Search

The attention and sentiment of the public are crucial for better implementation of waste sorting behaviors and moving towards green living. In this study, web scraping technology was used to collect 367,856 Weibo posts related to waste sorting from Sina Weibo. Utilizing text co-occurrence networks, Latent Dirichlet Allocation (LDA) topic modeling, and a deep learning model combining the Affective Cognitive Model (OCC) with Long Short-Term Memory Model (LSTM) (referred to as OCC-LSTM), we comprehensively understand the text at both micro and macro levels, analyzing the attention and sentiment of the public towards waste sorting behaviors on the Sina Weibo platform. Several important findings emerged from the empirical results. First, highly engaging posts were predominantly published by users with a large following, and the number of posts fluctuated over time. This reflects the influence of social hot topics and the timeliness of information dissemination. Second, there was heterogeneity in the user groups and their locations, often influenced by cultural differences due to geographical location. Third, positive sentiment towards waste sorting behavior was higher than negative sentiment on the Weibo platform. Moreover, public attention varied under different emotional influences concerning the topic of waste sorting behavior. The innovation of this study lies in the development of a research framework combining co-occurrence networks and deep learning, expanding the analysis on both micro and macro levels. This framework broadens the research paradigms and dimensions of public perception in waste sorting. This study is significant for promoting waste sorting behaviors and implementing climate policies., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Effectively sorting and recycling waste has consequently emerged as a key strategy for environmental preservation and the creation of sustainable communities. The current study aimed to examine the factors influencing consumers' intentions to sort household waste, utilizing the theory of planned behaviour. Collecting 300 responses from Brazilian consumers through structured questionnaires, the study employed a partial least square structural equation modelling approach to assess the proposed hypotheses. The findings emphasized the significant impact of the perceived cost and benefit factor, alongside the influence of information on proper waste disposal (perceived effectiveness), as communicated by entities managing selective waste collection. These findings emphasize the key role of effective communication from waste management agency regarding the outcomes of domestic waste separation efforts for recycling, as well as the perceived benefits and costs by consumers. Such communication is essential for fostering and maintaining consumer engagement in recycling initiatives., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

This paper highlights that metrics from the machine learning field (e.g., entropy and information gain) used to qualify a classifier model can be used to evaluate the effectiveness of separation systems. To evaluate the efficiency of separation systems and their operation units, entropy- and information gain-based metrics were developed. The receiver operating characteristic (ROC) curve is used to determine the optimal cut point in a separation system. The proposed metrics are verified by simulation experiments conducted on the stochastic model of a waste-sorting system.

Objective: Waste sorting has received considerable attention in recent decades. However, research on the mechanisms underlying the relationships among cultural worldview, environmental risk perception, and waste sorting is rather scarce. This study aims to explore the cultural worldviews, environmental risk perception, and waste sorting among urban Chinese and their mechanisms., Methods: This was a cross-sectional study involving 744 urban Chinese residents (371 men and 373 women). A questionnaire was utilized to measure cultural worldviews, environmental risk perception, and waste sorting. Pearson correlation analysis and structural equation modeling were used to examine the relationship between cultural worldviews, perceptions of environmental risk, and waste sorting., Results: Waste sorting had a relatively insignificant negative relationship with fatalism and individualism. The correlation between environmental risk perception and cultural worldviews was negative except for egalitarianism, and the correlation between hierarchy and environmental risk perception was higher than the others, while individualism was higher than fatalism. Heightened environmental risk perception mediates the relationship between egalitarianism and waste sorting. Reduced environmental risk perception mediates the relationship between hierarchy and waste sorting, and mediates the relationship between individualism and waste sorting., Conclusion: These new findings provide initial support for the mediating role of environmental risk perception in the relationship between cultural worldviews and waste sorting. Both theoretical and practical implications for understanding the psychological mechanisms of waste sorting are discussed., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Cai, Li, Wan, Luo and Tao.)

Considerable resources are spent globally on actions to improve the separate collection of municipal waste aiming to minimise the environmental and economic impacts of municipal waste management. One of such actions are know-as-you-throw (KAYT) schemes, which aim to change the behaviour of waste generators through tailored communication of information. KAYT schemes offer a relatively uncontroversial and simple tool, yet their environmental and economic performance remains unknown due to their limited implementation. To fill this gap, the LIFE-funded REthinkWASTE project applied a novel KAYT scheme in four pilot areas in Italy and Spain. The results of such pilots were evaluated in terms of carbon footprint and life-cycle costs of municipal waste management. The carbon footprint was notably reduced in all pilot areas, ranging from a 46% to 19% reduction, mainly due to notable reductions in unsorted waste (between 10 and 17% reduction) and subsequent lower treatment impacts. Life-cycle costs slightly increased overall, ranging from 4.6% to a -0.4% change. In addition to various sources of uncertainty, self-selection and recency biases are highlighted as major sources for potentially overestimating the benefits of KAYT in the context of large-scale and long-term KAYT implementation. The results however consistently show that the additional carbon footprint from KAYT actions can be offset with less than a 5% reduction in unsorted waste, well below the observed values. The results robustly reveal the potential of KAYT to notably reduce the carbon footprint of waste management systems with limited investment of economic resources., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Sorting Municipal Solid Waste (MSW) has helped promote the awareness of sustainable development of environment. A robot equipped with an intelligent deep learning (DL) detection algorithm have been proposed to improve the sorting task. But most of the related studies aimed to better the DL algorithms on MSW detection, and few studies integrated the DL algorithms with a robot to identify the dominated factors to Intelligent MSW Sorter (IMSWS). Therefore, this study is to develop IMSWS prototype to better sort MSW, based on the pick-and-place process, and preliminarily evaluate the dominated factors. First, the delta robot prototype was manufactured, and IMSWS was performed with a camera to acquire the RGB image and the height of a MSW in the conveyor belt. The DL algorithm, YOLOv3 or YOLOv4, detected the type and plane location of the MSWs in the conveyor belt. Next, the sequence program transferred the valid MSW data to the delta robot. After the calculation of the absorbed location of the target MSW was made, the arm of this delta robot moved to absorb and then transfer the MSW to the bin. Results showed that the IMSWS prototype could sort the multi-object MSWs in the MSW stream. Both YOLOv3 and YOLOv4 reached high detection accuracy on the MSW image dataset. However, the improvement should be made in the actually moving MSW stream even though the YOLOv4 performed the acceptable detection accuracy. The gripping stability of the arm mainly dominated the performance of IMSWS, and this should be improved first., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Dioxins (including 2,3,7,8-tetrachlorodibenzo-p-dioxin, as Group 1 Carcinogen) in the atmosphere mainly originate from incomplete combustion during municipal solid waste (MSW) incineration. To significantly reduce dioxins emission from the MSW incineration industry, China has promulgated a set of ambitious plans regulating MSW-related pollution; however, the emission reduction potentials and concomitant environmental and health impacts associated with the implementation of these programs on a national scale remain unknown. Here, we use real measurements from official environmental impact assessment systems and continuous emissions monitoring systems (covering 96.6% of national MSW incinerators) to estimate unit-level dioxins emission and concomitant environmental and health impacts. We find that in 2018, 99.3% and 66.7% of Chinese incinerators met such concentration and temperature standards, respectively, controlling the total emissions to 19.6 g toxic equivalency quantity and maintaining carcinogenic and noncarcinogenic risks significantly below safety levels nationwide. Fully achieving both current standards and future regulations will reduce emissions and health risks by 67.7% and 62.6%, respectively, with waste sorting program contributing the majority. This study reveals substantial benefits from curbing MSW-related dioxins pollution and underscores the promise of ongoing management., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Household waste source separation substantially reduces the amount of rubbish sent to landfills and incinerators. It enables value recovery from useful waste for transitioning to a more resource efficient and circular economy. Confronted by the severe waste management problems, China recently implemented its most strict compulsory waste sorting program in big cities to date. Despite the failures of waste sorting projects in China in the past, it is unclear what the implementation barriers are, how they interact, and how they can be overcome. This study addresses this knowledge gap through a systematic barrier study involving all the relevant stakeholders in Shanghai and Beijing. It uncovers the complex interrelationships between barriers using the fuzzy decision-making trial and evaluation laboratory (Fuzzy DEMATEL) method. "Hasty and inappropriate planning" and "lack of policy support at the grassroots level", two new barriers that are not reported in the literature, are found to be the most influential barriers. Policy implications are discussed based on the study findings to inform the policy deliberations on the implementation of compulsory waste sorting., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Purpose: Occupational exposure to bioaerosols during waste handling remains a health concern for exposed workers. However, exposure-related health effects and underlying immunological mechanisms are still poorly described., Methods: The present study assessed the inflammatory potential of work-air samples (n = 56) in vitro and investigated biomarker expression in exposed workers (n = 69) compared to unexposed controls (n = 25). These quantitative results were compared to self-reported health conditions., Results: Personal air samples provoked an activation of TLR2 and TLR4 HEK reporter cells in one-third of all samples, indicating that the work environment contained ligands capable of inducing an immune response in vitro. Monocyte levels, as well as plasma biomarker levels, such as IL-1Ra, IL-18 and TNFα were significantly higher in exposed workers, compared to the control group when confounding factors such as BMI, sex, age and smoking habits were accounted for. Furthermore, a significant exposure-related increase in midweek IL-8 levels was measured among exposed workers. Tendencies of increased prevalence of health effects of the respiratory tract were identified in exposed workers., Conclusion: Inhalable dust provoked TLR activation in vitro, indicating that an exposure-related immune response may be expected in susceptible workers. However, despite significant differences in inflammatory plasma biomarker levels between exposed and unexposed workers, prevalence of self-reported health effects did not differ between the groups. This may be due to the healthy worker effect, or other factors such as adequate use of personal protective respiratory devices or adaptation to the work environment with reduced activation of the immune system., (© 2023. The Author(s).)

Waste sorting, as an embodiment of behavioral cognition, is regulated by two cognitive processes, namely, Categorization (C) and Category-Based Induction (CBI). This study employed the event-related potential (ERP) technique to assess whether there is a transformation between C and CBI in waste sorting cognition, in order to help individuals establish a correct waste sorting behavior. We reported a case of intervention in waste sorting education with a 58-year-old Chinese woman to discriminate whether such intervention facilitates the transition between C and CBI. The results showed that the waste sorting cognition follows a developmental model as C-CBI-C, where education may help the subject build a cognitive framework for waste sorting by altering inherent misperceptions and filling gaps in classification knowledge. The results also noticed that FN400 is identified as a characteristic waveform in the CBI process, by which it is indicated that the first 4 to 7 days of education is a critical period for establishing the cognitive framework. Through a comparison of the ERP waveforms at different stages of intervention, the results are insightful to help individuals improve their cognition of waste sorting., Competing Interests: The authors declare no conflicts of interest in this work., (© 2023 Zhao et al.)

Sustainable management of household solid waste (HSW) is an essential step in realizing the development of a circular economy (CE). However, for many developing countries, HSW sorting is evolving incrementally, and focusing on the intervention role of policy and the sorting behaviour of residents can help achieve sustainable waste management. This study aims to investigate the main determinants of residents' HSW sorting behaviour and how policy particularly contributes to it. Drawing upon the theory of planned behaviour (TPB) and incorporating experiences, a conceptual framework is tested on a sample of Chinese residents in Shanghai ( n  = 560, from November to December 2020) using structural equation modelling analysis. The empirical results show that experience and behavioural intention greatly influence HSW sorting behaviour. Moreover, the positive attitude of residents promotes the success of HSW sorting. Subjective norms and perceived behaviour control indirectly affect behavioural intention and behaviour via attitude. The findings of this study provide policymakers with critical factors for the successful implementation of HSW sorting. We also propose policy implications to maintain and improve sorting efficiency from the perspective of residents (education, communication and publicity), neighbourhood committees (degree and efficiency of supervision) and property management companies (good infrastructure, services and processes).

Central to the development of a successful waste sorting robot lies an accurate and fast object detection system. This study assesses the performance of the most representative deep-learning models for the real-time localisation and classification of Construction and Demolition Waste (CDW). For the investigation, both single-stage (SSD, YOLO) and two-stage (Faster-RCNN) detector architectures coupled with various backbone feature extractors (ResNet, MobileNetV2, efficientDet) were considered. A total of 18 models of variable depth were trained and tested on the first openly accessible CDW dataset developed by the authors of this study. This dataset consists of images of 6600 samples of CDW belonging to three object categories: brick, concrete, and tile. For an in-depth examination of the performance of the developed models under working conditions, two testing datasets containing normally and heavily stacked and adhered samples of CDW were developed. A comprehensive comparison between the different models yields that the latest version of the YOLO series (YoloV7) attains the best accuracy (mAP 50 :95 ≈ 70%) at the highest inference speed (<30 ms), while also exhibiting enough precision to deal with severely stacked and adhered samples of CDW. Additionally, it was observed that despite the rising popularity of single-stage detectors, apart from YoloV7, Faster-RCNN models remain the most robust in terms of exhibiting the least mAP fluctuations over the testing datasets considered., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Demetris Nicolaides reports financial support was provided by European Regional Development Fund. Demetris Nicolaides reports financial support was provided by Cyprus Research and Innovation Foundation., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Improving residents' waste recycling behavior is crucial for enhancing resource efficiency and reducing carbon emissions. Previous questionnaire-based studies have reported that individuals exhibit a high willingness to recycle, yet often fail to convert this intention into action. Analyzing 180,417 Internet of Things (IoT) behavior data points, we discovered that the intention-behavior gap might be larger than anticipated. Our findings indicate that: 1) Intentions to recycle alone can predict self-reported recycling behavior (p < 0.01, t = 2.841), but not actual recycling behavior in the absence of other possible moderators (p > 0.1, t = 0.777); 2) Self-reported behavior predicts real behavior, but with limited explanatory power; and 3) The intention-behavior gap primarily results from forgetting or habituation (p < 0.01, t = 2.653), while social desirability plays an insignificant role (p > 0.1, t = 0.246). This study contributes to our understanding of the intention-behavior gap and provides direction for future pro-environmental behavior research., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

China fully implemented the new emission standards in 2016 to further reduce the emissions of air pollutants from the municipal solid waste (MSW) incineration industry; however, the implementation effect of the new standards remains unknown. This study developed the first nationwide air pollutant emission inventory of MSW incineration plants in China based on the measured concentration data from China's continuous emissions monitoring systems (CEMS) network, and activity level data from the China Urban Construction Statistical Yearbook, to evaluate the effectiveness of implementing the new emission standards and estimate the future reduction potentials. Our results demonstrated that the overall standard-reaching proportions of particulate matter (PM), sulfur dioxide (SO 2 ), nitrogen oxide (NO X ), hydrogen chloride (HCl) and carbon monoxide (CO) were 98.8%, 99.3%, 99.4%, 99.4% and 97.6%, respectively, by comparing with the corresponding concentration limits of new emission standards. The total emissions of PM, SO 2 , NO X , HCl and CO from 412 MSW incineration plants in 2019 were 1.9, 6.2, 50.8, 4.3 and 6.6 kt yr -1 , respectively, which is 33.6-75.8% lower than those in 2015, mainly due to the sharp decrease in emission factors. Pollutant emission hotspots were mainly concentrated in eastern and central and southern regions with large populations and well-developed economies. The analysis of future scenario results shows that despite the continuous increase of MSW incineration amount in the future, if the government strengthens pollutant emission standards and comprehensively implements waste sorting, total emissions and emission factors of air pollutants could be further reduced by 25.8-72.7% and 59.8-81.2%, respectively, by 2050. These findings provide helpful insights into future policymaking and technology selection for China and other countries seeking to reduce pollutant emissions from the MSW incineration industry., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The dispersed sources and inconvenient transportation of rural domestic waste (RDW) lead to difficult centralized treatment. Gasification is suitable for decentralized waste treatment, which can effectively avoid RDW long-distance transportation and reduce dioxin emissions compared with small-scale incineration. Hence, economically-affordable and environmentally-friendly RDW treatment models with different gasification scales are required, and village, town and county models were compared via life cycle assessment (LCA) and life cycle cost (LCC) methods in this study. Furthermore, scenario analysis investigated waste sorting based on two food waste (FW) treatment technologies, different FW separate collection efficiency, and electricity recovery to explore the environmental and economic improvement potentials of three models. LCA results show that electricity consumption and direct emissions are significant contributors to environmental impacts, and the county model outperforms village and town models. Moreover, transportation accounts for 6% of the overall environmental impact in the county model. Scenario analysis reveals that waste sorting and electricity recovery can reduce the overall environmental impact by 29% to 146% for three models. LCC results demonstrate that the town model delivers the lowest economic cost, while the village model is the highest. In scenario analysis, resource utilization of FW and electricity recovery of other waste exhibit promising economic benefits. The findings provide comprehensive references for sustainable RDW treatment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

An incentives-based residential recycling programme was designed and implemented for improving residential waste sorting in Shanghai city, but showed very limited success in its performance. To identify why , this study systematically analysed each step of implementation using key informant interviews and site observations. Results show that policy intentions were retained in the policy devolution processes from Municipality to District, and then to Street (ward) levels, but the incentives concepts were effectively nullified in the further devolution to community-level governance. The local implementers focused on formal key performance indicators (KPIs) in order to satisfy inspections. However, the KPIs, which had been devised to allow ease of measurement, were found to unintentionally cause divergence from the policy intention of incentivisation of residents. Furthermore, high scores for these KPIs masked the implementation failure. This identification of the effective derailing of a policy via conscientious implementation is worth highlighting for avoidance in other programmes, in recycling or elsewhere.

In the context of the circular economy, the sorting process during recycling of polymers is essential as regards the efficiency of the process itself and the quality of the so-obtained recycled materials. In this paper, the application of Hyperspectral Imaging (HSI) is proposed for this purpose, providing additional insight into the state of aging and the polymer quality. The underlying study comprises HSI in the wavelength range of 1115-1678 nm considering artificially aged Styrene-Butadiene-Styrene (SBS), where aging is performed for 2, 5, 10, 15 and 20 days in a forced-draft oven at a temperature of 105 °C. The obtained HSI spectra are normalized using the Standard Normal Variate (SNV) method, with the normalized spectra as well as their first and second derivative entering the modeling attempt for SBS aging. For the latter, different partial least squares regression (PLSR) models are evaluated, where the original spectra achieved a correlation of R 2 =0.94 and a root mean squared error of prediction (RMSEP) of 1.83 days, showing the suitability of HSI for the proper identification of the state of aging of SBS and its potential use for other polymers., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.)

Municipal solid waste (MSW) composting is one of the most effective strategies for MSW management but detrimental litter such as plastic and glass debris must be discarded elsewhere. Well-segregated wastes are necessary in this context. A compost bin is a waste collection tool for source separation. To date, the deployment of compost bins for source separation has received scant investigation. This study investigated the effects of compost bin design in terms of user design preferences, waste collection and sorting execution, and segregation behavior. The study comprised a survey and an on-site experiment. Design preferences of nine designed compost bins were evaluated by surveying 400 respondents using the pairwise comparison method. It was revealed that design preference was determined by bin shape and slot position. On-site experiments were conducted to establish collection rate, contamination rate, capture rate, and effective capture rate under different conditions. Under the experimental conditions, better segregation rates were observed in comparison with the control condition. The contamination rate was reduced by 55.9%. The capture rate and the effective capture rate were increased by 8.90%, and 53.4%, respectively. The significant effects of design preferences, physical designs, visual prompts, and past behavior were identified via statistical methods. Source-separated waste collection can be improved through preferred compost bin adoption, enhanced design, appropriate visual prompts, and experience in waste segregation. Therefore, the findings of this study will help to generate effective source-separated collection and allow compost bins to be placed in public areas for integrated and sustainable waste management., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Waste sorting is an important aspect of environmental protection, which is now being enforced on a large scale in China. More broadly, it is beneficial to improve the implementation strategies for waste sorting policy and programmes. This study analyses the psychology of consumers that influences the mechanisms of consumer waste sorting and the governmental policies influencing consumers' attitudes and behaviours. About 295 validated participants were collected from four regions of China. Regression analysis was used to examine the relationship among consumers' internal motivation, government's external publicity and consumer behaviour, and the Hayes' PROCESS macro was used to test mediating effect and moderating effect. The results show that consumers' internal motivation and government's external publicity have a positive effect on consumer behaviour. Consumer attitude played a complete mediating role between consumers' internal motivation and consumer behaviour. Between the government's external publicity and consumer behaviour, consumer attitude played a complementary mediating role. Consumers with self-transcendence values, positive motivation of waste sorting and the government's external publicity had a greater positive impact on their attitudes than consumers with self-enhancement values. The greater the material benefits and psychic income consumers received from waste sorting, the more it promoted a positive attitude to consumer behaviour. The article puts forward some management suggestions to improve the government's implementation of its waste sorting policy.

Waste sorting is highly recommended for municipal solid waste (MSW) management. Increasingly, computer vision (CV), robotics, and other smart technologies are used for MSW sorting. Particularly, the field of CV-enabled waste sorting is experiencing an unprecedented explosion of academic research. However, little attention has been paid to understanding its evolvement path, status quo, and prospects and challenges ahead. To address the knowledge gap, this paper provides a critical review of academic research that focuses on CV-enabled MSW sorting. Prevalent CV algorithms, in particular their technical rationales and prediction performance, are introduced and compared. The distribution of academic research outputs is also examined from the aspects of waste sources, task objectives, application domains, and dataset accessibility. The review discovers a trend of shifting from traditional machine learning to deep learning algorithms. The robustness of CV for waste sorting is increasingly enhanced owing to the improved computation powers and algorithms. Academic studies were unevenly distributed in different sectors such as household, commerce and institution, and construction. Too often, researchers reported some preliminary studies using simplified environments and artificially collected data. Future research efforts are encouraged to consider the complexities of real-world scenarios and implement CV in industrial waste sorting practice. This paper also calls for open sharing of waste image datasets for interested researchers to train and evaluate their CV algorithms., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

In this work, a multi-exposure method is proposed to increase the dynamic range (DR) of hyperspectral imaging using an InGaAs-based short-wave infrared (SWIR) hyperspectral line camera. Spectral signatures of materials were captured for scenarios in which the DR of a scene was greater than the DR of a line camera. To demonstrate the problem and test the proposed multi-exposure method, plastic detection in food waste and polymer sorting were chosen as the test application cases. The DR of the hyperspectral camera and the test samples were calculated experimentally. A multi-exposure method is proposed to create high-dynamic-range (HDR) images of food waste and plastic samples. Using the proposed method, the DR of SWIR imaging was increased from 43 dB to 73 dB, with the lowest allowable signal-to-noise ratio (SNR) set to 20 dB. Principal Component Analysis (PCA) was performed on both HDR and non-HDR image data from each test case to prepare the training and testing data sets. Finally, two support vector machine (SVM) classifiers were trained for each test case to compare the classification performance of the proposed multi-exposure HDR method against the single-exposure non-HDR method. The HDR method was found to outperform the non-HDR method in both test cases, with the classification accuracies of 98% and 90% respectively, for the food waste classification, and with 95% and 35% for the polymer classification.

Economic growth and rapid urbanization have resulted in various urban issues related to sustainable development in emerging economies such as China. Nowadays, two-thirds of China's cities are besieged by waste and one-fourth of the cities have no space to build landfills. China is embarking on a top-down waste sorting revolution, in which residents' awareness and behaviour of participation are fundamental to the success of garbage classification. The purpose of this paper is to understand residents' waste sorting behaviour and identify the influencing factors in China. The subjects of this study are urban and rural residents in Jiaxing, where local government has begun to encourage waste classification but has not yet legalized it. With the integration of the theory of planned behaviour (TPB) and value-belief-norm theory (NAM), this study represents a "motivation-intention-behaviour" theoretical model for the systemic illustration of the antecedents of household waste sorting behaviour. A total of 541 questionnaires were administered in person in households in Jiaxing, China. Structural equation modelling with partial least squares was applied to analyse empirically. The results show that attitudes (ATT), subjective norm (SN), and perceived behavioural control (PBC) have a significant positive effect on the intention of household waste sorting (WSI), and the perceived policy effectiveness (PPE) has a positive and significant effect on the attitudes and waste sorting intention. The waste sorting intention has a positive and significant effect on waste sorting behaviour (WSB). In addition, individual characteristics have a significant impact on waste sorting behaviour, where respondents of women, higher income, and middle and old age are more willing to implement waste sorting behaviours. This study theoretically contributes to the literature by improving the understanding of the determinants of household solid waste sorting behaviour. It also provides several recommendations to improve existing policies at the practitioner level. These recommendations can be valuable references for waste management in China and other emerging economies.

Waste sorting is an effective means of enhancing resource or energy recovery from municipal solid waste (MSW). Waste sorting management system is not limited to source separation, but also involves at least three stages, i.e., collection and transportation (C&T), pretreatment, and resource utilization. This review focuses on the whole process of MSW management strategy based on the waste sorting perspective. Firstly, as the sources of MSW play an essential role in the means of subsequent valorization, the factors affecting the generation of MSW and its prediction methods are introduced. Secondly, a detailed comparison of approaches to source separation across countries is presented. Constructing a top-down management system and incentivizing or constraining residents' sorting behavior from the bottom up is believed to be a practical approach to promote source separation. Then, the current state of C&T techniques and its network optimization are reviewed, facilitated by artificial intelligence (AI) and the Internet of Things technologies. Furthermore, the advances in pretreatment strategies for enhanced sorting and resource recovery are introduced briefly. Finally, appropriate methods to valorize different MSW are proposed. It is worth noting that new technologies, such as AI, show high application potential in waste management. The sharing of (intermediate) products or energy of varying processing units will inject vitality into the waste management network and achieve sustainable development., Competing Interests: Conflict of interestThe authors declared that there is no conflict of interest., (© The Author(s), under exclusive licence to Springer Nature B.V. 2021.)

The increasing amount of waste in cities poses a great challenge for sustainable development. Promoting waste sorting is one of the priorities for various levels of public authorities in the context of the rapid growth of waste generation all around China. To achieve this goal, waste-sorting policies should be precisely designed to ensure successful waste reduction at all stages. Previous studies have neglected the spillover effects of different regulatory policies, which may affect the overall goal of reducing waste by influencing different waste production stages. This paper fills this gap by comparing the spillover effects of two typical waste-sorting policies on sustainable consumption behaviours through a survey conducted in Shanghai and Beijing (control group). By combining quasi-natural experiment and questionnaire methods, this paper analyses data through a mediation test to explore the spillover effects between different regulatory policy groups and the effects of the mediation psychological factors. Results show that a penalty policy significantly decreases people's sustainable consumption behaviours through a negative spillover effect, while a voluntary participation policy significantly increases sustainable consumption behaviours through a positive spillover effect. Results can provide implications for policymaking in waste management and other pro-environmental fields to help cities become more sustainable by shifting multiple behaviours.

Environmental pollution threatens public health and has become a social concern in recent years. Despite the conditions for public participation in environmental governance have improved considerably, the level of public engagement in government projects still falls short of expectations. Therefore, this article introduced two key variables, hoping to answer the following research question that how environmental concerns and governance performance affect public environmental participation. Through principal component analysis of the data from the "Survey of Chinese Urban Residents' Attitudes toward Environmental Protection", the findings of this article are as follows: First, public environmental concerns have no significant impact on their environmental engagement; second, the improvement of residents' confidence in the government performance of environmental management reduces their willingness to participate in official projects. The higher the confidence in the government's performance, the lower the level of public engagement is. Moreover, due to the consideration of self-interest or lack of environmental awareness, those who oppose waste incineration in waste terminal disposal tend to take a non-participatory role in waste sorting programs. Therefore, we suggest that the government have more diverse shareholders in environmental protection, so it should expand public participation through education, publicity, mobilization, and incentives.

An emerging body of research has contributed to understanding the spillover effect of pro-environmental behavior. However, most of the previous studies focused on the spillover effects of initial PEBs but neglected the spillover effects of different regulatory policies. This study conducts an experiment through survey questionnaire in Shanghai and Beijing to compare the spillover effects of two different kinds of waste sorting policy, i.e. voluntary participation policy and penalty policy. This study examines the spillover effects of these two policies on people's energy-saving policy acceptance. The examined energy-saving policy include price increase policy and subsidy policy. Results show that initial penalty policy targeted at waste sorting significantly decreases people's acceptability of price increase policy through negative spillover effect, while initial voluntary participation policy significantly increases people's acceptability of price increase policy through positive spillover effect. Nonetheless, no spillover effects are observed for subsidy policy acceptability. It indicates that penalty policy should not be used easily since there is a risk of resulting in negative spillover effects, while the voluntary participation policy should be better made use of in the future policy designment. The findings are meaningful for the local governments to better select and design their regulatory policies for waste sorting, while the Chinese government is going to promote the waste sorting behaviors nationwide. Results can also be used to inform policy development and revision in private and public pro-environmental spheres to achieve overall environmental goals by driving a broader shift in behaviors., Competing Interests: Declaration of Competing Interest This paper is original and no conflict of interest exits in the submission of this manuscript, and manuscript is approved by all authors for publication. I would like to declare on behalf of my co-authors that the work described was original research that has not been published previously, and not under consideration for publication elsewhere, in whole or in part. All the authors listed have approved the manuscript that is enclosed., (Copyright © 2021. Published by Elsevier Ltd.)

As municipal solid waste severely threatens human health and the ecological environment, since 2019, China has started to fully practice MSW sorting in all prefecture-level cities. In this paper, we apply the event study and difference-in-difference methods to investigate how China's green policy of promoting MSW sorting influences listed waste sorting companies from the perspective of investors' short-term and long-term reactions. This paper finds that investors are not sensitive to the introduction of MSW sorting in the short term, the new environmental policy does not relieve the financing constraints of related enterprises in the long run, and the financing constraints of private enterprises are stricter than those of state-owned enterprises. These findings indicate that China's current encouragement of garbage sorting is not efficient enough as it has not brought benefits to the waste classification industry yet. More measures need to be taken to eliminate uncertainties in urban waste sorting. Our paper enriches the research on China's waste sorting practices and provides new evidence of the effects of environmental policy on related firms from the perspective of green industry.

The improvement of waste separation is of great interest in mitigating problems related to municipal solid waste (MSW) management. Trash bins are commonly used for waste separation at source. Thus, appropriate trash bin designs are promising to improve waste collection and separation performance. This study investigated the effect of trash bin design on waste collection and waste-sorting behaviors in Thailand, focusing on color preference, setting location, and perceived ease in finding a trash bin (noticeability). Trash bins to separately collect compostable waste, recyclable waste, and PET bottles were tested. Perceived preferences for colors and noticeability were evaluated using pairwise comparison by survey questionnaires with a sample size of 889 respondents. Waste collection experiments were conducted to reveal waste collection, capture, contamination, and effective capture rates in three locations for 15 weeks. The results were analyzed via statistical methods. They suggested that trash bins with the least preferred colors had the highest waste separation efficiencies. On the other hand, color preference towards trash bins had no significant impact on waste collection. In addition, lower color preference contributed to lower noticeability of trash bins. The effective capture rate had a significantly negative correlation with noticeability. Highlighting the location of less noticeable trash bins might have helped participants practice correct waste disposal. In conclusion, location, unit color, and noticeability of trash bins can affect waste collection and separation performance. Increasing human awareness through appropriate design and setting of trash bins might enable more efficient collection of segregated wastes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

With the economy growing rapidly, as well as the increasing diversification of human material and cultural needs, waste management poses a pressing challenge for local authorities in China. The primary aim of the present study is to examine the determinants of household waste-related behaviors, especially focusing on the roles of two important social interaction-based factors, social norms and networks, and their combinations. Specifically, this paper adopted the method of principal component analysis to capture social interactions and leveraged ordered logit models to explore their influences on the behaviors involving waste sorting, bringing their own shopping bags and reusing plastic bags in other aspects. Using the data from the Chinese General Social Survey in 2013 (CGSS2013), the results reveal that both social norms and social networks exert a significant positive influence on pure altruistic waste sorting while only social norms are positively associated with bringing their own shopping bags to store and reusing bags in other aspects with the nature of impure altruism. Meanwhile, there is no convincing evidence for the interaction effect between social norms and social networks on waste sorting, yet the interaction item does work together negatively influencing bringing their own bags and reusing bags behaviors. Moreover, the results show that social norms have a much larger effect on waste-related behaviors in males than females while social networks lead to significant promotion in waste sorting only for females. For people with higher education levels, the impacts of social norms and social networks on waste sorting and bringing their own bags behaviors are insignificant, while the higher income groups are weakly affected by social networks as well, partly because of time constraints and opportunity cost. Lastly, this paper provides new insight into waste management from the perspective of social interaction., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The use of Filtering Respiratory Protective Devices (FRPD) is mandatory in Portugal to protect workers from the waste industry of harmful exposures. Deleterious health effects of exposure to bioburden via inhalation and/or ingestion include respiratory symptoms and nephrotoxicity. Between January and February 2019, 118 FRPD samples were collected in one waste sorting industry and characterized regarding microbial contamination and cytotoxicity, defined as cell metabolic activity, through the MTT colorimetric assay (3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide). Cytotoxic effect was classified according to percentage of extinction values with respect to the control group, as follows: absent (≥90); low (80%-90%, +); medium (60%-79%, ++); and high (below 60%, +++). For 113 samples the MTT assay revealed a cytotoxic effect in A549 cells, of which 81 presented high cytotoxicity. In SK cells, a cytotoxic effect was observed in 56 samples, of which five displayed a high cytotoxic effect. Several moderate (p < 0.05) to strong (p < 0.01) correlations were found between higher bacterial and fungal counts both in interior layers (fungi and bacteria) and in exhalation valves (fungi) of FRPD samples and reduced cell metabolic activity of SK cells. On the basis of the obtained results for the cytotoxic effect of FRPD samples on two different cells lines, it was determined that A549 cells exhibited a cytotoxic effect for a higher number of FRPD, whereas the SK cells model correlated better with the other assessed parameters, namely, bacterial and fungal counts and conditions of FRPD use. Although the results are not conclusive on the most appropriate cell line to assess FRPD cytotoxicity, they reinforce the importance of in vitro toxicology in exposure assessments to determine the cytotoxicity of mixtures of contaminants, for better risk characterization and selection of appropriate risk management measures., (Copyright © 2020 Elsevier Inc. All rights reserved.)

China is facing the dual challenge of economic development and environment protection. Recently, Shanghai (tier-1 city) implemented the pilot project of household solid waste (HSW) management and expects to execute a similar project in 45 cities across China by 2020. The current research's aim is to examine the pilot project's progress by comparing it with existing HSW management practice in other cities. From a theoretical perspective, a socio-ecological framework is used to examine citizens' HSW sorting behavior (HSWSB), which is further mapped based on the theory of planned behavior to enrich the findings. A total of 1409 citizen responses are utilized to generalize the findings. The study concludes that replicating tier-1 practices in other cities could produce unsatisfactory results. The regulatory environment should focus on comparatively long-lasting citizen behavior change by designing a citizen-centric approach (i.e., awareness campaigns) related to ecological concerns (i.e., climate change) because it could define the future of HSWSB practice in Chinese society., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Waste sorting at the source is a vital strategy of waste management and to improve urban sustainability. If the strategy is implemented by relying solely on publicity and civic awareness, the impact is less significant. Proactive measures, such as policy regulations, supervisory guidance, and stimulating incentives, play essential roles for better management. The unknown waste-dumping behaviour of residents is a great challenge for decision-makers to allocate resources for waste-collection operations and to refine regulations. Traditional behaviour analysis methods such as questionnaire surveys and simulation methods have limitations considering the population size and the complexity of individual behaviour. This study aims to design a data-driven analytical framework to analyse household waste-dumping behaviour and facilitate policy regulations by using the Internet of Things (IoT) and data mining technologies. The analytical framework is further developed into a four-step management cycle. A case study in Shanghai is employed to demonstrate the effectiveness of the analytical framework and management cycle. The results of behaviour analyses reveal that (1) waste-dumping frequency is high in the evening but negligible in the early afternoon; (2) compared to working days, peak-value time at weekends occurs later in the morning and earlier in the evening; (3) residents require longer waste-dumping time windows than those empirically recommended by administrators. Managerial insights and decision support based on these research results have been presented for decision-makers to guide operations management and facilitate policy regulations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019. Published by Elsevier Ltd.)

This study has demonstrated the use of weighted-linear-combination approach in connection with fuzzy set functions of Total Population, Total Distance, Annual income per person and Total number of opening hours of Recycling Centers (RCs), in ArcGIS environment, to generate risk maps and characterize RCs based on risk for improper sorting of waste. Analysis of data shows that there are 73 RCs, at which, risk for improper sorting of waste is highest. On average, there is one RC for every 19,402 individuals in Sweden and a single round trip made by Swedes to nearest RC, results in emission of 1340 ktons of CO2. Furthermore, it is found that strategies needed (e.g. installation of new RCs or shifting of RCs closer to densely populated areas (DPAs) or increase in number of opening hours or availability of pre-visit sorting information etc.), to reduce risk for improper sorting of waste, are different for RCs that are operated under different management forms. Variations in tariffs, limited number of waste fractions to be collected per RC, confusing terminologies, design parameters of RCs and non-implementation of EU Directive 2018/851 with respect to packaging waste, are other factors that are affecting quality of waste sorting at RCs, and are discussed in the article. Results from this research can be utilized to identify site specific needs for improving sorting of waste and to identify priority areas for installation of new RCs., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Rapid economic development accelerates the generation of municipal solid waste (MSW), and thereby calls for an effective and reliable waste management strategy. In the present work, we systematically investigated the status of MSW management in a mega-city of China (Guangzhou). The data were collected from literatures, government statistics and field sampling work. It can be found that a combination of waste sorting by individual residents and a necessary quantity of sanitation workers is one of the most feasible strategies to achieve a sustainable waste management. With implementation of that integrated strategy, approximately 0.03 million tons of metal, 0.24 million tons of paper, as well as 0.46 million tons of plastics can be recycled/recovered for further processing. A cost reduction of 70 million US$ is achieved in comparison with the un-optimized system due to the sale revenue of recyclable materials and the saving from waste disposal fees. The values of environmental assessment were expressed as environmental load units. The developed scenarios could decrease the environmental cost, namely, 0.66 million US$. Based on the studies, waste sorting is urgently needed in Guangzhou. However, to make the proposed strategy to be more economically feasible, the sorting should be performed individually as well as with public participation. The establishment of a win-win situation for all stakeholders is an effective path for the improvement of the integrated waste management system.

Waste sorting is key to the process of waste recycling. Exact identification of plastic resin and wood products using Near Infrared (NIR, 1-1.7µm) sensing is currently in use. Yet, dark targets characterized by low reflectance, such as black plastics, are hard to identify by this method. Following the recent success of Midwave Infrared (MWIR, 3-12µm) measurements to identify coloured plastic polymers, the aim of this study was to assess whether this technique is applicable to sorting black plastic polymers and wood products. We performed infrared reflectance contact measurements of 234 plastic samples and 29 samples of wood and paper products. Plastic samples included black, coloured and transparent Polyethylene Terephthalate (PET), Polyethylene (PE), Polyvinyl Chloride (PVC), Polypropylene (PP), Polylactic acid (PLA) and Polystyrene (PS). The spectral signatures of the black and coloured plastic samples were compared with clear plastic samples and signatures documented in the literature to identify the polymer spectral features in the presence of coloured material. This information was used to determine the spectral bands that best suit the sorting of black plastic polymers. The main NIR-MWIR absorption features of wood, cardboard and paper were identified as well according to the spectral measurements. Good agreement was found between our measurements and the absorption features documented in the literature. The new approach using MWIR spectral features appears to be useful for black plastics as it overcomes some of the limitations in the NIR region to identify them. The main limitation of this technique for industrial applications is the trade-off between the signal-to-noise ratio of the sensor operating in standoff mode and the speed at which waste is moved under the sensor. This limitation can be resolved by reducing the system's spectral resolution to 16cm -1 , which allows for faster spectra acquisition while maintaining a reasonable signal-to-noise ratio., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Material recycling of post-consumer bulk plastics made up of polyolefins is well developed. In this article, it is examined which effects on waste sorting and treatment processes influence the qualities of polyolefin-recyclats. It is shown that the properties and their changes during the product life-cycle of a polyolefin are defined by its way of polymerisation, its nature as a thermoplast, additives, other compound and composite materials, but also by the mechanical treatments during the production, its use where contact to foreign materials is possible and the waste sorting and treatment processes. Because of the sum of the effects influencing the quality of polyolefin-recyclats, conclusions are drawn for the material recycling of polyolefins to reach high qualities of their recyclats. Also, legal requirements like the EU regulation 1907/2006 concerning the registration, evaluation, authorisation and restrictions on chemicals are considered.

Reliable national data on waste generation and composition that will inform effective planning on waste management in Ghana is absent. To help obtain this data on a regional basis, selected households in each region were recruited to obtain data on rate of waste generation, physical composition of waste, sorting and separation efficiency and per capita of waste. Results show that rate of waste generation in Ghana was 0.47 kg/person/day, which translates into about 12,710 tons of waste per day per the current population of 27,043,093. Nationally, biodegradable waste (organics and papers) was 0.318 kg/person/day and non-biodegradable or recyclables (metals, glass, textiles, leather and rubbers) was 0.096 kg/person/day. Inert and miscellaneous waste was 0.055 kg/person/day. The average household waste generation rate among the metropolitan cities, except Tamale, was high, 0.72 kg/person/day. Metropolises generated higher waste (average 0.63 kg/person/day) than the municipalities (0.40 kg/person/day) and the least in the districts (0.28 kg/person/day) which are less developed. The waste generation rate also varied across geographical locations, the coastal and forest zones generated higher waste than the northern savanna zone. Waste composition was 61% organics, 14% plastics, 6% inert, 5% miscellaneous, 5% paper, 3% metals, 3% glass, 1% leather and rubber, and 1% textiles. However, organics and plastics, the two major fractions of the household waste varied considerably across the geographical areas. In the coastal zone, the organic waste fraction was highest but decreased through the forest zone towards the northern savanna. However, through the same zones towards the north, plastic waste rather increased in percentage fraction. Households did separate their waste effectively averaging 80%. However, in terms of separating into the bin marked biodegradables, 84% effectiveness was obtained whiles 76% effectiveness for sorting into the bin labeled other waste was achieved., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Household waste management has become essential in industrialized countries. For the recycling programs to be a success, all citizens must comply with the developed residential procedures. Governmental bodies are thus dependent on as many people as possible adhering to the sorting systems they develop. Since the 1970s oil crisis, governments have called upon social psychologists to help develop effective communication strategies. These studies have been based on persuasion and behavioral commitment (Kiesler, 1971). Less common are studies based on developing participative communication (Horsley, 1977), a form of communication that relies on individuals to pass on information. After going through the main communication perspectives as they relate to the sorting of household waste, a comparative field study will be presented on the effectiveness of persuasive, committing and participative communication. Participative communication relied on users to pass along information to their neighbors. The results show that the participants who spread information in this way, along with those who made a commitment, changed their behavior to a greater degree than the other participants., (Copyright © 2014 Elsevier Ltd. All rights reserved.)