Search

The North China Plain (NCP) serves as a crucial production base for wheat and maize in China. However, the intensive winter wheat-summer maize (WM) cropping system has also led to high carbon emissions. It is imperative to optimize crop rotations to reduce greenhouse gas (GHG) emissions while ensuring food security. Thus, we conducted a 6-year field experiment in the NCP to evaluate the productivity, carbon footprint (CF), and sustainability of the five rotation systems. These included four 2-year rotation systems: spring maize → WM (WMME), spring millet → WM (WMML), spring peanut → WM (WMMP), and spring soybean→ WM (WMMS), with WM serving as the control. Our results indicated that the 2-year rotation systems significantly reduced GHG emissions and improved agricultural sustainability. Wheat yield following the spring crops was 38.6%–47.5% higher than that following summer maize. The energy use efficiency, energy productivity, maize economic equivalent yield (MEEY), and net income in WMMP were higher by 9.7%, 51.8%, 4.4%, and 15.5%, respectively, compared to WM. This was mainly attributed to the high yield, price, energy equivalent coefficient, and pre-crop effect of spring peanut. The reduction of N and electricity inputs in the 2-year rotation systems reduced on-farm N 2 O emissions and indirect emissions by 39.0%–56.2% and 41.9%–42.9%, respectively, thus lowering CF per unit area by 25.7%–36.6% compared with WM. WMMP demonstrated a 38.2% reduction in CF per kg MEEY, 16.1% reduction in CF per unit net energy, and 44.1% reduction in CF per unit net income, while increasing the sustainable evaluation index by 42.9% compared to WM. In conclusion, the 2-year rotation systems can reduce carbon footprint and improve agricultural sustainability in the NCP, among which the introduction of spring peanut into winter wheat-summer maize rotation can simultaneously enhance system productivity. [Display omitted] • Productivity and carbon footprint of five rotation systems were evaluated. • The 2-year rotations reduced GHG emissions and enhanced system sustainability. • Provide options for sustainable production via optimized rotations in the NCP. [ABSTRACT FROM AUTHOR]

Ships are considered important contributors to air pollution and have seriously health impact globally. Although many researchers have carried out studies on emission factors (EFs) in recent years, studies covering various types of ships are rare and the chemical characteristics of particulate matter (PM) emitted by them are unclear. Due to the diversity of different national fleets, the current emission inventory in China established by citing foreign EFs will lead to inaccurate calculation results and generate large uncertainty. In this study, the EFs for ocean-going, harbour, offshore and inland vessels were measured by the portable emission measurement system (PEMS). The specific compositions of PM were analyzed, including carbonaceous components, water-soluble ions (WSI), elements, and polycyclic aromatic hydrocarbons (PAHs). Combined with localized EFs, the ship emission inventory of Qingdao Port was established based on Automatic Identification System (AIS) data. The results show nitrogen oxide (NOx) is the primary pollutant discharged by all ships, followed by sulfur dioxide (SO 2). The emissions of SO 2 and PM from inland and offshore vessels fueled with high sulfur fuel (HSF) are significantly higher than other ships. Carbonaceous components accounted for 43.4%–53.9% of the total mass of PM, WSI accounted for 9.8%–14.3%, and elements accounted for 16.5%–28.6%. Although the use of low sulfur fuel (LSF) has reduced the emission of V and Ni from ships, it could still be treated as tracer elements of ship emissions. The annual emissions of SO 2 , NO X , PM 2.5 , THC and CO from ships in Qingdao port in 2020 were 9728.5, 38503.9, 1424.9, 1331.5 and 2440.4 tons, respectively. The ship emission inventory established based on EPA-recommended EFs resulted in underestimating approximately 16.8% of ship pollutants, especially for SO 2 and PM. Ocean-going ships and offshore vessels are major emitters in the study waters. This study is hoped to provide a valuable reference for the further regulation and policy formulation of ship emissions in China. [Display omitted] • On-board measurements were carried out on typical ships by PEMS. • EFs for gas pollutants and particle components of various vessel types are provided. • Fuel types have a significant impact on the particulate fraction of ships. • It reveals the current emissions from Chinese ships may be underestimated. • Approximately 16.8% of ship emissions in Qingdao Port are undervalued in 2020. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the issue of remanufacturing in a dual-channel supply chain. The manufacturer can produce/remanufacture the products and sell them at the same price through his own direct channel or a retail channel. Based on the cap-and-trade regulation, we construct two models with and without remanufacturing to obtain the optimal levels of carbon emission reduction and pricing strategies. The results indicate that remanufacturing can effectively improve the level of carbon emission reduction, and it is profitable to the manufacturer and the retailer. Furthermore, with remanufacturing, we investigate the effect of product promotion where the manufacturer can promote via direct channel (manufacturer's promotion), and the retailer can promote via retail channel (retailer's promotion). With the manufacturer's promotion, the results show that both the level of carbon emission reduction and profit of the manufacturer increase, but the retailer's profit decreases. On the other hand, the retailer's promotion can improve the profits of the retailer and the manufacturer when more consumers prefer the retail channel. Finally, we provide more managerial insights in the sensitivity analysis and extension parts. [ABSTRACT FROM AUTHOR]

Environmental pollution has become a major threat to the survival and health of human beings, and has attracted the worldwide attention. With the implementation of low-carbon policies, how to change marketing strategy is a realistic and serious problem of enterprises. This paper examines the manufacturer's channel selection and emission reduction decisions when considering carbon emission constraints. A two-echelon supply chain consisting of one manufacturer and one retailer under the cap-and-trade regulation is explored. Non-perishable products' and perishable products' carbon emissions are distinguished according to their sales channels. The results provide useful insights for supply chain members. Firstly, the results show that products' properties and consumers' channel preference are key factors affecting manufacturer's channel selection. When consumers prefer online shopping, the manufacturer, who produces perishable/non-perishable products, should choose single online channel structure to maximize his profit. But, this choice cannot make as same contributions to the environment if the manufacturer produces perishable product as that under retail channel. Secondly, the results demonstrated that under cap-and-trade regulation, the channel conflict appears to have abated somewhat. The retailer can accommodate the additional online channel under certain conditions. Additionally, numerical results further illustrate the following insights from the respective of the government: It is more effective to set larger carbon quotas and encourage the manufacturer to develop a dual-channel mode when not too many consumers prefer to online channel. With more and more consumers preferring to online shopping, it can formulate more stringent emission control. [ABSTRACT FROM AUTHOR]

Literature of cleaner production demonstrates that the conduction of pro-environmental behaviour individually at work contributes to the improvement of an organisation's environmental performance. However, employees' intentions to engage in pro-environmental behaviour are susceptible to their perceived ethicality towards organisational behaviours, such as workplace green initiatives. An ongoing issue is that whether symbolic motives, particularly, the competitiveness motive, to PEB is perceived ethical by employees to perform at the workplace context. With a specific focus on that matter, this study aims to examine employees' perceived ethicality of promoting workplace energy conservation based on a competitiveness (motivational) message as an intervention initiated by the organisation. Results from survey data (N = 200) indicate that promoting workplace energy conservation through a competitiveness message leads to a lower perceived ethicality of message than via a control message. Also, the competitiveness message did not significantly affect employees' behavioural intention towards workplace energy conservation. Notably, employees' attitude towards message significantly affected their workplace energy conservation intention. [Display omitted] • The competitiveness motivational message leads to a lower perceived ethicality of message than via a control message. • The competitiveness motivational message did not significantly affect employees' behavioural intention. • Employees' attitude towards message significantly affected their workplace energy conservation intention. [ABSTRACT FROM AUTHOR]

As the largest container port in northern China, the prosperous maritime trade has not only promoted the economic development of Qingdao port but also brought serious pollution to the air quality. Ship emissions have caused a significant influence on public health. The establishment of the Domestic Emission Control Area (DECA) is a key policy to reduce ship emissions in recent years. It has been implemented in Qingdao Port from January 1, 2019. To evaluate the environmental benefits of the DECA policy, this study established a bottom-up ship emission inventory in 2020 for Qingdao based on Automatic Identification System (AIS) data. Changes in ship emissions and their impact on air quality in Qingdao are evaluated for the same study area before and after the implementation of DECA policy. The total emissions in all study area for SO 2 , NO X , PM 10 , PM 2.5 , HC and CO in 2020 are 8.16 × 103, 3.31 × 104, 1.25 × 103, 1.15 × 103, 1.18 × 103, 2.15 × 103 tons (t), respectively, reductions of 67.9%, 15.4%, 63.2%, 62.9%, 27.2% and 23.2% compared with 2016, and reductions of 73.42%, 29.97%, 69.54%, 69.26%, 39.71%, 36.44% compared with the scenario without DECA in 2020. The inter-month change and spatial distribution of ship emissions are similar in both years. Shinan District, Shibei District and Huangdao District are most affected by ship emissions, with the largest influence in summer. The ship's contribution to air pollution in each area had been significantly reduced, especially for SO 2 and PM after DECA policy. However, the emission reduction of other pollutants is limited, so it is necessary to further enhance the DECA policy. Our research aims to conduct a comprehensive assessment of the environmental benefits for DECA policy, and provide support for the further improvement of the subsequent measures. [Display omitted] • High spatiotemporal resolution ship emission inventory for Qingdao in 2020 is updated. • Total ship emission in Qingdao during 2020 was 46,965.7 tons, 37.7% lower than 2016. • More than 50% of ship pollutants occur within the baseline of territorial sea. • Ship emissions in summer have the most significant impact on urban air quality. • DECA policy has reduced ship emission of SO 2 by 73.4% and PM 2.5 by 69.5%. [ABSTRACT FROM AUTHOR]

This study explores choice of technology for sustainable operations in a port supply chain that consists of one port and one shipping company under a cap-and-trade scheme. To control emissions, the port supply chain can implement either shore power (SP) or low sulfur fuel oil (LSFO). The performances of the port supply chain when either SP or LSFO is adopted are compared in this paper. More specifically, according to relative bargaining power between the port and the shipping company, three different game models are constructed to analyze the effects of channel power on equilibrium results when either SP or LSFO is implemented. Results show that both profits and carbon emissions of supply chain using SP are lower than those using LSFO when carbon price is low, but are higher when carbon price is high. However, from the perspective of the social welfare, when both the carbon price and environmental concern are low, or both the carbon price and environmental concern are high, LSFO should be adopted. Otherwise, SP may be more attractive. Compared with the two Stackelberg games, the Nash game leads to higher profits and less emissions. The Nash game also leads to higher social welfare when environmental concern is small, but lower social welfare when environmental concern is large. These findings can provide insights for governments in formulating emission reduction strategies in port supply chain under different scenarios. • Two specific carbon-reduction technologies are considered in a port supply chain. • The power structure of a port supply chain affects total emissions. • Carbon price and environmental concern significantly affect technology choice. • Nash game leads to higher profits and less emissions. [ABSTRACT FROM AUTHOR]

Abstract Willingness to pay (WTP) for clean air is one of the most important indicators of the public's acceptance of air pollution mitigation policies. However, few studies have characterized the spatial distribution of WTP, explored its "hypothetical bias", or analyzed its relationship with air pollutant concentrations. To address this gap in knowledge, a nationwide empirical study (N = 9744) was conducted from December 2016 to February 2017 in China. The contingent valuation method (CVM) was adopted to assess WTP based on a scenario, and air purifier costs (APCs) incurred by the public were used as an indicator of WTP in the real-life scenario. The results show that the mean value of APCs (243.81 CNY (year ⋅ person) − 1 ) is lower than WTP (275.39 CNY (year ⋅ person) − 1 ), which means that the Chinese public may not pay as much money for clean air in the actual scenario as in the WTP scenario. This result is important for predicting and evaluating the feasibility and effectiveness of air pollution economic policies. We also observed significant spatial differences in APCs: the public in more heavily polluted areas such as the eastern coastal region, northern coastal region, Middle Yellow River region and northeast region have higher APCs than the public in other regions, the proportion of people who purchased air purifiers and the distribution of APCs positively correlated with concentrations of particulate matter with aerodynamic diameters less than 2.5 (PM 2.5), nitrogen dioxide (NO 2), carbon monoxide (CO), and ozone (O 3), while no significant spatial difference or correlation relationship was observed for WTP. This result indicates that pollutant concentration is not the main driving factor of WTP but they are driving factors for APCs, which may provide new evidence for the driving factors of WTP and APCs. Finally, the policy implications behind these results are discussed, providing references and scientific support for policy makers and subsequent research. Graphical abstract Image 1 Highlights • The spatial distribution of WTP and APCs for clean air are demonstrated. • APCs has significant spatial differences, while WTP does not. • WTP is higher than APCs, indicating the existence of "hypothesis bias". • APCs is correlated with air pollutant concentrations, while WTP is not. • Potential environmental policy implications are discussed. [ABSTRACT FROM AUTHOR]

The reduction of carbon emission has become an inevitable trend and a world-wide consensus. Under the low-carbon environment, it is an important task for supply chain members to reduce carbon emissions through low-carbon progressing. This paper focuses on the emission reduction behaviors for the chain members in both the retail-channel and dual-channel cases using the Stackelberg game model. The paper analyzes a detailed model which incorporates both cap-and-trade regulation and consumers' low-carbon preference. The results suggest that when the degree of consumers' low-carbon sensitivity satisfies certain conditions, the introduction of the online channel is profitable for the manufacturer. In addition, the cap-and-trade mechanism is acceptable for supply chain members when consumers have strong low-carbon preference. Furthermore, two emission reduction strategies are compared, including single manufacturer's emission reduction in production strategy and joint emission reduction strategy, of which entails manufacturer's and retailer's emission reduction. It can be concluded that the joint emission reduction strategy is more profitable for both the manufacturer and the retailer. When considering consumers' low-carbon preference, the retailer always has motivation to implement low-carbon promotion though without the manufacturer's incentives. The low-carbon promotion can help achieve emission reduction goals, promote economic development and social progress. The results can provide useful insights for policy-makers to implement effective regulations and for decision-makers to implement sustainability initiatives. [ABSTRACT FROM AUTHOR]

Water quality assessment is a crucial step in water resource management and pollution prevention, and is essential for achieving sustainable development. Current methods for evaluating water quality often fall short of meeting the needs of water resource management due to the lacks of accuracy and applicability. In this paper, an enhanced water quality evaluation system was established by Principal Component Analysis / Factor Analysis (PCA/FA), Analytic Hierarchy Process / Entropy Weight Method / Game Theory (AHP/EWM/GT) and Variable Fuzzy Set Theory (VFST). The accuracy of this method was verified by evaluating the water quality of a landfill in a karst area and comparing with the conventional evaluation models. The results indicated that the highest influence on groundwater quality in the study area came from human factor, dissolved solid factor, biological factor, and nutritional factor. The quality of surface water and groundwater in the study area was primarily Grade Ⅱ, accounting for 62.5% and 75%, respectively. The predominant groundwater type was HCO 3 -Ca·Mg, which was strongly affected by karstification. The NH 3 -N and TP in the surface water had the highest variability, and the variation coefficients of K+, Na+, Ca2+, Cl−, NH 3 -N, NO 3 −, TDS, and TH in the groundwater were greater than 1. The surface water quality gradually improved between 2018 and 2019. Overall, the groundwater quality in the southern and central regions was inferior to that in the northern and surrounding areas. There could be a hydraulic link between the surface water and landfill in the research location, while karstification and leachate primarily impacted the groundwater. The water quality evaluation method established in this study can make a significant contribution to water resource management, which has important practical significance for environmental protection and indirect social value to the public. [Display omitted] • PCA/FA is used to reduce the dimension and determine the evaluation index. • The comprehensive weight is obtained by GT coupling AHP and EWM. • An improved VFST water quality evaluation model is established and verified. • The hydrochemical features and water-quality temporospatial variation are analyzed. [ABSTRACT FROM AUTHOR]

The vast hydrocarbon resources (oil, gas, and gas hydrate) in deepwater areas are considered one of the most significant resources of the future. However, the dangerous flow patterns and blockage accidents caused by hydrates threaten the safety and efficiency of the transportation process. A mutual interaction exists between hydrate growth and multiphase flow. In this study, hydrate formation and gas–slurry two–phase flow tests were conducted in a pure water system with a constant pressure (4 MPa) and various liquid loadings (40–80%) in a visual flow loop. It was found that the hydrate growth process in the dynamic system included bubble promotion, subcooling promotion, and mass transfer inhibition. Meanwhile, two atypical slug patterns (rapid conversion slug and deposition slug) in the vertical upward flow were determined, which corresponded to the promotion and inhibition regions. In the rapid conversion slug flow, the churn segments replaced the original Taylor bubbles when the liquid loading was less than 60%. In the deposition slug flow, slurry shedding phenomena was observed. In addition, the hydrate particle deposition behavior was found to inhibit hydrate growth and cause flow pattern shifts, but did not trigger the differential pressure surge. The gas isolation caused by the liquid plug and energy dissipation due to the collision between hydrate particles and the tube wall may be responsible for the sudden increase in pressure drop. Furthermore, the feasibility of predicting hydrate blockage using the differential pressure method was explored. The experiment results showed that this warning method was effective when the liquid loading was below 76%. And an effective warning can improve the transport capacity by approximately 34%. • The hydrate formation and flow behaviors are complicated in deepwater risers. • Hydrate formation and multiphase flow behaviors were observed by a visual flow loop. • Three regions of growth kinetics and two atypical slug patterns were determined. • The differential-pressure hydrate blockage warning method was proposed. [ABSTRACT FROM AUTHOR]

Efficient removal of macromolecular microbial metabolites and nitrogen in receiving rivers lacking ecological base flow is needed to meet the stringent surface water quality standards in northwestern China. This study investigated the characteristics of water quality of a receiving river, further, the conversion of microbial metabolites and its influences on denitrification in pilot anaerobic biofilter (ABF) and biological aerated filter (BAF) were revealed. On this basis, the feasibility of using the combination of ABF and BAF to purify the receiving river was verified. Results showed that organics dominated by macromolecular microbial metabolites and nitrogen severely polluted the receiving river. Microbial metabolism along the river aromatized the organics and enlarged their molecular weight but failed to effectively remove them. In ABF, the bioavailability of organics was at least triply improved by cleaving macromolecular aromatic rings into small molecular aliphatic compounds. Under this circumstance, denitrifiers utilized aromatic carbon sources preferentially and generated aliphatic products. Low hydraulic loading (HL) enhanced not only the hydrolysis of macromolecular ingredients but the dearomatization. Similarly, although high HLs allowed retaining more aromatic compounds, they worsened the conversion of macromolecules. When the HL was 0.2 m/h, the balance was achieved and more than 80% of the nitrates were removed in ABF. Nearly 90% of both ammonia nitrogen and small molecular organics were removed in BAF under the optimal operating conditions, but the refractory macromolecules impeded the removal of organics and nitrogen. AFB and BAF showed a complementation. The effluent from BAF that followed ABF could meet the latest surface water quality standards. This combination is feasible to efficiently and stably purify the polluted receiving rivers of wastewater treatment plants. [ABSTRACT FROM AUTHOR]

The urgent need to address climate change, driven by the increasing concentrations of greenhouse gases, has made it imperative for the world to focus on enhancing carbon emission mitigation and carbon utilization. Consequently, carbon-negative technologies have garnered significant attention, such as Carbon Capture, Utilization, and Storage (CCUS). In order to achieve the circular utilization of carbon and improve the economic viability of conventional carbon-negative technologies, this paper proposes the innovative concept of Carbon Capture, Circular Utilization, and Sequestration (CCCUS). This multifunctional carbon-negative technology couples underground biomethanation of carbon dioxide and hydrogen-rich industrial by-product gases with geothermal energy production. CCCUS also offers several additional functions, such as renewable natural gas storage, natural gas displacement, and carbon dioxide geological sequestration. Furthermore, a preliminary assessment of the techno-economic feasibility of CCCUS is undertaken. A numerical case study, conducted using the XGS gas storage in the Sichuan Basin, China, unveiled that over a 425-day period, the conversion ratio of carbon dioxide to methane in the working gas can achieve 98.9%. Moreover, the net present value (NPV) of CCCUS over a 30-year period is estimated to be approximately 4.67 × 108 CNY under the base scenario. These findings, along with field monitoring and laboratory experiments, preliminarily present evidence supporting the potential techno-economic feasibility of CCCUS. This paper offers a fresh perspective on the development of the circular carbon economy. [ABSTRACT FROM AUTHOR]

In gas capture/storage and energy storage, tetrabutylammonium bromide (TBAB) hydrates have been regarded as superior carriers owing to their unique molecular selectivity and high latent heat. Hydrate conversion amount is a significant parameter in evaluating gas selection and cold storage characteristics. This study proposes a method for calculating hydrate conversion amount proposed based on the correlation between electrical conductivity and solution concentration. The correlation index (R2) between electrical conductivity and TBAB solution concentration was above 0.99 at concentrations less than below 5 wt%. The conversion amounts of different hydrate types were obtained using a unique hybrid calculation method. The differences in hydrate conversion amount, conversion ratio, and memory effect were compared at different mass fractions. The results indicated that the hydrate morphology and accumulation patterns were influenced by the TBAB solution ionization degree. Regular hexagonal TBAB hydrate crystals were observed at a low ionization degree. The maximum conversion ratio of TBAB hydrate reached 96% (1 °C/30 wt%). The variation trend of TBAB hydrate phase equilibrium temperature was consistent with that of the electrical conductivity of the solution. The investigation of the memory effect revealed that the phase change process of TBAB hydrate is more predictable in high-concentration initial solutions. [Display omitted] • Regular hexagonal hydrate was observed for the first time. • Insufficient ionization of TBAB slowed hydrate conversion. • TBAB hydrate phase equilibrium temperature was consistent with ionization degree. • Temperature, induction factor, and residual solution volume affected hydrate conversion. [ABSTRACT FROM AUTHOR]

Gasoline vehicle emission is a major source of urban particulate matter (PM), particularly ultra-fine PM (≤100 nm), exerting adverse health effects. While the PM emissions from port fuel injection (PFI) and gasoline direct injection (GDI) vehicles have been well addressed in previous studies, few studies have reported the PM emission from the new mixed injection (MI) vehicles. Here, we employed a chassis dynamometer to investigate particle emissions under the Worldwide Harmonized Light vehicles Test Cycles (WLTC) from vehicles with three different fuel injection technologies. The PM and particle number (PN) emission factors (EFs) for MI vehicles are 129.53 μg/km and 1.0 × 1013 #/km, respectively. A trend of PFI > MI > GDI is observed for both PM and PN EFs for vehicles with same emission standard. Notably, the PM emissions of MI vehicles are greatly affected by both fuel injection methods at low and medium speeds, but are more significantly affected by PFI at high speeds. MI vehicle shows much lower PM and PN emissions than other vehicles at low-, medium-, and high-speed phases, but substantial hiher ultra-fine PM emission at extra-high speed phase. This is because the insufficient air supplied by naturally-aspirated engine of MI vehicles in the high-load region leads to incomplete combustion and generate large formation of ultra-fine particles. Besides, the gasoline particulate filter reduces 94.5% of PM emission but produces abundant nucleation-mode particles during regeneration at the extra-high speed phase for MI vehicles. Our study gives an insight to the state-of-the-art engine technology, i.e., MI vehicles, and reveals that this new technology is a feasible alternative for simultaneously reducing pollutant emissions from gasoline vehicles. • ●PM and PN emissions from MI vehicles are lower than PFI and GDI vehicles. • The proportion of nucleation-mode particles from MI vehicles is the highest. • GPF regeneration leads to substantial nucleation-mode particle. [ABSTRACT FROM AUTHOR]

Previous studies have shown that coexisting ions in tungsten smelting wastewater (TSW) will have a significant impact on fluoride removal by calcium ions. Therefore, in this work, the removal of fluoride from TSW by aluminum ions was studied. Electrocoagulation (EC) is essentially the use of aluminum ions to remove fluoride. The EC technology is widely favored by researchers due to its advantages of high treatment efficiency, simple operation, and easy automatic control. However, in the current research, EC technology as a deep defluorination method is mostly in the laboratory research stage, and there are few pilot test studies on large processing capacity, which slows down the industrial application of this technology to a certain extent. In this work, laboratory tests were carried out to study the removal of fluoride in wastewater by chemical coagulation and EC in detail. On this basis, the combined process of chemical coagulation pretreatment and EC advanced treatment was used to treat TSW with a capacity of 250–500 L/h. The results show that the coexisting ions in TSW have no effect on the defluorination of aluminum ions, and the optimal defluorination final pH of chemical coagulation and EC is 6–7. The pilot test could stably reduce the concentration of fluoride in TSW from 66 to 128 mg/L to less than 10 mg/L, and the total operating cost was 0.99–1.51 USD/m3 of wastewater. Cost analysis showed that the three items with the highest proportions in the chemical coagulation pretreatment costs were liquid caustic soda fee, aluminum sulfate fee, and solid waste treatment fee; while the three items with the highest proportions in the EC advanced treatment costs were aluminum plate loss fee, electricity fee, and solid waste treatment fee. This study is helpful to promote the application of EC advanced treatment technology in the defluorination of industrial wastewater. [Display omitted] • A large capacity and continuous pilot test of EC defluorination was carried out. • Coagulation main costs were NaOH (35%), Al 2 (SO 4) 3 (30%), and solid waste treatment (20%) fees. • EC main costs were Al plate loss (56%), electricity (15%), and solid waste treatment (14%) fees. • This study provides direct data for the subsequent industrial application of EC. [ABSTRACT FROM AUTHOR]

To efficiently separate essential oil from the roots and rhizomes of Asarum heterotropoides var. mandshuricum , a modified dynamic nitrogen-protected microwave-assisted hydrodistillation connected liquid-liquid extraction (DNMHDLLE) technique was developed. In addition to collect essential oil at the bottom of hydrosol in the conventional oil-water separation process, another extraction process was realized for extracting some essential oil components from the hydrosol using a small amount of organic solvents, which can significantly enhance the essential oil yield, effectively reduce the organic content in wastewater and its further disposal burden. The addition of glass beads as the packing in the second separation column had a positive influence on the essential oil yield. After the investigation using a single factor experiment and a response surface analysis, the optimum conditions were determined to be 28 min microwave irradiation time, 11 mL/g liquid-solid ratio, and 550 W microwave irradiation power. Under the optimum conditions, the yields of A. heterotropoides var. mandshuricum essential oil obtained in the first and second separation columns were 1.92 ± 0.07% and 0.50 ± 0.02%, respectively. Using GC-MS analysis, the essential oil containing oxy-compounds with a higher relative content was separated in the second separation column. In addition, the proposed method was compared with other techniques, including efficiency, environmental impact and economic effect, which indicated that the developed technique can effectively improve the essential oil yield, and take full advantage of raw material resources. [ABSTRACT FROM AUTHOR]

The essential oil was separated from the fresh leaves of Phellodendron amurense Rupr. by solvent-free microwave-assisted distillation in a rotating state with n-hexane extraction and LiCl addition, which ingeniously designed lithium salt addition, rotation unit, and n-hexane extraction effectively improved the yield and separation rate of essential oils. The factors that may affect essential oils yield were screened and optimized by single factor optimization, response surface methodology, and kinetic model to obtain the optimal conditions for the separation of essential oils by this method, which were LiCl content of 8%FW, microwave irradiation power 600 W and microwave irradiation time 40 min. And the yield of essential oils is 2.39 ± 0.12 mg/g in the optimum conditions by this method, which is highly consistent with the predictions from the response surface method (2.39 mg/g) and the first-order kinetic model (2.42 ± 0.04 mg/g). This method effectively ensures the uniform heating of the plant material and the rapid overflow of the essential oil by employing the rotating unit and the addition of LiCl, which effectively avoids the loss of the heat-sensitive components in the essential oil. Moreover, the solvent-free distillation of this method highly improves the heating rate, and the added LiCl can also be effectively recovered and reused, which effectively reduces the economic cost, and environmental stress and will result in a cleaner product. And an accurate quantitative analysis method of essential oils was established by n-hexane extraction-ultraviolet spectroscopy, which not only effectively avoided the loss of water-soluble components but also provided a new strategy for quantitative analysis of essential oils. In addition, the results of the kinetic model indicated that the separation rate constant of essential oils in this method was 1.34 times that of microwave-assisted hydrodistillation and 5.05 times that of conventional hydrodistillation. Therefore, this method is an efficient, green, and clean essential oil preparation method, which is very promising to replace existing methods in the future. [Display omitted] • The innovative design of the rotating unit ensures that the biomass is heated evenly. • LiCl addition increases the conductivity to accelerate the heating rate. • n-Hexane extraction to develop a new quantitative analysis method for essential oils. • CO 2 release and economic cost of this method are only 0.24 times that of hydrodistillation. • The essential oil yield of this method is 1.5 times that of the traditional hydrodistillation. [ABSTRACT FROM AUTHOR]

The CaO–MgO–Al 2 O 3 –SiO 2 (CMAS) glass-ceramics are a new type of building decoration materials. They can be prepared using silicate-bearing metallurgical slags as raw materials for both economic and environmental benefits. This study offered a systematic review of preparation of CMAS glass-ceramics from various metallurgical slags based on analyses of characteristics, preparation methods of slag-based glass-ceramics, and the influence of heat treatment, chemical components and nucleating agents on the phase composition, microstructure and properties of glass-ceramics. It was found that a large number of metallurgical slags, including blast furnace slag (BFS), steel slag (SS), stainless-steel slag (SSS), electric furnace ferronickel slag (EFFS), copper slag (CS), ferromanganese slag (FS) and lead fuming slag (LFS), have the potential to serve as the main raw materials for producing CMAS glass-ceramics because of their chemical composition similarities to the products. However, the minor or residual elements, such as chromium, in the slags may directly affect the properties of the glass-ceramics mainly because of their impacts on the nucleation and crystallization in parent glasses which are in need of control. Special attention of this review was devoted to the challenges from the aspects of cost, safety and diversification in preparing the glass-ceramics from metallurgical slags and to corresponding solutions for maximizing utilization of the wastes with desirable product quality. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper designs a novel maximum power point tracking (MPPT) technique for centralized thermoelectric generation (TEG) system under heterogeneous temperature difference (HeTD). Since the HeTD can result in multiple local maximum power points (LMPPs) for centralized TEG system, a fast atom search optimization (FASO) is designed to approximate the global maximum power point (GMPP) from multiple LMPPs. In order to accelerate the convergence for a high quality solution, the Euclidian distance ratio of the original atom search optimization (ASO) is employed to adaptively update according to the dynamic optimization results, as well as for the number of neighbours for each atom. Through case studies such as start-up test, step variation of temperature, stochastic temperature change, and analyse of sensitivity are carried out, in which the practicability and superiority of FASO are compared with that of MPPT method based on a single LMPP and four meta-heuristic algorithms. Simulation results show that the energy output produced by FASO ranges from 101.64% to 451.49% to the alternatives. Finally, through hardware-in-the-loop (HIL) experiment based on a dSpace, the feasibility of the hardware realization is confirmed, in which the difference between simulation results and HIL experiment results is less than 2.3%. • A novel MPPT model of centralized thermoelectric generation system is established. • Heterogeneous temperature difference causes multiple local maximum power points. • A novel fast atom search optimization is designed for MPPT of centralized TEG system. • Adynamic balance between exploration and exploitation is constructed in FASO. • FASObased MPPTobtainsalarger energy output than other five comparative methods. [ABSTRACT FROM AUTHOR]

In this study, in order to simultaneously extract procyanidins and essential oil from pinecones of Pinus koraiensis , aqueous enzymatic pretreatment ionic liquid–lithium salt based microwave–assisted extraction (AEILLME) with a modified hydrodistillation concatenated Soxhlet extraction apparatus was proposed. 1-Butyl-3-methylimidazolium bromide solution was selected as extraction solvent, while LiCl and mixture of cellulase and pectinase (1:1, w/w) as additives by single factor experiment. Other parameters that affect the yield of target components were investigated and optimized by Plackett–Burman design and Box–Behnken design. The obtained optimal conditions were: microwave irradiation power 581.49 W, microwave irradiation time 15.95 min and liquid–solid ratio 11.91 mL/g. Under the optimized conditions, the predicted yields of oligomeric procyanidins, polymeric procyanidins and essential oil were 13.02, 32.19 and 7.76 mg/g, respectively. Analysis of chemical constituents in the essential oil was performed on gas chromatography–mass spectrometry and there was no significant difference on the components of essential oil obtained by proposed method and traditional methods. Ionic liquids were successfully recycled and reused, which could lower the process cost and being beneficial to industrial production. This study provides an approach with good prospects for the application in extracting active components from natural plant material. Image 1 • Ionic liquid-lithium salt aqueous solution as extractant. • Ionic liquid-lithium salt, enzymes and microwave were combined to disrupt cell wall. • A modified hydrodistillation concatenated soxhlet extraction apparatus was proposed. • Simultaneous extraction of essential oil and procyanidins. [ABSTRACT FROM AUTHOR]