Environmental Analysis Research Articles

Biodiesel production using various methanol sources and catalytic routes: A techno-environmental analysis

The primary objective of this research is to investigate the biodiesel production via the transesterification reaction between triolein and methanol in the presence of a basic and acidic catalysts, namely sodium hydroxide and sulfuric acid, using CHEMCAD simulation software as a process modelling and simulation tool. Methanol, one of the raw-materials used in biodiesel manufacturing, was synthesized using reforming technology applied to: i) coke oven gas and carbon dioxide, and ii) glycerol that represents an important by-product of the biodiesel synthesis. Four different cases were developed and compared, with detailed operating parameters and equipment designs for each of the investigated scenarios. The production capacity was set to 1,000.00 kg/h of biodiesel and a purity higher than 98% was registered in all investigated cases. Based on the material and energy balances derived from modelling and simulation section, an environmental analysis using the Life Cycle Assessment methodology was performed with the aid of the GaBi software. Ten environmental impact categories (i.e., Global Warming Potential, Fossil Depletion Potential, Human Toxicity, Water Depletion, etc.) are generated and relevant discussions about the sub-processes that exhibit the highest influence are given. The environmental evaluation shows that the most environmentally friendly scenario consists of the methanol production using coke oven gas and carbon dioxide, and its subsequent utilization for the biodiesel production following the alkali catalysis. A scenario analysis regarding several electric and thermal energy sources (i.e., natural gas, biogas, biomass, grid mix) was performed. According to this scenario analysis, while evaluating the synthesis of biodiesel through the alkali catalysis pathway, using biomass as a renewable source improves the environmental performances across certain impact categories.

Application of molecularly imprinted polymers in the water environmental field: A review on the detection and efficient removal of emerging contaminants

The emerging contaminants in the environment pose a threat to ecological security and human health. At present, traditional technologies are difficult to detect and remove existing trace emerging contaminants in water bodies. Therefore, efficient removal of low concentration emerging contaminants is a key issue in ensuring water safety. As an emerging technology, molecular imprinting technology (MIT) can synthesize polymers with specific recognition ability for target pollutants, providing a new approach for efficient removal of emerging contaminants. It is worth noting that combining MIT with traditional catalysts is an effective method to improve detection limits and removal efficiency. This review mainly introduced the research progress of using MIT to detect pollutants in various sensors and using advanced oxidation technology to remove pollutants in recent years, focusing on the preparation and application of MIT-based photocatalysts, electrocatalysts, and Fenton-like catalysts. In addition, possible interactions between the target analyte and MIT were discussed, as well as the reusability and stability of imprinted catalysts in water treatment, and their potential ecological toxicity risks were analyzed. Finally, the challenges of MIT based pollutant mitigation and the application prospects of molecular imprinting technology in environmental analysis were elaborated from multiple perspectives.

Analysis of the non-uniform thermal environment of local floor and ceiling radiant heating: Numerical simulation and thermal comfort experiment

Local radiant heating is a crucial method for avoiding inefficient heating and reducing energy consumption in buildings. To supplement existing research, which primarily focuses on local vertical-wall radiant heating, this paper investigates the non-uniform thermal environment of local floor and ceiling radiant heating rooms under various radiant positions, areas, and temperatures. The study utilizes numerical analysis by Ansys Fluent and thermal comfort experiments in Xi'an, China, which has a Dwa Köppen climate classification. When the local heating zone is located near windows and doors, the radiant film preferentially exchanges heat with them, resulting in a decrease in air temperature and mean radiant temperature. In such cases, it is recommended to increase the radiant temperature or area. With a radiant area of 5 m2 and a radiant temperature of 25 °C, expanding the radiant area to 15 m2 increases the average air temperature in the local heating zone by 5.0 °C, while raising the radiant temperature to 29 °C increases it by 1.4 °C. Moreover, enlarging the radiant area can effectively improve occupants' skin temperature, thermal sensation, and overall thermal comfort. When the radiant area and temperature are determined, priority should be given to local floor radiant heating over local ceiling radiant heating due to its lower air temperature, larger temperature gradients, and smaller mean radiant temperatures. This study aims to provide references for proposing refined design and regulation parameters of local floor and ceiling radiant heating systems in the future.

Cathodic electrochemiluminescence of boron and nitrogen-codoped carbon dots for the detection of dissolved oxygen in seawater

Electrochemiluminescence (ECL) is widely used in various fields due to its high sensitivity and controllable characteristics. Carbon dots (CDs) have emerged as promising ECL emitters due to their simple synthesis, low toxicity, and excellent biocompatibility. However, the practical application of many CDs emitters is hindered by their limited luminous efficiency, often necessitating additional coreactants to enhance the ECL signal intensity. In this study, we synthesized boron and nitrogen-codoped carbon dots (BN-CDs) as ECL emitters, utilizing dissolved oxygen (DO) as the coreactant. The BN-CDs/DO system exhibited a strong cathodic ECL signal. We proposed a reaction mechanism for the BN-CDs/DO ECL system. Additionally, we developed an ECL sensor for DO detection based on this system, showing a linear correlation between ECL peak intensity and DO concentration from 0.5 to 19.8 mg/L, with a detection limit of 0.12 mg/L. It was proven reliable for DO analysis in seawater and freshwater environments. This study provides insights into the synthesis and utilization of BN-CDs, highlighting the potential of DO as an intrinsic coreactant in CDs ECL systems. Furthermore, it provides new perspectives on the detection of DO in seawater and the design of innovative DO sensors.

Hero or Devil: A comparison of different carbon tax policies for China

A carbon tax is a promising environmental regulation. Given its heavy industrial base and substantial reliance on coal, China is under immense pressure to transition to greener energy systems. This paper enriches Annicchiarico and Di Dio’s (2015) dynamic general equilibrium model for environmental policy analysis by integrating a Schumpeterian innovation-driven clean energy transition that endogenizes the carbon intensity of energy inputs. We analyze the environmental, energy, economic, and social impacts of various hypothetical carbon taxes – including an energy excise tax on households, an emission tax on general producers, and an energy tax on energy suppliers – across different tax rates and subsidy strategies for both short-term and long-term effects. We show that: (i) by internalizing carbon intensity, a carbon tax can achieve a “quadruple dividend”, encompassing emission reduction, energy transition, economic growth, and welfare enhancement; (ii) the optimal carbon tax strategy, integrating both an emission tax and an energy tax, directs revenue towards supporting the clean energy transition; (iii) under a single environmental regime, a composite carbon tax exceeding 250 CNY/ton is optimal, while under multiple regimes, 25 CNY/ton suffices to reduce carbon emissions per unit of output by over 90%; (iv) despite their benefits, all carbon taxes compel firms to reorganize production, inevitably risking unemployment

Energy, environmental, and economic analysis of novel R744/R290 cascade refrigeration systems designed for warm ambient conditions utilizing ejector

There is a growing global awareness about the need to reduce total carbon equivalent emissions and other environmental problems caused due to synthetic refrigerants. The study utilizes cascade refrigeration systems (CRS) with R744 in the low-temperature circuit and R290 in the high-temperature circuit. Two evaporators are present in the LTC; one is direct expansion (DX) type at −40 °C with a cooling load of 70 kW, and other is gravity-fed evaporator at −25 °C with 60 kW cooling load. The study aims to enhance the performance and economic and environmental impact of CRS by incorporating parallel compression (PC) in LTC, a gravity-fed evaporator, and an ejector in HTC. The performance is compared to a baseline CRS system using a flash-gas bypass arrangement (FGB) in the LTC, bypassing generated flash gas to compressor suction. PC in LTC removes flash gas from receiver pressure to cascade condenser pressure in the first suggested CRS. While the second proposed CRS (PCEJ) employs an ejector in HTC over and above PC in LTC. The CRSs demonstrate significant higher COP of 1.43, 1.58 and 1.65, leading to an improvement upto 62.4 %, 79 %, and 86 % over the reference HFC-404A system at 45 °C ambient temperature. SEER analysis also establishes higher year-round efficiency compared to reference HFC-404A by 22 %, 36 %, and 44 %. The total TEWI of FGB, PC, and PCEJ is 43.1 %, 53.2 %, and 53.5 % lower compared to the reference system, indicating substantial potential for lowering global warming when implemented. Economic analysis brings out relative cost comparisons under various measures.

Novel integrated system for power, hydrogen, and ammonia production using direct oxy-combustion sCO2 power cycle with automatic CO2 capture, water electrolyzer, and Haber-Bosch process

Renewable energy-based multigeneration systems for power, hydrogen, and ammonia production suffer from intermittency issues and high production costs. On the other hand, conventional fossil-fuel-based systems yield high levels of CO2 emissions. Thus, to eliminate the intermittency issue with low production costs and near zero CO2 emissions, a novel integrated, efficient, compact, and interactive system for power, hydrogen (H2), and ammonia (NH3) production is developed and investigated in this study. A direct oxy-combustion supercritical carbon dioxide (DOC-sCO2) power plant is integrated with a water electrolyzer (WE) and Haber-Bosch process (HBP) system for the cogeneration of power, H2, and NH3, respectively. The power consumption of the air separation unit (ASU) of the DOC-sCO2 cycle is significantly reduced by the utilization of the oxygen produced from the WE system. Moreover, the cost of ammonia production is minimized by the internal utilization of the nitrogen gas produced by the ASU. Furthermore, the feedwater of the WE system is supplied internally from the DOC-sCO2 power block. In addition, the CO2 emissions of the system are captured to realize near-zero emissions to the ambiance. Based on these features, thorough energy, exergy, economic, and environmental (4E) analyses were performed to evaluate the performance of the proposed system. The obtained results showed an impressive levelized cost of electricity of 3.72¢/kWh, levelized cost of hydrogen of 1.162$/kgH2, and ammonia of 0.197$/kgNH3 at an overall energy and exergy efficiencies of 44.09%, and 63.6%, respectively. The system has no emissions of nitrogen oxides (NOx) and reduces the CO2 emissions of the H2 production by 49.6% and of the NH3 production by 48.8% compared to the conventional gasification, SMR, and HBP systems, respectively. This research work also provides insights into wet versus dry cooling, part load operation, and the advantages over renewable-based systems in terms of stability, reliability, and economic feasibility.

Environmental Impact Analysis in 3x10 MW Coal Fired Power Plant Through Life Cycle Assessment

Environmental Impact Analysis in 3x10 MW Coal Fired Power Plant Through Life Cycle Assessment

Enhancing Earth Dam Slope Stability Prediction with Integrated AI and Statistical Models

This study introduces an innovative approach integrating artificial intelligence (AI) and statistical modelling technique to enhance the prediction of earth dam slope stability. Utilizing advanced methodologies, including the Classification and Regression Tree (CART), Classification and Regression Random Forests (CRRF), and Multiple Linear Regression (MLR), this research provides a comprehensive, data-driven analysis for slope stability prediction. The integration of AI with traditional statistical models significantly improves the predictive accuracy over conventional methods. The findings reveal the model's capability in terms of reliability and precision in predicting slope stability, demonstrating its potential as a powerful tool in the engineering. Additionally, this work highlights the effective application of AI in complex environmental systems analysis, opening new avenues for research and practice in the field.

Environmental Impact Analysis of Waste Lithium-Ion Battery Cathode Recycling

Environmental Impact Analysis of Waste Lithium-Ion Battery Cathode Recycling

Assessment of microbial communities in a dairy farm from a food safety perspective

Microbial communities associated with dairy farm operations have a significant influence on food safety, dairy product quality, and animal health. This study aimed to create a microbial mapping at a dairy farm to learn about their bacterial diversity, distribution, and potential dissemination pathways. The investigation included the detection of key zoonotic pathogens, enumeration of Staphylococcus aureus and Escherichia coli as indicators of typical bacterial loads in a dairy production environment, and a microbiome analysis using metagenomics. A total of 160 samples (environmental, udder swabs, feed, feces, raw milk, and water) were collected during winter (N = 80) and spring (N = 80). In winter, Cronobacter spp. were detected in four feed and two water samples; L. monocytogenes was identified in two samples, one from feces and one from a cattle mat; E. coli O157:H7 was found in two feed samples. On the other hand, during spring, Cronobacter spp. were present in four feed samples and one hallway drain, with only one feed sample testing positive for E. coli O157:H7, while L. monocytogenes was absent during the spring season. Regarding microbial counts, there was no significant difference between the two seasons (p = 0.068) for S. aureus; however, a significant difference (p = 0.025) was observed for E. coli. Environmental microbiome analysis showed the presence of Proteobacteria (46.0 %) and Firmicutes (27.2 %) as the dominant phyla during both seasons. Moraxellaceae (11.8 %) and Pseudomonadaceae (10.62 %) were notable during winter, while Lactobacillaceae (13.0 %) and Enterobacteriaceae (12.6 %) were prominent during spring. These findings offer valuable insights into microbial distribution within a dairy farm and potential risks to animal and human health through environmental cross-contamination.

Techno-economic and environmental analysis of hybrid energy systems for remote areas: A sustainable case study in Bangladesh

This study provides a comprehensive evaluation of the techno-economic and environmental performance of six hybrid energy systems (HESs) in Kunder Char, Bangladesh, incorporating both conventional (diesel and natural gas) and renewable energy sources (solar and wind). Using HOMER Pro software, a comparative analysis of five off-grid systems and one on-grid system are conducted for assessing their cost-effectiveness, energy efficiencies, and environmental impacts under various sensitivity conditions. After thorough evaluation the on-grid system has emerged as the most economically viable option, with a levelized cost of energy (LCOE) of $0.0436/kWh and a net present cost (NPC) of $1.43 million. It also produced minimal waste energy (0.381 %) but with high CO2 emissions. In contrast, the PV-Battery setup, though the most expensive with an LCOE of $0.266/kWh and an NPC of $3.36 million, offered the benefit of zero emissions and generated 40 % excess electricity. Sensitivity analyses highlighted the influence of solar radiation (4.45 kWh/m2/day), wind speed (4.81 m/s), and fuel price (Diesel: $1/L) on these systems, providing insights into their operational dynamics under varying environmental and economic scenarios. The findings highlight the trade-offs between cost, sustainability, and efficiency, promoting energy solutions customized to meet the specific needs of remote regions like Kunder Char. This study also helps in understanding the potential of hybrid systems to meet energy demands sustainably in challenging geographical and economic landscapes.

Sedimentary environment shift and organic matter enrichment mechanism in response to volcanic ash influence: a case study of the Permian Lucaogou Formation, Santanghu Basin, NW China

The second member of the Lucaogou Formation (P2l2) in the Tiaohu and Malang Sags of the Santanghu Basin (study area) underwent periodic volcanic activity and frequent lithological changes. This study comprehensively analyzed the organic geochemistry, mineral composition, organic matter (OM) types, volcanic cycle, and paleoenvironment of shale in the study area. Techniques such as total organic carbon (TOC), rock pyrolysis (Rock-Eval), organic petrology, scanning electron microscopy (SEM) with energy-dispersive spectrum (EDS) analysis, X-ray diffraction (XRD), trace elements, and saturated hydrocarbon gas chromatography and mass spectrometry (GC–MS) were employed. The findings suggest that limited terrigenous input during the sedimentary period of the P2l2 led to the deposition of a distinctive mixture of volcanic ash (felsic) and carbonate (dolomite and calcite), with a low average clay mineral content of 6%. The P2l2 shale emerged as a high-quality source rock, predominantly composed of type I and II kerogens, with moderate OM maturity. The deposition environment was characterized by hot and arid conditions, high salinity, and intensive reducibility, which was favorable for algae development and conducive to OM preservation. Notably, two Lamalginite types, labeled as Lamalginite “A” and Lamalginite “B,” were identified. Lamalginite “B”-rich shales were deposited in a hotter and drier climate compared to Lamalginite “A”-rich shales. Lamalginite “B”- rich shale inexhibited high levels of C28 regular sterane and β-carotenes, distinguishing it from lamalginite “A”-rich shale. A comprehensive analysis involving organic petrology, SEM, sedimentary environment analysis, and biomarker characteristics suggests that Lamalginite “B” may be a salt-tolerant green alga, while Lamalginite “A” may be a cyanobacterium. Finally, an OM enrichment model for the P2l2 shale was established.

Energy, economic, and environmental analysis of a novel combined cooling, heating, and power (CCHP) from infectious medical waste

The outbreak of coronavirus disease 2019 (COVID-19) has led to an increase in infectious medical waste (IMW). Waste-to-energy (WtE) technologies are considered to manage IMW in the context of the COVID-19 situation and to reduce illegal dumping and landfill problems. This study focuses on managing IMW by using WtE technology. Energy, economic, and environmental (3E) impacts are considered as a single implication value of WtE technology. Combined cooling, heating, and power (CCHP) is a novel system for generating energy from a treated IMW by using a steam sterilization system. The moisture from sterilization waste is extracted by a drying process to create refuse-derived fuel type 3 (RDF-3). An RDF-3 of 81.98 kg/h at a low heating value of 26.29 MJ/kg is used for a combustion–incineration process of 236.56 kW. A net power from an organic Rankine cycle of 15.80 kWe, an absorption cooling capacity of 4.62 kW, and a drying room unit of 13.21 kW are found from the combined CCHP system. The energy index is calculated at an overall energy efficiency of approximately 13.40 %. The energy–environmental impact is summarized by a single score of 5.63E-04 Pt. The energy–economic impact is summarized by a levelized energy cost of 0.35 USD/kWh. The economic-environmental perspective is an energy costing per life cycle assessment of 0.73 USD/kg emission-eq. The 3E analysis reveals a single indicator of 1.95E-04 USD·Pt/kWh2, which is used in the decision to compare with other energy systems. The CCHP system shows advantages in terms of sustainability, quality, and efficiency. Consequently, a novel in this study promotes the sustainability of energy, avoiding environmental impact, and IMW management.

Exergetic and environment assessment of linear fresnel concentrating photovoltaic systems integrated with a porous-wall mini-channel heat sink: Outdoor experimental tests

The photovoltaic heat sink integrated systems can effectively control the temperature of solar cells and increase output power. The linear Fresnel concentrator photovoltaic heat sink integrated systems (LFC-PV systems) consists of a solar cell, a porous-wall mini-channel heat sink (MFP-channel) and a linear Fresnel concentrator (LFC) mirror array. Cooling fluid R141b absorbs heat from solar cell back by flow boiling heat transfer. In this work, we tested the system performance outdoors and the collected experimental data were used for energy analysis, exergy analysis and environmental analysis to evaluate the advantages and disadvantages of the integrated system. The experimental data show that the heat dissipation of solar cells by using a porous-wall mini-channel heat sink can not only well control the surface temperature of solar cells between 35 °C and 40 °C, but also increase the output power and exergy, where the output power can reach a maximum of 10.73 W. Therefore, it is recommended to use a porous-wall mini-channel heat sink for the thermal management of the LFC photovoltaic system.

Techno-Economic and Environmental Analysis of a Renewable Hybrid System in Southern Morocco

Techno-Economic and Environmental Analysis of a Renewable Hybrid System in Southern Morocco

Thermodynamic and life cycle assessment analysis of polymer-containing oily sludge supercritical water gasification system combined with Organic Rankine Cycle

With the development of polymer flooding technology, polymer-containing oily sludge (PCOS) has become a major pollutant on offshore oil platforms. Supercritical water gasification system is an efficient and pollution-free technology compared to conventional PCOS treatment. However, the system model for PCOS has not yet been established and the theoretical model for system optimization is insufficient. In this work, a novel auto-thermal system is established based on supercritical water gasification technology for the treatment of PCOS. Through the thermodynamic analysis, an optimization plan is concluded and used for the establishment of a modified system with Organic Rankine Cycle. Results show that the two-stage reactor reduces the gasification reaction temperature from 652 °C to 502 °C, and the Organic Rankine Cycle system using Isopropanol recover 9.1 % chemical exergy of feedstock with the optimal parameters (superheat, evaporation temperature and circulating pressure). The energy and exergy efficiency of the modified system has increased by 52.4 % and 42.4 % compared to the original system. Besides, a life cycle assessment is adopted for the environment analysis. The results show that the increasing gasification temperature and PCOS slurry concentration can reduce system unit exergy loss. Global Warming Potential reaching the minimum value of 26.1 at 65 wt%.

Anomaly Detection in Blockchain Transactions: A Machine Learning Approach within the Open Metaverse

This study investigates the application of machine learning models for anomaly detection and fraud analysis in blockchain transactions within the Open Metaverse, amid the growing complexity of digital transactions in virtual spaces. Utilizing a dataset of 78,600 transactions that reflect a broad spectrum of user behaviors and transaction types, we evaluated the efficacy of several predictive models, including RandomForest, LinearRegression, SVR, DecisionTree, KNeighbors, GradientBoosting, AdaBoost, Bagging, XGB, and LightGBM, based on their Mean Cross-Validation Mean Squared Error (Mean CV MSE). Our analysis revealed that ensemble methods, particularly RandomForest and Bagging, demonstrated superior performance with Mean CV MSEs of -0.00445 and -0.00415, respectively, thereby highlighting their robustness in the complex transaction dataset. In contrast, LinearRegression and SVR were among the least effective, with Mean CV MSEs of -224.67 and -468.57, indicating a potential misalignment with the dataset's characteristics. This research underlines the importance of selecting appropriate machine learning strategies in the context of blockchain transactions within the Open Metaverse, showcasing the need for advanced, adaptable approaches. The findings contribute significantly to the financial technology field, particularly in enhancing security and integrity within virtual economic systems, and advocate for a nuanced approach to anomaly detection and fraud analysis in blockchain environments.

Adult Verbal Responses Facilitating Child Vocalizations

Objectives: This study aimed to investigate whether adults in the vicinity of children respond differently to various child vocalization types within three-event sequences of “child vocalization-adult verbal response-child vocalization” occurring in everyday life. Additionally, this study examined the types of adult verbal responses that facilitate child vocalizations within the series of three-event sequential interactions between children and adults. Methods: Data was collected using the LENA (Language ENvironment Analysis) from 30 children aged 12 to 18 months and their families. Three-event sequences of interactions between children and adults were selected from twenty 5-minute recorded segments with the highest conversational turn counts. Child vocalizations before and after adult verbal responses were broadly classified into canonical babblings and non-canonical babblings, and then coded into subcategories for each babbling type. Adult verbal responses were classified into different pragmatic types. Results: Adults responded differently depending on children’s non-canonical and canonical babblings. Among pragmatic types of adult verbal responses, imitation, recast, and expansion were prominently observed following canonical babblings with more than two syllables. Adult verbal responses such as acknowledgment and recast facilitated children in producing more advanced vocalization forms. Conclusion: This study supports bi-directional relationships in interactions between children and adults and provides insights into which child-adult vocal exchanges facilitate child vocalizations and early speech-language development.

Business Development Strategy for Bunga Melati Women’s Farming Groups in Bunutin Village, Bangli District, Bangli Regency.

Business Development Strategy for Bunga Melati Women’s Farming Groups in Bunutin Village, Bangli District, Bangli Regency.