Terrestrial anionic surfactants (AS) enter the marine environment through coastal region. Despite that, in general limited knowledge is available on the coastal AS transfer pathway. This paper aims to assess the distributions and exchange of AS in the Peninsular Malaysia coastal environments, adjacent to the southern waters of South China Sea and Strait of Malacca. An assessment case study was conducted by a review on the available data from the workgroup that span between the year 2008 and 2019. The findings showed that AS dominated in the sea surface microlayer (SML, 57%) compared to subsurface water (SSW, 43 %). AS were also found to have dominated in fine mode (FM, 71 %) compared to coarse mode (CM, 29 %) atmospheric aerosols. SML AS correspond to the SSW AS (p < 0.01); however, highest enrichment factor (EF) of the SML AS was not consistent with highest SSW AS. Direct AS exchange between SML and FM and CM was not observed. Furthermore, the paper concludes AS mainly located in the SML and FM and could potentially be the main transfer pathway in the coastal environment.
Enterprises across the globe are facing increasing pressure to effectively utilize resources and reduce costs through green supply chain practices. Emerging technology, such as blockchain technology which enables green practices, has become a contemporary industrial paradigm. However, enterprises need to build green intellectual capital to implement blockchain technology, which can be key to realizing green supply chain practices. This research examines the impact of green intellectual capital (GIC) on blockchain technology and its role in implementing green manufacturing to achieve sustainability. Partial least squares structural equation modeling was utilized for assessing the proposed hypotheses, and cross-sectional data was accumulated from manufacturing firms. As per the results, GIC, which includes green human capital, green structural capital, and green relational capital has a crucial role in the implementation of blockchain technology. The outcomes also indicated that the adoption of blockchain technology significantly influences green manufacturing. Moreover, green manufacturing (GM) has a substantial role in improving business sustainability. This empirical research provides a deeper understanding of how GIC and blockchain technology contribute to the implementation of GM. This research also provides guidelines that managers, policymakers, and producers can use to facilitate the incorporation of GM practice into business activities.
This study investigates hydrocarbon pollution in the Ahoada community of the Niger Delta region of Nigeria. The study uses a geographic information system (GIS) for mapping oil spill hotspots in the region. The resistivity method was used to delineate the extent of hydrocarbon pollution to a depth of 19.7 m in the Ahoada area of the region. Three categories of soil samples, impacted soil (IMS), remediated soil (RS), and control soil (CS), were collected and analyzed for the presence of BTEX, PAH, TPH, TOC, and TOG. The concentrations of the samples from the IMS and RS were compared to that of the CS to determine the extent of pollution. The GIS mapping shows that the most polluted areas in the Niger Delta Region are Rivers, Bayelsa, and Delta states. Results of the geophysical images revealed contaminants' presence to depths beyond 20 m at some locations in the study area. The highest depth of contaminant travel was at Ukperede. Soil samples' analysis showed that the range of concentrations of TPH in IMS at Oshie was 17.27-58.36 mg/kg; RS was 11.73-50.78 mg/kg which were higher than the concentrations of 0.68 mg/kg in the CS. PAHs are more prevalent in Ukperede, ranging from 54.56 to 77.54 mg/kg. BTEX concentrations ranged from 0.02 to 0.38 mg/kg for IMP and 0.01-2.7 mg/kg for RS against a CS value of 0.01 mg/kg. The study revealed that there are characteristically high resistivity values in the samples which were corroborated by the findings from the resistivity survey. TOC was found to be higher in the IMS and RS than in the CS, demonstrating that a significant quantity of the hydrocarbon has undergone appreciable decomposition.
The increasing level of greenhouse gas carbon emission currently exacerbates the devastating effect of global warming on the Earth's ecosystem. Energy usage is one of the most important determinants that is increasing the amount of carbon gases being released. Simultaneously, the level of energy usage is derived by the price, and therefore, this study examines the contribution of energy price to carbon gas emissions in thirteen African nations for the period spanning 1990 to 2017. It does this by utilising the cross-sectional dependence (CD), augmented mean group (AMG) and pooled mean group (PMG) panel modelling methods. The findings of the AMG model suggest that a 1% increase in energy price leads to a 0.02% decrease in carbon emission. The results further reveal that a 1% increase in energy intensity and technological innovation leads to 0.04% and 3.65% increase in carbon emission, respectively, in the selected African countries. Findings will help policymakers to implement effective energy price policies to reduce carbon emissions and achieve sustainable development goals especially in the emerging economies of Africa.
Empirical studies pertaining to the effects of fiscal policy instruments on environmental quality have provided mixed evidence. We consider the asymmetric effects of fiscal policy instruments on environmental quality for the top ten Asian carbon emitters over the period 1981-2018. We go beyond the literature and claim that the effects could be asymmetric. More specifically, we found that a positive shock in government expenditure will worsen environmental quality in Malaysia, UAE, Thailand, Indonesia, Turkey, Iran, India, and China, and improve it in Japan. On the other hand, we found that cutting government expenditure will improve environmental quality in these economies and will worsen only in Japan. Moreover, a higher government income tax revenue uniquely increases the government's spending that increases the carbon emissions in Malaysia, UAE, Thailand, Indonesia, Turkey, Iran, India, and China, and decrease in Japan. The negative shock of government revenue has adverse results on carbon emissions in these economies. However, short-run asymmetric effects translate to long-run effects in most Asian economies.
Sungai Puloh mangrove estuary supports a large diversity of macrobenthic organisms and provides social benefits to the local community. Recently, it became a major recipient of heavy metals originating from industries in the hinterland as a result of industrialization and urbanization. This study was conducted to evaluate mobility and pollution status of heavy metals (Cd, Cu, Ni, Pb, Zn, and Fe) in intertidal surface sediments of this area. Surface sediment samples were collected based on four different anthropogenic sources. Metals concentrations were analyzed using an atomic absorption spectrophotometer (AAS). Results revealed that the mean concentrations were Zn (1023.68 ± 762.93 μg/g), Pb (78.8 ± 49.61 μg/g), Cu (46.89 ± 43.79 μg/g), Ni (35.54 ± 10.75 μg/g), Cd (0.94 ± 0.29 μg/g), and Fe (7.14 ± 0.94%). Most of the mean values of analyzed metals were below both the interim sediment quality guidelines (ISQG-low and ISQG-high), except for Pb concentration (above ISQG-low) and Zn concentration (above ISQG-high), thus suggesting that Pb and Zn may pose some environmental concern. Cadmium, Pb, and Zn concentrations were above the threshold effect level (TEL), indicating seldom adverse effect of these metals on macrobenthic organisms. Pollution load index (PLI) indicated deterioration and other indices revealed the intertidal surface sediment is moderately polluted with Cd, Pb, and Zn. Therefore, this mangrove area requires urgent attention to mitigate further contamination. Finally, this study will contribute to data sources for Malaysia in establishing her own ISQG since it is a baseline study with detailed contamination assessment indices for surface sediment of intertidal mangrove area.
The relationship between national income growth and the environment of 14 Asian economies over a 50 year period is examined using the Environmental Kuznets Curve (EKC) hypothesis. Ecological Footprint (EF) measures environmental impacts and gross domestic product (GDP) measures economic growth. It is hypothesised that increased rates of economic growth come at a cost to the natural environment. The EKC hypothesis has been mainly tested in the literature by cross-sectional or panel data methods. In this study, it is tested using time series analysis through initially examining the relationship between EF and GDP using linear, quadratic and cubic estimating OLS regression functions. In the second stage, the long-run relationship between EF and GDP is investigated using an augmented error correction trend model. There is a statistically significant cointegrated long-run relationship between the variables in most of the countries. The EKC hypothesis is supported in the case of India, Nepal, Malaysia and Pakistan with the other countries exhibiting a positive linear relationship between the two variables. Almost all error correction terms are correct in sign and significance that implies that some percentage of disequilibria in EF in the previous year adjusts back to the long-run equilibrium in the current year. Based on the long-run relationship, it is apparent that rapid economic growth has had an impact on the environment and the ecosystems of these countries over the last 50 years. Despite that, until now, not many of them have taken sufficient steps to reduce their EF or to improve their bioproductive capacity.
The purpose of this research is to synthesize environmentally friendly nanosorbents for the novel adsorption of diesel range organics (DRO) from contaminated water. Central composite design (CCD) analysis of response surface methodology (RSM) was employed in a model fitting of the variables predicting the adsorption efficiency of Moringa oleifera-functionalized zerovalent iron particles (ZINPs) for the removal of DRO. The effects of the reaction parameters on the response were screened using 24 factorial designs to determine the statistically significant independent variables. A quadratic model predicting the DRO adsorption efficiency of ZINPs with an F value of 276.84 (p value
Economic growth is a global requirement that requires extensive energy consumption, and this phenomenon needs researchers' attention and regulators' focus. Thereby, the paper scrutinizes the determinants of energy consumption such as fossil fuel energy consumption (FFEC), energy use, nuclear energy consumption (NEC), energy import, and renewable energy consumption (REC) and sustainability-oriented eco-innovation and their effectiveness on the economic growth of Saudi Arabia. The study extracted data from the World Bank from 1989 to 2020. Stationarity was examined using augmented Dickey-Fuller (ADF) tests, and the associations among constructs were analyzed through QARDL model. The findings revealed that FFEC, EU, NEC, EI, REC, and sustainability-oriented eco-innovation are significantly correlated with the EG of Saudi Arabia. The study also provides insights to new researchers who will investigate this area in the future and guides regulators in developing regulations related to economic growth using an appropriate level of energy and adoption of sustainability-oriented eco-innovation.
This study conducts a comprehensive literature review of articles on the triple bottom line (TBL) published from January 1997 to September 2018 to provide significant insights and support to guide further discussion. There were three booms in TBL publications, occurring in 2003, 2011, and 2015, and many articles attempt to address the issue of sustainability by employing the TBL. This literature analysis includes 720, 132, and 58 articles from the Web of Science (WOS), Inspec, and Scopus databases, respectively, and reveals the gaps in existing research. To discover the barriers and points of overlap, these articles are categorized into six aspects of the TBL: economic, environmental, social, operations, technology, and engineering. Examining the top 3 journals in terms of published articles on each aspect reveals the research trends and gaps. The findings provide solid evidence confirming the argument that the TBL as currently defined is insufficient to cover the entire concept of sustainability. The social and engineering aspects still require more discussion to support the linkage of the TBL and to reinforce its theoretical basis. Additionally, to discover the gaps in the data sources, theories applied, methods adopted, and types of contributions, this article summarizes 82 highly cited articles covering each aspect. This article offers theoretical insights by identifying the top contributing countries, institutions, authors, keyword networks, and authorship networks to encourage scholars to push the current discussion further forward, and it provides practical insights to bridge the gap between theory and practice for enhancing the efficiency and effectiveness of improvements.
Dye-sensitized solar cell (DSSC) is a photovoltaic device that can be produced from natural source pigments or natural dyes. The selection of natural dyes for DSSC application is currently under research. The utilization of natural dye materials that are easy to obtain, cost-effective, and non-toxic can reduce waste during DSSC fabrication. Natural dyes can be extracted from plants through extraction and chromatography methods. The suitability and viability of utilizing natural dyes as photosensitizers in DSSCs can be predicted using appropriate software simulation by varying related parameters to produce high power conversion efficiency. In this context, the purpose of the review is to highlight the evolution of performance improvement in the development of DSSCs with consideration of natural dye extraction and software simulation. This review also focuses on the results of extracting natural dyes from herbal ingredients, which are still very limited in information, and several parts of herbal plants that can be used as natural dye sources in the future of solid-state DSSCs have been identified. Based on the results of this review, the highest efficiency was obtained for the DSSC that used chlorophyll pigments as natural dyes using Peltophorum pterocarpum leaves with 6.07%, followed by anthocyanin pigments as natural dyes using raspberries (black) fruits with 1.5%, flavonoid pigments as natural dyes using Curcuma longa herbs with 0.64%, and flavonoid pigments as natural dyes using Indigofera tinctoria flowers with 0.46%.
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.
This study investigates the moderating role of environmental disclosures on the market performance of 48 Fintech and 140 non-Fintech firms during the pandemic using data from 2011 to 2022. Ordinary least squares and correlations were used for data analysis. The study's first finding revealed that Fintech firms had a better environmental performance (78.4%) than non-Fintech firms during the pandemic. The study's second finding indicated that environmental disclosures are crucial for shareholders and contributed almost 10.2% to the Fintech firms' market performance during the pandemic. This study's contribution is significant in enhancing the understanding of the shareholders' sensitivity towards sustainability disclosures during financial crisis. The findings of this study are essential for policymakers, start-up entrepreneurs, and shareholders.
This study aims to investigate the relationship between renewable energy and ecological footprint during the period of 1994-2018 from selected developing countries in Europe (Czechia, Croatia, Poland, Romania, Romania, and Turkey). In this context, the ecological footprint (EF), which has recently been the most widely used environmental indicator in the literature and is known as the most comprehensive because it includes many environmental factors, has been determined as the dependent variable. As independent variables, renewable energy consumption (REC), energy-related tax revenue (ETR), and energy productivity (EP) are included in the model. GDP and development of environment-related technologies (DET), which affect the ecological footprint in the model, are determined as control variables. As a result of the panel data analysis, according to the Durbin-Hausman cointegration test result, a long-term relationship between the variables was determined. According to the CCE estimator analysis, it can be said that there is a positive relationship between ETR and GDP variables and EF. For the AMG estimator analysis, it can be said that there is a positive relationship between GDP and EP variables and EF. Finally, according to the results of the Konya Causality test, a unidirectional causality relationship is detected from environmental technologies to the ecological footprint in Turkey, and a unidirectional causality relationship from the ecological footprint to GDP in Czechia, Romania, and Turkey. Furthermore, no causality relationship is detected between other variables. Based on the results, several policy implications are suggested.
Photocatalytic fuel cell (PFC) was employed to provide renewable power sources to photoelectro-Fenton (PEF) process to fabricate a double-chambered hybrid system for the treatment of azo dye, Amaranth. The PFC-PEF hybrid system was interconnected by a circuit attached to the electrodes in PFC and PEF. Circuit connection is the principal channel for the electron transfer and mobility between PFC and PEF. Thus, different circuit connections were evaluated in the hybrid system for their influences on the Amaranth dye degradation. The PFC-PEF system under the complete circuit connection condition attained the highest decolourization efficiency of Amaranth (PFC: 98.85%; PEF: 95.69%), which indicated that the complete circuit connection was crucial for in-situ formation of reactive species in dye degradation. Besides, the pivotal role of ultraviolet (UV) light irradiation in the PFC-PEF system for both dye degradation and electricity generation was revealed through various UV light-illuminating conditions applied for PFC and PEF. A remarkable influence of UV light irradiation on the production of hydrogen peroxide and generation and regeneration of Fe2+ in PEF was demonstrated. This study provided a comprehensive mechanistic insight into the dye degradation and electricity generation by the PFC-PEF system.
Southeast Asia has undergone rapid developments in terms of urbanization, economic and population growth. The progress in sewerage treatment infrastructure has not kept pace with such developments. The inadequacy and inefficiency of sewerage systems has prompted the release of untreated sewage into the aquatic environment of Southeast Asia causing many waterborne illnesses since surface water is utilized for recreational, agricultural and aquaculture purposes and, above all, as a source of water intake in Southeast Asia. This paper will review the current data on molecular markers of sewage pollution including sterols and linear alkylbenzenes (LABs) in Southeast Asian aquatic environment to clarify the state of sewage pollution and the competence of sewage treatment plants (STPs) in this area. Despite the importance of sewage pollution research in the region, the number of studies using molecular markers to trace the sources of sewage pollution is limited. So far, indicators of sewage pollution have been investigated in aquatic environments of Indonesia, Vietnam, Malaysia, the Philippines, Thailand, Cambodia and Brunei among Southeast Asian countries. The concentrations and diagnostic ratios of faecal sterols and LABs show the release of untreated and primary treated urban waste into water bodies of these countries. Further studies are required to fill the data gaps in Southeast Asia and come to a better understanding of the trends of sewage pollution in this part of the world. Graphical abstract.
Textile wastewater contains methylene blue (MB), a major coloring agent in textile industry. Activated carbon (AC) is the most widely used adsorbent in removing dyes from industrial wastewater. However, high production cost of AC is the major obstacle for its wide application in dye wastewater treatment. In this study, a sustainable approach in synthesizing graphenic adsorbent from palm oil mill effluent (POME), a potential carbonaceous source, has been explored. This new development in adsorption technique is considered as green synthesis as it does not require any binder during the synthesis process, and at the same time, it helps to solve the bottleneck of palm oil industry as POME is the main cause contributed to Malaysia's water pollution problem. The synthesized GSC was characterized through XRD, FESEM, and EDX. The adsorption performance of the synthesized GSC was evaluated by adsorption of MB. The effect of initial concentration of synthetic MB solution (1-20 mg/L) and weight of GSC (5-20 g) were investigated. A remarkable change in color of synthetic MB solution from blue to crystal clear was observed at the end of adsorption study. High efficiency of the synthesized GSC for dye-contaminated wastewater treatment is concluded.
The treatment of single and binary azo dyes, as well as the effect of the circuit connection, aeration, and plant on the performance of UFCW-MFC, were explored in this study. The decolorization efficiency of Remazol Yellow FG (RY) (single dye: 98.2 %; binary dye: 92.3 %) was higher than Reactive Black 5 (RB5) (single: 92.3 %; binary: 86.7 %), which could be due to monoazo dye (RY) requiring fewer electrons to break the azo bond compared to the diazo dye (RB5). In contrast, the higher decolorization rate of RB5 in binary dye indicated the removal rate was affected by the electron-withdrawing groups in the dye structure. The closed circuit enhanced about 2% of color and 4% of COD removal. Aeration improved the COD removal by 6%, which could be contributed by the mineralization of intermediates. The toxicity of azo dyes was reduced by 11-26% and the degradation pathways were proposed. The dye removal by the plants was increased with a higher contact time. RB5 was more favorable to be uptook by the plant as RB5 holds a higher partial positive charge. 127.39 (RY), 125.82 (RB5), and 58.66 mW/m3 (binary) of maximum power density were generated. The lower power production in treating the binary dye could be due to more electrons being utilized for the degradation of higher dye concentration. Overall, the UFCW-MFC operated in a closed circuit, aerated, and planted conditions achieved the optimum performance in treating binary azo dyes containing wastewater (dye: 87-92%; COD: 91%) compared to the other conditions (dye: 83-92%; COD: 78-87%).
This study aimed to compare the performance of biofiltration, constructed wetland, and constructed wetland microbial fuel cell (CW-MFC). The transformation from a biofiltration unit to a hybrid CW-MFC was demonstrated with the advantages of improvement of wastewater treatment while generating electricity simultaneously. The introduction of plants to the upper region of the bioreactor enhanced the DO level by 0.8 mg/L, ammonium removal by 5 %, and COD removal by 1 %. The integration of electrodes and external circuits stimulated the degradation rate of organic matter in the anodic region (1 % without aeration and 3 % with aeration) and produced 5.13 mW/m3 of maximum power density. Artificial aeration improved the nitrification efficiency by 38 % and further removed the residual COD to an efficiency of 99 %. The maximum power density was also increased by 3.2 times (16.71 mW/m3) with the aid of aeration. In treating higher organic loading wastewater (3M), the maximum power density showed a significant increment to 78.01 mW/m3 (4.6-fold) and the COD removal efficiency was 98 %. The ohmic overpotential dominated the proportion of total loss (67-91 %), which could be ascribed to the low ionic conductivity. The reduction in activation and concentration loss contributed to the lower internal resistance with the additional aeration and higher organic loading. Overall, the transformation from biofiltration to a hybrid CW-MFC system is worthwhile since the systems quite resemble while CW-MFC could improve the wastewater treatment as well as recover energy from the treated wastewater.