardised method for its assessment through a combination of very-high-resolution (VHR) satellite imagery, field surveys, questionnaires, and solid waste measurements on the ground. This was carried out in order to identify underutilised resources and to obtain discrete planning values at city level. The procedure proved to be a suitable method for reliable data gathering. To describe HSW generation, 818 valid datasets, subdivided into five building types, and their location were used. The average HSW generation rate was 297 g per capita per day. Within a total of 19 subcategories, organic waste had a share of 62.9%. The specific generation and composition of HSW correlates positively with both the building type and the spatial location within the city. The most HSW (509 g per capita per day), by far, was generated in the ‘villa-type’ building while in the ‘basic-type’ building, this was the least (167 g per capita per day). Taking into account the number of individual buildings, the total HSW generation in Da Nang in 2015 was estimated between 109,844 and 164,455 tonnes per year, which corresponds to about one-third to one-half of the total municipal solid waste. Full article

Source-separated policy is very important for household solid waste (HSW) management in global megacities. The low proportion of source-separated collection has led to a low comprehensive utilization rate of municipal solid waste (MSW) in China. In March 2017, the Chinese government required major cities to fully implement compulsory source-separated systems by 2020. To determine policy impacts and efficiency in improving HSW sorting, the government launched a mandatory MSW source-separated program in Nanjing in November 2016. A household survey was implemented in three types of 11 communities over a period of 10 weeks. The results showed that approximately 52% of the respondents supported the mandatory policy and that household size was the most important sociodemographic factor influencing the support of the source separation policy. Income, gender, age, and knowledge play significant roles in different groups of respondents. This mandatory policy effectively improved the source-separated rate of HSW by 49.7%. Source-separated facilities investment, publicity investment, and special supervision coverage in these communities had significant positive effects on source-separated HSW. Every 1 million CNY investment in source-separated facilities and publicity will increase the source-separated rate of HSW by 1.1%. A 1.0% increase of special supervision coverage in communities can increase the source-separated rate by 3.6%. The findings from this study may help improve source-separated management of HSW for other cities in the future. Full article

Though the Suzhou government has provided household solid waste (HSW) source separation since 2000, the program remains largely ineffective. Between January and March 2014, the authors conducted an intercept survey in five different community groups in Suzhou, and 505 valid surveys were completed. Based on the survey, the authors used an ordered probit regression to study residents’ HSW source separation activities for both Suzhou and for the five community groups. Results showed that 43% of the respondents in Suzhou thought they knew how to source separate HSW, and 29% of them have source separated HSW accurately. The results also found that the current HSW source separation pilot program in Suzhou is valid, as HSW source separation facilities and residents’ separation behavior both became better and better along with the program implementation. The main determinants of residents’ HSW source separation behavior are residents’ age, HSW source separation facilities and government preferential policies. The accessibility to waste management service is particularly important. Attitudes and willingness do not have significant impacts on residents’ HSW source separation behavior. Full article