International Journal of Environmental Science and Technology最新文献

The green growth impact of global value chain embedding becomes more complex in the context of digital transformation. Based on partially linear functional-coefficient model, this paper used panel data for 16 Chinese industrial sectors from 2007 to 2020 to assess the impact and underlying mechanisms of global value chain on green total factor productivity considering the moderating role of digitalization. The results revealed that global value chain position and backward participation caused green productivity to decrease, while forward participation had a non-significant effect. As the digitalization level rose, the impact of global value chain position on green productivity changed from negative to positive. Moreover, green productivity was increasingly inhibited by forward participation, but the adverse effects of backward participation gradually subsided. Actually, digitalization boosted green technological progress effects of global value chain position and backward participation, but impeded the technological progress of forward participation, thus affecting green productivity. Therefore, to achieve green growth, China's industrial sector must accelerate the synergistic development of digital transformation and global value chain, and focus on the different impacts of participation modes.

Carbon emission policies have gained significant attention internationally as natural disasters are occurring rapidly and the environment worsens. This research aims to determine the causal relationship between various factors, such as the carbon emission of the South Asian Association for Regional Cooperation countries from 1990 to 2018. To achieve this, the study employs non-linear auto-regressive distributed lag models to analyze Load capacity factor, Fossil fuel consumption, Economic Complexity, Foreign direct investment, Renewable electricity consumption, and Economic Growth on carbon emission. Using this method also aids in capturing the non-linear interaction and temporal dependencies of the data. More specifically, the findings indicate a positive and direct relationship between economic complexity, renewable electricity consumption, and foreign direct investment in achieving sustainable development targets. In contrast, the direct influence of fossil fuel consumption and economic growth has been negative. These findings help understand the extent of progress toward carbon emissions and help the policymakers and stakeholders to design and implement sound and effective strategies for sustainable development that are appropriate to the economic and environmental realities of the countries.

The firms from textile sector are increasingly integrating industry 4.0 technologies alongside micro-level circular economy, considering cleaner production to enhance sustainable performance. The objective of this study is to assess the extent to which industry 4.0 technologies fosters circular economy practices at the micro level, considering cleaner production, thereby bolstering sustainable performance within large textile industry located in Brazil. A systematic literature review was developed with the aim of evaluating the relationship between Industry 4.0 Technologies, Circular Economy, Cleaner Production and Performance. To this end, the current state of the art on this subject was identified, however, no exploratory studies were identified. Survey method was employed, complemented by expert analysis to refine the research instrument. Structural equation modeling was utilized for hypothesis testing, alongside Pearson correlation analysis to examine relationships between variables. Findings indicate that the adoption of industry 4.0 technologies within large textile industry located in Brazil has moderately spurred micro-level circular economy initiatives, because a lack of established mechanisms for valorizing residue and restoring the value of products and packaging after consumption. In addition, sustainable performance was not validated because the focus was only on environmental and economic performance aimed at supplying the foreign market and moderately influenced social performance. Another result showed that the cloud computing, cybersecurity systems, and additive manufacturing did not stimulate micro-level circular economy actions and performance. On the other hand, the industry 4.0 technologies that boosted micro-level circular economy and performance were cyber physical system, autonomous robots, augmented reality, big data analytics, simulation, artificial intelligence and the internet of things.

The most effective methods to protect from epidemics are to comply with personal hygiene and to use personal protective equipment such as masks and gloves. In this context, the use of disposable face masks has become mandatory in many countries, and accordingly, a type of waste with great potential has emerged in the world. As known that single-use face masks caused enormous waste worldwide and environmentally friendly alternatives must be promoted. This study aims to examine the pyrolysis and combustion behaviors of disposable mask wastes using the thermogravimetric analysis method and to determine the thermal degradation kinetics using Kissenger-Akahira-Sunosa and Flynn–Wall–Ozawa methods for further utilization areas or disposal. As a result of the analysis, it was seen that the total mass loss occurred in a single temperature range for pyrolysis and combustion, and these losses were approximately 92% and 95%, respectively. The average activation energy values calculated by Kissenger-Akahira-Sunosa and Flynn–Wall–Ozawa methods were 43.666 kJ mol⁻¹ and 52.126 kJ mol⁻¹ for pyrolysis and 67.774 kJ mol⁻¹ and 73.657 kJ mol⁻¹ for combustion, respectively. According to these results, it has been understood that these wastes are quite suitable for use in pyrolysis and combustion processes.

Extracellular polymeric substances (EPS) are products of microbial metabolism that exist as a complex of polymers found outside the cells and interior of cell aggregates. Microorganisms use EPS to protect themselves from toxic environment and this property enables the application of EPS in the treatment of wastewater. Removal of lead (II) and chromium (VI) from simulated wastewater by EPS from Penicillium expansum was studied. Maximum uptake of lead (II) was 773.05 mg/g of EPS, while the maximum uptake of chromium (VI) was found to be 618.75 mg/g of EPS in the simulated wastewater under the same removal conditions of 180 rpm, 90 mg/L EPS, 100 min contact time, 5.0 pH, 40 °C temperature, 120 mg/L initial concentration of lead (II) and 100 mg/L initial concentration of chromium (VI). Thermodynamic analyses gave respective enthalpy values of − 1.093 kJ/mol and − 1.030 kJ/mol for lead (II) and chromium (VI), with corresponding entropy values of 2.673 kJ/mol/K and 1.896 kJ/mol/K, these values indicated that the metal uptake by EPS was exothermic and the process can occur spontaneously. Pseudo-second order was the predominant model in the kinetic studies, having the highest R² values of 0.997 for lead (II) and 0.992 for chromium (VI) compared to the other studied kinetic models. Out of the 5 adsorption isotherms considered in this study, the removal process by EPS for both lead (II) and chromium (VI) fitted into the 3 models which can be ranked based on the R² values as Redlich-Peterson, Temkin and Langmuir isotherms. The findings indicate the ability of EPS produced by P. expansum to remove lead (II) and chromium (VI) simultaneously from simulated wastewater which could be due to identical binding sites for both metals with possible involvement of chemical bonds in the stabilization of complexes formed between EPS and Pb²⁺ or EPS and Cr⁶.

This study investigated the production of renewable activated carbon derived from residual ashes generated during the boiler combustion process for the treatment of food industry wastewater. The chemical modification of ashes into activated carbon was optimized using potassium hydroxide, phosphoric acid, and nitric acid. The results indicated that the adsorbent synthesized with phosphoric acid exhibited the best performance in removing indigo carmine dye, achieving 98% removal rate when using the adsorbent at a concentration of 0.5 g L⁻¹, with an average particle diameter of 0.088 mm. The surface area increased from 120.3 to 605.1 m² g⁻¹ with phosphoric acid activation, resulting in a high-quality adsorbent with a capacity for reuse up to four times. The Redlich–Peterson isotherm model provided the best fit for experimental data on indigo carmine dye adsorption, with a maximum adsorption capacity of approximately 100 mg g⁻¹ according to the Langmuir model. In the treatment of food industry wastewater (cheese whey), the adsorbent reduced the lactose content (32.45%), turbidity (62.92%), BOD₅ (90.48%), and COD (93.07%). The removal of these adsorbates from cheese whey effluent reduced the organic load of cheese whey, enabling the water reuse within the food industry. In conclusion, activated carbon produced from residual ashes can be considered as a sustainable alternative for treating food industry effluents, advocating water reuse.

Fly ash, a hazardous waste byproduct of incineration processes, necessitates proper management to mitigate environmental risks. Among the disposal and reuse methods, water washing stands out as a cost-effective solution. This study utilized the response surface methodology to optimize chloride extraction from fly ash through washing. Experimentation encompassed varying washing times and liquid-to-solid ratios, with an emphasis on identifying key factors influencing optimal outcomes. Utilizing Design-Expert software, experiments spanned liquid-to-solid ratios of 1–10 (mL/g) and mixing times of 2–240 min. Results revealed that the liquid-to-solid ratio significantly impacted chloride removal, with ratios below 5 yielding suboptimal outcomes. Additionally, analytical techniques, including X-ray diffraction, X-ray fluorescence, and scanning electron microscopy, were employed. The study aims to optimize parameters for effective chloride extraction while minimizing water consumption. Findings underscore the efficacy and cost-efficiency of water washing in chloride reduction, contingent upon the appropriate ratio and time selection. Maximum chloride removal occurred at a liquid-to-solid ratio of 10 mL/g and a mixing time of 121 min, yielding 41.51 mol of extracted chloride.

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In this study, a novel draw solution based on trisodium dicarboxymethyl alaninate and citric acid was evaluated for its potential to be utilized in forward osmosis water desalination systems. The effect of various operation parameters (including draw solution concentration, feed stream salination, and operation temperature) on desalination efficiency of the forward osmosis system utilizing such novel draw solutions was investigated, utilizing a bench-scale cross/tangential flow membrane testing system. In addition, images of membranes’ surfaces produced by scanning electron microscopes were also studied to determine the nature of fouling resulting from prolonged operations, and the effectiveness of applied cleaning procedures. Compared to the more well-established trisodium citrate-based draw solution, the novel draw solution exhibited higher water flux against deionized water, while also offering low reverse solute flux and good regeneration capability through low-pressure reverse osmosis. In particular, experiment results showed that at the initial concentration of 250 g L⁻¹, the forward osmosis system utilizing such novel draw solution could achieve specific water fluxes of up to 9.23 L m⁻² h⁻¹ against deionized water, and up to 4.95 L m⁻² h⁻¹ against feed streams of 20‰ salinity. Additionally, such system also has relatively low operational loss, with specific reverse solute flux and reverse osmosis recovery rate of 0.22 g L⁻¹ and 98.65%, respectively. Overall, the novel draw solution was proven to be effective for water desalination applications, while also being relatively cheap, readily-available in large quantities, low in toxicity, and relatively eco-friendly.

Graphical Abstract

Organic micropollutants, found at trace levels in nature, are causing significant concern due to their toxic, carcinogenic, and mutagenic effects. In this study, the fate and removal of organic micropollutants were monitored covering all seasons in an urban wastewater treatment plant in Turkey. The plant influent, effluent, and aeration basin were sampled seven times in the years of 2019–2020; and three surfactants (linear alkylbenzene sulfonate, nonylphenol mono-di-ethoxylate, nonylphenol), polychlorinated biphenyls and polyaromatic hydrocarbons were monitored in this context. The plant was being operated in the endogenous respiration phase during the monitoring period without sludge removal. Results obtained showed that the highest NH₃-N removal (41%) of the study period was realized in March when the lowest mixed liquid volatile suspended solids value (380 mg/L) and the lowest sludge age were observed. In this month, the highest organic micropollutants removal efficiency was obtained in relation to the increased metabolic activity. On the other hand, in August, when the highest mixed liquid volatile suspended solids value (1,750 mg/L) was observed, the lowest organic micropollutants removal was recorded, with the lowest NH₃-N removal (6%). The removal of linear alkylbenzene sulfonate and nonylphenol mono-di-ethoxylate was high during the period, and microorganisms could metabolize these pollutants efficiently. Polychlorinated biphenyls, polyaromatic hydrocarbons, and nonylphenol were resistant to metabolic degradation, so they were present in high amounts at various stages of the treatment process. Due to the poor plant treatment performance, a high quantity of organic micropollutants was discharged into the receiving environment.