Supercritical fluid technology as a sustainable alternative method for textile dyeing: An approach on waste, energy, and CO2 emission reduction

The clothing industry is considered one of the most polluting industries on the planet due to the high consumption of water, energy, chemicals/dyes, and high generation of solid waste and effluents. Faced with environmental concerns, the textile ennoblement sector is the most critical of the textile production chain, especially the traditional dyeing processes. As an alternative to current problems, dyeing with supercritical CO2 (scCO2) has been presented as a clean and efficient process for a sustainable textile future. Supercritical fluid dyeing (SFD) has shown a growing interest due to its significant impact on environmental preservation and social, economic, and financial gains. The main SFD benefits include economy and reuse of non-adsorbed dyes; reduction of process time and energy expenditure; capture of atmospheric CO2 (greenhouse gas); use and recycling of CO2 in SFD; generation of carbon credits; water-free process; effluent-free process; reduction of CO2 emission and auxiliary chemicals. Despite being still a non-scalable and evolving technology, SFD is the future of dyeing. This review presented a comprehensive overview of the environmental impacts caused by traditional processes and confronted the advantages of SFD. The SFD technique was introduced, along with its latest advances and future perspectives. Financial and environmental gains were also discussed.

An exploratory diagnosis and proposed index of technological change and sustainable industrial development in selected OECD member countries

Industrial development has resulted in economic progress and the well-being of the society. At the same time, the impact of the industrial complex has disrupted the environment and resulted in climate change related impacts. The purpose of this study was to carry out an exploratory diagnosis and propose a technological change and sustainable industrial development index at the international level. Therefore, a network study was conducted to identify the main nodes and thematic clusters associated with cleaner production. A patent analysis was applied to technologies related three selected/relevant areas of cleaner production, i.e. carbon footprint, wastewater treatment, and renewable energy. Additionally, based on factor analysis, an index including different indicators related to scientific, technological, economic, environmental, and social issues was developed and proposed in this study.

Resource utilization in the sub-sectors of the textile industry: opportunities for sustainability

It was aimed to determine the specific resource use and reduction potential profiles in various textile sub-sectors (cotton woven fabric dyeing-finishing, wool woven fabric dyeing-finishing, synthetic woven fabric dyeing-finishing, cotton knitted fabric, synthetic knit fabric dyeing-finishing, non-woven fabric, dyeing-finishing of knitted fabric). The main focus was to elucidate opportunities for sustainability in terms of decreasing resource utilization in the textile sector. On-site surveys and detailed data collection studies were carried out at 150 textile facilities. Average specific values for water, auxiliary chemicals, dyestuff, electricity, and steam consumptions, and related reduction potentials were calculated and compared within facilities and sub-sectors. The minimum specific resource consumption values reported in the Best Available Techniques Reference Document (BREF) for the textile industry and data of similar facilities from the literature were evaluated and used. A detailed environmental performance profile of the Turkish textile sector in terms of resource usage and reduction potential was generated. The highest specific water consumption was found in the wool-woven fabric sub-sector (345 ± 262 L/kg product). Although the specific auxiliary chemical consumption shows similarities within sub-sectors, the highest specific auxiliary chemical consumption (397 ± 237 g/kg product) was found in the synthetic woven fabric sub-sector. The sub-sector with the highest specific dyestuff consumption (30 ± 13 g/kg product) was the cotton knitted fabric sub-sector. The wool woven fabric industry had the highest specific electricity (7 ± 5.3 kWh/kg product) and steam (20 ± 11 kg steam/kg product) consumption. In addition, for all the studied sub-sectors country-wide, the lowest and highest reduction potentials in resource uses were 18 ± 15% and 73 ± 13%, respectively, suggesting a need for major full-scale implementations of cleaner production for enhancing sustainability in the textile industry.

Novel method for recovering valuable metals from Sn ash: Vacuum carbothermal reduction-directional condensation

Sn ash recycling is an industry with positive development prospects, as it provides better-protected resources, promotes sustainable development, and lays a solid foundation for future development. In this study, an innovative vacuum carbothermal reduction-directional condensation process was developed. The thermodynamic analysis results indicated that the initial reaction pressure and temperature for the carbothermal reduction of the system was 1-10 Pa and 998-1063 K, respectively. The saturation vapor pressure, separation coefficient, and condensation temperature of Sn, Pb, and Zn in the reduced products differed significantly, and their separation could be achieved by controlling the volatilization and condensation temperatures. A single-factor experiment investigated the effects of carbon ratio, temperature, and time on the reduction efficiency, direct yield, and recovery rate. The optimal experimental conditions were the ratio of MeO to C of 4:1, temperature of 1373 K, and time of 120 min. Sn, Pb, and Zn products were obtained at different positions. This process shortens the traditional process, reduces the reduction cost of Sn, and enables the implementation of the process, making it environmentally friendly.

Cleaner production evaluation system for textile industry: An empirical study from LCA perspectives

The contradiction between the rapid textile expansion and intensive energy consumption, highly environmental pollution calls for the adoption of cleaner production (CP). However, current evaluation system mainly targeted on CP at production stage, guidance and support on the life cycle assessment is still in its infancy. Meanwhile few studies brought the combination of water conservation and carbon reduction into considerations. This study compared the existing CP evaluation systems including guidelines for the whole industry, standards for textile industry and indicators for the dyeing and finishing sector by quantifying the differences of indicator score compositions. Comparisons analysis from six aspects suggested that all the evaluation systems had relevant indicators regarding "pollutant emissions". "Management", "process equipment and techniques" and "resource and energy consumption" have also been well concerned while "product characteristic" seemed to be overlooked at current stage. From the perspective of whole life cycle, the key of textile processing is the "printing and dyeing" (44.23 %) followed by "fabric manufacturing"(28.85 %) and setting (15.38 %). With regards to the environmental impacts, resources depletion gained the highest attention since their indicator scores reached up to 25.71 %, 18.47 % and 20.62 % for EMAS, ERG 2018 and HJ-1852006. Cleaner production awareness and social impact also played significant roles in ISO 14031:2021 and WMG. Subsequently, a set of new comprehensive CP evaluation indicator system was established, including 3 scopes and 7 goals. The newly-built indicator system incorporated with life cycle perspectives gave a powerful tool to measure the CP level in textile industry and of CP will benefit from water reuse and energy utilization with high efficiency.

Foliar co-application of zinc oxide and copper oxide nanoparticles promotes phytochemicals and essential oil production in dragonhead (Dracocephalum moldavica)

Individual nanoparticle application has been documented to promote plant production; however, whether co-application of two nanoparticles (NPs) is more sustainable and significantly promotes plant production is unclear. Herein, foliar co-applications of two NPs or their conventional fertilizer forms on the growth, micronutrient (copper and zinc) enrichment, primary productivity, and essential oil (EO) production in a medicinal annual, dragonhead (Dracocephalum moldavica L.), were investigated. Treatments included 1:1 ratio of zinc oxide nanoparticles (ZnONPs):copper oxide nanoparticles (CuONPs) (40-400 mg/L), and compared with individual NPs, individual zinc suspension (ZnS) and chelated copper (chelated-Cu), and their combination, at equivalent concentrations. Results showed that the highest bioenrichment of Zn and Cu was observed with 80-160 mg/L ZnS+chelated-Cu, 400 mg/L ZnONPs+CuONPs, or ionic combination treatments. A dose-dependent increase in hydrogen peroxide and malondialdehyde was observed with co-treatment of NPs or ions, and oxidative stress responses were higher with NPs or ions co-treatment than individual treatment. With 160 mg/L ZnONPs+CuONPs treatment, total chlorophyll, aboveground biomass, and essential oil production increased significantly compared to control, 160 mg/L CuONPs, and 160 mg/L ZnONPs (227, 157 and 823 %; 58, 79, and 51 %; and 46, 80, and 3 %, respectively). Flavonoid and anthocyanin content also increased significantly (58 and 50 %, respectively) with ZnONPs+CuONPs compared to ZnS+chelated-Cu and were higher than ZnONPs or CuONPs alone by 10 and 25 %, and 37 and 36 %, respectively. More importantly, EO production and quality improved with 160 mg/L ZnONPs+CuONPs treatment compared to control. Taken together, our findings showed that foliar co-treatment of 160 mg/L ZnONPs+CuONPs could significantly improve primary productivity, aboveground biomass, and EO quality and yield in dragonhead grown in semi-arid field conditions; and thus, 160 mg/L ZnONPs+CuONPs is recommended as an optimal foliar co-treatment strategy for promoting sustainable plant production in semi-arid regions where soil nutrients and water are limiting factors inhibiting crop yield.

Comparative environmental sustainability assessment of biohydrogen production methods

As energy crisis is recognized as an increasingly serious concern, the topic on biohydrogen (bioH2) production, which is renewable and eco-friendly, appears to be a highly-demanding subject. Although bioH2 production technologies are still at the developmental stage, there are many reported works available on lab- and pilot-scale systems with a promising future. This paper presents various potential methods of bioH2 production using biomass resources and comparatively assesses them for environmental impacts with a special emphasis on the specific biological processes. The environmental impact factors are then normalized with the feature scaling and normalization methods to evaluate the environmental sustainability dimensions of each bioH2 production method. The results reveals that the photofermentation (PF) process is more environmentally sustainable than the other investigated biological and thermochemical processes, in terms of emissions, water-fossil-mineral uses, and health issues. The global warming potential (GWP) and acidification potential (AP) for the PF process are then found to be 1.88 kg-CO2 eq. and 3.61 g-SO2 eq., which become the lowest among all processes, including renewable energy-based H2 production processes. However, the dark fermentation-microbial electrolysis cell (DF-MEC) hybrid process is considered the most environmentally harmful technique, with the highest GWP value of 14.6 kg-CO2 eq. due to their superior electricity and heat requirements. The water conception potential (WCP) of 84.5 m3 and water scarcity footprint (WSF) of 3632.9 m3 for the DF-MEC process is also the highest compared to all other processes due to the huge amount of wastewater formation potential of the system. Finally, the overall rankings confirm that biological processes are primarily promising candidates to produce bioH2 from an environmentally friendly point of view.

Cleaner production auditing for plastic recycling industry in Pakistan: A baseline study

Recycling plastics is a good alternative to manage the plastic waste generated in Pakistan. Unfortunately, the country lacks efficient system to manage or recycle the plastic waste it generates. Lack of government support, absence of standard operating procedures, negligence towards health and safety of workers, increasing costs of raw materials and poor quality of the recyclates are some of the issues currently faced by plastic recyclers in Pakistan. Considering the need of cleaner production audits in plastic recycling industries, this study was carried out to establish an initial reference benchmark. Production processes in 10 recycling industries were evaluated from cleaner production perspective. The study showed the average water consumption of a recycling industry as high as 3315 L/ton. All the consumed water is wasted in the nearby community sewer while, only 3 recyclers recycled between 70 and 75% the treated wastewater. In addition, a recycling facility on an average consumed 172.5 kWh of power for processing 1 ton of plastic waste. The average temperature was observed to be 36.5 °C and noise levels exceeded the permissible limits. Moreover, the industry is male-dominated, workers are mostly underpaid and have no access to good healthcare facilities. Recyclers lack standardization and have no national guidelines to follow. Guidelines and standardization of recycling process, wastewater treatment, use of renewable energy, water reuse etc, are direly needed for uplifting this sector and reducing its impacts on the environment.

How does environmental regulation influence green technological innovation? Moderating effect of green finance

The main factor behind green economic development is green technology innovation (GTI). Environmental regulation and green finance (GF), as important ways to promote ecological civilization construction, run through the entire procedure of GTI. The purpose of this study is to investigate the influence of heterogeneous environmental regulation on GTI and the moderating effect of GF on GTI from both theoretical and empirical perspectives, to provide useful ideas for China's economic reform path selection and environmental governance system optimization. This paper uses information from 30 provinces between 2002 and 2019, and a bidirectional fixed model was constructed. The results show that: First, regulatory environmental regulation (ER₁), legal environmental regulation (ER₂), and economic environmental regulation (ER₃) all have greatly boosted the degree of GTI in each province. Second, GF acts as a highly effective moderator between heterogeneous environmental regulation and GTI. Finally, this article investigates how GF can act as a moderator in various circumstances. The beneficial moderating effect of it is found to be more pronounced in inland areas, areas with weak spending on research and development, and areas with high energy consumption. These research results provide valuable references for accelerating the green development process in China.

Urban mobility trends and climate change: sustainability policies in the parking industry

The concern to create cleaner and more ecosystem-friendly production processes has extended to the parking sector in Spain. Since the creation of the multi-level institutional framework for sustainable mobility management (mainly composed of the Infrastructure, Transport and Housing Plan 2012-2024, the Sustainable Urban Mobility Plans, Law 9/2006, and Law 9/2017), environmental considerations, including sustainable management certificates, have occupied a privileged place in public procedures for the management of parking structures and regulated surface parking facilities. Although there have been previous academic studies on the design and implementation of SUMPs and the growth of the parking sector, this article is novel in that it analyzes the market concentration of the parking sector in a scenario where climate change policies are crucial and the importance of sustainability certificates takes on a new meaning. Therefore, the objective of this article is to analyze whether the growing importance of environmental aspects has led to an increase in the concentration level of the parking sector in Spain. For this purpose, several concentration and stability indices are calculated. The results show that, although there are additional factors, the certification of a cleaner activity is relevant in the process of public tenders in the sector, which has served to strengthen the dominance of the most prominent companies in the sector that are in possession of environmental certificates. This shows that environmental policies can also have negative effects on the market, so the results of this analysis are of great value to policymakers.

Facility planning and schedule design in the pandemic: Eliminating contacts at construction workplace

The construction industry has been severely affected by the COVID-19 pandemic and the associated restrictions on person-to-person contacts issued by the government. A construction site usually has a high number of workers working at the same time; therefore, the question of how to ensure their safety during the pandemic-that is, how to protect them from getting infected-has become an urgent problem. In this study, we propose a bi-objective integer programming model to establish the optimal schedule plan under COVID-19 regulations. We develop a solution method and conduct numerical experiments to solve and validate our model. The optimal schedule plan can avoid contacts between workers of different groups while minimizing the total costs of complying with government policy. Our proposed model can be applied in practice to help project managers establish a reasonable and cost-effective schedule plan. This study contributes to reducing the operating costs of contractors and protecting the health of construction workers.

Sustainability for wastewater treatment: bioelectricity generation and emission reduction

This review covers the technological measures of a self-sustainable anaerobic up-flow sludge blanket (UASB) system compared with an aerobic activated sludge process (ASP) for wastewater treatment plants (WWTPs). The ASP requires a huge amount of electricity and chemicals and also results in the emission of carbon. The UASB system, instead, is based on greenhouse gas (GHG) emission reduction and is associated with biogas production for cleaner electricity. WWTPs including the ASP system are not sustainable due to the massive financial power required for clean wastewater. When the ASP system was used, the amount of production was estimated to be 10658.98 tonnes CO₂eq-d^- of carbon dioxide. Whereas it was 239.19 tonnes CO₂eq-d^-1 with the UASB. The UASB system is advantageous over the ASP system as it has a high production of biogas, needs low maintenance, yields a low amount of sludge, and is also a source of electricity that can be used as a power source for the WWTPs. Also, the UASB system produces less biomass, and this helps in reducing costs and maintaining work. Moreover, the aeration tank of the ASP needs 60% of energy distribution; on the other hand, the UASB consumes less energy, approximately 3-11%.

The effect of geopolitical risk on environmental stress: evidence from a panel analysis

The current paper concentrates on whether geopolitical risk can create environmental stress or not. It empirically explores the geopolitical risk effect on energy and carbon intensities of human well-being. Our paper postulates that geopolitical risk's impacts change over time because of the continuous amendments in the decision process through the geopolitical events' reoccurrence and the interaction with unobserved variables or the time-specific disturbances. Thus, our paper uses the two-way fixed Prais-Winsten regression approach to measure this dynamic relationship period yearly. It extracts evidence from 18 countries worldwide during the period (1992-2018). It finds that the effect of geopolitical risk on environmental stress is changing between positive and negative signs. The results show that geopolitical risk is biased toward reducing environmental stress or supporting environmental sustainability. From a policy implication side, policymakers and scholars should pay more attention to understand how geopolitical risk effects evolve on the country and the international levels and how to manage the geopolitical events to encourage their positive impacts on the environment.

Recent advances in biowaste management towards sustainable environment

Bio-wastes and their utilization has been increasing enormously, due to its generation and management practices towards making the clearner environment. Bio-waste disposal that follow the emerging global human population has commended the hunt to certain methods sustainably for the bio-waste management to overwhelmed the ecological issues, prompted by means of the collection of such waste materials. The bio-conversion process of the various bio-wastes into high value added products seems to be practicable in various venues in terms of technological and financial supports. Thereby, this preface presentat about of bio-wastes management and new trends towards circular economy and challenges to acheive it by considering the Virtual Special Issue (VSI) dedicated in Bioresourse Technology Journal.

Experimental research on atomization process and dust reduction performance of swirl pressure nozzle

In this study, experimental studies on atomization process and dust reduction performance of four swirl nozzles with different inlet/outlet diameter ratio (D) were performed. The results of the atomization process study of the nozzle show that with the increase of D, the droplet breakup range of the spray field is gradually increasing, but the droplet breakup intensity of the spray field is gradually decreasing. At D = 3.33 and 3.63, droplet breakup occurs mainly in the range of 0-4 mm in the strong turbulent region. At D = 3.75, droplet breakup occurs mainly in the range of 0-2 mm in the strong turbulent region. At D = 3.96, droplet breakup occurs mainly in the range of 0-1 mm in the strong turbulent region. Droplet breakup in the spray field at D = 3.33 and D = 3.67 was better than that at D = 3.75 and D = 3.96. From the dust reduction experimental results, the dust reduction efficiency increases and then decreases with the increase of D. The dust reduction efficiency is highest among the four nozzles at D = 3.67. Based on the dust reduction curves of four different D of nozzles, it is predicted that the optimal dust reduction condition will be achieved at D of 3.60, which provides a reference for the design and optimization of nozzles.

Does the Emission Trading Scheme achieve the dual dividend of reducing pollution and improving energy efficiency? Micro evidence from China

Resolving the negative externality of environmental pollution has always been a concern in both the theoretical and practical space. To stimulate enterprises to participate in environmental governance actively, China has implemented a series of environmental regulation policies. The Emission Trading Pilot Scheme (ETPS) is an example of such policies implemented to ensure the gradual transition toward marketization. From a micro-enterprise perspective, the study examines how this policy achieves the dual effects of reducing emissions and promoting energy efficiency. We further explore potential channels through which this policy influences the dual effects. We empirically find ETPS to reduce the pollution emissions of enterprises significantly. However, the pollution reduction effect is mainly achieved by encouraging enterprises to strengthen cleaner production rather than through end governance. In addition to bringing environmental dividends, we observe ETPS to improve fossil energy efficiency by about 7.5% indirectly. We conclude by urging policy makers and participants to optimize energy structures and adjust intermediate input as they serve as significant pathways through which ETPS can affect fossil energy efficiency. The ETPS can encourage enterprises to actively step out of their "comfort zone" of environmental governance to be viewed as an effective environmental regulation policy.

A systematic review of gold extraction: Fundamentals, advancements, and challenges toward alternative lixiviants

Since the birth of cyanidation, it has been dominant in the gold extraction industry. Recently, with the increasing awareness of environmental hazards and potential risks posed by the severe toxicity of cyanide, attempts to seek alternative lixiviants have arisen. Over the past three decades, a significant amount of literature has examined alternative lixiviants to cyanide for recovering gold, while few industrial applications have been reported due to various obstacles, such as toxicity, excessive consumption, or low leaching efficiency. These obstacles are progressively overcome in multiple ways, including process improvement, system optimization, use of co-intensifying systems, and development of additives. In this paper, related studies about alternative lixiviants and methods such as cyanide, thiosulfate, thiourea, thiocyanate, polysulfides, halides, and microbial leaching are summarized. The history, fundamentals, advancements, and challenges of alternative lixiviants are fully concluded to provide a reference for cleaner gold production. In addition, the comprehensive performance of lixiviants was evaluated according to a novel evaluation criterion proposed in terms of economy, efficiency, and environment.

Life cycle assessment of rice bran oil production: a case study in China

Environmental problems caused by the food processing industry have always been one of the concerns for the public. Herein, for the first time, a gate-to-gate life cycle assessment (LCA) was employed to evaluate the environmental impact of rice bran oil production. Four subsystems, namely, transportation of the raw rice bran to oil factory, crude oil extraction, oil refining, and oil storage, were established. The product sustainability software GaBi and the method CML 2001-Jan. 2016 were used to calculate and analyze the environmental burdens at each stage of the rice bran oil production chain. The results show the oil refining stage had the greatest environmental impact, followed by the oil extraction stage. High demands for coal and electricity make a critical difference in generating vast majority of environmental impacts. Modifying the electricity source and replacing traditional fuels with cleaner ones will do bring benefits to the sustainable development of the industry.

Heterogeneous impacts of financial development on carbon emissions: evidence from China's provincial data

The effect of financial development on carbon emissions is a hot topic. Although some researches study the heterogeneous impacts of financial development on carbon emissions at the country level, few paper has investigated their heterogeneous relations within the same country. This paper, applying geographically and temporally weighted regression (GTWR), studies the spatial-temporal heterogeneity of the impacts of financial development on carbon emissions across China's 30 provinces from 2003 to 2017. The results show that financial development proxied by bank credit indicators curbs carbon emissions in most provinces most of the time, while that proxied by stock market indicator exhibits nonlinear relationships in most provinces, such as U-shaped, inverse U-shaped, and inverse N-shaped. The paper concludes first that financial development proxied by different indicators may exert varied impacts on carbon emissions. Second, the impact of financial development on carbon emissions shows great heterogeneity among different provinces and different years: it may be curbing or increasing, and even it is curbing, its curbing effects differ greatly across provinces and years. Third, the impact of financial development on CO2 is not always monotonic; instead, it may be nonlinear. Regional segmentation of financial markets may explain the heterogeneity. Some policy suggestions are also given.

Life cycle environmental impacts of disposable medical masks

A massive increase in the use and production of masks worldwide has been seen in the current COVID-19 pandemic, which has contributed to reducing the transmission of the virus globally. This paper aims to evaluate the life cycle environmental impacts of disposable medical masks to identify the life cycle stages that cause the highest impact on the environment. A further goal is to estimate the total environmental impacts at the global level in 2020. The inventory data was constructed directly from the industry. The system boundary of the study is from cradle to grave comprising raw material extraction and processing, production, packaging, distribution, use, and disposal as well as transport and waste management along the supply chain. Eleven environmental impacts have been estimated. The results suggest that the global warming potential of a disposable medical mask is 0.02 g CO₂-eq. for which the main contributor is the raw material supply (40.5%) followed by the packaging (30.0%) and production (15.5%). Sensitivity analysis was carried out to test the environmental impacts. In total, 52 billion disposable medical masks used worldwide consumes 22 TJ of energy in 2020. The global warming potential of disposable medical masks supplied in a year of the COVID-19 pandemic is 1.1 Mt CO₂ eq. This paper assessed the hotspots in the medical mask. The findings of this study will be of interest to policymakers, global mask manufacturers, and users, allowing them to make more informed decisions about the medical mask industry.

Place-specific product relatedness and the environmental performance of non-polluting exports in China

Does the growth of non-polluting exports lead to better environmental performance? The answer depends on how these exports rest on local comparative advantages. The more exports rely on polluting inputs, the worse their environmental performance would be. In practice, it is difficult to directly measure the polluting inputs for exporting products at the local level. This study proposes an approach to measure the reliance of exports on local polluting inputs, based on the product relatedness theories and the resource-based view of firms. This approach applies the locational quotient to indicate local resource advantages. Then, it uses the co-occurrence probability to measure the product relatedness of one export to local resource advantages. Finally, it distinguishes the product relatedness to polluting resource advantages from non-polluting ones. A higher level of polluting product relatedness is expected to depress the environmental performance of exports. Using 30 sectors in 281 Chinese cities as a case, this study applies the fixed effect model and the threshold regression model to examine the effects of product relatedness on environmental performance. Empirical results support the efficiency of using product relatedness to predict the environmental performance of exports. A higher level of polluting product relatedness leads to poorer environmental performance and more adverse effects of export growth on the environment.

Analyzing and visualizing global research trends on COVID-19 linked to sustainable development goals

This study is intended to afford a comprehensive overview of the implications of COVID-19 on progress toward achieving the sustainable development goals (SDGs) set out in the United Nations (UN) 2030 Agenda and the state of related research activities on COVID-19 linked to the SDGs. Bibliometric techniques and visual mapping are proposed as methodological tools to better approach the objectives of the present work. This includes: retrieving related publications from Scopus database, investigating the trends and growth trajectories of research works, and analyzing the scenarios post-COVID-19 either optimistic or pessimistic outlooks. The national and international contributions and collaboration toward this theme of research are further analyzed at countries, institutions, and sources levels. This analysis indicates that research works conducted on the impacts of COVID-19 on the achievement of the SDGs are still in the immaturity level. The global research productivity on this topic was just 160 documents (0.19% of total global research productivity in all fields of science with relevance to COVID-19). The implications of COVID-19 on good health and well-being, SDG-3, have attracted considerable attention. It is followed by SDG-13 that concerned with climate changes. The post-COVID-19 scenarios showed deep and justified worries in relation to achieving the SDGs by 2030. This study figures the major issues debated in the literature with respect to COVID-19 and its implications on the SDGs. The study, furthermore, attempts to assess the required actions to advance the SDGs post-COVID-19.

Construction of cleaner production management system in China: mode innovation of cleaner production

This study is based on the practice of cleaner production (CP) audits in more than 300 enterprises. After reviewing 1484 CP options, it is found that 82.5% of the options are directly and indirectly related to management. Moreover, there are common problems such as the poor sustainability of CP audit results. This shows that enterprise management plays a significant role in implementing CP options. Based on these, this study proposes a new concept of cleaner production management (CPM) system, and draws lessons from the modern environmental management theory and method to establish the framework of CPM system. This system combines the theory and method of CP with the management system of enterprises and presents the CPM requirements in the current enterprise management system, which mainly includes CPM responsibilities, CP objectives, CPM indexes, CP energy resources management, CP process control, CP product management, CPM inspections, and CP performance evaluation. The characteristic of the proposed system is to construct a modern information-based CPM system. With highly systematic, concise structure, and easy operability, this system not only simplifies and improves the CP work in enterprises and reduces several tedious tasks such as document preparation, but also enhance the enterprise management efficiency and motivate the willingness of employees to participate in CP. Innovated and developed for CP implementation, the system has been implemented and applied in Chinese enterprises, and the implementation and application have obvious effects on improving production level as well as environmental and economic benefits.

Contract farming, social trust, and cleaner production behavior: field evidence from broiler farmers in China

Pollution from livestock and poultry is the main source of rural pollution, which directly affects the rural ecological environment as well as the quality and safety of agricultural products. Based on field experiment data on broiler farmers in China, this paper analyzes farmers' cleaner production behavior from the perspective of incomplete contracts and social trust. We find that social trust can promote farmers' cleaner production behavior. Moreover, our evidence suggests that contract farming (CF) has a significant positive effect on farmers' social trust and cleaner production behaviors. Further analysis indicates that CF not only directly promotes farmers' cleaner production, but can also indirectly promote farmers' cleaner production by improving their interpersonal trust and institutional trust. Overall, this paper offers a new point of view for improving the rural environment and sheds light upon how the government can formulate relevant policies to promote farmers' cleaner production behavior.

Biostimulants decreased nitrogen leaching and NH3 volatilization but increased N2O emission from plastic-shed greenhouse vegetable soil

Biostimulant application is an effective strategy to enhance soil fertility and plant growth. However, its comprehensive impacts on nitrogen (N) uptake and reactive N (Nr) losses via leaching, ammonia (NH₃) volatilization, and nitrous oxide (N₂O) emission from plastic-shed greenhouse vegetable system are still little known. Therefore, a field experiment was conducted with cauliflower-tomato growth rotation (from September 6, 2018, to July 17, 2019) receiving three biostimulants, i.e., humic acid (HA), algae extract (AE), and chitosan (CT), as well as a control without stimulant. The cumulative Nr losses over the cauliflower-tomato growth cycle via leaching, NH₃ volatilization, and N₂O emission were 104-175 kg N ha^-1, 2.32-3.85 kg N ha^-1, and 0.70-0.85 kg N ha^-1, respectively. Biostimulant application significantly (P < 0.05) retarded the total N leaching by 17-44% in tomato season, while suppressed the NH₃ volatilization by 18-38% in cauliflower season. Overall, AE showed the best inhibition efficiency on Nr losses by significantly (P < 0.05) decreasing total N leaching and NH₃ volatilization by 36-44% and 38-52% in both vegetable seasons, compare to the control. However, all three biostimulants stimulated the N₂O emission under both vegetable cycles. Interestingly, all biostimulant-added treatments promote the cauliflower and tomato yield, particularly following the HA and AE amendments, which bring local farmers approximately 4,384-10,035 yuan RMB ha^-1 more income. Enhanced yield under biostimulant treatments was due to higher N uptake capacity and enhanced root morphology. In summary, biostimulants have a contrasting influence on three major Nr lost pathways in greenhouse vegetable production. We recommend that AE is the most optimal biostimulant as it increases vegetable yield and decreases total N leaching and NH₃ volatilization while not dramatically increase the N₂O emission.

Towards a green industry through cleaner production development

The growth in global production and consumption rates has resulted in increased pollution generation by industrial companies. To this end, cleaner production is one of the most widely used strategies to reduce the environmental impacts of industry and gain competitive advantage. However, it is still adopted slowly in many places. Therefore, the objective of this study is to propose a framework composed of governmental, scientific, and industrial strategies, policies, initiatives, and research opportunities for the development of cleaner production. The best practices of the top countries in the cleaner production technical-scientific scenario and the main implementation challenges and opportunities for its scientific development were identified and were the reference for the framework proposals. In the government sector, the framework suggests actions to encourage the adoption of cleaner production practices through national policies, legislation, tax incentives, and educational campaigns. In the scientific sector, it suggested the development of studies about the factors that motivate its adoption, studies about clean technologies, and studies about the cleaner production implementation difficulties. In the industrial sector, it highlighted the importance of the engagement of upper management to focus on efforts to increase the efficiency of manufacturing processes with the adoption of clean technologies, management systems, strengthening of the research and development areas, and replacement of hazardous raw materials. Thus, this study contributes with initiatives that will help the implementation of cleaner production practices, reducing the generation of pollution in industry, increasing the efficiency of its processes, and aligning countries and societies to sustainable development.

The impact of market factors on the development of eco-friendly energy technologies: the case of bioethanol

Global warming is emerging as the most serious concern for the planet, with greenhouse gas emissions (GHG) contributing considerably to the problem. Consequently, warranting energy sustainability has turned into an urgent issue for scholars and policy-makers alike. Bioethanol has emerged as a viable eco-friendly replacement for avoiding GHG generating fossil fuels. However, bioethanol has faced several hurdles that have discouraged its development during these years. Apart from unpractical technological applications and failed ventures, bioethanol has been experiencing heavy competition from hydrocarbon fuels and adverse economic cycles. Currently, bioethanol is facing an uncertain scenario due to the combination of climbing crop prices and slow innovative production processes, including the cost-effective utilization of agriculture waste. Here, the impact of market conditions upon the competitive development of bioethanol is analyzed. It is argued that fluctuating fossil fuel prices over the last ten years has discouraged bioethanol's technological viability. As a result, the consolidation of industrial biotechnology, especially for biorefineries, has slowed down. Policy implications of recurrent fluctuations in the bioethanol market are also discussed.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10098-021-02225-6.

Macrophytes as wastewater treatment agents: Nutrient uptake and potential of produced biomass utilization toward circular economy initiatives

Macrophytes have been widely used as agents in wastewater treatment. The involvement of plants in wastewater treatment cannot be separated from wetland utilization. As one of the green technologies in wastewater treatment plants, wetland exhibits a great performance, especially in removing nutrients from wastewater before the final discharge. It involves the use of plants and consequently produces plant biomasses as treatment byproducts. The produced plant biomasses can be utilized or converted into several valuable compounds, but related information is still limited and scattered. This review summarizes wastewater's nutrient content (macro and micronutrient) that can support plant growth and the performance of constructed wetland (CW) in performing nutrient uptake by using macrophytes as treatment agents. This paper further discusses the potential of the utilization of the produced plant biomasses as bioenergy production materials, including bioethanol, biohydrogen, biogas, and biodiesel. This paper also highlights the conversion of plant biomasses into animal feed, biochar, adsorbent, and fertilizer, which may support clean production and circular economy efforts. The presented review aims to emphasize and explore the utilization of plant biomasses and their conversion into valuable products, which may solve problems related to plant biomass handling during the adoption of CW in wastewater treatment plants.

A critical review on various feedstocks as sustainable substrates for biosurfactants production: a way towards cleaner production

The quest for a chemical surfactant substitute has been fuelled by increased environmental awareness. The benefits that biosurfactants present like biodegradability, and biocompatibility over their chemical and synthetic counterparts has contributed immensely to their popularity and use in various industries such as petrochemicals, mining, metallurgy, agrochemicals, fertilizers, beverages, cosmetics, etc. With the growing demand for biosurfactants, researchers are looking for low-cost waste materials to use them as substrates, which will lower the manufacturing costs while providing waste management services as an add-on benefit. The use of low-cost substrates will significantly reduce the cost of producing biosurfactants. This paper discusses the use of various feedstocks in the production of biosurfactants, which not only reduces the cost of waste treatment but also provides an opportunity to profit from the sale of the biosurfactant. Furthermore, it includes state-of-the-art information about employing municipal solid waste as a sustainable feedstock for biosurfactant production, which has not been simultaneously covered in many published literatures on biosurfactant production from different feedstocks. It also addresses the myriad of other issues associated with the processing of biosurfactants, as well as the methods used to address these issues and perspectives, which will move society towards cleaner production.

Lead release kinetics and film transformation of Pb-MnO2 pre-coated anode in long-term zinc electrowinning

Lead pollution precaution caused by lead-based anode corrosion is a hot and challenging issue for zinc electrowinning. A novel functional lead-based anode (MnO₂ pre-coated anode-MPA) was precisely fabricated and its long-term performances were studied compared with typical Pb-1%Ag anode (TPA). Results indicated that MPA posed excellent effects on synergistic inhibiting lead dissolution and reducing hazardous pollutants generation, and decreasing the lead content of zinc products by 81%. Further, the underlying mechanism of film growth and transformation in structure, composition and crystal phase, the migration and distribution of lead and anode slime during electrolytic, were clarified in-depth. Dynamic material flow analysis confirmed that MPA reduced the entire lead migration amount by over 92% compared with TPA. The compact multilayer structure of the MPA film and self-reparation effects of local structure provided better and persistent protection for the lead matrix, which greatly retarded the high-speed corrosion of lead anode. Compared with α-MnO₂ in TPA, the formation and maintenance of γ-MnO₂ in MPA accelerated the oxygen evolution reaction and inhibited the anode slime generation. This finding provides new insights in pollution precaution and control by designing and tuning new functional anode in hydrometallurgy process.

Process assessment, integration and optimisation: The path towards cleaner production

This contribution starts from the broad perspective of the global material cycles, analysing the main resource and pollution issues world-wide from the viewpoint of the disturbances to these cycles caused by human activities. The issues are analysed in the light of the currently developing COVID-19 pandemic with the resulting behavioural and business pattern changes. It has been revealed in the analysis of previous reviews that there is a need for a more comprehensive analysis of the resource and environmental impact contributions by industrial and urban processes, as well as product supply chains. The review discusses the recent key developments in the areas of Process Integration and Optimisation, the assessment and reduction of process environmental impacts, waste management and integration, green technologies. That is accompanied by a review of the papers in the current Virtual Special Issue of the Journal of Cleaner Production which is dedicated to the extended articles developed on the basis of the papers presented at the 22nd Conference on Process Integration for Energy Saving and Pollution Reduction. The follow-up analysis reveals significant advances in the efficiency and emission cleaning effects of key processes, as well as water/wastewater management and energy storage. The further analysis of the developments identifies several key areas for further research and development - including increases of the safety and robustness of supply networks for products and services, increase of the resources use efficiency of core production and resource conversion processes, as well as the emphasis on improved product and process design for minimising product wastage.

Product design from waste: A novel eco-efficient pyramidal microwave absorber using rice husks and medium density fibreboard residues

The sustainable future of contemporary society has been compromised due to environmental pollution from industrial systems and the generation of solid waste. Consequentially, the managed exploitation of natural resources to a sustainable level within the Earth's capacity remains a present and future challenge. Furthermore, the pursuit of materials free from toxic substances made from renewable sources is a tendency towards effective cleaner production and waste management. To address these problems, this article reports the results of exploratory and experimental research that developed a novel eco-efficient product - a pyramidal absorber of electromagnetic radiation - from rice husks and MDF (Medium Density Fibreboard) residues through design from waste principles. Key findings indicated that the technical performance of the absorber is better in the frequency of 2.45 GHz, resulting in a difference of -18.71 dB concerning the reflective metal plate used in the tests. This result is above the expected limit of -10 dB found in similar commercial products. This study is an innovation in improving the design from waste of pyramidal microwave absorbers used in radio frequency anechoic chambers. The product represents a new and sustainable alternative to similar products in the market that are produced from toxic materials extracted from non-renewable raw materials. The limitations and technical characteristics of usage for which the pyramidal absorbers of electromagnetic radiation are applicable should be considered.

'Unlocking circular economy for prevention of marine plastic pollution: An exploration of G20 policy and initiatives'

Marine plastic pollution (MPP) is an urgent environmental and socio-economic problem. MPP amounts to 300 million tons annually, originates largely from land-based sources and severely impacts marine ecosystem, harms livelihoods and causes costs for businesses and governments. Plastics permeate the whole width and depth of seas and oceans, near well-developed coastal zones and equally in remotest corners. This undermines economic and social value of the oceans, particularly in terms of fisheries productivity and tourism. The G20 members, responsible for about two-thirds of global plastic waste, recognize the problem and undertake preventive measures - individually and collectively. Yet, are there efficient, effective and sufficient given the urgency of MPP and the contribution of G20 countries. This article highlights existing policies and identifies further policy options using a custom framework for MPP policy that merges Circular Economy (CE) and life-cycle perspectives.

Green textile production: a chemical minimization and substitution study in a woolen fabric production

This study aimed to decrease chemical costs and increase productivity and environmental performance by applying various practices for chemical minimization and substitution in an integrated textile mill producing woolen textile fabric. Detailed on-site process investigations and data collection studies were carried out in the mill. Process-based specific auxiliary chemical and dyestuff consumptions were calculated. Process and composite wastewater samples were collected at different periods and analyzed. The chemical loads of wastewaters were also calculated. The specific dyestuff and auxiliary chemical consumptions of the mill were compared with the data of a similar textile mill in the literature and the Integrated Pollution Prevention and Control (IPPC), Textile Best Available Techniques Reference (BREF) document. Thus, the chemical saving potential of the mill was evaluated. A detailed chemical inventory study was also carried out in the mill. The material safety data sheets (MSDSs) of 371 chemicals were examined in terms of biodegradation ratio, toxicity, and micropollutant content. As a result, 23 chemicals were proposed to be replaced with environmentally friendly substitutes. A total of 10 minimization and substitution practices were identified for the mill according to the investigation and analysis results. After the implementation of the suggested practices, reductions of 15-32 and 13-37% are estimated to be achieved in total chemical consumption and chemical oxygen demand (COD) load of wastewater, respectively. The potential payback periods of the suggested practices were calculated to range between 4 and 36 months. The employed methodology and the findings of this study may be useful for similar textile mills, stakeholders, and regulators. This study may also provide a road map to the textile industry for their sustainable and green production applications.

Recent developments on alternative fuels, energy and environment for sustainability

Enhancing energy and environmental systems through sustainable development, in particular integrating concepts of circular economy and cleaner production are important for the emerging needs of humankind. In recent years, the developments in alternative sources of renewable energy counterparts has been prompted to substitute the nonrenewable fossil fuel consumptions towards clearner environment. However, environmental problems arising currently must be carefully addressed and to be solved to conserve the energy, water and other environmental resources for the future. This article highlights the recent developments on alternative energy sources that mainly focus on energy and environmental sustainability, that has been discussed on "The 4th International Conference on Alternative Fuels & Energy (ICAFE-2019)", which was held at Taichung City, Taiwan on October 18-21, 2019. Additionally, it provides useful insights from some of the papers published on a virtual special issue (VSI) of the Bioresourse Technology Journal. The highlighted research works in this review can be used as route-map towards sustainable development and energy efficiency.

Sustainability in the dairy industry: a systematic literature review

The dairy industry can contribute to global food security in a sustainable way by efficiently converting milk into dairy ingredients and products, even though they are polluting on a large scale. In this context, this study aimed to conduct a systematic literature review on sustainable indicators and dairy industries. The methodology used has a qualitative and quantitative approach and its technical procedure was the systematic literature review. The bases of journals consulted, using the keywords "sustainability indicator" and "dairy industry" which resulted in 130 valid scientific articles. The main results show that the sustainability indicators in the dairy industry are emerging and lacking research; being found seven papers, that highlight 12 indicators of the environmental, 11 of the social and eight economic dimensions, that may be considered fragile and initial. The studied problems are related to wastewater treatment methods, electric power consumption, efficiency of the industrial plant, among others, and the benefits on the theme are related to solutions to the difficulties, such as electricity reduction, sustainable practices. Among others, it is concluded that the dairy industries address the sustainability theme since 2011, with an ambiguous trend, being found evidence of the fragility of the sustainability indicators was found, mainly in the initial stage of their conception, when considering holistic approach (triple bottom line).

Synthesis and characterization of reduced graphene oxide using the aqueous extract of Eclipta prostrata

In this study, biological deoxygenation of graphene oxide (GO) using an Eclipta prostrata phytoextract was performed via the infusion method. The presence of oxide groups on the surface of graphene and removal of oxides groups by reduction were characterized through morphological and structural analyses. Field emission scanning electron microscopy images revealed that the synthesized GO and rGO were smooth and morphologically sound. Transmission electron microscopy images showed rGO developing lattice fringes with smooth edges and transparent sheets. Atomic force microscopy images showed an increase in the surface roughness of graphite oxide (14.29 nm) compared with that of graphite (1.784 nm) due to the presence of oxide groups after oxidation, and the restoration of surface roughness to 2.051 nm upon reduction. Energy dispersive X-ray analysis indicated a difference in the carbon/oxygen ratio between GO (1.90) and rGO (2.70). Fourier-transform infrared spectroscopy spectrum revealed peak stretches at 1029, 1388, 1578, and 1630 cm^-1 for GO, and a decrease in the peak intensity after reduction that confirmed the removal of oxide groups. X-ray photoelectron microscopy also showed a decrease in the intensity of oxygen peak after reduction. In addition, thermogravimetric analysis suggested that rGO was less thermally stable than graphite, graphite oxide, and GO, with rGO decomposing after heating at temperatures ranging from room temperature to 600 °C.

Coupling life cycle assessment with scenario analysis for sustainable management of Disperse blue 60

Sustainable management of dyeing industry is of paramount importance in order to minimize resource consumption and reduce related environmental impacts. Herein, an environmental study is conducted wherein life cycle assessment (LCA) is applied to a two-scenario process for Disperse blue 60 production with short and long processing chains with different (a) material types, (b) consumptions, (c) processes, and (d) functional units with yields of 300 t/a. The most important influenced substances of the two scenarios were sodium cyanide and electricity next. Results proved that the largest damage of the dye production was attributed to resources and reached 46 and 62 kPt in the two scenarios. Compared with the conventional coal-fired power generation, damaged values of electricity from nature gas (NG) could reduce from 102 to 86 kPt in scenarios 1 and from 123 to 104 kPt in scenarios 2, respectively. When the electricity switched from NG to solar power, the values of the two scenarios could further decrease by 17 and 27 kPt, respectively. Therefore, the process of scenario 1 with the short process chain was more environmentally friendly for the production of Disperse blue 60 owing to the more efficient process and lower resource consumption. Graphic abstract.

Wastewater from leather tanning and processing in Palestine: Characterization and management aspects

Leather manufacturing industry has major environmental impacts. Characterization of tannery's wastewater (WW) is a key step in the management of wastewater released from various processes. This study presents some physicochemical characteristics measured in wastewater. It compares the pollution loads released from both goat and cow hides processing. The main pollution characteristics of wastewater released from two local tanneries were determined experimentally, through analyzing real samples of industrial discharges. These include chemical oxygen demand (COD), total solids (TS), total dissolved solids (TDS), total suspended solids (TSS), pH, and the concentrations of chloride, ammonia (NH₃) and chromium in both states, Cr (III) and Cr (VI). Characterization of such processes effluents assists in identifying waste generation rates and discharges, and then in recommending cleaner production options. The results shows that the amount of WW produced in the local Palestinian tanneries is much lower than tanneries worldwide, whereas it is more concentrated with pollutants. Liming process has the highest COD and the highest pH value, where tanning process releases WW highly concentrated with chromium. Real process measurements and mass balance calculations indicated that the chromium uptake efficiency is only 46.6%. Such a low efficiency indicates that cleaner production measures are essential in local tanneries.

Development of novel hydrophilic ionic liquid membranes for the recovery of biobutanol through pervaporation

This paper aims to develop novel hydrophilic ionic liquid membranes using pervaporation for the recovery of biobutanol. Multiple polyvinyl alcohol (PVA) membranes based on three commercial ionic liquids with different loading were prepared for various experimental trials. The ionic liquids selected for the study include tributyl (tetradecyl) phosphonium chloride ([TBTDP][Cl]), tetrabutyl phosphonium bromide ([TBP][Br]) and tributyl methyl phosphonium methylsulphate ([TBMP][MS]). The synthesized membranes were characterized and tested in a custom-built pervaporation set-up. All ionic liquid membranes showed better results with total flux of 1.58 kg/m²h, 1.43 kg/m²h, 1.38 kg/m²h at 30% loading of [TBP][Br], [TBMP][MS] and [TBTDP][Cl] respectively. The comparison of ionic liquid membranes revealed that by incorporating [TBMP]MS to PVA matrix resulted in a maximum separation factor of 147 at 30 wt% loading combined with a relatively higher total flux of 1.43 kg/m²h. Density functional theory (DFT) calculations were also carried out to evaluate the experimental observations along with theoretical studies. The improved permeation properties make these phosphonium based ionic liquid a promising additive in PVA matrix for butanol-water separation under varying temperature conditions.

Pollution estimation from olive mills wastewater in Jordan

Olive mill wastewaters (OMWWs) are a significant source of environmental pollution, especially in important olive oil producing countries such as Spain, Greece, Syria, Jordan and other countries in the Mediterranean. Due to cost issue no treatments plants are currently available at the mills; therefore, OMWW is normally discharged into the environment causing serious environmental problems such as: coloring and pollution of surface and ground waters, soil surface, and foul odors problems. Approximately 209,000 tons of olives have been processed in Jordan in 2017, which generated 175,000 m³ of OMWWs. They generated rougly 3,069 tons of BOD₅, 7,956 tons of COD, 149 tons of residual olive oil, 2.07 tons of phenols, 3,753 ton total suspended solids and 4.2 ton of phosphorous. The OMWW is rich in organic matter expressed as BOD₅ and COD with COD/BOD₅ of 2.6 indicated that OMWWs is not suitable for biological treatment and therefore must be treated before discharge to the environment or sewer system. Cleaner production options and proper environmental waste management systems at the mills are needed to reduce their environmental impact. This may include the adoption of the two-phase mills to reduce water use to less than half the quantities used in traditional and three phases mills.

A bibliometric and network analysis of Lean and Clean(er) production research (1990/2017)

In recent years, the renewed interest in environmental issues has gradually required manufacturers to simultaneously pursue a more rational use of resources and a reduction in wastes production. New strategies, technologies and organisational innovations must be therefore conceived to "create more value with less impact" (WBCSD, 2010). An interesting and promising perspective for achieving internal efficiency, market effectiveness and environmental eco-efficiency is that of integrating the environmental variable in the Lean Production (LP) paradigm. Scholars and practitioners have been working for some years in this direction of eco-innovation. The present article aims at obtaining a quali/quantitative overview of Lean and Clean(er) production (L&C) research through a bibliometric and network analysis, by using a scientific literature database; in particular, it investigates how Clean(er) Production research and publications are progressively embedded in the field of LP, what are the main topics in this sub-field and common research themes. A comprehensive picture was made by analysing data concerning publications, authors, affiliations, and the countries of origin. Evolutionary profiles, major topics investigated, leading authors and collaborations have been reported. The results also reveal promising spaces for the development of L&C production research, in order to achieve economic and environmental benefits.

What determines compliance with cleaner production? An appraisal of the tanning industry in Sialkot, Pakistan

Leather tanneries which produce significant amounts of solid waste, effluents, and emissions are a major contributor to industrial waste. A cleaner production program was launched by the government of Pakistan to implement the cleaner production measures for tanneries of Sialkot from 1999 to 2005. The main objective of this study is to identify the impact of a cleaner production program, along with other determinants of a cleaner production in the leather industry. The study analyses firm-level primary data collected from leather tanneries in Sialkot. The primary data were collected from tanneries in Sialkot. The econometric analysis is conducted using the Poisson regression analysis. Overall results show that there is no significant impact of cleaner production in 2015, while the panel data results indicate that the effect of cleaner production support by CPC on cleaner production practices diminished once the support came to an end. The other main factor is firm size, which indicates the financial position of the firm; international and regulator pressures are major determinants of the adoption of cleaner production measures. The analysis also indicates that there is higher probability of large firms adopting a cleaner production in comparison with small ones. Export orientation of firms is another important determinant of cleaner production. The enforcement of the environment compliance laws also has positive effect. The compliance with cleaner production measures is quite low, at 6.4 out of 19 cleaner production practice measures. There is a need to adopt measures that are environmentally friendly and are favorable towards both labor health and product quality, which are important for the sustainable growth of the tanning industry.

Recovery of tailings from the vanadium extraction process by carbothermic reduction method: Thermodynamic, experimental and hazardous potential assessment

A cleaner process is tremendously required to deal with the vanadium tailings, which may cause serious environmental problem due to the high content of water soluble hazardous elements such as V and Cr. This problem can be possibly solved by proposed high temperature reduction-magnetic separation process, in which, V, Cr and Fe can be recycled as ferroalloy. The thermodynamic calculation results reveal that a higher temperature (>1127.8 °C) promotes the reduction of Fe, V and Cr, and improves the recovery rates of V and Cr in liquid iron. The reduction behavior of vanadium tailings was investigated using XRD, TG/DSC, SEM, EDS and ICP-OES techniques. The EDS results show that a small portion of V was remained in the slag phase when roasted at 1300 °C, while nearly all of V and Cr can concentrate in ferroalloy at 1400 °C. Approximatly 90% of V and 95% of Cr recovery in magnetic fraction can be obtained for the magnetic separation step. A small portion of V and Cr is remained in the non-magnetic final tailings, however, the hazardous potential assessments results indicate that such kind of tailings can safely use as secondary materials or stockpiled as an end-waste.

Green remediation of contaminated sediment by stabilization/solidification with industrial by-products and CO2 utilization

Navigational dredging is an excavation of marine/freshwater sediment to maintain channels of sufficient depth for shipping safety. Due to historical inputs of anthropogenic contaminants, sediments are often contaminated by metals/metalloids, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and other contaminants. Its disposal can present significant environmental and financial burdens. This study developed a novel and green remediation method for contaminated sediment using stabilization/solidification with calcium-rich/low-calcium industrial by-products and CO₂ utilization. The hydration products were evaluated by quantitative X-ray diffraction analysis and thermogravimetric analysis. The incorporation of calcium carbide residue (CCR) facilitated hydration reaction and provided relatively high 7-d strength. In contrast, the addition of Class-F pulverized fly ash (PFA) and ground granulated blast furnace slag (GGBS) was beneficial to the 28-d strength development due to supplementary pozzolanic and hydration reactions. The employment of 1-d CO₂ curing was found to promote strength development (98%) and carbon sequestration (4.3wt%), while additional 7-d air curing facilitated cement rehydration and further carbonation in the sediment blocks. The leachability tests indicated that all studied binders, especially CCR binder, effectively immobilized contaminants in the sediments. The calcium-rich CCR and GGBS were regarded as promising candidates for augmenting the efficacy of CO₂ curing, whereas GGBS samples could be applicable as eco-paving blocks in view of their superior 28-d strength. This study presents a new and sustainable way to transform contaminated sediment into value-added materials.

Analysis of the best available techniques for wastewaters from a denim manufacturing textile mill

The present study was undertaken as the first plant scale application and evaluation of Best Available Techniques (BAT) within the context of the Integrated Pollution Prevention and Control/Industrial Emissions Directive to a textile mill in Turkey. A "best practice example" was developed for the textile sector; and within this context, BAT requirements for one of the World's leading denim manufacturing textile mills were determined. In order to achieve a sustainable wastewater management; firstly, a detailed wastewater characterization study was conducted and the possible candidate wastewaters to be reused within the mill were identified. A wastewater management strategy was adopted to investigate the possible reuse opportunities for the dyeing and finishing process wastewaters along with the composite mill effluent. In line with this strategy, production processes were analysed in depth in accordance with the BAT Reference Document not only to treat the generated wastewaters for their possible reuse, but also to reduce the amount of water consumed and wastewater generated. As a result, several applicable BAT options and strategies were determined such as reuse of dyeing wastewaters after treatment, recovery of caustic from alkaline finishing wastewaters, reuse of biologically treated composite mill effluent after membrane processes, minimization of wash water consumption in the water softening plant, reuse of concentrate stream from reverse osmosis plant, reducing water consumption by adoption of counter-current washing in the dyeing and finishing processes. The adoption of the selected in-process BAT options for the minimization of water use provided a 30% reduction in the total specific water consumption of the mill. The treatability studies adopted for both segregated and composite wastewaters indicated that nanofiltration is satisfactory in meeting the reuse criteria for all the wastewater streams considered.

Multistage utilization process for the gradient-recovery of V, Fe, and Ti from vanadium-bearing converter slag

A multistage utilization process was developed to fully recover valuable metals from vanadium-bearing converter slag and reduce the content of hazardous elements, such as vanadium and chromium, in the tailings. A mechanical activation-calcification roasting-acid leaching process was firstly employed to recover vanadium. This process generated two products, viz. a V-bearing solution accounting for ∼95% V recovery and vanadium tailings with Fe and Ti contents of 31.85% and 8.94%, respectively. Then, based on theoretical calculations and physical measurements, a coal-based direct reduction-magnetic separation process and a hydrochloric acid leaching process were employed for the stepwise recovery of iron and titanium, respectively, from the vanadium tailings. Iron was recovered in the form of high chromium-vanadium iron with 81.53% Fe, 1.31% Cr, and 2.04% V, and titanium was recovered as titanium dioxide pigment with 85-90% yield. Such a comprehensive and clean utilization of vanadium-bearing converter slag has great potential for practical application.

Temporal and spatial characteristics of lead emissions from the lead-acid battery manufacturing industry in China

An inventory of lead emissions was established for the lead-acid battery (LAB) manufacturing industry in China from 2000 to 2014. The lead emissions from the LAB manufacturing industry increased from 133 t in 2000 to a peak at 281 t in 2010 with the rapid development of LAB industry. Since 2011, a mandatory national clean action on LAB industry and a series of retrofitting measures have been implemented in China. As a result, more than 80% of small and low-efficient LAB manufacturers were closed, and technical-environmental performance of the industry has been improved significantly. Thus the lead emissions from the industry declined to 113 t in 2014. Geographically, lead emissions were attributed to several provinces with intensive LAB manufacturers, including Zhejiang, Guangdong, Jiangsu, Shandong, and Hebei Province. Spatial transfer of the LAB manufacturing industry from developed areas to developing areas in China was manifest due to strict environmental regulation, posing potential environmental risks to the areas undertaking the industry transfer. In light of the effectiveness of the national clean action, the LAB manufacturing industry will reduce lead emissions further by implementing the entry criteria strictly, adopting policy of total lead emissions control, and establishing a long-term regulatory mechanism for LAB manufacturers. The local authorities in some developing areas should improve abilities of environmental supervision and environmental risk prevention to deal with the spillover of lead emissions.

How China achieved its 11th Five-Year Plan emissions reduction target: A structural decomposition analysis of industrial SO2 and chemical oxygen demand

To curb the increasing pollutant emissions that have accompanied rapid economic growth, China implemented a mandatory emissions control system since the 11th Five-Year Plan (FYP) period, and the emission reduction targets have been met and even exceeded. This article explores how China achieved its emissions reduction targets by systematically identifying the main emission reduction pathways, including both the environmental and economic factors, and evaluates the contribution of each factor using structure decomposition analysis. A study of the two key controlled pollutants, industrial sulfur dioxide (SO₂) and chemical oxygen demand (COD), during the 11th FYP period showed that (i) changes in the end-of-pipe treatment and pollutant generation coefficient were the dominant contributors to emissions reduction. The power and metal smelting sectors played important roles in SO₂ abatement, while the paper products and food products sectors were important in COD reduction; (ii) changes to the input coefficient increased overall emissions although there was a decrease in SO₂ emissions in 2007-2010 mainly due to input structure improvements in the construction sector; (iii) the trade effect largely offset the domestic emission reduction effects, although the trade effect declined during the study period; (iv) domestic demand was the main factor increasing domestic emissions; domestic investment changes (especially in the construction sector) were the major contributor to increases in SO₂ emissions, and final consumption changes (especially consumption in the food production sector) were the main contributor to the increase in COD emissions. The results yield important implications for China's pollution emissions control policies.

Wright (DZW)

A novel method utilizing microbial treatment for cleaner production of diosgenin from Dioscorea zingiberensis C.H. Wright (DZW) was presented. A new Bacillus pumilus HR19, which has the great ability to secrete pectinase, was screened and applied in the microbial treatment. Low-pressure steam expansion pretreatment (LSEP) was employed in advance to assist microbial treatment efficiently in releasing saponins, which are the precursors of diosgenin. Compared with the traditional process of acid hydrolysis, this novel process reduced the consumptions of water, acid and organic solvent by more than 92.5%, 97.0%, 97.0%, respectively, while simultaneously increasing the diosgenin yield by 6.21%. In addition, the microbial treatment was more efficient than enzymatic treatment, which arised from that microorganisms could be induced to secrete related enzymes by the compositions of DZW and relieve product inhibition by utilizing enzyme hydrolysates.