Article
Optics
Shengjun Zhou, Zhefu Liao, Ke Sun, Ziqi Zhang, Yinzuo Qian, Pengfei Liu, Peng Du, Jingjing Jiang, Zhenxing Lv, Shengli Qi
Summary: This study develops ultrathin tunnel junction (UTJ) deep-UV light-emitting diodes (LEDs) with a low operating voltage of 5.7 V. The formation of Ohmic contact between high-work-function Ni/Au and Mg-Si co-doped n(+)- Al0.45Ga0.55N layer in UTJ is discovered. A high-efficiency sterilization deep-UV light source integrated with 120 UTJ deep-UV LED chips is developed.
LASER & PHOTONICS REVIEWS
(2023)
Article
Engineering, Environmental
Leonardo Romero-Martinez, Paola Duque-Sarango, Claudia Gonzalez-Martin, Javier Moreno-Andres, Asuncion Acevedo-Merino, Enrique Nebot
Summary: Treatment with UV light is commonly used to deactivate waterborne organisms. In this study, the UV resistance and reactivation degree of different strains of E. coli and E. faecalis were evaluated and compared using LEDs with an emission range of 265-285 nm. The results showed that the intraspecific differences between E. coli strains were greater than the interspecific differences with respect to E. faecalis in terms of UV resistance and repairing potential. The UV doses required for a four log-reduction ranged from 10.2 to 16.3 mJ cm(-2) for E. coli and from 11.1 to 11.4 mJ cm(-2) for E. faecalis. Dark repair was not observed within 24 hours, and photorepair depended on the bacterial strain and the applied UV dose. The exposed organisms required an increased UV dose of 18-160% to achieve a four log-reduction compared to unexposed organisms.
JOURNAL OF WATER PROCESS ENGINEERING
(2023)
Article
Engineering, Environmental
Chien-Ping Wang, Chin-Sheng Chang, Wei-Chen Lin
Summary: This study investigated the effects of irradiance distribution, outer radius, radiative power, and flow rate on the inactivation efficiency of Escherichia coli using UV-C LEDs in a flow-through reactor. Results showed that using 24 LEDs yielded the highest inactivation efficiency, and increasing the outer radius increased exposure time but reduced average irradiance. Additionally, an increase in flow rate led to a sharp decrease in inactivation rate due to reduced exposure time.
JOURNAL OF WATER PROCESS ENGINEERING
(2021)
Article
Engineering, Environmental
Chien-Ping Wang, Wei-Chen Lin
Summary: The study found that using a spiral-channel configuration in a water disinfection flow reactor can effectively improve the sterilization efficiency of Escherichia coli. A shorter spiral pitch leads to a higher Dean number and longer exposure time, which is beneficial for enhancing sterilization effects.
JOURNAL OF WATER PROCESS ENGINEERING
(2021)
Article
Engineering, Environmental
Hojung Rho, Pingfeng Yu, Zhe Zhao, Chung-Seop Lee, Kangmin Chon, Francois Perreault, Pedro J. J. Alvarez, Gary Amy, Paul Westerhoff
Summary: Biofouling on membrane surfaces is a problem for desalination and wastewater reuse. Ultraviolet (UV) light can control biofilm growth, but delivering light to membrane surfaces is challenging. Nano-enabled optical fibers emitting UV light from LEDs can disinfect and oxidize. We used these fibers as spacers on RO membranes and found that UV-C fibers were more effective in preventing biofouling than UV-A fibers.
Article
Engineering, Environmental
Amirmohamad Soleymani Kooshan, Alireza Jalali, Seyed Farshid Chini
Summary: This paper discusses the traditional method of water disinfection and the development of ultraviolet (UV) radiation technology, as well as the potential of UV-LED technology in water treatment. The performance of cylindrical water disinfection UV-LED photoreactors made of UV reflective materials is analyzed using computational fluid dynamics (CFD). The optimal radius and length of the photoreactors for different configurations are determined. The results indicate that U-shaped and S-shaped photoreactors using UV-LEDs outperform L-shaped photoreactors in terms of disinfection effectiveness.
JOURNAL OF WATER PROCESS ENGINEERING
(2022)
Article
Optics
Yu-Hsuan Hsu, Kang-Wei Peng, Yi-Hsin Lin, Ming-Chun Tseng, Su-Hui Lin, Meng-Chun Shen, Ting-Zhu Wu, Zhong Chen, Ray-Hua Horng
Summary: This study fabricated high-voltage, low-current DUV-LEDs with better current spreading and enhanced reflective mirror effect, resulting in higher power output and efficiency compared to traditional devices. It has potential applications in high-voltage circuits to eliminate extra power consumption.
Article
Environmental Sciences
Chien-Ping Wang, Lo-Chieh Chan, Jun-You Liao
Summary: A novel self-cooling water disinfection reactor was developed to dissipate Joule heat from UV-C LEDs, improving their lifespan and radiant power. Experimental results showed that compared to a traditional flow-through reactor, the self-cooling reactor had lower LED temperature, shorter time to reach steady state, and higher average irradiance and inactivation values.
ENVIRONMENTAL TECHNOLOGY
(2023)
Article
Mechanics
Hongying Li, Xuechuan Shan, Te Ba, Yu Chan Liu, Chang-Wei Kang, Candice Au Ka Hing, Nitin Loganathan, Uvarajan M. M. Velayutham
Summary: Given the current situation of the COVID-19 pandemic, it is necessary to develop techniques for improving air quality in buildings, particularly in healthcare settings. This study presents the development of Ultraviolet-C (UVC) LED modules that can be used for airborne disinfection in air ducts. The results show that one LED module can inactivate over 76% and 85% of pathogens within 60 and 90 minutes, respectively, in a 107 m(3) meeting room. Simulations also demonstrate that using two LED modules significantly enhances the disinfection efficacy. Furthermore, numerical investigations indicate a nearly 89.10% disinfection rate for the SARS-CoV-2 virus within one hour using two LED modules in the same meeting room.
Article
Chemistry, Multidisciplinary
Young-Chul Leem, NoSoung Myoung, Sang-Hyun Hong, Sehee Jeong, Okkyun Seo, Seong-Ju Park, Sang-Youp Yim, Joon Heon Kim
Summary: A new design for light-emitting diodes (LEDs) with on-chip photocatalysts is proposed for purification applications. The integration of TiO2/SiO2 nanodisk/pedestal array with near-UV LEDs enhances the photocatalytic activity, showing three times higher degradation of malachite green compared to LEDs with a TiO2 planar layer. This integrated system holds promise for various purification applications.
NANOSCALE ADVANCES
(2022)
Article
Environmental Sciences
Jason B. K. Park, Louise Weaver, Rob Davies-Colley, Rebecca Stott, Wendy Williamson, Margaret Mackenzie, Erin McGill, Susan Lin, Judith Webber, Rupert J. Craggs
Summary: This study compared the light and dark disinfection of faecal bacteria/viral indicator organisms and human viruses in Wastewater Treatment Pond mesocosms. The results showed that UVB contributes to the inactivation of E. coli and viruses by direct sunlight, but UVB disinfection may be less important in WTP water. Additionally, dark disinfection processes were appreciably slower than sunlight-mediated inactivation, with dark control achieving higher removal of E. coli and viruses.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Optics
Qifeng Lyu, Huaxing Jiang, Kei May Lau
Summary: The study demonstrates the first integration of monolithically integrated UV LEDs and visible-blind UV PDs on Si substrate, achieving high sensitivity and low dark current. By optimizing the structure and materials, it offers potential for various applications with high-performance UV PDs and LEDs.
Article
Engineering, Environmental
D. Gordon Knight, Natalie M. Hull
Summary: The International Ultraviolet Association (IUVA) formed a task force to develop guidelines for testing and reporting the performance of UV LED water disinfection systems. They recommended some protocol changes for measuring the performance of UV LED systems to accommodate their unique characteristics.
WATER ENVIRONMENT RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Xiangyu Fu, Yash Mehta, Yi-An Chen, Lei Lei, Liping Zhu, Nilesh Barange, Qi Dong, Shichen Yin, Juliana Mendes, Siliang He, Renuka Gogusetti, Chih-Hao Chang, Franky So
Summary: The study demonstrates highly directional and polarized light emission from LEDs by selectively diffracting the TE waveguide mode, showing potential for more efficient photonic applications.
ADVANCED MATERIALS
(2021)
Article
Multidisciplinary Sciences
Jin-Hoon Kim, Jin-Woo Park
Summary: An intrinsically stretchable organic light-emitting diode, made of highly stretchable constituent materials, is able to emit light under strains as large as 80%. It has a low turn-on voltage of 8 V and a maximum luminance of 4400 cd m(-2) from both the anode and cathode sides. The device can withstand repeated stretching cycles up to 200 times and shows improved light-emitting efficiency with small stretches up to 50%.
Review
Green & Sustainable Science & Technology
Mokgehle R. Letsoalo, Thandiwe Sithole, Steven Mufamadi, Zvanaka Mazhandu, Mika Sillanpaa, Ajeet Kaushik, Tebogo Mashifana
Summary: The presence of pharmaceutical contaminants (PCs) in the environment, including water and aquatic life, is a continuous threat to human health and the natural cycle. In particular, the accumulation of non-degradable water-soluble residues in water streams and groundwater has raised serious concerns and is now a focus of the United Nations' Sustainable Development Goals 2030. This article explores the challenges and potential solutions for the selective detection and efficient remediation of PCs in wastewater using nano-enabled functional systems.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Biochemistry & Molecular Biology
Muhammad Pervaiz, Muti Ur Rehman, Faisal Ali, Umer Younas, Mika Sillanpaa, Rizwan Kausar, Asma A. Alothman, Mohamed Ouladsmane, Mohammad Abdul Mazid
Summary: Cellulose/MoS2/GO nanocomposite was synthesized using a hydrothermal method. The formation of the nanocomposite was confirmed by UV-visible and FTIR spectroscopy, and its particle size and morphology were characterized. The nanocomposite exhibited promising biomolecule protective and photocatalytic potential, making it suitable for environmental remediation.
BIOINORGANIC CHEMISTRY AND APPLICATIONS
(2023)
Article
Thermodynamics
Yiran Yang, Gang Li, Tao Luo, Mohammed Al-Bahrani, Essam A. Al-Ammar, Mika Sillanpaa, Shafaqat Ali, Xiujuan Leng
Summary: This study aims to predict building energy consumption by using neural networks such as support vector machine, gated recurrent unit, extreme learning machine, long short-term memory, and shuffled frog leaping algorithm as an optimizer. Statistical results indicate that long short-term memory and support vector machine are the best neural networks for cooling and heating load forecast, respectively.
Article
Engineering, Environmental
Mohua Li, Liang Bai, Shengtao Jiang, Mika Sillanpaa, Yingping Huang, Yanbiao Liu
Summary: Selective electrochemical reduction of oxygen (O-2) via 3e(-) pathway to produce hydroxyl radicals (HO) is a promising alternative to conventional electro-Fenton processes. A nitrogen-doped CNT-encapsulated Ni nanoparticle electrocatalyst (Ni@N-CNT) was developed, which exhibited high selectivity towards O-2 reduction and generation of HO•via 3e(-) pathway. The exposed graphitized N on the CNT shell and Ni nanoparticles encapsulated within the tip of the N-CNT played crucial roles in the generation of *HOOH through a 2e(-) oxygen reduction reaction. The encapsulated Ni nanoparticles at the tip of the N-CNT also facilitated the direct decomposition of electrogenerated *H2O2, leading to sequential generation of HO• through a 1e(-) reduction reaction on the N-CNT shell without inducing Fenton reaction. Improved bisphenol A (BPA) degradation efficiency was observed compared to conventional batch systems (97.5% vs 66.4%). Trials using Ni@N-CNT in a flow-through configuration demonstrated complete removal of BPA within 30 minutes (k = 0.12 min(-1)) with a limited energy consumption of 0.068 kW.h.g(-1) TOC.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Biochemistry & Molecular Biology
Atef El Jery, Hayder Mahmood Salman, Rusul Mohammed Al-Khafaji, Maadh Fawzi Nassar, Mika Sillanpaa
Summary: Hydrogen production using polymer membrane electrolyzers is an effective method for generating environmentally friendly energy. The study analyzed the performance of the electrolyzers in the water electrolysis process and investigated the impact of variables such as radiation intensity and current density on hydrogen production. Machine-learning-based predictions were also conducted to forecast efficiency and hydrogen production rate in different scenarios.
Article
Green & Sustainable Science & Technology
Rajesh Babu Katiyar, Suresh Sundaramurthy, Anil Kumar Sharma, Suresh Arisutha, Moonis Ali Khan, Mika Sillanpaa
Summary: Urbanization and population growth lead to a substantial increase in solid waste generation. Vermicomposting, which employs earthworms to recycle solid waste, proves to be a sustainable solution. This study explores the impact of earthworm-processed solid waste manure (vermicompost) on the growth, productivity, and chemical characteristics of chili and brinjal plants in different wooden reactors. The findings reveal that polyculture reactors with vermicompost soil exhibit significantly higher yields of both chili and brinjal compared to monoculture reactors.
Article
Horticulture
Mervat A. Ali, Samir G. Farag, Mika Sillanpaa, Saleh Al-Farraj, Mohamed E. A. El-Sayed
Summary: The addition of superabsorbent polymers (SAPs) to soil improves soil properties and increases plant yields. The goal of the study was to investigate the effectiveness of SAPs in reducing mineral fertilizer usage and producing high-quality grapes. The study was conducted in a private vineyard in Egypt over three seasons and found that increasing the amount of applied polymer significantly enhanced bud burst, growth parameters, nutrient content, and yield.
Article
Chemistry, Physical
Abir Melliti, Murat Yilmaz, Mika Sillanpaa, Bechir Hamrouni, Radek Vurm
Summary: In this study, low-cost activated carbon (AC-DPF) made from date palm fiber waste was used to remove lead and copper from water systems. AC-DPF had a large surface area and high adsorption capacity, with removal efficiencies of 92% for Pb(II) and 80% for Cu(II). The adsorption kinetics and thermodynamics of AC-DPF were investigated, and competitive and antagonistic effects were observed in the multicomponent system. Overall, AC-DPF showed great potential as a highly promising, effective, and feasible adsorbent for heavy metal removal.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Chemistry, Analytical
Shilpi Verma, Mamleshwar Kumar, Ramanpreet Kaur, Praveen Kumar, Mika Sillanpaa, Urska Lavrencic Stangar
Summary: This study analyzed the combustion and pyrolysis behaviors of PTA wastewater sludge and observed reaction orders, exothermic reactions, and auto gasification. The sludges were found to be promising for energy recovery due to their high calorific values. The experimental results were successfully validated using an artificial neural network model.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2023)
Article
Engineering, Environmental
Jingyao Zhang, Jiadong Liu, Bo Gao, Mika Sillanpaa, Jin Han
Summary: This study utilized biochar produced from dehydrated excess sludge to catalytically ozonate pollutants from landfill leachate. The biochar contained necessary catalytic sites originating from inorganic metals and organic matters in the sludge. These sites promoted the generation of reactive oxygen species and the removal rates of pollutants were enhanced by the synergistic interaction between microorganisms. The study provides insight into the mechanism of catalytic ozonation and offers a new approach for practical landfill leachate treatment.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Chemistry, Physical
Imran Ali, Yu Pakharukov, F. K. Shabiev, E. Galunin, R. F. Safargaliev, S. A. Vasiljev, B. S. Ezdin, A. E. Burakov, Zeid A. Alothman, Mika Sillanpaa
Summary: In this study, graphene-based nanofluids were synthesized and their viscosities were determined. The molecular interactions of graphene nanoparticles were theoretically analyzed to understand the mechanisms affecting the viscosity of nanofluids. An analytical function describing the dependence of the relative viscosity on the concentration of graphene nanoparticles was obtained based on experimental results. It was found that the viscosity of the nanofluid was influenced by the structure of the graphene sheets, and the self-assembly of the nanoparticles played a crucial role in the viscosity changes.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Chemistry, Physical
Anasheh Mardiroosi, Ali Reza Mahjoub, Amir Hossein Cheshme Khavar, Rabah Boukherroub, Mika Sillanpaeae, Parminder Kaur
Summary: This study synthesizes a variety of perovskite-type titanates (MTiO3, M = Zn, and Mn) and loads them onto functionalized magnetic graphene oxide (EDFG) to produce MTiO3 @EDFG nanocomposites. The materials were fully characterized, and the MTiO3 @EDFG nanocomposites were found to exhibit enhanced photocatalytic activity for the degradation of Rhodamine B under visible light irradiation. The enhanced activity was attributed to the inhibition of nanoparticle aggregation, improved electron transfer, increased surface area, and extended absorption range.
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Biochemistry & Molecular Biology
Imran Ali, Anastasya Gaydukova, Tatiana Kon'kova, Zeid Abdullah ALOthman, Mika Sillanpaa
Summary: This study investigated the acid leaching process of grinding waste from a heat-resistant nickel alloy. Optimal conditions for acid dissolution were established to maximize the extraction of nickel, the main component of the alloy. These results are significant for industry professionals in metal recovery and environmentalists in waste treatment.
Review
Engineering, Civil
B. K. Pandey, C. Shukla, M. Sillanpaeae, S. K. Shukla
Summary: The aim of this study was to evaluate the global research trends in the application of electrokinetics in soil stabilization and remediation. A total of 1562 articles published from 1960 to 2022 were analyzed using the Scopus database. The results show that publication output has significantly increased in the last 5 years, with China, USA, Spain, and South Korea being the top contributing countries.
INNOVATIVE INFRASTRUCTURE SOLUTIONS
(2023)
Article
Engineering, Chemical
Shabnam Ahmadi, Soumya Ghosh, Alhadji Malloum, Mika Sillanpaa, Chinenye Adaobi Igwegbe, Prosper E. Ovuoraye, Joshua O. Ighalo
Summary: Molecular modelling and simulation were used to investigate the removal of amoxicillin (AMX) from water using iron nanoparticles (Fe3O4-NPs). The optimal conditions for adsorption were determined. The results showed that AMX molecules have high chemical potential and electrophilicity index, making them reactive. The adsorption of AMX onto Fe3O4-NPs was highly efficient under optimal conditions of pH 3, dosage of 0.5 g/L, AMX concentration of 60 mg/L, and a contact time of 60 min. Langmuir isotherm and pseudo-second-order kinetics provided the best fit to the adsorption data.
INDIAN CHEMICAL ENGINEER
(2023)