The present study reported the synthesis and utilization of a graphene-based hybrid nanocomposite (MnFe2O4/G) to mitigate several synthetic dyes, including methylene blue, malachite green, crystal violet, and Rhodamine B. This adsorbent was structurally analyzed by several physicochemical techniques such as X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, Raman spectroscopy, N2 adsorption-desorption isotherm measurement, point of zero charge, and Boehm titrations. BET surface area of MnFe2O4/G was measured at 382.98 m2/g, which was substantially higher than that of MnFe2O4. MnFe2O4/G possessed diverse surface chemistry properties with the presence of many functional groups such as carboxylic acid, phenolic, lactone, and basic groups. MnFe2O4/G was used to remove synthetic dyes in the aqueous media. The effect of many factors, e.g., concentration (5-50 mg/L), pH (4-10), dose (5-20 mg), and temperature (25-45 °C) on adsorption performance of MnFe2O4/G was conducted. Kinetic, isotherm, intraparticle, and thermodynamic models were adopted for investigating adsorption phenomenon of dyes on MnFe2O4/G. The maximum adsorption capacity of dyes over MnFe2O4/G was found as Rhodamine B (67.8 mg/g) < crystal violet (81.3 mg/g) < methylene blue (137.7 mg/g) < malachite green (394.5 mg/g). Some tests were performed to remove mixed dyes, and mixed dyes in the presence of antibiotics with total efficiencies of 65.8-87.9% after 120 min. Moreover, the major role of π-π stacking interaction was clarified to gain insight into the adsorption mechanism. MnFe2O4/G could recycle up to 4 cycles, which may be beneficial for further practical water treatment.
Non-edible Ceiba oil has the potential to be a sustainable biofuel resource in tropical countries that can replace a portion of today's fossil fuels. Catalytic deoxygenation of the Ceiba oil (high O/C ratio) was conducted to produce hydrocarbon biofuel (high H/C ratio) over NiO-CaO5/SiO2-Al2O3 catalyst with aims of high diesel selectivity and catalyst reusability. In the present study, response surface methodology (RSM) technique with Box-Behnken experimental designs (BBD) was used to evaluate and optimize liquid hydrocarbon yield by considering the following deoxygenation parameters: catalyst loading (1-9 wt. %), reaction temperature (300-380 °C) and reaction time (30-180 min). According to the RSM results, the maximum yield for liquid hydrocarbon n-(C8-C20) was found to be 77% at 340 °C within 105 min and 5 wt. % catalyst loading. In addition, the deoxygenation model showed that the catalyst loading-reaction time interaction has a major impact on the deoxygenation activity. Based on the product analysis, oxygenated species from Ceiba oil were successfully removed in the form of CO2/CO via decarboxylation/decarbonylation (deCOx) pathways. The NiO-CaO5/SiO2-Al2O3 catalyst rendered stable reusability for five consecutive runs with liquid hydrocarbon yield within the range of 66-75% with n-(C15 + C17) selectivity of 64-72%. Despite this, coke deposition was observed after several times of catalyst usage, which is due to the high deoxygenation temperature (> 300 °C) that resulted in unfavourable polymerization side reaction.
Reduced electricity demand through the implementation of an energy efficiency policy is a central pillar of the Malaysian government's energy strategy. Energy efficiency first emerged as part of Malaysia's energy policy agenda in 1979 but only came into force during the 2000s. Initially, it was seen from global fears about the shortage of fossil fuels, then as a way of combating climate change. This paper offers a comprehensive review of Malaysia's energy policies with a focus on adopting policies to improve energy efficiency. Starting with Malaysia's preliminary policy in response to the OPEC-driven global oil crisis in 1973, the paper discusses how policymakers are considering energy efficiency from Malaysia's sustainable development perspective and what relevant government efforts have been made to improve it. The review evaluates the progress that has been made over the past 25 years to address energy efficiency in the economy and highlights the achievements and remaining difficulties. Findings show that the level of energy efficiency while having shown improvement during 1990-2015 was lower than expected. In terms of electricity intensity of GDP, Malaysia has a relatively large position among the ASEAN countries and the world's largest electricity consumers. Researchers, scientists, and practitioners will benefit from the extensive review material of this study, which will help them better understand energy efficiency and the sustainability strategy implemented in Malaysia to date.
The seed extract of Abelmoschus esculentus (AE), also known as Okra, was used as a source of reducing and capping agents to synthesized biogenic titanium dioxide nanoparticles (TiO2 NPs) due to its rich flavonoid contents. The synthesized AE-TiO2 nanoparticles were further evaluated by the effect of loading of TiO2 NPs and irradiation time on the photocatalytic degradation of methylene blue dye. The synthesized TiO2 NPs were then characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), energy dispersive X-ray spectroscopy (EDS), Fourier transformed infrared (FTIR) spectroscopy, Raman spectra, UV-visible spectrophotometry, and particle size distribution (PSD). The findings confirmed the successful synthesis of the spherical anatase phase of TiO2 NPs, as well as the existence of phytochemicals in the extract, which were involved in the capping/stabilization of NPs. The synthesized TiO2 NPs were found to be 60-120 nm in size and almost uniformly distributed throughout the sample. The photocatalytic activity measured in a 300 mL cylindrical photochemical reactor and irradiated with 250 watts UV lamp was investigated based on methylene blue degradation. Effects of irradiation time and catalyst loading were elucidated and correlated with the characteristics of the catalysts. The findings revealed that the synthesized TiO2 NPs were well-dispersed, stable, and could achieve more than 80 % degradation in 240 min of irradiation with 90 mg/L of AE-TiO2 NPs loading compared to only 70 % by the commercial one. These results suggested that AE-TiO2 NPs possesses significant catalytic activity, and the photocatalytic process could be used to degrade, decolorize, and mineralize the methylene blue dye. The polyphenolic tannins present in the extract were the reason behind the desirable characteristics of the nanoparticles and better photocatalytic activity of AE-TiO2 NPs.
Environmental degradation has been a major concern for nations globally in recent years as carbon emissions have increased. Environmental degradation, if not controlled, is one of the dangers faced by humankind, and achieving sustainable development goals is not possible without improving environmental quality. Thus, reliable carbon emission measurement plays an important role in developing an effective climate strategy to address the current environmental issues. Following the trade-adjusted carbon emission measure, an effective climate strategy can be formulated especially following the 17 United Nation Sustainable Development Goals that are intended to lead to improvements toward a sustainable future. To fill the gap in the literature, we empirically explore the interrelationship between foreign capital flows and environmental quality measured by trade-adjusted consumption-based carbon dioxide (CCO2) emissions for a panel of 125 countries in 1990-2018 by revisiting the pollution haven hypothesis (PHH). The results obtained using system GMM analysis show that FDI has a significantly positive link with CCO2 in Asia and Africa, but the links between these two variables are insignificant in the Latin American, Caribbean, and European regions. In the cases of the full-sample and developing countries, a significantly positive relationship is found between FDI and CCO2. In the case of income-based samples, results reveal that FDI is the cause of environmental degradation in low-income, lower-middle-income, and upper-middle-income countries. These findings suggest that developing countries should adopt environmentally friendly policies to attract foreign investors by setting strict regulations on environmental pollution control to achieve sustainable development goals (SDGs).
Building and its environment are in focus owing to health impact attributed to indoor air quality. This study was carried out to assess indoor air quality in terms of particulate matter (PM) and carbon dioxide in a residential building, during COVD-19 pandemic lockdown from March 25 to April 23, 2020, Abha, Saudi Arabia. The PM concentration range for kitchen, bedroom, and hall were 40,000-81000 μg/m3 (PM0.3), 15,000-26000 μg/m3 (PM0.5), 4000-6000 μg/m3 (PM1), 1100-1500 μg/m3 (PM2.5), 160-247 μg/m3 (PM5), and 60-95 μg/m3 (PM10). The results of this study suggest that bedroom needs to be ventilated as CO2 concentration was reaching 700 ppm during sleep hours. PM concentration was exceeding 300 μg/m3 (unhealthy) for all particle sizes of PM0.3, PM0.5, PM1, and PM2.5 except for PM10 which was also above safe limits (0-50 μg/m3). Also, with influential habit (aromatic smoke), these concentrations increased 2-28 times for PM. The hazard quotient value greater than 1 revealed potential health risk to the inhabitants. Hence, future studies are needed for developing indoor air quality guidelines for residential buildings in Saudi Arabia and better planning and management of energy consumption.
Untainted environment promotes health, but the last few decades experienced steep upsurge in environmental contaminants posing detrimental physiological impact. The responsible factors mainly include the exponential growth of human population, havoc rise in industrialization, poorly planned urbanization, and slapdash environment management. Environmental degradation can increase the likelihood of human exposure to heavy metals, resulting in health consequences such as reproductive problems. As a result, research into metal-induced causes of reproductive impairment at the genetic, epigenetic, and biochemical levels must be strengthened further. These metals impact upon the female reproduction at all strata of its regulation and functions, be it development, maturation, or endocrine functions, and are linked to an increase in the causes of infertility in women. Chronic exposures to the heavy metals may lead to breast cancer, endometriosis, endometrial cancer, menstrual disorders, and spontaneous abortions, as well as pre-term deliveries, stillbirths. For example, endometriosis, endometrial cancer, and spontaneous abortions are all caused by the metalloestrogen cadmium (Cd); lead (Pb) levels over a certain threshold can cause spontaneous abortion and have a teratogenic impact; toxic amounts of mercury (Hg) have an influence on the menstrual cycle, which can lead to infertility. Impact of environmental exposure to heavy metals on female fertility is therefore a well-known fact. Thus, the underlying mechanisms must be explained and periodically updated, given the growing evidence on the influence of increasing environmental heavy metal load on female fertility. The purpose of this review is to give a concise overview of how heavy metal affects female reproductive health.
Nutrition plays a significant role in the prevention and treatment of common diseases. Some superb dietary choices such as functional foods and nutriments can surely help fight against certain diseases and provide various advantages to an individual's health. Plants have been regarded as a primary source of highly effective conventional drugs leading to the development of potential novel agents, which may boost the treatment. Growing demand for functional foods acts as an aid for the producers to expand in agriculture and pave the way for innovation and research by the nutraceutical industry. The given review highlights how various functional foods such as tomatoes, chocolates, garlic and flaxseed are currently being defined, their sources, benefit in treating various ailments and the challenges with their use.
The present paper discussed the comparison of the persistence and mobility of metsulfuron-methyl from a residue field trial experiment and simulation using a VARLEACH model. The residue field trial experiment was performed at Sungai Buloh Oil Palm Estate, Selangor. The plots were treated with metsulfuron-methyl at two treatment rates of 15 g a.i ha-1 (T1) and 30 g a.i ha-1 (T2). Soil samples were collected at 0, 1, 3, 7, 14, 21, 30, 60 and 90 days after treatment (DAT) and analysed subsequently by HPLC-UV. The results show that metsulfuron-methyl degraded rapidly in the soil with the half-life (t½) of 6.3 days in T1 and 7.9 days in T2. The simulation of VARLEACH model gave similar pattern of persistence and mobility of metsulfuron-methyl in the soil profile. However, total residues and the mobility of the metsulfuron-methyl were poorly simulated by the VARLEACH model due to consistent overestimation of the quantified residues. Results indicated that the metsulfuron-methyl lost more rapidly than the prediction values from VARLEACH model. In this case, simulation models which use transformation routines similar and which include additional degraded processes such as leaching, volatilisation, plant uptake or runoff could be considered. Albeit, overestimated values on the concentrations of metsulfuron-methyl are reported using VARLEACH model, the model still can be used as rapid and fast approach to predict the behaviour of pesticide at minimum cost.
This research examines how financial transformative power sector reforms affect energy efficiency and the economy in a sample of economies from South Asia, the Middle East, and Europe. We applied two stages of OLS, Bayesian VAR, and Data Envelopment Analysis (DEA) methods to a panel data set from 1995 to 2018. According to empirical findings, institutional deficiency has a negative effect on electricity reforms, implying that the greater the impact of reforms on electricity performance, the higher the institutional efficiency, A collection of reform initiatives involving a variety of reform agencies will boost energy efficiency by up to 13% and per capita electricity access by 62%. Despite recent reforms and regulatory measures, the electricity sector continues to face challenges in terms of private investment and structural flaws such as energy inefficiency, significant technological and financial losses, low power quality, and outdated transmission and network infrastructure. Interestingly 13.2% increases can be found in energy efficiency after electricity reforms. Unlike previous studies, our findings reveal a conflict between the broader economic effects and the welfare impact on electricity consumers.
It is observed that an educated labor force can increase the absorption capacity of the economy and improve the effectiveness of green technologies that lead to a reduction in potential CO2 emissions. The study investigates whether an educated labor force contributes to the management of the green economy or not in BRCS economies. Panel ARDL-PMG and NARDL-PMG approaches have been employed for empirical analysis for data ranging from 1995 to 2019. According to the ARDL-PMG results, a highly educated labor force contributes to alleviating CO2 emissions in the long run. In contrast, the findings of NARDL-PMG infer that positive component of a highly educated labor force has a significant negative impact on CO2 emissions, while negative component of a highly educated labor force has a positive impact on CO2 emissions in the long run. The study suggests that BRCS countries' policymakers should promote education and training for the labor force to maintain a reduction in CO2 emissions.
Transportation of crude oil and refined petroleum is the main function of pipeline system in petroleum industry. Unfortunately, wax precipitation has become a serious problem for the petroleum industry where it causes pipeline blockage and eventually results in operational catastrophe. Up-to-date, the technique used to mitigate wax deposition by injecting chemical wax inhibiting agent remains a debate amongst researchers. This review addresses the evolution of chemical wax inhibitor generations started from polymer-based in the early 1980s, followed by biosurfactant-based in the late 1990s and finally plant-based or agricultural-based in recent years. Pivoting to environmental impact, petroleum industry is amidst finding a green wax inhibiting agent to solve wax deposition problem that occurs during the transportation of crude oil whilst facilitating the remediation process of contaminated groundwater.
In a context of climate change and global warming, the literature paid more and more attention to the determinants of energy consumption. This article aims at examining the influences of the financial development and the institutional quality on the energy consumption in a global sample of 112 countries between 2002 and 2014. Our analysis is based on dynamic two-step system GMM estimations for three different energy consumption indicators-our findings are interesting. First, the financial development induces a higher energy consumption per capita; a higher energy consumption per output, and a lower renewable energy consumption. Second, the institutions have an insignificant positive influence on the energy use per capita and the energy use per output. Third, and this is our major contribution, the institutional quality can actually reverse the effect of the financial development. In other words, the effect of financial development on the energy use per capita is positive in weak institutional environment but it is negative when the latter is well developed. This article discusses these finding and their implications.
Mapping potential changes in bioclimatic characteristics are critical for planning mitigation goals and climate change adaptation. Assessment of such changes is particularly important for Southeast Asia (SEA) - home to global largest ecological diversity. Twenty-three global climate models (GCMs) of Coupled Model Intercomparison Project Phase 6 (CMIP6) were used in this study to evaluate changes in 11 thermal bioclimatic indicators over SEA for two shared socioeconomic pathways (SSPs), 2-4.5 and 5-8.5. Spatial changes in the ensemble mean, 5th, and 95th percentile of each indicator for near (2020-2059) and far (2060-2099) periods were examined in order to understand temporal changes and associated uncertainty. The results indicated large spatial heterogeneity and temporal variability in projected changes of bioclimatic indicators. A higher change was projected for mainland SEA in the far future and less in maritime region during the near future. At the same time, uncertainty in the projected bioclimatic indices was higher for mainland than maritime SEA. Analysis of mean multi-model ensemble revealed a change in mean temperature ranged from - 0.71 to 3.23 °C in near and from 0.00 to 4.07 °C in far futures. The diurnal temperature range was projected to reduce over most of SEA (ranging from - 1.1 to - 2.0 °C), while isothermality is likely to decrease from - 1.1 to - 4.6%. A decrease in isothermality along with narrowing of seasonality indicated a possible shift in climate, particularly in the north of mainland SEA. Maximum temperature in the warmest month/quarter was projected to increase a little more than the coldest month/quarter and the mean temperature in the driest month to increase more than the wettest month. This would cause an increase in the annual temperature range in the future.
Modeling three-dimensional contaminant transport released from arbitrary shape source geometries is useful in hydrological and environmental sciences. This article produces several analytical solutions for three-dimensional contaminant transport in a homogeneous and isotropic aquifer by using Green's function with the groundwater flow which is assumed to be in three directions. The solutions are obtained for both finite depth aquifer and semi-infinite depth aquifer. Various types of sources are discussed: point, line, plane, or cuboid sources. The continuous and instantaneous sources are also investigated. A MATLAB coding is developed to calculate the numerical integrals which occur at the solutions. Some solutions are verified with the solutions obtained in the literature. This study confirms the effect of groundwater velocities in all directions on the degree and the directions of contaminant spreading. Additionally, the results highlight the significant effect of the geometrical shape of the contaminant sources on contaminant concentrations for instantaneous and continuous sources. In particular, the cuboid source and the horizontal rectangular source provide the highest concentrations. The analytical solutions developed in this article can be applied for a wide range of contaminant transport.
The aim of this research was to develop a model for a solar refrigeration system (SRS) that utilizes an External Compound Parabolic Collector and a thermal energy storage system (TESS) for solar water heating in Chennai, India. The system parameters were optimized using TRNSYS software by varying factors such as collector area, mass flow rate of heat transfer fluid, and storage system volume and height. The resulting optimized system was found to meet 80% of hot water requirements for the application on an annual basis, with an annual collector energy efficiency of 58% and an annual TESS exergy efficiency of 64% for a discharge period of 6 h per day. In addition, the thermal performance of 3.5 kW SRS was studied by connecting it to an optimized solar water heating system (SWHS). The system was found to generate an average cooling energy of 12.26 MJ/h annually, with a coefficient of performance of 0.59. By demonstrating the ability to efficiently generate both hot water and cooling energy, the results of this study indicate the potential for utilizing a SWHS in combination with STST and SRS. The optimization of system parameters and the use of exergy analysis provide valuable insights into the thermal behavior and performance of the system, which can inform future designs and improve the overall efficiency of similar systems.
This study seeks to ascertain whether there is an unbalanced link between CO2 emissions, foreign direct investment, and economic growth in Malaysia over a 40-year timeframe between 1980 and 2019. We investigated the asymmetric relationship , using non-linear autoregressive distributed lag (NARDL) technique. The findings showed a noteworthy asymmetry between FDI, CO2 emissions, and GDP in Malaysia. The long-term and short-term effects of negative FDI on GDP are both equivalent to 0.028 and 0.021, respectively. This suggests that, compared to short-term fluctuations, long-term negative FDI adjustments have a considerably more negative impact on economic growth. The coefficient of positive (CO2+) and negative (CO2-) changes in economic growth is equal to 0.086 and - 0.152, respectively. It indicates that positive changes in CO2 emissions have stronger effects in the long run than negative shocks. Considering an asymmetric association between these two variables in the short and long term, Malaysian policymakers must comprehend the dynamic relationship between FDI, CO2 emissions, and GDP to plan appropriate economic and environmental policies that will support sustainable economic development and ensure a safer environment.
Urban-dwelling birds can be useful biomonitors to assess the impact of the urbanisation on both public and wildlife health. Widely distributed urban bird species, the House crow, was studied for heavy metal accumulation levels from nine cities of South Asia, Southeast Asia and Africa that border the Indian Ocean. Feathers were spectroscopically investigated for the deposition of ten heavy metals, i.e. As, Zn, Pb, Cd, Ni, iron Fe, Mn, Cr, Cu and Li. Fe and Zn were found to be the most prevalent metals in all sites. Measured concentrations of Pb (4.38-14.77 mg kg-1) overall, and Fe (935.66 mg kg-1) and Cu (67.17 mg kg-1) at some studied sites were above the toxicity levels reported lethal in avian toxicological studies. Multivariate analysis and linear models supported geographical location as a significant predictor for the level of most of the metals. Zn and Cu, generally and Pb, Cd, Mn, Cr at some sites exhibited potential bioaccumulation from surrounding environments. Inter-species comparisons strengthen the inference that the House crow is a reliable bioindicator species for the qualitative assessment of local urban environmental pollution and could be a useful tool for inter-regional monitoring programs.
Recent years have seen a burgeoning interest in the involvement of corporate sustainability (CS) in sustainable development (SD), yet both concepts are fewer and newer in the academic field. This study aims to present a thorough bibliometric analysis that provides fresh new insights on the subject. Using VOSviewer software, this study analyzed and visualized 1214 documents for the period 2005-2021 in the Web of Science (WoS) database. The findings of the study indicate that the co-theme CS and SD are lasting but thriving research subjects. The findings also revealed that authors from the USA published the highest number of articles followed by the UK, Spain, Italy, and Germany. The co-authorship network showed strong links between these countries. Three main clusters are identified based on research titles frequently co-cited and have significant co-citation connections. In general, this study provides valuable insight into the current status and future trends for research on SDGs. The outcome of the study could be useful to policymakers, regulators, sustainability practitioners, and researchers in understanding the key research areas, influential authors, institutions, and countries actively involved in the field. Considering the involvement of corporate sustainability in sustainable development is a useful and informative endeavor for all community actors. To the best of the authors' knowledge, this is the first comprehensive study that presents the holistic picture of CS and SD-related research to identify the knowledge map between the two subjects.
Global warming has amplified the frequency of temperature extremes, especially in hot dry countries, which could have serious consequences for the natural and built environments. Egypt is one of the hot desert climate regions that are more susceptible to climate change and associated hazards. This study attempted to project the changes in temperature extremes for three Shared Socioeconomic Pathways (SSPs), namely, SSP1-2.6, SSP2-4.5, and SSP5-8.5 and two future periods (early future: 2020-2059 and late future: 2060-2099) by using daily maximum (Tmax) and minimum temperature (Tmin) of general circulation model (GCMs) of Coupled Model Inter-comparison Project phase 6 (CMIP6). The findings showed that most temperature extreme indices would increase especially by the end of the century. In the late future, the change in the mean Tmin (4.3 °C) was projected to be higher than the mean Tmax (3.7 °C). Annual maximum Tmax, temperature above 95th percentile of Tmax, and the number of hot days above 40 °C and 45 °C were projected to increase in the range 3.0‒5.4 °C, 1.5‒4.8 °C, 20‒95 days, and 10‒52 days, respectively. In contrast, the annual minimum of Tmin, temperature below the 5th percentile, and the annual percentage of cold nights were projected to change in the range of 2.95‒5.0 °C, 1.4‒3.6 °C, and - 0.1‒0.1%, respectively. In all the cases, the lowest changes would be for SSP1-2.6 in the early period and the greatest changes for SSP5-8.5 in the late period. The study indicates that the country is likely to experience a rise in hot extremes and a decline in cold extremes. Therefore, Egypt should take long-term adaptation plans to build social resiliency to rising hot extremes.