خيارات البحث
النتائج 3921 - 3930 من 7,291
Drivers of food waste generation and best practice towards sustainable food waste management in the hotel sector: a systematic review النص الكامل
2022
Kasavan, Saraswathy | Siron, Rusinah | Yusoff, Sumiani | Fakri, Mohd Fadhli Rahmat
The growing volumes of food globally are lost or wasted along the entire food chain. However, a high effort in investigating why food waste (FW) occurs remains scattered for each subsector in detail, particularly in the hotel sector. Therefore, this systematic review focuses on FW issues in the hotel sector to identify FW generation drivers and good business practices towards mitigating FW. The review compiled literature from 25 related studies and adopted the PRISMA statement, utilising two leading journal databases: Scopus and Web of Science. This review shows that hoteliers initially feel guilty about wasting food, primarily based on financial loss rather than concerns about the social and environmental footprint. Based on the review, hotel staff from various internal departments faced conflicts between good intentions with reducing FW and the guests’ unsustainable food consumption patterns. Within the scope of this review, we suggest that further research is necessary with a focus on procedures and regulations (hotel policy) to encourage guests to minimise plate waste and redistribute unsold hotel food to charities or food banks. Overall, this review offers some interesting guidelines and actionable inferences to reduce FW generation in the hotel sector.
اظهر المزيد [+] اقل [-]Towards Microplastic Reduction Within Institutions النص الكامل
2022
Willis, Bruce | Fytianos, Georgios
Globally, universities, institutions, and companies are aiming to reduce the use of single-use plastics as plastic litter, and plastic degradation generates secondary microplastics, all of which cause negative impacts on the environment. In this study the authors conducted a questionnaire-based survey to assess the willingness and motivation of stakeholders within academic settings to change daily habits to minimize plastic and microplastic pollution. The questionnaire, which was answered by 276 individuals with affiliation to the American Farm School or collaborating academic institutions, but primarily the American Farm School, was used to draw conclusions. Results showed that most stakeholders are ready to adapt to eliminate the use of single-use plastic within their institution and showed a high level of willingness to participate in cleaning campaigns. It is crucial to combine any new measures or policies with the proper education around why these measures are being enforced, so as to raise awareness and receptivity to those that are not familiar with microplastics and microplastic pollution.
اظهر المزيد [+] اقل [-]Enhanced ultraviolet-visible photocatalysis of RGO/equaixial geometry TiO2 composites on degradation of organic dyes in water النص الكامل
2022
Hasan, Jaafar | Wang, Jing | Wang, Zhentao | Idrees, Muhammad | Batool, Saima | Zhang, Caiwei | Qin, Chuanguang
The reduced graphene oxide dopped equaixial geometry TiO₂ (rGO/egTiO₂) composite as photocatalyst was synthesized hydrothermally with various mass ratios of tetrabutyl titanate. The photocatalyst is considered to be rGO/equaixial geometry TiO₂ in terms of modifying the combined reduced graphene Oxide and TiO₂. The rGO plays a vital role in rGO/egTiO₂ composite as photocatalysts were analyzed in methylene blue (MB) and rhodamine B (RhB) photocatalytic degradation under UV and simulated solar light irradiation. This synthesized catalyst was characterized by various analytical techniques such as XPS, XRD, SEM, BET, and TEM. The rGO/egTiO₂ composite exhibits enhanced photocatalytic performance with degradation rates of 97.5 and 97% on RhB and MB for 60 min under UV radiation respectively, while the degradation rate of 94 and 92 % was observed on the same dyes for 6 h under the simulated sunlight radiation. The enhanced photocatalytic performance of the rGO/egTiO₂ composite under ultraviolet irradiation source was owing to a high separation efficiency of the photo-induced electron-hole pairs, while the photocatalytic performance under simulated sunlight radiation was due to the photosensitive and charge separator behavior of rGO. This offers us an excellent potential of significant photocatalytic activity for the removal of organic contaminants from wastewater.
اظهر المزيد [+] اقل [-]Effective adsorption of nutrients from simulated domestic sewage by modified maifanite [Erratum: April 2022, v.29(17); p.25952] النص الكامل
2022
Liu, Zisen | Zou, Yilingyun | Liu, Yunli | Luo, Feng | Wang, Rou | Wu, Zhenbin | Zhang, Yi
Modified maifanite (MMF) was prepared by the synthesized method with sulfuric acid treatment and high-temperature calcination and evaluated as an effective adsorption material to remove the nutrient salt in waste watery. Compared with the raw maifanite (RMF), the MMF exhibited a higher adsorption capacity and higher removal efficiency. The results showed that the adsorption rates of total phosphorus (TP), total nitrogen (TN), ammonia nitrogen (NH₃-N), nitrate-nitrogen (NOₓ-N), and chemical oxygen demand (COD) by MMF were 86.7%, 44.9%, 29.1%, 19.8%, and 11.9%, respectively, and compared to RMF, the average adsorption capacity of these nutrients by MMF increased by 20.5 mg/kg, 126.2 mg/kg, 61.9 mg/kg, 117.18 mg/kg, and 86.9 mg/kg, respectively. MMF maintained the basic structure and composition of maifanite, while having a rougher and looser surface, more irregular pores, wider gaps, and more active materials such as oxidizing Fe. This study suggests that MMF can be further applied to treat domestic sewage and eutrophic water.
اظهر المزيد [+] اقل [-]Unravelling the molecular mechanism of mutagenic factors impacting human health النص الكامل
2022
Goyal, Keshav | Goel, Harsh | Baranwal, Pritika | Dixit, Aman | Khan, Fahad | Jha, Niraj Kumar | Kesari, Kavindra Kumar | Pandey, Pratibha | Pandey, Avanish | Benjamin, Mercilena | Maurya, Ankit | Yadav, Vandana | Sinh, Rana Suryauday | Tanwar, Pranay | Upadhyay, Tarun Kumar | Mittan, Sandeep
Environmental mutagens are chemical and physical substances in the environment that has a potential to induce a wide range of mutations and generate multiple physiological, biochemical, and genetic modifications in humans. Most mutagens are having genotoxic effects on the following generation through germ cells. The influence of germinal mutations on health will be determined by their frequency, nature, and the mechanisms that keep a specific mutation in the population. Early prenatal lethal mutations have less public health consequences than genetic illnesses linked with long-term medical and social difficulties. Physical and chemical mutagens are common mutagens found in the environment. These two environmental mutagens have been associated with multiple neurological disorders and carcinogenesis in humans. Thus in this study, we aim to unravel the molecular mechanism of physical mutagens (UV rays, X-rays, gamma rays), chemical mutagens (dimethyl sulfate (DMS), bisphenol A (BPA), polycyclic aromatic hydrocarbons (PAHs), 5-chlorocytosine (5ClC)), and several heavy metals (Ar, Pb, Al, Hg, Cd, Cr) implicated in DNA damage, carcinogenesis, chromosomal abnormalities, and oxidative stress which leads to multiple disorders and impacting human health. Biological tests for mutagen detection are crucial; therefore, we also discuss several approaches (Ames test and Mutatox test) to estimate mutagenic factors in the environment. The potential risks of environmental mutagens impacting humans require a deeper basic knowledge of human genetics as well as ongoing research on humans, animals, and their tissues and fluids.
اظهر المزيد [+] اقل [-]Amelioration of sodium and arsenic toxicity in Salvinia natans L. with 2,4-D priming through physiological responses النص الكامل
2022
Dolui, Debabrata | Hasanuzzaman, Mirza | Saha, Indraneel | Ghosh, Arijit | Adak, Malay Kumar
Sodium (Na) and arsenic (As) toxicity were monitored by hyperaccumulation of metals in Salvinia natans L. with 2,4-dichlorophenoxyacetic acid (2,4-D) induction. Salvinia was recorded with significant bioaccumulation of those metals with de-folding of cellular attributes in sustenance under toxic environment. 2,4-D priming has revised the growth components like net assimilation rate and relative water content to register initial plants’ survival against Na and As. Proline biosynthesis supported in the maintenance of osmotic adjustment and plants sustained better activity through subdued electrolytic leakage. Oxidative stress due to both Na and As exposure is responsible for induction under significant moderation of lipid peroxidation and protein carbonization by 2,4-D application was evident to release the stress from metal and metalloids. Reactive oxygen species (ROS) like superoxide and hydrogen peroxide accumulation were monitored with activity of NADP(H)-oxidase. However, it was downregulated by 2,4-D to check the oxidative damages. Superoxide dismutase and peroxidases were significantly moderated to reduce the oxidative degradation for both metals with 2,4-D induction. Glutathione metabolism and recycling of ascorbate with monodehydroascorbate activity were other features to maintain the redox homeostasis for metal toxicity. At the molecular level, polymorphic variations of concern genes in redox cascades demarked significantly for those two metals and established the biomarker for those metals, respectively. As a whole, the biocompatibility of auxin herbicide in Salvinia may raise the possibility for auxin metabolism and thereby, the bioaccumulation to Na and As vis-à-vis tolerance for ecological safety is established.
اظهر المزيد [+] اقل [-]Intensified salinity intrusion in coastal aquifers due to groundwater overextraction: a case study in the Mekong Delta, Vietnam النص الكامل
2022
Tran, Dang An | Tsujimura, Maki | Pham, Hai V. | Nguyen, Tam V. | Ho, Loc Huu | Le Vo, Phu | Ha, Khai Quang | Dang, Thanh Duc | Van Binh, Doan | Doan, Quang-Van
Groundwater salinization is one of the most severe environmental problems in coastal aquifers worldwide, causing exceeding salinity in groundwater supply systems for many purposes. High salinity concentration in groundwater can be detected several kilometers inland and may result in an increased risk for coastal water supply systems and human health problems. This study investigates the impacts of groundwater pumping practices and regional groundwater flow dynamics on groundwater flow and salinity intrusion in the coastal aquifers of the Vietnamese Mekong Delta using the SEAWAT model—a variable-density groundwater flow and solute transport model. The model was constructed in three dimensions (3D) and accounted for multi-aquifers, variation of groundwater levels in neighboring areas, pumping, and paleo-salinity. Model calibration was carried for 13 years (2000 to 2012), and validation was conducted for 4 years (2013 to 2016). The best-calibrated model was used to develop prediction models for the next 14 years (2017 to 2030). Six future scenarios were introduced based on pumping rates and regional groundwater levels. Modeling results revealed that groundwater pumping activities and variation of regional groundwater flow systems strongly influence groundwater level depletion and saline movement from upper layers to lower layers. High salinity (>2.0 g/L) was expected to expand downward up to 150 m in depth and 2000 m toward surrounding areas in the next 14 years under increasing groundwater pumping capacity. A slight recovery in water level was also observed with decreasing groundwater exploitation. The reduction in the pumping rate from both local and regional scales will be necessary to recover groundwater levels and protect fresh aquifers from expanding paleo-saline in groundwater.
اظهر المزيد [+] اقل [-]Trend analysis and obstacle factor of inter provincial water resources carrying capacity in China: from the perspective of decoupling pressure and support capacity النص الكامل
2022
Sun, Weixin | Zhang, Yuhan | Chen, Heli | Zhu, Lin | Wang, Yong
The high distribution of water resources among provinces in China considerably impacts the development of society and economy in each region. Thus, it is of great practical significance to examine the water resources carrying capacity (WRCC) of each Chinese province. This paper constructs a comprehensive evaluation index system for the WRCC from two aspects: pressure and support. First, it analyzes dynamic changes in the WRCC of 31 Chinese provinces in China by using the decoupling model (DM). Second, it analyzes the key factors that hinder the improvement of WRCC by using the obstacle degree model (ODM). The study found that there are significant inter-provincial differences in China’s WRCC. Provinces with greater natural water resources have a higher WRCC. Under the condition of similar natural water resources, WRCC in economically developed provinces is higher. From 2008 to 2015, China’s overall WRCC has been increasing. Moreover, three-fifth of China’s provinces can be classified as Upward-type (Upward I, Upward II, and Upward III) provinces and their WRCC is in a good state by considering the decoupling type and trend of WRCC in two periods together. The main obstacle factors hindering the improvement of the WRCC are total water resources ([Formula: see text]), water supply per capita ([Formula: see text]), total water supply ([Formula: see text]), forest cover rate ([Formula: see text]), soil erosion control area ([Formula: see text]), water consumption saving ([Formula: see text]), and water usage penetration rate ([Formula: see text]). This study can provide a scientific basis for understanding change trend of WRCC in Chinese provinces and improve their WRCC.
اظهر المزيد [+] اقل [-]Convergence of energy carbon emission efficiency: evidence from manufacturing sub-sectors in China النص الكامل
2022
Liu, Dongdong
With China’s economy entering the stage of high-quality development, manufacturing energy carbon emission efficiency has become the focus of academic attention. It is of great significance to study the convergence of manufacturing energy carbon emission efficiency for realizing high-quality development of manufacturing in China. Based on the panel data of China’s manufacturing sub-sectors, this paper measures and analyzes the evolution trend of manufacturing energy carbon emission and its efficiency. On this basis, this paper uses the coefficient of variation and convergence model to test the convergence of manufacturing energy carbon emission efficiency. The results show that China’s manufacturing energy carbon emissions and its efficiency demonstrate an increasing trend. Coal was the main source of manufacturing energy carbon emissions. The manufacturing energy carbon emission efficiency does not have σ convergence, but has [Formula: see text] convergence, and its convergence has industry heterogeneity. The manufacturing energy carbon emission efficiency exits scale effect and technology effect, but not the effect of opening to the outside world and institutional effect, and its effect exists industry heterogeneity. By reducing carbon emissions, adopting differentiated policies, adjusting the industry scale, and enhancing the industry technology intensity, China’s manufacturing can improve the energy carbon emission efficiency and promote high-quality economic development.
اظهر المزيد [+] اقل [-]The impact of high-tech product export trade on regional carbon performance in China: the mediating roles of industrial structure supererogation, low-carbon technological innovation, and human capital accumulation النص الكامل
2022
Han, Miao | Zhou, Yan
The role of expanding the proportion of high-tech products in the export trade of various countries to identify the appropriate export structure has gradually attracted the attention of governments and scholars. While there is some knowledge on how high-tech product exports affect carbon dioxide emissions, the mechanisms involved in that link have not been adequately addressed in previous studies. This study is based on China’s inter-provincial panel data from 2006 to 2017 and uses the stepwise regression method and the bootstrap method to systematically investigate the mediating effects of industrial structure supererogation, low-carbon technological innovation, and human capital accumulation, operating in the impact of high-tech product export trade on regional carbon performance. Since the Pesaran’s CD test and the P&Y slope homogeneity test confirm the presence of cross-sectional dependence and slope heterogeneity in the panel data, we use the CADF and CIPS unit root tests to verify the stationarity of the variables and therefore employ the CCEMG and DCCE estimators for regression estimation. The research results show that high-tech product exports can help improve regional carbon performance. The mediating variables, industrial structure supererogation, low-carbon technological innovation, and human capital accumulation separately have positive and complete mediating effects on the link between high-tech product export trade and regional carbon performance. The research results highlight the important part of expanding high-tech product exports in improving regional carbon performance and have significance in promoting China’s green and low-carbon transition.
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