Case Studies in Chemical and Environmental Engineering最新文献

{"title":"Heat stress in landfill environments: Evaluating worker exposure and occupational risks","authors":"Azham Umar Abidin ,&nbsp;Anisful Lailil Munawaroh ,&nbsp;Aulia Rosinta ,&nbsp;Arvi Tri Sulistiyani","doi":"10.1016/j.cscee.2025.101097","DOIUrl":"10.1016/j.cscee.2025.101097","url":null,"abstract":"<div><div>Heat stress is a notable occupational health hazard, particularly because global climate change intensified environmental heat exposure. Workers in high-temperature environments, such as landfill sites, encounter significant health risks associated with heat stress, including dehydration, excessive sweating, fatigue, headaches, and potentially more severe conditions. This study examined landfill workers in Yogyakarta, where outdoor conditions increased their susceptibility to heat-related hazards. This study aimed to quantify heat stress in landfill operations via objective data analysis, which refers to the quantitative assessment of environmental heat conditions using the wet bulb globe temperature (WBGT) index, with the goal of informing practical interventions and improving worker health and safety protocols. This cross-sectional study, a type of observational research design, examined data collected at specific points in time. This study involved 39 landfill workers, with WBGT measurements collected at 25 sampling locations in the morning, daylight, and afternoon. This study evaluated the risk of heat stress at various times of the day using WBGT values. The results demonstrated notable fluctuations in WBGT, with peak levels occurring in daylight, consequently increasing the risk of heat stress. Age and body weight are significant factors because older individuals and those with increased body mass exhibit heightened susceptibility to heat retention. Statistical analysis revealed significant differences in WBGT measurements between morning and daylight and between daylight and afternoon (p &lt; 0.001). These findings highlight the necessity for timely monitoring and management strategies to reduce heat stress risk, especially during daylight hours.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101097"},"PeriodicalIF":0.0,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on the preparation and denitrification performance of CeOx/ACN-Al2O3 new SCR catalyst","authors":"Guo Xuewei ,&nbsp;Qu Changsheng ,&nbsp;Liu Yatao ,&nbsp;Xu Dongyao","doi":"10.1016/j.cscee.2025.101099","DOIUrl":"10.1016/j.cscee.2025.101099","url":null,"abstract":"<div><div>Selective catalytic reduction technology is the most widely used method in flue gas denitrification. This article uses the kneading-ultrasonic equal volume impregnation method to prepare a modified activated carbon-alumina supported cerium oxide catalyst (CeO_x/ACN-Al₂O₃) for flue gas denitrification in coal-fired power plants. The relationship between the catalyst with different carrier and active component under different conditions and the conversion rate of nitrogen oxides is studied. XRD and other characterization methods are used to explore the intrinsic mechanism of the catalyst, and the main preparation parameters of the catalyst are optimized, including CeO_x loading amount, starch content, different concentrations of HNO₃, calcination temperature, calcination time, etc. The research results show that the catalyst with a calcination temperature of 400 °C, a starch content of 30 %, a CeO_x loading rate of 13 %, and a 40 % HNO₃ modified CeO_x/ACN-Al₂O₃ has the highest denitrification efficiency, reaching 96.18 % at the optimal operating temperature of 300 °C.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101099"},"PeriodicalIF":0.0,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The thermal-flow performance of water-Al2O3 nanofluid flow in an elliptical duct heat exchanger equipped with two rotating twisted tapes","authors":"Hassan Wathiq Ayoob ,&nbsp;Ihab Omar ,&nbsp;Wed khalid Ghanim ,&nbsp;Mohammad N. Fares ,&nbsp;Mohammad Ali Fazilati ,&nbsp;Soheil Salahshour ,&nbsp;Sh Esmaeili","doi":"10.1016/j.cscee.2025.101094","DOIUrl":"10.1016/j.cscee.2025.101094","url":null,"abstract":"<div><h3>Background</h3><div>The thermal-flow performance of nanofluid (<em>NF</em>) flow in an elliptical duct heat exchanger fitted and turbulated with two rotating tapes is investigated. The issues concerning rotating twisted tapes inside the oval tubes using <em>NF</em> as the working fluid simulated with two-phase modeling have received less attention in previous studies.</div></div><div><h3>Methods</h3><div>Considering the importance of employing the heat transfer improving methods in tubular heat exchangers, the passive and ative heat transfer improving methods examined here. As a novel study case, the rotated tapes beside the water-<em>Al</em>_<em>2</em><em>O</em>_<em>3</em> <em>NF</em> of was used; and sensitivity analysis was performed to reveal the effect of the volume fraction of nanoparticles (<em>ϕ</em>), tapes rotational speed and Re number on the <em>Nu</em> number, pumping power and figure of merit (<em>FOM</em>). The heat flux of 5000 Wm⁻² was applied to the wall surface, and the two-phase mixture method was employed for the simulation. The heat exchanger performance is studied in cases of fixed and rotating twisted tapes with three different rotational speeds. The results show that increasing the Re number, <em>ϕ</em> and the rotation speed of the blades would increase the <em>Nu</em> number and pumping power in all cases. The increase in <em>ϕ</em> improves the <em>Nu</em> number by 6.1 %–19.4 % and the pumping power by 59.2–280 %. The <em>Nu</em> number change by increasing <em>ϕ</em> is lower at low Re numbers and becomes higher at high Re numbers. The effect of <em>ϕ</em> increment on heat transfer is increasing but took place with a higher inclination rate in rotating tapes rather than stationary tapes and plain tube cases. In the cases of rotated twisted tape mode, the value of <em>FOM</em> is always greater than one and is below 0.9 for stationary mode.</div></div><div><h3>Significant findings</h3><div>The highest value of <em>FOM</em> is 1.57, which is for the highest rotational speeds, the lowest Re number, and ϕ = 1 %. Increasing the Re number reduces the <em>FOM</em> while increasing <em>ϕ</em> improves it.</div></div><div><h3>Practical significance and potential area of application</h3><div>The increasing need for efficient heat transfer in heat exchanger devices necessitated the application of heat transfer augmentation techniques. The effects of twisted tapes, their rotation, and the application of <em>NF</em>s in heat exchangers as the active and passive heat transfer increment methods are studied numerically.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101094"},"PeriodicalIF":0.0,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microwave-assisted enzymatic production of cosmetic ester 2-ethylhexyl oleate and myristate","authors":"Eko K. Sitepu ,&nbsp;Emilia Abdulmalek ,&nbsp;Helmina Sembiring ,&nbsp;Rodiah N. Sari ,&nbsp;Ella Parawita ,&nbsp;Dea Hafizah ,&nbsp;Novia Ramadhani ,&nbsp;Maya R.S. Siregar ,&nbsp;Firman Sebayang ,&nbsp;Juliati Br. Tarigan","doi":"10.1016/j.cscee.2024.101089","DOIUrl":"10.1016/j.cscee.2024.101089","url":null,"abstract":"<div><div>The enzymatic microwave-assisted cosmetic esters production from esterification of fatty acids with 2-ethylhexanol using enzyme lipase as a biocatalyst was developed. The parameters of enzyme weight, molar ratio, reaction time and microwave power were investigated to determine the maximum conversion of 2-ethylhexyl myristate (EHM) and 2-ethylhexyl oleate (EHO). The maximum conversion of EHM and EHO of 92.0 ± 0.4 % and 98.2 ± 0.3 %, respectively, were achieved under reaction conditions of enzyme weight of 5 wt%, molar ratio of 1:3, reaction time of 0.5 minutes and microwave power of 20 %. All the parameters tested significantly affect the conversion. The reusability test revealed that the liquid lipase lost its catalytic activity after two subsequent cycles. However, the availability of low-cost enzyme lipase derived from genetically modified microorganisms increases its competitiveness. Microwave radiation system has better performance and offers a fast route of cosmetic esters production, which is also more energy-efficient and cost-effective.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101089"},"PeriodicalIF":0.0,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermodynamic modeling of calcium sulfate hemihydrate formed from seawater and concentrated brine at elevated temperature","authors":"Ali Al-Hamzah ,&nbsp;Caillan J. Fellows ,&nbsp;Christopher M. Fellows","doi":"10.1016/j.cscee.2024.101088","DOIUrl":"10.1016/j.cscee.2024.101088","url":null,"abstract":"<div><div>Formation of hard scale, predominantly calcium sulfate, is the limiting factor in the operation of multi-stage flash (MSF) thermal desalination of seawater, restricting the top temperature and top brine concentration that can be achieved. More accurate prediction of the solubility product of calcium sulfate hemihydrate, the scaling species formed initially above 100 °C, under conditions found in MSF plants, would allow better control of MSF operations. In this report literature data for calcium sulfate solubility is analysed and the Pitzer model applied to determine solubility product values at temperatures up to 148 °C and total dissolved solids concentration up to 99 g/L (equivalent to a concentration factor for Arabian Gulf seawater of 2.2). From these an analytical expression is determined for predicting the supersaturation index (SI) under these conditions to simplify the task of MSF plant operators, SI = 61.5891–0.4783 ln(TDS) + 0.3223 (ln(TDS))²–31.7890 ln(T) + 3.7977 (ln(T))²</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101088"},"PeriodicalIF":0.0,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detecting and measuring Microplastic pollution in Al Hoceima City's harbor, northern Morocco","authors":"Iliass Achoukhi ,&nbsp;Yahya EL Hammoudani ,&nbsp;Khadija Haboubi ,&nbsp;Abdelhak Bourjila ,&nbsp;Abdelaziz Touzani ,&nbsp;Kamal Reklaoui ,&nbsp;Fouad Dimane","doi":"10.1016/j.cscee.2024.101093","DOIUrl":"10.1016/j.cscee.2024.101093","url":null,"abstract":"<div><div>This study investigates microplastic pollution in Al Hoceima City's harbor, Northern Morocco, with a focus on their isolation, identification, and quantification. In December 2023, surface water and sediment samples were systematically collected using manta nets and core samplers. The samples underwent wet sieving, drying, and digestion using hydrogen peroxide with an iron catalyst to remove organic matter. Density separation with a saturated sodium chloride solution was employed to isolate microplastics, which were then analyzed using ATR-FTIR spectroscopy for polymer identification. The analysis revealed a dominance of polyethylene (70.2 %) and polypropylene (20.5 %) among the microplastics, primarily in fiber, fragment, and film forms, with sizes ranging from 0.10 to 6 mm. Predominant size categories were 0.2–0.5 mm, accounting for over 50 % of the total, and clear and blue were the most common colors. The average microplastic density was calculated at 9.40 ± 4.50 items/m³. This study highlights the widespread distribution of microplastics in the harbor, identifying their sources and impacts, while providing a robust methodology and findings to inform future marine pollution mitigation efforts in the Mediterranean region.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101093"},"PeriodicalIF":0.0,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The temporal evolution of HCHO and changes in atmospheric composition in the southeast of the United Kingdom","authors":"Balendra V.S. Chauhan ,&nbsp;Kirsty L. Smallbone ,&nbsp;Maureen Berg ,&nbsp;Kevin P. Wyche","doi":"10.1016/j.cscee.2024.101092","DOIUrl":"10.1016/j.cscee.2024.101092","url":null,"abstract":"<div><div>Formaldehyde (HCHO) is a significant atmospheric pollutant with adverse effects on human and environmental health. This case study investigates seasonal variations in HCHO concentrations and their relationship with tropospheric ozone (O₃) levels in the Southeast of the United Kingdom. Using hourly data collected from June 2015 to May 2023 at the Brighton Atmospheric Observatory, the research analyzes the interplay between atmospheric chemistry, meteorological parameters, and pollutant transport dynamics. Results reveal pronounced peaks in HCHO concentrations during summer months, reaching up to 9.5–10 μg/m³ around 12:00. This surge is attributed to heightened photochemical activity driven by increased solar radiation and temperatures. Regression analyses demonstrate a strong positive correlation (97 %) between summertime HCHO concentrations and air temperature. Elevated temperatures accelerate VOC oxidation reactions, leading to increased HCHO formation. The study also finds a significant correlation (81 %) between summertime tropospheric O₃ and air temperature. This suggests that higher temperatures enhance photochemical reactions involving O₃ precursors, contributing to elevated O₃ levels. Wind pattern analysis reveals the dominance of southwesterly winds in transporting HCHO throughout the year, with concentrations peaking at wind speeds of 15–20 m/s. During summer, northeastern and easterly winds become more influential in carrying tropospheric O₃, highlighting seasonal shifts in transport pathways. These findings provide valuable insights into air quality dynamics and underscore the importance of targeted interventions for sustainable air quality management. Understanding the factors influencing HCHO and O₃ concentrations is crucial for developing effective mitigation strategies to protect human and environmental health.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101092"},"PeriodicalIF":0.0,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Liquid smoke-infused edible coatings: Antimicrobial agents for preserving cherry tomatoes","authors":"Muhammad Faisal ,&nbsp;Dieni Mansur ,&nbsp;Hera Desvita ,&nbsp;M. Bagas Heriansyah","doi":"10.1016/j.cscee.2024.101091","DOIUrl":"10.1016/j.cscee.2024.101091","url":null,"abstract":"<div><div>This study aimed to explore the effectiveness of edible coating to extend the shelf life of cherry tomato at room temperature. The edible coating was made from a mixture of liquid smoke with a concentration of 2–6% v/v (pyrolysis of rice husks <em>(Oriza sativa)</em> and cajuput <em>(Melaleuca leucadendron)</em> twigs) at a temperature of 500 °C), 0.5 % gelatin, 4 % chitosan, 1.5 % CMC (<em>Carboxymethyl Cellulose</em>), and distilled water. All ingredients were mixed into a homogeneous solution and cherry tomato was soaked for 15 minutes in the edible coating solution. The effectiveness of edible coating was tested based on antibacterial activity against 4 types of pathogenic bacteria, namely <em>Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus,</em> and <em>Bacillus subtili</em>s, as well as 2 fungi including <em>Candida albicans</em> and <em>Aspergillus niger</em>. The quality of cherry tomato was also analyzed through the Most Probable Number (MPN) test for <em>E. coli</em> and the measurement of the L∗ value. The results showed that edible coating was effective in inhibiting the growth of pathogenic microbes and could maintain the freshness of cherry tomato for approximately 15 days of storage at room temperature in sample RK3 as well as 9 days in SP2 and SP3 (liquid smoke from rice husks). Furthermore, changes in L∗ values significantly reduced in cherry tomato during storage. These results showed that edible coating can prevent the decline in the quality of cherry tomato during storage at room temperature.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101091"},"PeriodicalIF":0.0,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced performance of visible-light-induced Bi2MoO6–N-doped biochar for rhodamine B degradation and textile wastewater decontamination","authors":"Rajesh Chanda ,&nbsp;Anik Karmokar ,&nbsp;Md. Nahid Hassan ,&nbsp;Toslim Jahid ,&nbsp;Shoyeb Muhammad ,&nbsp;Nirupam Aich ,&nbsp;Biplob Kumar Biswas","doi":"10.1016/j.cscee.2024.101090","DOIUrl":"10.1016/j.cscee.2024.101090","url":null,"abstract":"<div><div>Organic dyes are a significant source of growing wastewater pollution. Biochar-supported visible-light photocatalysts are gaining attention due to their cost-effectiveness and green perspective. This study presents a novel N-doped-coconut-husk-derived biochar (NBC)-supported bismuth molybdate (BMO) as a photocatalyst. Urea, KOH were mixed with coconut-husk and pyrolyzed at 600–800 °C to prepare NBC. The ball-mill mixed BMO-NBC composites having 77 wt% BMO-23 wt% of 800 °C pyrolyzed NBC degraded 99.1 % of 10 mg/L RhB solution within 120 minutes. The photocatalyst was evaluated for on-site-collected textile-effluent remediation. The role of biochar functionalization, pyrolysis temperature, as well as composite composition, in its photocatalytic performance, are presented.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101090"},"PeriodicalIF":0.0,"publicationDate":"2024-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel efficiency of turmeric extract as a green inhibitor of low carbon steel corrosion in 3.5% NaCl solution","authors":"Hajir Amer Jaddoa,&nbsp;Basheer A. Abdulhussein,&nbsp;Jamal M. Ali","doi":"10.1016/j.cscee.2024.101086","DOIUrl":"10.1016/j.cscee.2024.101086","url":null,"abstract":"<div><div>Carbon steel's atmospheric corrosion susceptibility is well-studied. Marine chlorides were poorly studied until recently. Because of their importance to civilization, coastal areas are prone to corrosion. As developing nations industrialize, they move production facilities to coastal areas, where half the world's population lives. Little was known about rust formation in Cl-rich environments before the millennium. Recently, we understand marine atmospheric corrosion better. An aqueous turmeric powder extract is used as a corrosion inhibitor to control low carbon steel corrosion in 3.5 % NaCl. Weight loss and polarization studies were used. A FTIR spectrum was used to analyze the protective film, FESEM examined surface morphology and AFM. Metal hardness before and after immersion is known. A weight loss study found that 1200 ppm turmeric extract inhibits corrosion at 97.52 %. Use these findings in petroleum equipment.</div></div>","PeriodicalId":34388,"journal":{"name":"Case Studies in Chemical and Environmental Engineering","volume":"11 ","pages":"Article 101086"},"PeriodicalIF":0.0,"publicationDate":"2024-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}