Hasil untuk "Environmental technology. Sanitary engineering"

A. Bhargava, F. F. Carmona, M. Bhargava et al.

Feras Alasali, Mohammed I. Abuashour, Waleed Hammad et al.

The rapidly growing global need for environmentally friendly energy solutions has inspired extensive research and development efforts aimed at harnessing the potential of hydrogen energy. Hydrogen, with its diverse applications and relatively straightforward acquisition, is viewed as a promising energy carrier capable of tackling pressing issues, such as carbon emissions reduction and energy storage. This study conducts a preliminary investigation into effective hydrogen generation and storage systems, encompassing methods like water electrolysis, biomass reforming, and solar‐driven processes. Specifically, the study focuses on assessing the potential of nanostructured catalysts and innovative materials to enhance the productivity and versatility of hydrogen energy systems. Additionally, the utilization of novel materials not only improves hydrogen storage capacity and safety but also opens up possibilities for inventive applications, including on‐demand release and efficient transportation. Furthermore, critical factors such as catalyst design, material engineering, system integration, and technoeconomic viability are examined to identify challenges and chart paths for future advancements. The research emphasizes the importance of fostering interdisciplinary collaborations to advance hydrogen energy technologies and contribute to a sustainable energy future.

G. Jeevi, S. Nayak, M. Abdul Kader

Abstract Composites have been used extensively in various engineering applications including automotive, aerospace, and building industries. Hybrid composites made from two or more different reinforcements show enhanced mechanical properties required for advanced engineering applications. Several issues in composites were resolved during the last few years through the development of new materials, new methods and models for hybrid joints. Many components in automobile are joined together either by permanent or temporary fastener such as rivets, welding joint and adhesively bonded joints. Increasing use of bonded structures is envisaged for reducing fastener count and riveted joints and there by drastically reducing assembly cost. Adhesive bonding has been applied successfully in many technologies. In this paper, scientific work on adhesively bonded composites and hybrid composites are reviewed and discussed. Several parameters such as surface treatment, joint configuration, material properties, geometric parameters, failure modes, etc. that affect the performance of adhesive bonded joints are discussed. Environmental factors like pre-bond moisture and temperature, method of adhesive application are also cited in detail. A specific case of adhesive joints in hybrid bonded-bolted joints is elaborated. As new applications are expanding in the field of composites joining and adhesive joints, it is imperative to use information on multiple adhesives and their behaviour in different environmental conditions to develop improved adhesive joint structure in mechanical applications.

Yuhang Liang, Zhaoyong Li, Xiaolin Li et al.

In view of the subjectivity and limitations of scenario setting, as well as the time-consuming nature of computations and difficulty of obtaining global optimal solutions, this paper proposes an ecological water replenishment optimisation model by coupling a hydrodynamic model and an optimisation algorithm. The proposed model aims to obtain the most optimal water replenishment plan to meet specific objectives, by using the hydrodynamic model to obtain relationship curves between various hydrodynamic indicators (e.g. water level, discharge, flow velocity) and different ecological water replenishment flows, and combining these curves with the optimisation algorithm. The model was applied to the Beijing section of the Yongding River. The minimum water replenishment flow at the cross section of Guanting Reservoir is 30 m3/s, to meet the goal of full-channel waterflow connectivity in the Beijing section of Yongding River. A comprehensive optimal ecological water replenishment plan is proposed under the consideration of three objectives in the best state possible, i.e. the maximum guaranteed rate of suitable ecological flow, the highest monthly average ecological water replenishment efficiency and the maximum guaranteed rate of full-channel waterflow connectivity. This study provides novel insights and methodologies for the formulation of ecological water replenishment plans for water-deficient rivers.

Grace I. Adebayo-Gege, Samuel B. Olaleye

Sodium arsenite toxicity has been a major problem due to its extensive presence in contaminated water and food, leading to oxidative stress and formation of ulcers in the gastrointestinal tracts. This study elucidated the therapeutic actions of Kolaviron and vitamin E against toxicity of sodium arsenite during gastric ulceration, and insights into molecular docking against NADH oxidases. Experimental animals (male, n = 12, ±200) were grouped in to seven groups; I(control),II(gastric ulcer induced by acetic acid(ACIU), III(ACIU+ 5 mg/kg Sodium Arsenite(SA), IV(ACIU +SA+100 mg/kg vitamin E(ACIU+ SA+ 100 mg/kg Kolaviron(KV), VI(ACIU +KV),VII(ACIU+ Vit. E). The KV was gotten from Garcinia kola. Ulcer induced by60 % acetic acid.Kolaviron and vitamin E were administered for two weeks post-ulcer induction. The ulcer area was determined by using planimetry, while Biochemical indices, H/ATPase and NO concentration were evaluated. H and E, immunohistochemistry was done on the gastric tissue to evaluate the expression of CD31, ki67, and P53 to investigate angiogenesis, proliferation and apoptosis. Data were subjected to analysis of variance, P < 0.05. The molecular docking of Kolaviron and vitamin E against NADPH oxidases was evaluated. Finding shows that kolaviron and vitamin E significantly mitigated sodium arsenite-induced oxidative stress, and gastric ulceration, P < 0.05. In the ulcerated control animals, the ulcer areas were 0.74 ± 0.01 cm², 0.57 ± 0.08 cm², 0.53 ± 0.12 cm² and 0.24 ± 0.04 cm² while SA exposure significantly increased ulcer areas for 100.0 %, 66.7 %, 40 %, 66.7 % by days 3, 7, 14 and 21, respectively. By day 21 post-ulcer induction, Kolaviron and vitamin E had reduced ulcer areas relative to SA-treated group by 100 % respectively. Kolaviron and vitamin E significantly decrease the lipid peroxidation and increase the anti-oxidants, P < 0.05. There was enhanced angiogenesis(CD38),proliferation(Ki67),and inhibition of apoptosis(P53). Molecular docking analyses revealed that kolaviron exhibited a high binding affinity for NADPH oxidase, implicated in gastric ulcer pathogenesis. These findings suggest that kolaviron and vitamin E may be a promising agents for preventing and treating gastric ulcers induced by sodium arsenite toxicity

Manel Mebarki, Gabriella Joge Ngale, Mathieu Lapointe

Abstract A compact three-in-one water treatment process, combining a flocculant, a fibrous super-bridging agent, and a screen-based floc retention system, simultaneously improves water treatment and sludge dewatering. The presence of fibrous materials allows for the formation of very large flocs, efficient floc separation via screening (without settling), and sludge dewatering through a compact press-filter system. The implementation of this three-in-one process is possible due to the formation of very large fiber-based flocs. The sludge containing fibers was subsequently dewatered using a screen-based press filter without further chemical addition. The use of fibers also significantly improved the removal of total organic carbon, nanoplastics, and microplastics. This three-in-one process could be used for decentralized water treatment in drinking water and wastewater applications in small cities, marginalized communities, and developing countries. The compact process, which also performs sludge dewatering, would reduce the risks associated with mismanaged sludge to the environment and human health.

Manimegalai R, Dhanyasri K, Dakshin Priya T S et al.

Xi Wang, Miaoyang Hu, Muhan Li et al.

Polyhalogenated carbazoles (PHCZs) are emerging environmental pollutants, yet limited information is available on their embryotoxicity and neurotoxicity. Therefore, the current work was performed to investigate the adverse effects of 3,6-dibromocarbazole (3,6-DBCZ), a typical PHCZs homolog, on the early life stages of zebrafish larvae. It revealed that the 96-hour post-fertilization (hpf) median lethal concentration (LC50) value of 3,6-DBCZ in zebrafish larvae was determined to be 0.7988 mg/L. Besides, 3,6-DBCZ reduced survival rates at concentrations ≥ 1 mg/L and decreased hatching rates at ≥ 0.25 mg/L at 48 hpf. In behavior tests, it inhibited locomotor activities and reduced the frequency of recorded acceleration states in response to optesthesia (a sudden bright light stimulus) at concentrations ≥ 160 μg/L. Meanwhile, 3,6-DBCZ exposure decreased the frequency of recorded acceleration states in the startle response (tapping mode) at concentrations ≥ 6.4 μg/L. Pathologically, with the transgenic zebrafish model (hb9-eGFP), we observed a strikingly decreased axon length and number in motor neurons after 3,6-DBCZ treatment, which may be ascribed to the activation of the AhR signaling pathway, as evidenced by the molecular docking analysis and Microscale thermophoresis (MST) assay suggested that 3,6-DBCZ binding to AhR-ARNT2 compound proteins. Through interaction with AhR-ARNT, a striking reduction of the anti-oxidative stress (sod1/2, nqo1, nrf2) and neurodevelopment-related genes (elavl3, gfap, mbp, syn2a) were observed after 3,6-DBCZ challenge, accompanied by a marked increased inflammatory genes (TNFβ, IL1β, IL6). Collectively, our findings reveal a previously unrecognized adverse effect of 3,6-DBCZ on zebrafish neurodevelopment and locomotor behaviors, potentially mediated through the activation of the AhR pathway. Furthermore, it provides direct evidence for the toxic concentrations of 3,6-DBCZ and the potential target signaling in zebrafish larvae, which may be beneficial for the risk assessment of the aquatic ecosystems.

Shuming Liu, Bo Yang, Yunshan Liang et al.

Peter Onu, A. Pradhan, C. Mbohwa

With the increasing global emphasis on sustainability, it is crucial to explore strategies that enable industries to adopt environmentally friendly and resource-efficient manufacturing processes. The study specifically focuses on enhancing the competencies of professionals in additive manufacturing, a multidisciplinary field encompassing mechanical engineering, electronics, and computer science, to contribute to sustainable production practices. Problem-centered and guided expert interviews were conducted with 12 experts from diverse industries to accomplish this. The interviews were transcribed verbatim, and Mayring's content analysis method was employed to evaluate the transcripts. This methodology identified vital competencies, including knowledge of technology and materials, part identification skills, and a comprehensive understanding of the AM process chain. The findings also highlighted the significance of soft or interpersonal skills, such as teamwork, effective communication, adapting to multicultural and diverse environments, and more. Furthermore, the interviews revealed opportunities for sustainability and emphasized the importance of increased collaboration among companies and universities involved in AM. The insights gained from this research will inform the development of training programs and guidelines to foster sustainable production in advanced manufacturing.

Haowen Zhang, Jianghua Yang, Lijuan Zhang et al.

Rapeepan Yongyod, PhatcharapornPhusomya, Peechanika Chopjitt

Consumption of food from food stalls and water from vending machines has recently increased in Sakon Nakon Province, Thailand. This study investigated the microbial quality of food stalls and the sanitation of drinking water distributed through water vending machines. Escherichia coli, Salmonella spp., Staphylococcus aureus, and Vibrio cholerae were detected using polymerase chain reaction. In total, 33 food samples were collected from food stalls and 63 drinking water samples were collected from water vending machines. The results identified E. coli in 6.06% of the food and 11.11% of the drinking water samples. Salmonella spp., S. aureus, and V. cholerae were not detected in any of the food or drinking water samples. Food sanitation assessment indicated 21 (63.64%) of the food stalls did not meet the standards for drinking water as it was not stored in clean and closed containers equipped with a tap or nozzle. Regarding the sanitation of the water vending machines, the businesses failed to inspect the physical, chemical and biological aspects of water quality and never used a simple bacterial test kit to check water quality. It is concluded that the relevant government officials should educate the vender on food safety and hygiene as well as enforcing regular monitoring of the quality of food stall and drinking water vending machines.

M. Ramalho, Toni Jovanović, A. Afonso et al.

Samarjeet Singh Siwal, Harjot Kaur, Adesh Kumar Saini et al.

Carbon dots (CDs), an emerging category of carbon nanomaterials, have bright destiny in a vast diversity of engineering areas due to their great variety in design, arrangement, and characteristics. Their possible implementations have recently traversed from electrochemical energy storage (EES), fluorescent probing, and catalysis, particularly as materials into the critical elements of the electrochemical system. Herein, the current investigation based upon the preface of CDs in batteries, supercapacitors, hydrogen/oxygen evolution reaction, oxygen reduction reaction, electromagnetic interference shielding, and solar‐assisted energy generation used as electrode materials integrated with an active substance as an auxiliary mechanism is shown. Different aspects conferred upon selected illustrations outline the electrochemical activity, and eventually, current issues and future viewpoints are recollected toward the following optimization method of electrode substances. This review article is anticipated to demand broad attention within active CD materials and encourage the growth of high‐performance EES systems.

B. Cao, Jian Xu, Fei Wang et al.

Soil pollution is one of the major threats to the environment and jeopardizes the provision of key soil ecosystem services. Vertical barriers, including slurry trench walls and walls constructed with soil mix technology, have been employed for decades to control groundwater flow and subsurface contaminant transport. This paper comprehensively reviewed and assessed the typical materials and mechanical and permeability properties of soil–bentonite, cement–bentonite and soil mix barriers, with the values of mix design and engineering properties summarized and compared. In addition, the damage and durability of barrier materials under mechanical, chemical, and environmental stresses were discussed. A number of landmark remediation projects were documented to demonstrate the effectiveness of the use of barrier systems. Recent research about crack-resistant and self-healing barrier materials incorporating polymers and minerals at Cambridge University and performance monitoring techniques were analyzed. Future work should focus on two main areas: the use of geophysical methods for non-destructive monitoring and the optimization of resilient barrier materials.

J. Wanner

The paper summarizes the development in the understanding and practical application of the activated sludge process over the last 50 years. Since its invention, the activated sludge process has been a big challenge to design engineers. Traditionally, the technology was covered by sanitary engineers. However, with the development in the understanding of activated sludge process principles, further progress was not possible without knowledge of reaction kinetics and reactor theory. The shift from BOD removal only to combined removal of organic pollution, nitrogen and phosphorus required a chemical engineering approach with outputs of activated sludge microbiology and microbial ecology. Molecular biology enabled more accurate identification of important activated sludge microorganisms. The development in activated sludge process also required more efficient activated sludge separation and thickening. The paper describes the development from secondary clarifiers to membrane separation. Increasing water stress around the globe has also changed the main wastewater paradigm from wastewater treatment and safe discharge to safe reuse.

S. Panda, S. Mishra, E. Kayitesi et al.

Chen Chen, Qi Zhou, Ruiyue Yang et al.

Background: Excessive copper (Cu) has risky effect on insulin resistance (IR), oxidative stress and inflammation. Instead, some studies reported serum Cu to be protective for non-alcoholic fatty liver disease (NAFLD). The aim of this study was to reevaluate the evidence for a potential risky correlation of serum Cu to NAFLD in large-scale and non-institutionalized American subjects. Methods: A cross-sectional study of 3211 subjects was from the National Health and Nutrition Examination Survey (NHANES). Logistic regression and cubic spline-based curve-fitting analyses were used to estimate the independent risky effect of Cu to hepatic steatosis index (HSI), US fatty liver index (USFLI) and NAFLD and their dose-effect relationship. Moreover, this association was analyzed in stratification of HOMA-IR, Metabolic syndrome (MetS) and severity of NAFLD, besides age and gender. Results: The average level of serum Cu was 18.67 μmol/L and the prevalence of NAFLD was 54.53% and 32.60%, respectively defined by HSI and USFLI. Generally, the level of Cu was higher in females than males. Serum Cu was positively associated with higher HSI, USFLI index and risk of NAFLD. In fully adjusted models, compared with the lowest quartile, the risk of NAFLD increased 97% in the highest quartile of Cu. Interestingly, stratified analysis showed that the risky effect of Cu to NAFLD was more prominent in the middle-aged, females and subjects with improved status of IR (lower HOMA-IR and non-Mets) compared with their counterparts. Moreover, we further found that circulating copper was correlated to severity of NAFLD only in males. Conclusion: Excess serum Cu is significantly associated with risk of NAFLD, which is prominent in females, middle-aged and subjects with improved status of IR, and seems to be related to the severity of NAFLD, additionally. It is necessary to be cautious of the toxic effect of Cu and prospective cohort and mechanism studies are needed to verify the causal effect of Cu to NAFLD.

Tsukasa Ito, Yu Yamanashi, Naoki Noguchi et al.

The public sewage (PS) and night soil mixed with johkasou sludge (JO) have similar chemical compositions; however, the concentrations of organic matter and nitrogen compounds were different. We investigated the microbial community of the rotating biological contactor (RBC) units treating PS and JO, in which the RBC was submerged in the mixed liquor of activated sludge. Here, we observed that the microbial community compositions at the phylum and class levels were similar between the PS-RBC and JO-RBC, whereas the relative abundances of several phyla (Euryarchaeota, Acidobacteria, Chloroflexi, Firmicutes, Patescibacteria, and Betaproteobacteria) significantly differed between them. The microbial community composition of RBC (an attached growth process) was similar to that of the activated sludge (a suspended growth process). The microbial community of activated sludge likely affected that of RBC. The relative abundance of total denitrifying bacteria in the PS-RBC was twice as much as that in JO-RBC, while nitrifying bacterial phylotypes had a similar relative abundance. The predominant denitrifying genera were different between the PS-RBC and JO-RBC, as well as in the cross-sectional layers of the PS-RBC, suggesting the functional diversity of denitrifying bacterial genera inhabiting the RBC.

Dongyang Li, R. Zhao, Xing Peng et al.