In recent years, off-site volumetric construction has been promoted as a viable strategy for improving the sustainability of the construction industry. Most prefabricated prefinished volumetric construction (PPVC) structures are composed of either steel or concrete; thus, it is imperative to carry out life cycle assessments (LCAs) for both types of structures. PPVC is a method by which free-standing volumetric modules-complete with finishes for walls, floors, and ceilings-are prefabricated and then transferred and erected on-site. Although many studies have examined these structures, few have combined economic and environmental life cycle analyses, particularly for prefinished volumetric construction buildings. The purpose of this study is to utilize LCA and life cycle cost (LCC) methods to compare the environmental impacts and costs of steel and concrete PPVCs "from cradle to grave." The results show that steel necessitates higher electricity usage than concrete in all environmental categories, while concrete has a higher emission rate. Steel outperforms concrete by approximately 37% in non-renewable energy measures, 38% in respiratory inorganics, 43% in land occupation, and 40% in mineral extraction. Concrete, on the other hand, performs 54% better on average in terms of measures adopted for greenhouse gas (GHG) emissions. Steel incurs a higher cost in the construction stage but is ultimately the more economical choice, costing 4% less than concrete PPVC owing to the recovery, recycling, and reuse of materials. In general, steel PPVC exhibits better performance, both in terms of cost and environmental factors (excluding GHG emissions). This study endeavors to improve the implementation and general understanding of PPVC.
This study attempts to investigate the environment cleanness between the total factor productivity, natural resources and green taxation on Malaysia's clean environment. Using the environmental Kuznets curve (EKC) hypothesis, this study employs the bootstrap quantile estimates based on the annual data series covering the period of 1970-2018 to analyse the quantile effect factors affecting environment cleanness in Malaysia. The empirical estimates of this study reject the EKC hypothesis throughout the quantile levels, while the green taxation shows a negative sign which indicated government fiscal policies are reducing carbon emission in the upper quantiles. There is also homogeneity slope equality effect between total factor of productivity and green taxation on carbon emissions in the middle and upper quantile levels, while natural resources are indication heterogeneity effect on all quantile levels. From the policy point of view, if Malaysia wants to get environment cleanness, there is a need for comprehensive policies of total factor of productivity with environment innovation-friendly and technological improvement in all major economic sectors of the country.
The broad purpose of this study is to empirically explore the impact of globalization and financial development on environmental pollution by carbon (CO2) emissions in the six Middle East and North Africa (MENA) countries using balanced panel data from 1971 to 2015. We also aimed to test the legitimacy of the environmental Kuznets curve (EKC) hypothesis for this region. The fixed-effects approach preferred by the Hausman specification test is used to estimate the empirical model, and the feasible generalized least squares (F.G.L.S.) estimator is employed to cope with any issue of heteroscedasticity and serial correlation. This study found that globalization and financial development have adverse and significant effects on environmental degradation and affirm the legitimacy of the EKC hypothesis for these countries. The finding of this study suggests that the governments of MENA countries should design and implement appropriate policies for strengthening the renewable sources of energy like wind, solar, bio-fuel, and thermal to decrease CO2 emissions and boost sustainable economic development. The policymakers should focus on the efficiency of institutions and enhancement of energy-saving projects in this region.
Economic integration in the form of Belt and Road Initiative project opens many opportunities and hazards, especially of the participating nations' environment. The current study attempted to empirically test the economic and energy usage (renewable and non-renewable) impact on some selected countries of belt and road projects. For this purpose, the panel data set of twenty-four emerging economies of belt and road projects was selected from 1995 to 2014. The autoregressive distributed lags technique of econometric applied to determine the effect of renewable and non-renewable energy, GDP and GDP2 for EKC, and gross fixed capital formation on carbon emission in the selected countries of Belt and Road Initiative project. The outcomes of this study confirm the existence of EKC in these underlined countries. Here, fossil fuel-based energy consumption is a source of environmental degradation, while renewable and clean energy usage can help sustain environmental conditions without affecting economic growth progress. Capital fixed formation in these economies can enhance economic growth and help to sustainable environmental conditions in the belt and road countries. Thus, based on these empirical outcomes, this study suggests economic and financial assistance in green renewable energy sources and clean technological innovation to enhance economic benefits of Belt and Road Initiative project without compromising the environmental conditions of the region.
Considering the importance of green economic growth and environmental sustainability in the discussion, it is crucial to understand its critical contributing factors and to draw results implications for the green policy. This research used the data of the South Asian Association for Regional Cooperation (SAARC) member countries for a period from 2005 to 2017. It adopted the panel autoregressive distributed lag technique to examine the hypotheses. The findings revealed that environmental sustainability is strongly and positively associated with national scale-level green practices, including renewable energy, regulatory pressure, and eco-friendly policies, and sustainable use of natural resources. Conversely, in our model, the "regulatory pressure" has an insignificant effect on economic growth. A necessary contribution of the present study is that a positive effect of green practices on national scale economic and environmental variables, particularly in the scenario of SAARC member states, can be noticed. At the end of the present study, we have provided policy implications for regulatory authorities and discussed potential areas for future research.
The study aims to analyze two objectives: first is to explore the non-linear relationship between tourism development, economic growth, urbanization, and environmental degradation, and also to analyze the threshold level of the contribution of tourism development on environmental degradation in top tourist arrival destinations. We applied the newly proposed econometric method panel smooth transition regression (PSTR) framework with two regimes on yearly panel data from 1995 to 2017. Findings suggest that the relationship between tourism development and environmental degradation is non-linear and regime dependent. Furthermore, the findings indicated that the relationship above the threshold level is negative and significant, while below the threshold, tourism development is positive and significant effect on environmental degradation. Tourism development and environmental degradation also exhibit the inverted U-shape relationship meaning that at a particular point, increase in tourism development increases in environmental degradation but after a particular point, increase in tourism development decreases the environmental degradation. The economic growth and urbanization also portray a non-linear and regime-dependent relationship with environmental degradation. The study assists policies and empirical information.
There is a need to develop an accurate and reliable model for predicting suspended sediment load (SSL) because of its complexity and difficulty in practice. This is due to the fact that sediment transportation is extremely nonlinear and is directed by numerous parameters such as rainfall, sediment supply, and strength of flow. Thus, this study examined two scenarios to investigate the effectiveness of the artificial neural network (ANN) models and determine the sensitivity of the predictive accuracy of the model to specific input parameters. The first scenario proposed three advanced optimisers-whale algorithm (WA), particle swarm optimization (PSO), and bat algorithm (BA)-for the optimisation of the performance of artificial neural network (ANN) in accurately predicting the suspended sediment load rate at the Goorganrood basin, Iran. In total, 5 different input combinations were examined in various lag days of up to 5 days to make a 1-day-ahead SSL prediction. Scenario 2 introduced a multi-objective (MO) optimisation algorithm that utilises the same inputs from scenario 1 as a way of determining the best combination of inputs. Results from scenario 1 revealed that high accuracy levels were achieved upon utilisation of a hybrid ANN-WA model over the ANN-BA with an RMSE value ranging from 1 to 6%. Furthermore, the ANN-WA model performed better than the ANN-PSO with an accuracy improvement value of 5-20%. Scenario 2 achieved the highest R2 when ANN-MOWA was introduced which shows that hybridisation of the multi-objective algorithm with WA and ANN model significantly improves the accuracy of ANN in predicting the daily suspended sediment load.
This paper assesses the Environmental Kuznets curve based on quantile behavior of the relationship between economic growth, forest area, agriculture production, renewable energy, and environmental degradation. The current literature generally used a single indicator to address environmental issues; however single indicator neither measures overall environmental conditions nor does specify that the environment issue is generally diminishing. Our study is the first one that used ecological footprint (EF) as an indicator to test environmental Kuznets curve (EKC) hypothesis for Pakistan by employing recent approach of quantile autoregressive distributed lag (QARDL) initiated by Cho et al. (J Econ 188(1):281-300, 2015). The result of this study validates the EKC hypothesis for Pakistan and shows quantile-dependent relationship, and in that case, using the conventional methods may somewhat lead to biased results. Moreover, the rejection of the null hypothesis of parameter constancy is also confirmed by Wald test. In the long run, the findings of renewable energy consumption and forest area show significant negative effects on ecological footprints, which indicates that by increasing renewable energy usage and forest area, ecological footprints can be minimized. Interestingly, the short-term effects of agricultural production findings on EF show statistically negative results. This illustrates that EF can also be reduced in the agriculture sector by adopting environment-friendly technologies. In order to create efficient policies for environment deterioration, the empirical findings of the current analysis can be used as a guideline for policy implications.
This study highlights the importance of mineralogical composition for potential carbon dioxide (CO2) capture and storage of mine waste materials. In particular, this study attempts to evaluate the role of mineral carbonation of sedimentary mine waste and their potential reutilization as supplementary cementitious material (SCM). Limestone and gold mine wastes were recovered from mine processing sites for their use as SCM in brick-making and for evaluation of potential carbon sequestration. Dominant minerals in the limestone mine waste were calcite and akermanite (calcium silicate) while the gold mine waste was dominated by illite (iron silicate) and chlorite-serpentine (magnesium silicate). Calcium oxide, CaO and silica, SiO2, were the highest composition in the limestone and gold mine waste, respectively, with maximum CO2 storage of between 7.17 and 61.37%. Greater potential for CO2 capture was observed for limestone mine waste as due to higher CaO content alongside magnesium oxide. Mineral carbonation of the limestone mine waste was accelerated at smaller particle size of
The rapidly increasing generation of municipal solid waste (MSW) threatens the environmental integrity and well-being of humans at a global level. Incineration is regarded as a technically sound technology for the management of MSW. However, the effective management of the municipal solid waste incineration (MSWI) ashes remains a challenge. This article presents the global dynamics of MSWI ashes research from 1994 to 2018 based on a bibliometric analysis of 1810 publications (research articles and conference proceedings) extracted from the Web of Science database, followed by a comprehensive summary on the research developments in the field. The results indicate the rapid growth of annual publications on MSWI ashes research, with China observed as the most productive country within the study period. Waste Management, Journal of Hazardous Materials, Chemosphere and Waste Management & Research, which accounted for 35.42% of documents on MSWI research, are the most prominent journals in the field. The most critical thematic areas on this topic are MSWI ashes characterisation, dioxin emissions from fly ash, valorisation of bottom ash and heavy metal removal. The evolution of MSWI ashes treatment technologies is also discussed, together with the challenges and future research directions. This is the first bibliometric analysis on global MSWI ashes research based on a sufficiently large dataset, which could provide new insights for researchers to initiate further research with leading institutions/authors and ultimately advance this research field.
The need for the sensing of environmental pollutants cannot be overemphasized in the twenty-first century. Herein, a sensor has been developed for the sensitive and selective detection of copper (Cu2+), lead (Pb2+) and cadmium (Cd2+) as major heavy metals polluting water environment. A screen-printed carbon electrode (SPCE) modified by fluorescent carbon dots (CDs) and gold nanoparticles (AuNPs) was successfully fabricated for sensing Cu2+, Pb2+ and Cd2+. Differential pulse voltammetry (DPV) and cyclic voltammetry (CV) were deployed for the analysis of ternary analytes. CV was set at a potential range of - 0.8 to + 0.2 V at a scan rate of 100 mV/s, and DPV at a potential range of - 0.8 to + 0.1 V, scan rate of 50 mV/s, pulse rate of 0.2 V and pulse width of 50 ms. DPV technique was applied through the modified electrode for sensitive and selective determination of Cu2+, Pb2+ and Cd2+ at a concentration range of 0.01 to 0.27 ppm for Cu2+, Pb2+ and Cd2+. Tolerance for the highest possible concentration of foreign substances such as Mg2+, K+, Na+, NO3-, and SO42- was observed with a relative error less than ± 3%. The sensitivity of the modified electrode was at 0.17, 0.42 and 0.18 ppm for Cd2+, Pb2+ and Cu2+, respectively, while the limits of detection (LOD) achieved for cadmium, lead and copper were 0.0028, 0.0042 and 0.014 ppm, respectively. The quality of the modified electrode for sensing Cu2+, Pb2+ and Cd2+ at trace levels is in accordance with the World Health Organization (WHO) and Environmental Protection Agency (EPA) water regulation standard. The modified SPCE provides a cost-effective, dependable and stable means of detecting heavy metal ions (Cu2+, Pb2+ and Cd2+) in an aqueous solution. Graphical abstract .
Corbicula fluminea (C. fluminea) is one of the mollusc species commonly eaten as a popular snack in Kelantan, Malaysia. This species contributes to the local economic activity. However, the handling process of C. fluminea at different processing stages (raw, smoke and selling stages) is believed to have affected the nutritional value in their soft tissue. Hence, this study aims to provide information about the chemical content (moisture, crude fat, ash, crude protein and carbohydrate) of C. fluminea and fatty acid of smoked C. fluminea at different processing stages. Samples were collected from Pasir Mas and Tumpat, Kelantan, Malaysia. The chemical content analysis was carried out based on the Association of Official Analytical Chemists (AOAC) standard procedures. The results have indicated that moisture (80.93 ± 0.37%) and crude fat (10.82 ± 0.21%) in C. fluminea were significantly higher (p
Adsorption capacity and percentage removal efficiency of Cu(II) and Ni(II) ions were studied and compared between raw kaolinite and acid-activated kaolinite. Acid-activated kaolin was prepared by refluxing raw kaolinite with concentrated sulphuric acid followed by calcination to enhance its surface properties and adsorption ability. Both raw and acid-activated kaolinite samples were characterized by Fourier transform infrared spectroscopy, energy dispersive X-ray, scanning electron micrograph and zeta potential analysis. Upon acid treatment, acid-activated kaolinite was discovered to have altered chemical composition and larger BET surface area as compared with raw kaolinite. The batch adsorption studies on aqueous solution were performed under different factors such as contact time, pH condition, adsorbent dosage, initial metal ion concentration and temperature. The optimum condition was selected for each factor including a contact time of 60 min, pH of 7.0, adsorbent dosage of 0.1 g, initial metal ion concentration of 100 mg/L and temperature of 25 °C. Then, the adsorption studies on wastewater samples were carried out at the selected optimum conditions. Acid-activated kaolinite always had better adsorption capacity and percentage removal efficiency than raw kaolinite due to the increasing amount of negative charges on the adsorbent surface and the number of metal ion binding sites upon acid treatment. The adsorption kinetic obtained was well described by the pseudo-second-order model, whereas the adsorption isotherms obtained were well described by either the Freundlich or the Langmuir adsorption model. The results showed that acid-activated kaolinite adsorbent is a better option as a favourable and feasible commercial low-cost adsorbent for wastewater treatment.
This study aims to gain more understanding on highland farmers' adaptation towards the impacts of climate change in Malaysia. Via a multi-stage cluster sampling, this quantitative study has surveyed a total of 400 highland farmers as respondents. The results indicated that the highest climate change-resilient farmers were from Kundasang, specifically among the females, Dusun ethnic group, and those who work side jobs to cover household expenses. Furthermore, recorded factors such as age and years of experience yielded significant negative relationship with adaptation whereas income yielded significant positive relationship with adaptation. The paper concludes with recommendations related to occupational diversification, consistent information disseminations, access to financial assistance, and the need to empower extension officers and local leaders in the hope that a comprehensive approach can help implement any community climate change-adaptation plan.
The anaerobic decomposition of coconut endosperm waste (CEW), residue derived from cooking, has been insidiously spewing greenhouse gasses. Thus, the bioconversion of CEW via in situ fermentation by exo-microbes from commercial Rid-X and subsequent valorization by black soldier fly larvae (BSFL) was the primary objective of the current study to gain sustainable larval lipid and protein. Accordingly, various concentrations of exo-microbes were separately homogenized with CEW to perform fermentation amidst feeding to BSFL. It was found that 2.50% of exo-microbes was the threshold amount entailed to assuage competition between exo-microbes and BSFL for common nutrients. The presence of remnant nutrients exuded from the fermentation using 2.50% of exo-microbes was confirmed to promote BSFL growth measured as maximum larval weight gained and growth rate. Although the BSFL could accumulate the highest protein (16 mg/larva) upon feeding with CEW containing 2.50% of exo-microbes, more lipid (13 mg/larva) was stored in employing 0.10% of exo-microbes because of minimum loss to metabolic processes while prolonging the BSFL in its 5th instar stage.
This paper uses the quantile autoregressive distributed lag (QARDL) model to analyze the impact of economic growth, tourism, transportation, and globalization on carbon dioxide (CO2) emissions in the Malaysian economy. The QARDL model is employed utilizing quarterly data from 1995Q1 to 2018Q4. The results demonstrate that economic growth is significantly positive with CO2 emissions at lower to upper quantiles. Interestingly, tourism has a negative effect on CO2 emissions at higher quantiles. Moreover, globalization and transportation services are positive, with CO2 emissions at upper-middle to higher quantiles. Furthermore, we tested the environmental Kuznets curve, and the outcomes confirm the presence of the inverted U-shaped curve in the Malaysian economy. The results of this study suggest that ecotourism is beneficial for economic growth in underdeveloped areas; it increases employment opportunities and, thus, achieves a win-win situation for protection and development. The government should encourage the low-carbon development of ecotourism and achieve green development of both tourism and the economy.
Photo-Fenton oxidation is one of the most promising processes to remove recalcitrant contaminants from industrial wastewater. In this study, we developed a novel heterogeneous catalyst to enhance photo-Fenton oxidation. Multi-composition (Fe-Cu-Zn) on aluminosilicate zeolite (ZSM-5) was prepared using a chemical process. Subsequently, the synthesized catalyst was characterized by using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (spectroscopy) (EDX), and Brunauer-Emmett-Teller (BET). Activity of the synthesized catalyst is analysed to degrade an azo dye, methyl orange. Taguchi method is used to optimize color removal and total carbon content (TOC) removal. The dye completely degraded, and 76% of TOC removal was obtained at optimized process conditions. The amount of catalyst required for the desired degradation of dye significantly reduced up to 92% and 30% compared to conventional homogenous and heterogeneous Fenton oxidation processes, respectively.
With the ever-increasing energy demands, fossil fuels are gradually depleting and eventually, these nonrenewable sources of energy will be exhausted. Hence, there is an urgent need to formulate alternative fuels that are both renewable and sustainable. Biomass is one of the reliable sources of energy because it is replenishable. Rice is the staple food in many countries, particularly in Asia. The number of paddy fields has increased tremendously over the years and is expected to increase in the future in response to the growing world population. This will lead to significant amounts of agricultural wastes annually, particularly rice straw. In some countries, open burning and soil incorporation are used to manage agricultural wastes. Open burning is the preferred method because it is inexpensive. However, this method is highly undesirable because of its detrimental impact on the environment resulting from the release of carbon dioxide and methane gas. Hence, it is important to develop an energy-harvesting method from rice straw for power generation. More studies need to be carried out on the availability and characteristics of rice straw as well as logistic analysis to assess the potential of rice straw for power generation. This paper is focused on reviewing studies pertaining to the characteristics and potential of rice straw for power generation, current rice straw management practices, and logistic analysis in order to develop a suitable energy-harvesting method from rice straw in Malaysia.
This study examined behavioural intention to dispose of unused medicines using a comprehensive model integrating the theory of planned behaviour (TPB), with knowledge as a driver of personal norms; attitudes, personal norms, and perceived busyness as additional drivers of behavioural intention; and perceived convenience as a moderator. The model was tested with data collected from 204 respondents using the partial least squares technique. Knowledge about the proper disposal of unused medicines was recognized as a strong predictor of personal norms and attitudes towards proper disposal of waste medications. The results showed that attitudes, personal norms, perceived busyness, and perceived behavioural control have significant effects on intention to dispose of unused medicines. Furthermore, perceived convenience moderates the impacts of attitude, personal norms, and perceived behavioural control on intention to dispose of unused medicines. The extended TPB explained 55.7% of the variance of intention to dispose of unused medicines properly. Our results indicate the importance of integrating additional variables into the TPB to enhance its explanatory power in predicting behavioural intention. The results suggest to governments that in order to implement planned programs for proper collection and destruction of waste medication, a plan is needed to enhance public knowledge on the impacts of improper medication waste disposal on the environment, and also that collection points should become accessible for anyone.
Pyroligneous acid (PA) obtained from slow pyrolysis of palm kernel shell (PKS) has high total phenolic contents and exhibits various biological activities including antioxidant, antibacterial and antifungal. In this study, PA obtained using slow pyrolysis method and fractionated using column chromatography was characterized (chemical and antioxidative properties) and investigated for its cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) inhibition activities using the in vitro and in silico approaches. The F9 PA fraction exhibited highest total phenolic content of 181.75 ± 17.0 μg/mL. Fraction F21-25 showed ferric reducing antioxidant power (FRAP) (331.80 ± 4.60 mg TE/g) and IC50 of 18.56 ± 0.01 μg/mL towards COX-2 and 5.25 ± 0.03 μg/mL towards the 5-LOX enzymes, respectively. Molecular docking analysis suggested favourable binding energy for all chemical compounds present in fraction F21-25, notably 1-(2,4,6-trihydroxyphenyl)-2-pentanone, towards both COX-2 (- 6.9 kcal/mol) and 5-LOX (- 6.4 kcal/mol) enzymes. As a conclusion, PA from PKS has the potential to be used as an alternative antioxidant and antiinflammatory agents which is biodegradable and a more sustainable supply of raw materials.