Hasil untuk "Environmental technology. Sanitary engineering"

Adharsh Rajasekar, Stephen Wilkinson, Charles K. S. Moy

In the last two decades, developments in the area of biomineralization has yielded promising results making it a potentially environmentally friendly technique for a wide range of applications in engineering and wastewater/heavy metal remediation. Microbially Induced Carbonate Precipitation (MICP) has led to numerous patented applications ranging from novel strains and nutrient sources for the precipitation of biominerals. Studies are being constantly published to optimize the process to become a promising, cost effective, ecofriendly approach when compared with the existing traditional remediation technologies which are implemented to solve multiple contamination/pollution issues. Heavy metal pollution still poses a major threat towards compromising the ecosystem. The removal of heavy metals is of high importance due to their recalcitrance and persistence in the environment. In that perspective, this paper reviews the current and most significant discoveries and applications of MICP towards the conversion of heavy metals into heavy metal carbonates and removal of calcium from contaminated media such as polluted water. It is evident from the literature survey that although heavy metal carbonate research is very effective in removal, is still in its early stages but could serve as a solution if the microorganisms are stimulated directly in the heavy metal environment.

Jiaqin He, Max Malyi, Jonathan Shek

Environmental licensing related to underwater acoustic emissions represents a critical bottleneck for the commercial deployment of marine renewable energy. This study presents a control engineering framework to mitigate acoustic risks from tidal current converters without compromising project viability. A MATLAB/Simulink model of a tidal current converter was utilised to evaluate two distinct mitigation tiers: (1) architectural modification, comparing a geared induction generator against a direct-drive permanent magnet synchronous generator, and (2) operational control, analysing the impact of switching frequencies and maximum power point tracking coefficient tuning. Results indicate that lowering switching frequencies is ineffective, increasing power electronic losses by over 2000% with negligible acoustic benefit. Conversely, the direct-drive permanent magnet synchronous generator architecture reduced sound pressure levels, effectively eliminating mechanical tonal noise. For existing geared systems, de-tuning the maximum power point tracking coefficient by a factor of 1.2 reduced the probability of exceeding temporary threshold shift limits for marine mammals, with a quantified energy yield reduction of 3.58%. These findings propose a hierarchical mitigation strategy: selecting direct-drive topologies for acoustically sensitive sites, and utilising maximum power point tracking coefficient based power curtailment as a transient operational mode during critical biological migration periods.

Jannatul Bushra, Md Habibor Rahman, Mohammed Shafae et al.

Reverse engineering can be used to derive a 3D model of an existing physical part when such a model is not readily available. For parts that will be fabricated with subtractive and formative manufacturing processes, existing reverse engineering techniques can be readily applied, but parts produced with additive manufacturing can present new challenges due to the high level of process-induced distortions and unique part attributes. This paper introduces an integrated 3D scanning and process simulation data-driven framework to minimize distortions of reverse-engineered additively manufactured components. This framework employs iterative finite element simulations to predict geometric distortions to minimize errors between the predicted and measured geometrical deviations of the key dimensional characteristics of the part. The effectiveness of this approach is then demonstrated by reverse engineering two Inconel-718 components manufactured using laser powder bed fusion additive manufacturing. This paper presents a remanufacturing process that combines reverse engineering and additive manufacturing, leveraging geometric feature-based part compensation through process simulation. Our approach can generate both compensated STL and parametric CAD models, eliminating laborious experimentation during reverse engineering. We evaluate the merits of STL-based and CAD-based approaches by quantifying the errors induced at the different steps of the proposed approach and analyzing the influence of varying part geometries. Using the proposed CAD-based method, the average absolute percent error between simulation-predicted distorted dimensions and actual measured dimensions of the manufactured parts was 0.087%, with better accuracy than the STL-based method.

Allysson Allex Araújo, Marcos Kalinowski, Matheus Paixao et al.

[Background] Emotional Intelligence (EI) can impact Software Engineering (SE) outcomes through improved team communication, conflict resolution, and stress management. SE workers face increasing pressure to develop both technical and interpersonal skills, as modern software development emphasizes collaborative work and complex team interactions. Despite EI's documented importance in professional practice, SE education continues to prioritize technical knowledge over emotional and social competencies. [Objective] This paper analyzes SE students' self-perceptions of their EI after a two-month cooperative learning project, using Mayer and Salovey's four-ability model to examine how students handle emotions in collaborative development. [Method] We conducted a case study with 29 SE students organized into four squads within a project-based learning course, collecting data through questionnaires and focus groups that included brainwriting and sharing circles, then analyzing the data using descriptive statistics and open coding. [Results] Students demonstrated stronger abilities in managing their own emotions compared to interpreting others' emotional states. Despite limited formal EI training, they developed informal strategies for emotional management, including structured planning and peer support networks, which they connected to improved productivity and conflict resolution. [Conclusion] This study shows how SE students perceive EI in a collaborative learning context and provides evidence-based insights into the important role of emotional competencies in SE education.

S. Tian, Chen Zhang, Danlian Huang et al.

Abstract The growing concerns over the environmental toxicity of sulfonamides (SNs) require immediate action to establish efficient and sustainable processes to address this issue. Adsorption, photodegradation and Fenton/Fenton-like reactions are the most applied processes to remove SNs. However, the adsorption behavior, degradation mechanisms and toxicity of intermediates need further investigation to guide engineering applications. The review focuses on the recent progress and challenges on adsorption, photodegradation and Fenton/Fenton-like techniques for SNs removal. In addition, influences of solution pH and matrix components on adsorption mechanisms are discussed. In particular, the degradation pathway of SNs and toxicity assessment of their intermediates are also analyzed. Finally, conclusions and research gaps in this field are briefly proposed. Publications on this topic have grown exponentially over the last decade. This review provides a unique and comprehensive environmental perspective, as well as the latest knowledge on SNs adsorption and reactive removal by different technologies.

Lixin Tang, Y. Meng

Nicholas A Fackler, B. Heijstra, Blake J. Rasor et al.

Owing to rising levels of greenhouse gases in our atmosphere and oceans, climate change poses significant environmental, economic, and social challenges globally. Technologies that enable carbon capture and conversion of greenhouse gases into useful products will help mitigate climate change by enabling a new circular carbon economy. Gas fermentation using carbon-fixing microorganisms offers an economically viable and scalable solution with unique feedstock and product flexibility that has been commercialized recently. We review the state of the art of gas fermentation and discuss opportunities to accelerate future development and rollout. We discuss the current commercial process for conversion of waste gases to ethanol, including the underlying biology, challenges in process scale-up, and progress on genetic tool development and metabolic engineering to expand the product spectrum. We emphasize key enabling technologies to accelerate strain development for acetogens and other nonmodel organisms. Expected final online publication date for the Annual Review of Chemical and Biomolecular Engineering, Volume 12 is June 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Andrea Pompigna, R. Mauro

Abstract The years we are experiencing are often identified as those of the Age of Smart Technologies. Smart is now a very popular term, with the meaning of clever, intelligent, sharp, quick on the uptake. Its extensive meaning can be grasped if we consider it as an acronym for Self-Monitoring Analysis and Reporting Technology to indicate the essential features of the innovative technologies that characterize today's society in its daily life. Thus, the advent of the Smart Age, which is therefore the era of smart technologies, has heavily characterized and modified many aspects of today's society compared to the past. In this panorama, some arising questions regard transport infrastructure systems and, first of all, road transport. This research proposes a focus on one main issue: how roads fit into this smart revolution? Actually, the paper aims to offer an overview of the smart approach in road engineering by proposing a broad discussion about the current state of innovation in the smart roads field, i.e. the roads of the Smart Age. After defining the key functions of a smart road, the paper reviews some innovative technologies that make these items effective. These are studied in depth both with regard to motorway-type infrastructures and urban roads and intersections, with attention to the various technological aspects and to the benefits perceivable by management, users and the community. The paper, therefore, offers a bird's eye view of this extremely dynamic sector with innovative technologies for a new intelligent and connected mobility, and discusses some of their criticalities and strengths allowing for optimization and development of new transport functions and services, improving energy efficiency and promoting social, economic and environmental sustainability.

KONG Wenjing, LIN Jiajia, ZHONG Xueyun et al.

In the field of new energy vehicles and related sectors, treating butyl acetate (BA), a typical oxygen-containing volatile organic compound (VOC), is becoming increasingly important. The surface structure and physicochemical properties of a CeO_2-U catalyst were adjusted by introducing 0.5% Pd, and compared with Al_2O_3 and TiO_2 catalysts containing the same Pd loading. Characterizations using SEM, XPS, in-situ DRIFTS, and other methods were conducted to explore the synergistic effect of Pd and Ce active components on catalytic oxidation of BA. The results showed that the introduction of Pd increased CeO_2-U′s CO_2 yield from 77.8% to 90.7% at 220 ℃, significantly promoting the deep oxidation process of BA and alleviating the issue of CO_2 selectivity delay. The introduction of Pd enhanced the mobility and reactivity of lattice oxygen in CeO_2, increased the proportion of surface Ce^3+, and boosted surface oxygen vacancy concentration. Additionally, the catalytic oxidation mechanism of BA over Pd/CeO_2-U was confirmed through in-situ DRIFTS analysis, indicating that the L-H mechanism was followed at low temperatures (T<200 ℃), while the MvK reaction mechaism occured followed at high temperature (T>200 ℃). It was found that the decomposition of intermediate carboxylate served as the rate-controlling step. These findings have implications for controlling BA in the field of related sectors.

Xuyuan Zhou, Yan Wang, Ruhai Liu et al.

Microplastics (MPs) weather after entering the environment gradually, and the interaction with metal ions in the aqueous environment has received extensive attention. However, there are few studies on Hg(Ⅱ), especially the effect of MPs on the release of Hg0(DEM) in water after entering the aqueous environment. In this study, four types of MPs (PP, PE, PET, PVC) were selected to study the adsorption and desorption behavior of Hg(Ⅱ) after photoaging and to explore the influence of MPs on the release of DEM in seawater under different lighting conditions. The results showed that the specific surface area, negative charges, and oxygen-containing functional group of MPs increased after aging. The adsorption capacity of aged MPs for Hg(Ⅱ) was significantly improved, which was consistent with the pseudo-first-order and pseudo-second-order model, indicating that the adsorption process was a chemical and physical adsorption. The fitting results of the in-particle diffusion model indicated that the adsorption was controlled by multiple steps. Hg(Ⅱ) was easier to desorb in the simulated gastric fluid environment. Because the aged MPs had the stronger binding force to Hg(Ⅱ), their desorption rate is lower than new MPs. Under visible light and UVA irradiation, MPs inhibited the release of Hg0. Under UVA, the mass of DEM produced in seawater with aged PE and PVC was higher than that of new PE and PVC. The aged PE and PVC could produce more ·O2-, which was conducive to the reduction of mercury. However, in UVB irradiation, the addition of MPs promoted the release of DEM, and ·O2- also played an important contribution in affecting the photochemical reaction of mercury. Therefore, the presence of aged MPs will significantly affect the water-air exchange of Hg in water. Compared with new MPs, aged MPs improved the contribution of free radicals in Hg transformation by releasing reactive oxygen species. This study extends the understanding of the effects of MPs on the geochemical cycle of Hg(Ⅱ) in seawater, better assesses the potential combined ecological risks of MPs and Hg(Ⅱ), and provides certain guidance for the pollution prevention and control of MPs.

Timo Häckel, Luca von Roenn, Nemo Juchmann et al.

The trend for Urban Air Mobility (UAM) is growing with prospective air taxis, parcel deliverers, and medical and industrial services. Safe and efficient UAM operation relies on timely communication and reliable data exchange. In this paper, we explore Cooperative Perception (CP) for Unmanned Aircraft Systems (UAS), considering the unique communication needs involving high dynamics and a large number of UAS. We propose a hybrid approach combining local broadcast with a central CP service, inspired by centrally managed U-space and broadcast mechanisms from automotive and aviation domains. In a simulation study, we show that our approach significantly enhances the environmental awareness for UAS compared to fully distributed approaches, with an increased communication channel load, which we also evaluate. These findings prompt a discussion on communication strategies for CP in UAM and the potential of a centralized CP service in future research.

Haochen Li, Jonathan Leung, Zhiqi Shen

Large Language Models (LLMs) have shown prominent performance in various downstream tasks and prompt engineering plays a pivotal role in optimizing LLMs' performance. This paper, not only as an overview of current prompt engineering methods, but also aims to highlight the limitation of designing prompts based on an anthropomorphic assumption that expects LLMs to think like humans. From our review of 50 representative studies, we demonstrate that a goal-oriented prompt formulation, which guides LLMs to follow established human logical thinking, significantly improves the performance of LLMs. Furthermore, We introduce a novel taxonomy that categorizes goal-oriented prompting methods into five interconnected stages and we demonstrate the broad applicability of our framework. With four future directions proposed, we hope to further emphasize the power and potential of goal-oriented prompt engineering in all fields.

A. Dubey, N. Dhami, K. Ravi et al.

Soil erosion is a complex natural process that occurs by either individual or combined actions of wind, hydraulic currents, waves, and rain. This study comprehensively reviews biocementation-based soil stabilisation techniques for developing erosion-resilient landforms through an ecologically conscious strategy. The different pathways for biocementation occurring in nature are discussed with a focused view on the microbially induced carbonate precipitation (MICP) technique. MICP relies on biogenic calcium carbonate (CaCO_3) precipitation via the urea hydrolysis route to bind the soil grains. The kinetics and factors affecting MICP are succinctly discussed to highlight the practical challenges associated with biocementation. This study emphasises the influence of MICP on erosion resistance (aeolian and hydraulic) and geotechnical properties of soils. The critical assessment of the previous studies revealed that aeolian and hydraulic erosion can be effectively controlled with a small to moderate quantity of biogenic CaCO_3 (2% to 10% of soil weight). MICP marginally influences the hydraulic conductivity of soils with a substantial improvement in compressive strength, making it desirous over traditional soil cementation agents for erosion control due to the limited intervention to natural groundwater flow. However, the scientific design and findings of the previous laboratory-scale and pilot-scale research are still inconsistent for standardising biocementation techniques to transition towards upscaling. This study presents critical insights to the researchers of the environmental, geotechnical and geoenvironmental engineering domains to design their upcoming studies to tackle the challenges required for upscaling biocementation technology.

Dongle Cheng, Huu Hao Ngo, Wenshan Guo et al.

Clean energy like hydrogen can be a promising strategy to solve problems of global warming. Photo-fermentation (PF) is an attractive technology for producing biohydrogen from various biowastes cost-effectively and environmentally friendly. However, challenges of low light conversion efficiency and small yields of biohydrogen production still limit its application. Thus, advanced strategies have been investigated to enhance photo-fermentative biohydrogen production. This review discusses advanced technologies that show positive outcomes in improving biohydrogen production by PF, including the following. Firstly, genetic engineering enhances light transfer efficiency, change the activity of enzymes, and improves the content of ATP, ammonium and antibiotic tolerance of photosynthetic bacteria. Secondly, immobilization technology is refined. Thirdly, nanotechnology makes great strides as a scientific technique and fourthly, integration of dark and photo-fermentation technology is possible. Some suggestions for further studies to achieve high levels of efficiency of photo-fermentative biohydrogen production are mentioned in this paper.

Xiaoyong Duan, P. Yin, N. Tsona et al.

Marine sediments are the world's largest known reservoir of methane. In many coastal regions, methane is trapped in sediments buried at depths ranging from centimeters to hundreds of meters below the seafloor, in the forms of gas pockets, dispersed gas bubbles and dissolved gas, also known as shallow gas (methane-dominated gas mixture). The existence of shallow gas affects the engineering geological environment and threatens the safety of artificial facilities. The escape of shallow gas from sediments into the atmosphere can even threaten ecosystem security and affect global climate change. However, until now, shallow gas has remained a mystery to the scientific community. For example, how it is generated, how it distributes and migrates in sediments, and what are the factors that influence these processes that are still unclear. In the context of increasingly intense offshore development and global warming, there is a huge gap between existing scientific understanding of shallow gas and the need to develop scientific solutions for related problems. Based on this, this paper systematically collects the information on all aspects of shallow gas mentioned above, comprehensively summarizes the current scientific understanding, and analyzes the existing shortcomings, which will provide systematic references for the research on environmental disaster prevention, engineering technology, climate change, and other fields.

Hui Yao, Yiran Wang, Pengrui Ma et al.

Asphalt pavement is the most widely used type of pavement in the world and is mainly utilized in the construction of infrastructures such as highways, urban roads, parking lots, and airstrips. The pavement maintenance technology and materials are gradually developing towards systematization and diversification with the extensive use of asphalt pavement. Choosing more economical technologies, and fast and sustainable materials is the future of asphalt pavement maintenance work. This paper provides an overview of asphalt pavement repair technology and asphalt pavement repair materials. We categorize and summarize the pavement repair technologies, which include cost-effective technologies such as crack sealing, overlay, seal coat, and hot-in-place recycling. Further, we summarized the repair materials applied in the repair technologies and compared the performance, cost-effectiveness, and sustainability of each type of material. The study shows that asphalt and cement are the most commonly used repair materials. The more potential, economical, and sustainable materials for asphalt pavement repair include epoxy resin, polyurethane, and hydrogel. The future of asphalt pavement repair requires advancing towards rapid, sustainable, environmentally friendly, and economical. The survey indicates that in addition to improving the performance of existing repair materials (e.g., modified asphalt, binder processes, material composition or ratios), attention can be given to new materials such as polyurethanes and hydrogels that have the potential for rapid repair and at low cost. More research can be done to perfect the application of new materials in road engineering.

Luis G. Ramírez Mérida, Richard A. Rodríguez Padrón

Industrial sustainability is a process that has been gaining space in recent years. The use of microalgae for wastewater treatment could solve some environmental challenges, optimize resources, and generate value-added products in agriculture, biofuel, food, and feed. The use of High Rate Algal Pond (HRAP) presents economic benefits, by treating contaminated effluents and taking advantage of the microalgae biomass generated. The microalgae growth in wastewater can be limited by lighting energy or the easily assimilable carbon source, due to the high load of nutrients and organic matter present in these effluents. In the same way, other physical, chemical, and biological parameters must be controlled to guarantee that the process reaches its maximum performance. The technology applied with microalgae for the waste industrial treatment seeks to generate sustainable, economical, and efficient processes that guarantee the discharge of water under standard parameters that allow for preserving the environment, the quality of life of citizens and generating inputs such as biofertilizers that allow avoiding crucial problems such as NPK ratio imbalance, soil hardening, salinization, nutrient depletion, groundwater contamination and food for animal consumption that allows generating nutritional alternatives. In this way, the treatment of wastewater with microalgae is an opportunity to solve sanitary and environmental problems under a sustainable approach to obtain inputs, although some challenges must be solved for scale production. This document intends to show outstanding aspects related to effluent treatment, water reuse, and sustainable production of agricultural inputs through the use of microalgae.

Shimelis Sishah Dagne, Hurgesa Hundera Hirpha, Addisu Teshome Tekoye et al.

Abstract Effective urban planning and management rely on accurate land cover mapping, which can be achieved through the combination of remote sensing data and machine learning algorithms. This study aimed to explore and demonstrate the potential benefits of integrating Sentinel-1 SAR and Sentinel-2 MSI satellite imagery for urban land cover classification in Gondar city, Ethiopia. Synthetic Aperture Radar (SAR) data from Sentinel-1A and Multispectral Instrument (MSI) data from Sentinel-2B for the year 2023 were utilized for this research work. Support Vector Machine (SVM) and Random Forest (RF) machine learning algorithms were utilized for the classification process. Google Earth Engine (GEE) was used for the processing, classification, and validation of the remote sensing data. The findings of the research provided valuable insights into the performance evaluation of the Support Vector Machine (SVM) and Random Forest (RF) algorithms for image classification using different datasets, namely Sentinel 2B Multispectral Instrument (MSI) and Sentinel 1A Synthetic Aperture Radar (SAR) data. When applied to the Sentinel 2B MSI dataset, both SVM and RF achieved an overall accuracy (OA) of 0.69, with a moderate level of agreement indicated by the Kappa score of 0.357. For the Sentinel 1A SAR data, SVM maintained the same OA of 0.69 but showed an improved Kappa score of 0.67, indicating its suitability for SAR image classification. In contrast, RF achieved a slightly lower OA of 0.66 with Sentinel 1A SAR data. However, when the datasets of Sentinel 2B MSI and Sentinel 1A SAR were combined, SVM achieved an impressive OA of 0.91 with a high Kappa score of 0.80, while RF achieved an OA of 0.81 with a Kappa score of 0.809. These findings highlight the potential of fusing satellite data from multiple sources to enhance the accuracy and effectiveness of image classification algorithms, making them valuable tools for various applications, including land use mapping and environmental monitoring.

S. Laha, S. Laha, A. Banerjee et al.

<p>The future changes in runoff of Himalayan glacierised catchments will be determined by the local climate forcing and the climate sensitivity of the runoff. Here, we investigate the sensitivity of summer runoff to precipitation and temperature changes in the winter-snow-dominated Chandra (the western Himalaya) and summer-rain-dominated upper Dudhkoshi (the eastern Himalaya) catchments. We analyse the interannual variability of summer runoff in these catchments during 1980–2018 using a semi-distributed glacio–hydrological model, which is calibrated with the available runoff and glacier mass-balance observations. Our results indicate that despite the contrasting precipitation regimes, the catchments have a similar runoff response: the summer runoff from the glacierised parts of both catchments is sensitive to temperature changes and insensitive to precipitation changes; the summer runoff from the non-glacierised parts of the catchments has the exact opposite pattern of sensitivity. The precipitation-independent glacier contribution stabilises the catchment runoff against precipitation variability to some degree. The estimated sensitivities capture the characteristic “peak water” in the long-term mean summer runoff, which is caused by the excess meltwater released by the shrinking ice reserve. As the glacier cover depletes, the summer runoff is expected to become more sensitive to precipitation forcing in these catchments. However, the net impact of the glacier loss on the catchment runoff may not be detectable, given the relatively large interannual runoff variability in these catchments.</p>

Chaoyang Yu, Yuliang Liao

In this work, porous sludge biochar (PSBC) was prepared by molten salt-assisted pyrolysis of municipal sludge, and PSBC loaded with Fe3O4 (Fe3O4@PSBC) was synthesized by chemical precipitation. The effects of pH (2.0–10.0), sorbent dosage (0.1–2 g/L), coexisting ions (Ca2+, Mg2+, Cu2+, Pb2+, Cl–, SiO32-, NO3-, CO32-, SO42-, and PO43-), adsorption temperature (288, 298, and 308 K), initial Cr(VI) ion concentrations (50–150 mg/L), and adsorption time (5–300 min) on the removal of Cr(VI) ions by the sorbent were investigated. The mechanism of the removal of Cr(VI) ions was characterized by scanning electron microscope (SEM), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The result showed that the removal of Cr(VI) ions on PSBC and Fe3O4@PSBC had a strong dependence on the pH of solution. The maximum adsorption capacity of Cr(VI) ions by PSBC and Fe3O4@PSBC was 162 and 209 mg/g, respectively, at a dosage of 0.4 g/L, pH of 3, and temperature of 298 K. The removal process of Cr(VI) ions could be fitted by the Langmuir isotherm model and pseudo-second-order kinetic model. The breakthrough curves were in good agreement with the theoretical values of the Thomas model. The mechanism of the removal of Cr(VI) ions by Fe3O4@PSBC mainly contain complexation, reduction, and electrostatic interaction. This work proposes a new removal material for Cr(VI)-containing wastewater. HIGHLIGHTS A porous Fe3O4@PSBC sorbent was prepared to remove Cr(VI) from aqueous solutions.; The maximum Cr(VI) adsorption capacity of Fe3O4@PSBC was 209 mg/g.; The Cr(VI) removal mechanism mainly included complexation, reduction, and electrostatic interaction.;