36 results on '"Balasubramanian, Rajasekhar"'
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2. Nitrogen and Sulfur Codoped Graphene Macroassemblies as High-Performance Electrocatalysts for the Oxygen Reduction Reaction in Microbial Fuel Cells.
- Author
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Verma, Rajneesh, Chakraborty, Indrajit, Chowdhury, Shamik, Ghangrekar, Makarand M., and Balasubramanian, Rajasekhar
- Published
- 2020
- Full Text
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3. Greenhouse Gas Emission Mitigation Pathways for Urban Passenger Land Transport under Ambitious Climate Targets
- Author
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Milovanoff, Alexandre, Minet, Laura, Cheah, Lynette, Posen, I. Daniel, MacLean, Heather L., and Balasubramanian, Rajasekhar
- Abstract
Urban passenger land transport is an important source of greenhouse gas (GHG) emissions globally, but it is challenging to mitigate these emissions as this sector interacts with many other economic sectors. We develop the Climate change constrained Urban passenger Transport Integrated Life cycle assessment (CURTAIL) model to outline mitigation pathways of urban passenger land transport that are consistent with ambitious climate targets. CURTAIL uses the transport activity of exogenously defined modal shares to simulate the associated annual vehicle stocks, sales, and life cycle GHG emissions. It estimates GHG emission budgets that are consistent with global warming below 2 and 1.5 °C above preindustrial levels and seeks mitigation strategies to remain within the budgets. We apply it to a case study of Singapore, a city-state. Meeting a 1.5 °C target requires strong commitments in the transport and electricity sectors, such as reducing the motorized passenger activity, accelerating the deployment of public transit and of electrification, and decarbonizing the power generation system. Focusing on one mitigation technology or one mode of transport alone will not be sufficient to meet the target. Our novel model could be applied to any city to provide insights relevant to the design of urban climate change mitigation targets and policies.
- Published
- 2021
- Full Text
- View/download PDF
4. Use of biochar as a low-cost adsorbent for removal of heavy metals from water and wastewater: A review.
- Author
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Biswal, Basanta Kumar and Balasubramanian, Rajasekhar
- Subjects
BIOCHAR ,HEAVY metals ,HEAVY metal toxicology ,HEAVY metals removal (Sewage purification) ,SEWAGE ,ADSORPTION isotherms - Abstract
In recent years, the removal of heavy metals from water and wastewater systems remains a challenging issue globally. Adsorption technology is widely used for the removal of heavy metals from aquatic systems due to several advantages including its simple operation, low cost and high efficiency. Biochar, which is an environmental benign and low-cost adsorbent, is increasingly used for remediation of heavy metal pollution in aquatic systems. This review critically analyzes recent developments on the biochar-based adsorptive removal of heavy metals from water and wastewater. Biochar is effective for the removal of several toxic metals (As, Cr and Mn) from groundwater and drinking water. Biochar also shows promising performance for the removal of various heavy metals (Cr, Pb, Cu, Cd and Zn) from wastewater. The heavy metal adsorption capacity of the biochar largely depends on the water/wastewater chemistry (pH, competing ions and initial concentrations of adsorbates), contact time between adsorbates and the adsorbent, adsorbent dose and environmental parameters (temperature). The adsorption isotherms and kinetics can be well explained by the Langmuir and pseudo-second order models, respectively. The key mechanisms which drive the heavy metal adsorption onto biochar include precipitation and ion exchange. Biochar-based adsorptive decontamination of heavy metal pollution is sustainable due to low environmental impacts, low energy consumption and low-costs. The key knowledge gaps and future research directions for improvement of biochar-based sorption capacities are highlighted. This review would help for the development of effective biochar-based adsorption technology for the removal of heavy metals from aquatic environments. [Display omitted] • Recent progress on biochar-based removal of heavy metals is critically analyzed. • Biochar is a low-cost, low-energy demand and environmentally friendly adsorbent. • Biochar is effective for heavy metal removal from water and wastewater systems. • Langmuir isotherm and pseudo-second order kinetic well explain the adsorption data. • Key mechanisms for heavy metal removal include surface precipitation and ion exchange. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
5. Nitrogen and sulfur codoped graphene aerogels as absorbents and visible light-active photocatalysts for environmental remediation applications.
- Author
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Jiang, Yiqun, Chowdhury, Shamik, and Balasubramanian, Rajasekhar
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NITROGEN ,ENVIRONMENTAL remediation ,PHOTOCATALYSTS ,ORGANIC compounds ,VISIBLE spectra ,ORGANIC solvents - Abstract
Graphene aerogels (GAs) are increasingly being recognized as high performance multifunctional materials to tackle our current and emerging environmental concerns. In order to extend the application potential of GAs, herein we have successfully synthesized nitrogen (N) and sulfur (S) codoped GAs (NSGAs) via a simple, scalable, and inexpensive approach. Owing to their large specific surface area (up to 132 m
2 g−1 ), profound porosity, superior mechanical properties, and coexistence of N and S atoms with tunable atomic content and bonding configurations, the as-prepared NSGAs demonstrated exceptional absorption capacity toward a broad spectrum of oils and organic solvents, with an average absorption rate many folds higher than conventional absorbents. Further, the NSGAs exhibited excellent photocatalytic activity for the decomposition of recalcitrant organic compounds under visible light illumination due to pronounced synergistic coupling effect between the heteroatoms. Specifically, after 5 h of exposure to visible light, a degradation efficiency of over 99% was observed and more than 84% of the total organic carbon was eliminated. Radical trapping experiments revealed that superoxide anion radicals are the predominant oxygen reactive species driving the photocatalytic reactions. More importantly, the mineralization byproducts did not pose any significant antibacterial activity, illustrating the environmentally benign nature of these macroscale photocatalysts. Image 1 • N/S codoped graphene aerogels (NSGAs) are prepared by facile hydrothermal method. • NSGAs can rapidly absorb oils and different types of organic solvents. • NSGAs induce near complete mineralization of a recalcitrant dye under visible light. • More than 80% of the total organic carbon is eliminated by NSGAs. • Coupling of N and S dopants synergistically enhance the application potential of GAs. Versatile nitrogen and sulfur codoped graphene aerogels were synthesized with unique geometrical configurations that show potential for a wide range of environmental applications. [ABSTRACT FROM AUTHOR]- Published
- 2019
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- View/download PDF
6. Use of biochar as a low-cost adsorbent for removal of heavy metals from water and wastewater: A review
- Author
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Biswal, Basanta Kumar and Balasubramanian, Rajasekhar
- Abstract
In recent years, the removal of heavy metals from water and wastewater systems remains a challenging issue globally. Adsorption technology is widely used for the removal of heavy metals from aquatic systems due to several advantages including its simple operation, low cost and high efficiency. Biochar, which is an environmental benign and low-cost adsorbent, is increasingly used for remediation of heavy metal pollution in aquatic systems. This review critically analyzes recent developments on the biochar-based adsorptive removal of heavy metals from water and wastewater. Biochar is effective for the removal of several toxic metals (As, Cr and Mn) from groundwater and drinking water. Biochar also shows promising performance for the removal of various heavy metals (Cr, Pb, Cu, Cd and Zn) from wastewater. The heavy metal adsorption capacity of the biochar largely depends on the water/wastewater chemistry (pH, competing ions and initial concentrations of adsorbates), contact time between adsorbates and the adsorbent, adsorbent dose and environmental parameters (temperature). The adsorption isotherms and kinetics can be well explained by the Langmuir and pseudo-second order models, respectively. The key mechanisms which drive the heavy metal adsorption onto biochar include precipitation and ion exchange. Biochar-based adsorptive decontamination of heavy metal pollution is sustainable due to low environmental impacts, low energy consumption and low-costs. The key knowledge gaps and future research directions for improvement of biochar-based sorption capacities are highlighted. This review would help for the development of effective biochar-based adsorption technology for the removal of heavy metals from aquatic environments.
- Published
- 2023
- Full Text
- View/download PDF
7. Effects of Cerium Oxide and Ferrocene Nanoparticles Addition As Fuel-Borne Catalysts on Diesel Engine Particulate Emissions: Environmental and Health Implications.
- Author
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Zhi-Hui Zhang and Balasubramanian, Rajasekhar
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- 2017
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8. Nature-based solution for mitigation of pedestrians' exposure to airborne particles of traffic origin in a tropical city.
- Author
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Tran, Phuong T.M., Kalairasan, Mano, Beshay, Peter F.R., Qi, Yihan, Ow, Lai Fern, Govindasamy, Vivek, Yusof, Mohamed Lokman Mohd, Ghosh, Subhadip, and Balasubramanian, Rajasekhar
- Subjects
CARBON-black ,ROADSIDE improvement ,PEDESTRIANS - Abstract
• Reduction in the exposure to BC and UFPs was assessed with three types of vegetation barriers (VBs). • All three configurations of VBs reduced the exposure of pedestrians to BC and UFPs. • Three-layered hedges of varying heights showed higher BC and UFPs reductions. • PM with diverse morphology and elemental composition was found on leaves of VBs. • This is the first study of its kind conducted in a tropical Asian city. This study investigated the effectiveness of vegetation barriers (VBs) planted along roadsides in a highly urbanized tropical Asian city-state to mitigate pedestrians' exposure to airborne particles (PM) of traffic origin for the first time. Mobile and fixed-site measurements of black carbon (BC) and ultrafine particles (UFPs) were conducted with three types of VBs (green walkway covered with creepers; hedgerow; and three-layer hedges with varying heights) using portable PM devices. The three-layered hedges showed higher BC and UFPs reductions (the average reduction of about 60%) than the other two configurations (20–40%). Deposition of PM with diverse size, morphology and elemental composition onto VBs leaves plays an important role in reducing PM exposure concentration, providing health benefits to pedestrians involved in active mobility on roads. Our findings provide a scientific basis for formulating appropriate guidelines for selecting and installing VBs to reduce the inhalation exposure of pedestrians to PM of traffic origin. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2022
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- View/download PDF
9. Nature-based Systems (NbS) for mitigation of stormwater and air pollution in urban areas: A review.
- Author
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Biswal, Basanta Kumar, Bolan, Nanthi, Zhu, Yong-Guan, and Balasubramanian, Rajasekhar
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GREEN roofs ,URBAN pollution ,AIR pollution ,AIR pollutants ,TOTAL suspended solids ,POLLUTION ,ECOSYSTEMS ,ECOSYSTEM services - Abstract
• Nature-based systems (NbS) can be retrofitted into the existing urban environment. • NbS show good performance for stormwater hydrology management and treatment. • Roadside vegetation acts as a biofilter to capture airborne environmental pollutants. • NbS provide ecosystem services, improve public health, and contribute to circularities. • Long-term studies are needed to develop guidelines for NbS installation and operation. In recent years, increasing attention has been given to the application of Nature-based systems (NbS) for mitigation of environmental pollution in cities. NbS namely bioretention systems, green roofs and constructed wetlands are widely adopted in urban environments for stormwater hydrology management and treatment, while roadside vegetation is utilized for mitigating air pollution of local traffic origin. Both bioretention systems and wetlands are capable of removing diverse pollutants such as total suspended solids, nutrients (nitrogen and phosphorous) and potentially toxic elements from runoff. Green roofs can act as a sink, or a source of pollutants to roof runoff outflow depending on the composition of engineered media used in support of vegetation growth. A holistic understanding of NbS in terms of their wide range of ecosystem services, multi-functionality nature, and contribution to circularity in cities is currently lacking. NbS can improve public health by providing clean air to breathe and natural waters of better quality for various purposes, but this application is not fully elucidated with an integrated approach involving both air and water quality assessments. For effective use of NbS, fundamental laboratory studies on the relative importance of phytoremediation versus bioremediation, laboratory studies to assess their actual performance under diverse weather conditions, and numerical simulations of hydrology and airflow should be conducted in tandem. Furthermore, it is important to develop guidelines for the design, installation, operation and maintenance of NbS for effective removal of environmental pollutants in the context of sustainable urban development. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2022
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10. Synthesis of biowaste-derived carbon foam for CO2 capture.
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Zhang, Bei, Jiang, Yiqun, and Balasubramanian, Rajasekhar
- Subjects
FOAM ,CARBON foams ,CARBON sequestration ,ATMOSPHERIC carbon dioxide ,HYDROTHERMAL carbonization ,CARBON dioxide - Abstract
• Carbon foam was obtained from biowaste by a self-foaming approach. • The aromatic segments identified by 2D NMR enhance the foaming process. • Hydrothermal and pyrolysis processes increase graphitic carbon in carbon foam. • Carbon foam shows significantly improved CO 2 uptake. • The favorable CO 2 uptake is attributed to the hierarchical 3D porous carbon. Thermal transformation of biowaste to carbon foam provides an economically attractive and eco-friendly strategy for biowaste recycling. Herein, we report a novel self-foaming approach involving modified hydrothermal carbonization (HTC) and pyrolysis to produce carbon foam from biowaste. Notably, biowaste-derived carbon foam consists of foam structure and multi-porous structure, originated from the self-forming process of aromatic segments during modified HTC and pyrolysis processes. Based on characterization results, biowaste-derived carbon foam possesses hierarchical micropore, mesopore and macropore with increasing sp
2 hybridized carbon atoms. We demonstrate the potential applications of this material for CO 2 capture. Biowaste-derived carbon foam exhibits 5.0-fold and 4.8-fold CO 2 uptake at 35 °C and 50 °C, respectively, compared to those of pristine biowaste. The recycling of biowaste to carbon foam for CO 2 capture contributes to decarbonization efforts worldwide by a synergistic way, including the photosynthesis of atmospheric CO 2 to biomass, carbon sequestration in carbon foam and CO 2 capture by carbon foam. [Display omitted] [ABSTRACT FROM AUTHOR]- Published
- 2022
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- View/download PDF
11. Three-Dimensional Graphene-Based Porous Adsorbents for Postcombustion CO2 Capture.
- Author
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Chowdhury, Shamik and Balasubramanian, Rajasekhar
- Published
- 2016
- Full Text
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12. Highly efficient, rapid and selective CO2 capture by thermally treated graphene nanosheets.
- Author
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Chowdhury, Shamik and Balasubramanian, Rajasekhar
- Subjects
CARBON dioxide analysis ,GRAPHENE synthesis ,TEMPERATURE measurements - Abstract
Graphene, by virtue of its unique molecular structure and many interesting properties, is receiving considerable attention as an adsorbent for separation and purification of gases. In this study, graphene nanosheets were subjected to heat treatment in the temperature range of 200–800 °C under flowing N 2 to improve their textural characteristics (surface area, pores size, and total pore volume) for efficient removal of CO 2 from flue gases. The resulting graphene materials showed highly ordered structure, large surface area (up to 484 m 2 g −1 ) and interconnected hierarchical pore networks with narrow pore size distribution in the large-micropore/small-mesopore range. As a consequence, the heat-treated graphene samples demonstrated significantly greater CO 2 uptake capabilities (up to 2.89 mmol g −1 ) compared to pristine graphene (0.81 mmol g −1 ) at 0 °C and 1 bar. More importantly, the materials displayed rapid adsorption kinetics with ultrahigh selectivity for CO 2 over N 2 , as well as stable and readily reversible adsorption/desorption cycling behavior. The isosteric heat of adsorption had an unusual dependence on surface loading because of the presence of attractive intermolecular forces between the adsorbed quadrupolar CO 2 molecules. These findings demonstrate for the first time that thermal treatment at high-temperatures can have a positive influence on the single component CO 2 adsorption characteristics of graphene sheets and should be explored further as an effective strategy in the design and development of graphene-based porous solid adsorbents for CO 2 abatement. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
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13. Effect of Oxygenated Fuels on Physicochemical and Toxicological Characteristics of Diesel Particulate Emissions.
- Author
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Zhi-Hui Zhang and Balasubramanian, Rajasekhar
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- 2014
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14. Thermal Investigation of Biochar-Lignite blends during Co-combustion.
- Author
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Zhengang Liu, Quek, Augustine, and Balasubramanian, Rajasekhar
- Abstract
The co-combustion of biochar and lignite was investigated by means of thermogravimetric analysis to understand their thermal behavior and assess their environmental benefits. In the present study, the biochars were produced hydrothermally from coconut fiber and eucalyptus leaves at 250 °C. The thermal effects of biochar addition in biochar-lignite blends including ignition temperature and burnout characteristics were examined during co-combustion process. The results indicated that hydrothermal treatment decreased the volatile matter content and increased the fixed carbon content of coconut fiber and leaves significantly. The elevated energy density and decreased ash content of the biochar improved the combustion behavior of the biochar when co-fired with lignite for energy generation. The biochar addition improved the fuel- to-energy conversion and shortened the combustion time of the biochar-lignite blends especially for coconut fiber-derived biochar. Synergistic reactions between the biochar and lignite occurred during the co-combustion process, resulting in high overall combustion efficiency of the biochar-lignite blends. This study revealed that the hydrothermal pre-treatment of waste biomaterials provided a promising process to upgrade the biomass for co-combustion with the lignite in existing lignite-fueled power plants. [ABSTRACT FROM AUTHOR]
- Published
- 2012
15. Modification of Pyrolytic Char From Waste Tires For Enhancing Contaminant Uptakes From Aqueous Solutions.
- Author
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Quek, Augustine and Balasubramanian, Rajasekhar
- Abstract
It is generally known that pyrolysis of rubber tires produces three product streams, separated by their phases: gaseous, liquid and solid. While the gaseous and liquid streams produce energy-rich fuels, the solid char can be used as an adsorbent for a number of applications including wastewater treatment. However, activation at high temperatures usually produced char with low yields, and chemical activation requires the use of toxic chemicals. In this study, chars produced from the pyrolysis of waste tires in a high-temperature furnace were activated through in situ oxygenation. Post-pyrolysis oxygenation (PPO) of the high-ash char was done under different temperature ranges and times to identify the optimal experimental conditions to prepare the most desired adsorption characteristics. The adsorption characteristics of the chars obtained with and without oxygenation were studied through the adsorption of three heavy metals (Cu, Pb, Cd) from aqueous solutions in batch mode. A temperature of 250°C and an oxygen content of 7% in air were found to provide the best trade-off between yield of char and adsorption capacity for the removal of these three metals. The chars formed with PPO had much higher heavy metal uptake than commercial activated carbons, even though it has much a lower surface area. This was in agreement with published data on heavy metal removal from activated carbon loaded with ZnO. Acidwashing of tile chars, which removed a significant amount of ZnO, showed a corresponding decrease in the adsorption of the three heavy metals. Surface elemental analysis by XPS suggested that the PPO process has formed ZnO in the char which enhanced its adsorption properties. Results obtained from this study will be presented and discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2008
16. Highly efficient, rapid and selective CO2capture by thermally treated graphene nanosheets
- Author
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Chowdhury, Shamik and Balasubramanian, Rajasekhar
- Published
- 2016
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17. 2013 Southeast Asian Smoke Haze: Fractionation of Particulate-Bound Elements and Associated Health Risk.
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Betha, Raghu, Behera, Sailesh N., and Balasubramanian, Rajasekhar
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- 2014
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18. Insights into Lipidomic Perturbations in Zebrafish Tissues upon Exposure to Microcystin-LR and Microcystin-RR.
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Pavagadhi, Shruti, Natera, Siria, Roessner, Ute, and Balasubramanian, Rajasekhar
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- 2013
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19. Nitrogen-doped graphene aerogels with rational indium hydroxide decoration for highly efficient photocatalytic of p-nitrophenol.
- Author
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Jiang, Yiqun, Zhang, Jingjing, and Balasubramanian, Rajasekhar
- Subjects
PHOTOCATALYSIS ,AEROGELS ,CHEMICAL bonds ,INDIUM ,PHOTODEGRADATION ,GRAPHENE ,NITROPHENOLS ,INDIUM oxide - Abstract
One of the key challenges in photocatalysis is the suppression of electron-hole pairs' recombination, which reduces the photocatalytic degradation efficiency of promising materials. In this study, a novel heterostructured photocatalyst (In(OH) 3 /NGAs) was synthesized by coupling indium hydroxide (In(OH) 3) with nitrogen-doped graphene aerogels (NGAs). A comprehensive evaluation of the photocatalytic degradation performance of In(OH) 3 /NGAs was conducted using para -nitrophenol (p -NP) as a model pollutant under visible light. Results show that impressive photocatalytic activities of In(OH) 3 /NGAs are mainly due to their strong synergistic effects of the heterojunction formed between In(OH) 3 and NGAs , and the active nitrogen doping of GAs. The synergistic effects result in a sizable bandgap and thus enhance the visible light absorption capability. The favorable formation of photo-generated holes and hydroxyl radicals is responsible for the efficient photocatalytic degradation of p -NP, leading to 98% removal of total organic carbon. Additionally, a comparative evaluation of the photodegradation performance of In(OH) 3 /NGAs with that of another indium-based heterostructured material (In 2 O 3 /g-C 3 N 4 (graphitic carbon nitride) shows the superior performance of the former photocatalyst which is attributed to its unique molecular configuration and chemical bonds. This work reveals how a rational combination of NGAs with In(OH) 3 can lead to efficient photocatalytic degradation of recalcitrant organic pollutants such as p -NP. [Display omitted] • In-based N-doped graphene aerosols (NGAs) and g-C 3 N 4 composites were synthesized. • Photocatalytic degradation of p-NP by In-NGAs and In g-C 3 N 4 was studied. • In-NGAs demonstrated better photocatalytic performance than In g-C 3 N 4. • The performance of In-NGAs was optimized to maximize their photocatalytic potential. • Insights into the photocatalytic degradation of p-NP by In-NGAs are provided. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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20. BIOLEACHING OF COPPER FROM BLACK SHALE ORE USING MESOPHILIC MIXED POPULATIONS IN AN AIR UP-LIFT BIOREACTOR.
- Author
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Sethurajan, Manivannan, Aruliah, Rajasekar, Karthikeyan, Obulisamy Parthiba, and Balasubramanian, Rajasekhar
- Abstract
Black shale (BS) deposits found in Europe (Kupferschiefer type) contain base (e.g., copper and aluminium) and precious (e.g., gold and silver) metals and also PGE (platinum group elements), but also high contents of organic matter that potentially impede with metal recovery by conventional techniques. The aim of the present investigation was to recover copper (Cu) from BS using microbial leaching. BS deposits were collected from a mining site in Lubin, Poland which consisted of 14 ± 2 mg/g of Al, 13 ± 2 mg/g of Cu, 10 ± 1 mg/g of Fe and relatively significant amounts of Mn and Zn. Several chemolithotrophic bacteria (Leptospirillum ferrooxidans, Leptospirillum ferriphilum, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Sulfobacillus thermosulfidooxidans) were evaluated for their ability to extract Cu selectively from BS with a 2% pulp density. Among these bacteria, the iron oxidizing L. ferrooxidans, L. ferriphilum, At. ferrooxidans were identified as the potential candidates, and their Cu extraction efficiencies were 62% ± 3%, 55% ± 3%, 25% ± 2%, respectively. Using a mixed population of these microorganisms, the bioleaching process was performed at different pulp densities of BS and their corresponding Cu leaching efficiency was evaluated. Following the batch experiments, the bioleaching process was scaled-up to a 5 liter laboratory scale custom-designed Air Up-lift Bioreactor (AUBR). The Cu extraction could be increased to > 70% at a higher pulp density (10% wt/v) under the experimental conditions set at pH 2.0 and 37o C with the aeration rate of 150 liter per hour for 15 days of continuous bioleaching operation. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
21. Passive Sampling of Gaseous Persistent Organic Pollutants in The Atmosphere.
- Author
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He, Jun and Balasubramanian, Rajasekhar
- Subjects
POLYURETHANES ,MASS transfer ,CALIBRATION ,STATISTICAL sampling ,ACENAPHTHENE ,POLLUTANTS - Abstract
Abstract: The polyurethane foam (PUF) disk-based passive air samplers (PAS), mounted inside two aluminium bowls to buffer the air flow to the disk and to shield it from precipitation and sunlight, were used for the collection of atmospheric POPs in Singapore during April 2008eJune 2008. Data obtained from PAS measurements are compared to those from active high-volume air sampling (AAS). Single factor ANOVA tests show that there were no significant differences in chemical distribution profiles between actively and passively collected samples(PAHs, F=3.38×10-8) < Fcritica l= 4.17 with p>0.05; OCPs, F=2.71×10-8< Fcritical = 4.75 with p > 0.05). The average air-side mass transfer coefficient (kA) for PAS, determined from the loss of depuration compounds such as 13C6-HCB (1000 ng), 13C12 - 4,4’ DDT (1000 ng) and 13C12-PCB 101 (1000 ng)spiked on the disks prior to deployment, was 0.12 ± 0.04 m s-1. These values are comparable to those reported previously in the literature. The average sampling rate was 3.78 ± 1.83 m3 d- 1 for the 365cm2 PUF disk. Throughout the entire sampling period (∼68 d), most of the PAHs and all OCPs exhibited a linear uptake trend on PAS, while naphthalene, acenaphthylene, acenaphthene and fluorene reached the curvilinear phase after the first ∼30 d exposure. Theoretically estimated times to equilibrium (teq) ranged from around one month for Acy to hundreds of years for DB(ah)A. Sampling rates, based on the time integrated active sampling-derived concentrations and masses collected by PUF disks during the linear uptake phase, were determined for all target compounds with the average values of 2.50 m3 d-1 and 3.43m3 d-1 for PAHs and OCPs, respectively. More variations were observed as compared to those from th depuration study. These variations were most likely due to the difference of physicochemical properties of individual species. The validation and calibration work conducted for PAS in this study clearly indicates that it would be feasible to use such an economic PAS for routine measurements of POPs in the tropical atmosphere at a large network of sampling locations. [Copyright &y& Elsevier]
- Published
- 2012
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22. ANN application for prediction of atmospheric nitrogen deposition to aquatic ecosystems.
- Author
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Palani, Sundarambal, Tkalich, Pavel, Balasubramanian, Rajasekhar, and Palanichamy, Jegathambal
- Subjects
ARTIFICIAL neural networks ,FORECASTING ,NITROGEN ,AQUATIC ecology ,SEDIMENTATION & deposition ,EUTROPHICATION ,REGRESSION analysis - Abstract
Abstract: The occurrences of increased atmospheric nitrogen deposition (ADN) in Southeast Asia during smoke haze episodes have undesired consequences on receiving aquatic ecosystems. A successful prediction of episodic ADN will allow a quantitative understanding of its possible impacts. In this study, an artificial neural network (ANN) model is used to estimate atmospheric deposition of total nitrogen (TN) and organic nitrogen (ON) concentrations to coastal aquatic ecosystems. The selected model input variables were nitrogen species from atmospheric deposition, Total Suspended Particulates, Pollutant Standards Index and meteorological parameters. ANN models predictions were also compared with multiple linear regression model having the same inputs and output. ANN model performance was found relatively more accurate in its predictions and adequate even for high-concentration events with acceptable minimum error. The developed ANN model can be used as a forecasting tool to complement the current TN and ON analysis within the atmospheric deposition-monitoring program in the region. [Copyright &y& Elsevier]
- Published
- 2011
- Full Text
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23. Characterization and Source Apportionment of Particulate Matter ⩽ 2.5 μm in Sumatra, Indonesia, during a Recent Peat Fire Episode.
- Author
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Siao Wei See, Balasubramanian, Rajasekhar, Rianawati, Elisabeth, Karthtkeyan, Sathrugnan, and Streets, David G.
- Published
- 2007
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24. Assessment and mitigation of personal exposure to particulate air pollution in cities: An exploratory study.
- Author
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Tran, Phuong T.M., Adam, Max G., Tham, Kwok Wai, Schiavon, Stefano, Pantelic, Jovan, Linden, Paul F., Sofianopoulou, Eleni, Sekhar, S. Chandra, Cheong, David Kok Wai, and Balasubramanian, Rajasekhar
- Subjects
AIR pollution ,INDOOR air pollution ,HEALTH risk assessment ,AIR pollutants ,PARTICULATE matter ,SCOOTERS ,AIR filters - Abstract
[Display omitted] • Elevated PM 2.5 and BC levels were observed in home and transport microenvironments. • High UFP levels were observed in recreation microenvironments. • Long-term exposure to toxic trace elements contained in PM 2.5 presents health risks. • Potential health risks were reduced while using the portable air cleaner. Assessment of integrated personal exposure (PE) to airborne particulate matter (PM) across diverse microenvironments (MEs) over 24 hours under different exposure scenarios is necessary to identify appropriate strategies to improve urban air quality and mitigate the health effects of PM. We carried out a collaborative study in a densely populated city-state (Singapore) to assess the integrated PE to fine particles (PM 2.5), ultrafine particles (UFPs) and black carbon (BC) across diverse indoor and outdoor urban MEs, estimate related health risks and make suitable recommendations for healthy living in cities. Two volunteers with different lifestyles participated in the study by tracking their PE to particulate air pollution and the time-activity patterns over 24 hours using portable PM monitoring devices and recording their whereabouts using GPS coordinates. Home, transport and recreation (i.e., food court) MEs represented pollution hotspots of PM 2.5 (21.0 μg/m
3 ), BC (3.4 μg/m3 ) and UFP (33.0 × 103 #/cm3 ), respectively. Among the different modes of transport used by the participants (walking, cycling, e-scooter, mass rapid transport (MRT), bus, car and taxi), the air pollutants had elevated concentrations while commuting by public transport (bus and MRT) as well as during active modes of transport (walking and cycling). Air-conditioned cars and taxis, equipped with air filtration systems, represented the lowest PE. The health risk assessment revealed that there are potential carcinogenic risks associated with the long-term exposure to elevated levels of PM 2.5 -bound toxic trace elements. These risks can be mitigated with the introduction of low-carbon and active modes of transport in place of internal combustion engines and the use of indoor air pollution exposure mitigation devices. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
25. Nitrogen-doped graphene aerogels with rational indium hydroxide decoration for highly efficient photocatalytic of p-nitrophenol
- Author
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Jiang, Yiqun, Zhang, Jingjing, and Balasubramanian, Rajasekhar
- Abstract
One of the key challenges in photocatalysis is the suppression of electron-hole pairs’ recombination, which reduces the photocatalytic degradation efficiency of promising materials. In this study, a novel heterostructured photocatalyst (In(OH)3/NGAs) was synthesized by coupling indium hydroxide (In(OH)3) with nitrogen-doped graphene aerogels (NGAs). A comprehensive evaluation of the photocatalytic degradation performance of In(OH)3/NGAs was conducted using para-nitrophenol (p-NP) as a model pollutant under visible light. Results show that impressive photocatalytic activities of In(OH)3/NGAs are mainly due to their strong synergistic effects of the heterojunction formed between In(OH)3and NGAs , and the active nitrogen doping of GAs. The synergistic effects result in a sizable bandgap and thus enhance the visible light absorption capability. The favorable formation of photo-generated holes and hydroxyl radicals is responsible for the efficient photocatalytic degradation of p-NP, leading to 98% removal of total organic carbon. Additionally, a comparative evaluation of the photodegradation performance of In(OH)3/NGAs with that of another indium-based heterostructured material (In2O3/g-C3N4(graphitic carbon nitride) shows the superior performance of the former photocatalyst which is attributed to its unique molecular configuration and chemical bonds. This work reveals how a rational combination of NGAs with In(OH)3can lead to efficient photocatalytic degradation of recalcitrant organic pollutants such as p-NP.
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- 2022
- Full Text
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26. Emission Characteristics of Ultrafine Particles and Volatile Organic Compounds in a Commercial Printing Center
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Betha, Raghu, Selvam, Valliappan, Blake, DonaldR., and Balasubramanian, Rajasekhar
- Abstract
ABSTRACTLaser printers are one of the common indoor equipment in schools, offices, and various other places. Laser printers have recently been identified as a potential source of indoor air pollution. This study examines the characteristics of ultrafine particles (UFPs, diameter <100 nm) and volatile organic compounds (VOCs) emitted from laser printers housed in a commercial printing center. The results indicated that apart from the printer type, the age of printers, and the number of pages printed, the characteristics of UFPs emitted from printers also depend on indoor ventilation conditions. It was found that at reduced ventilation rates of indoor air, there was a rise in the number concentration of UFPs in the printing center. Interestingly, the contribution of UFPs to the total number of submicrometer-sized particles was observed to be higher at a sampling point far away from the printer than the one in the immediate vicinity of the printer. Black carbon (BC) measurements showed a good correlation (rS= 0.82) with particles in the size range of 100–560 nm than those with diameters less than 100 nm (rS= 0.33 for 50–100 nm, and rS= −0.19 for 5.6–50 nm particles). Measurements of VOCs in the printing center showed high levels of m-, o-, and p-xylene, styrene, and ethylbenzenes during peak hours of printing. Although toluene was found in higher levels, its concentration decreased during peak hours compared to those during nonoperating hours of the printing center.IMPLICATIONSThis study reports the emission of ultrafine particles (UFPs) and volatile organic compounds (VOCs) from laser printers in a commercial printing center. It was found that the number concentration of UFPs released was not only influenced by the printer-related parameters, but also by indoor ventilation conditions. The fraction of UFPs was high at lower air change rate and at distances away from printers, presumably due to the formation of new particles. The results imply that laser printers equipped with particle traps and high ventilation rates in the commercial printing center are needed to reduce the exposure of occupants to UFPs and thus the associated health risk.
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- 2011
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27. Particulate Emissions from a Stationary Engine Fueled with Ultra-Low-Sulfur Diesel and Waste-Cooking-Oil-Derived Biodiesel
- Author
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Betha, Raghu and Balasubramanian, Rajasekhar
- Abstract
ABSTRACTStationary diesel engines, especially diesel generators, are increasingly being used in both developing countries and developed countries because of increased power demand. Emissions from such engines can have adverse effects on the environment and public health. In this study, particulate emissions from a domestic stationary diesel generator running on ultra-low-sulfur diesel (ULSD) and biodiesel derived from waste cooking oil were characterized for different load conditions. Results indicated a reduction in particulate matter (PM) mass and number emissions while switching diesel to biodiesel. With increase in engine load, it was observed that particle mass increased, although total particle counts decreased for all the fuels. The reduction in total number concentration at higher loads was, however, dependent on percentage of biodiesel in the diesel-biodiesel blend. For pure biodiesel (B100), the reduction in PM emissions for full load compared to idle mode was around 9%, whereas for ULSD the reduction was 26%. A large fraction of ultrafine particles (UFPs) was found in the emissions from biodiesel compared to ULSD. Nearly 90% of total particle concentration in biodiesel emissions comprised ultrafine particles. Particle peak diameter shifted from a smaller to a lower diameter with increase in biodiesel percentage in the fuel mixture.IMPLICATIONSThere has been an increased usage of stationary diesel engines, especially backup power generators to meet the growing energy demand. Biodiesel derived from waste cooking oil has received increasing attention as an alternative fuel. However, data are only sparsely available in the literature on particulate emissions from stationary engines, fueled with blends of diesel and biodiesel. This study provides insights into the influence of waste-cooking-oil-derived biodiesel on engine performance and the particulate emissions from a stationary engine. The results of the study form a scientific basis to evaluate the impact of biodiesel emissions on the environment and human health.
- Published
- 2011
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28. Low-Energy and Chemical-Free Activation of Pyrolytic Tire Char and Its Adsorption Characteristics
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Quek, Augustine and Balasubramanian, Rajasekhar
- Abstract
AbstractIt is generally known that the solid char obtained from pyrolysis of scrap rubber tires can be used as an adsorbent for several applications such as wastewater treatment. In this study, scrap tires were first pyrolyzed under nitrogen (N2) or carbon dioxide (CO2) gas under various temperatures to produce char. The char was activated in situ by post-pyrolysis oxygenation (PPO) at different temperature ranges as soon as the pyrolysis process was completed. Elemental and spectroscopic analyses showed significant zinc content in the char after PPO. Batch-mode removal of aqueous copper (Cu) using the chars revealed that, for N2and CO2, the optimum condition for pyrolysis was at 550 °C and for activation was from 550 to 250 °C. Although CO2-pyrolyzed char had lower Cu and lead (Pb) removal than N2-pyrolyzed char, it had higher char yields. For both N2- and CO2-pyrolyzed char, activation with PPO improved their heavy metal removal efficiencies significantly compared with unactivated char. PPO chars had much faster removal rates and higher Cu removal compared with both pyrolyzed, unactivated char and commercial activated carbons.
- Published
- 2009
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29. Characteristics of Indoor Aerosols in Residential Homes in Urban Locations: A Case Study in Singapore
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Balasubramanian, Rajasekhar and Lee, Sheng Sheng
- Abstract
AbstractAs part of a major study to investigate the indoor air quality in residential houses in Singapore, intensive aerosol measurements were made in an apartment in a multistory building for several consecutive days in 2004. The purpose of this work was to identify the major indoor sources of fine airborne particles and to assess their impact on indoor air quality for a typical residential home in an urban area in a densely populated country. Particle number and mass concentrations were measured in three rooms of the home using a real-time particle counter and a low-volume particulate sampler, respectively. Particle number concentrations were found to be elevated on several occasions during the measurements. All of the events of elevated particle concentrations were linked to indoor activities based on house occupant log entries. This enabled identification of the indoor sources that contributed to indoor particle concentrations. Activities such as cooking elevated particle number concentrations ≤2.05 × 105particles/cm3. The fine particles collected on Teflon filter substrates were analyzed for selected ions, trace elements, and metals, as well as elemental and organic carbon (OC) contents. To compare the quality of air between the indoors of the home and the outdoors, measurements were also made outside the home to obtain outdoor samples. The chemical composition of both outdoor and indoor particles was determined. Indoor/outdoor (I/O) ratios suggest that certain chemical constituents of indoor particles, such as chloride, sodium, aluminum, cobalt, copper, iron, manganese, titanium, vanadium, zinc, and elemental carbon, were derived through migration of outdoor particles (I/O<1 or ≈1), whereas the levels of others, such as nitrite, nitrate, sul-fate, ammonium, cadmium, chromium, nickel, lead, and OC, were largely influenced by the presence of indoor sources (I/O >1).
- Published
- 2007
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30. Determination of Ozone in Outdoor and Indoor Environments Using Nitrite-Impregnated Passive Samplers Followed by Ion Chromatography
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Karthikeyan, Sathrugnan, Perumal, Sundararajan Venkatesa, Balasubramanian, Rajasekhar, Zuraimi, Mohammed Sultan, and Tham, Kwok Wai
- Abstract
AbstractAn improved ion chromatographic (IC) method has been developed for the separation of nitrate in filter extracts in the presence of high concentrations of nitrite. This analytical method was successfully used for an indirect measurement of ozone (O3) in outdoor and indoor air, following its collection using a nitrite-impregnated passive sampler. The limit of detection and the limit of quantification, using the modified IC method, were 6 μg l-1(3σ) and 20 μg l-1(10σ), respectively. Improved detection limits and low baseline noise were obtained with the use of eluent generator and high-capacity ion exchange column. The optimized method was used for assessing O3concentration in both indoor and outdoor environments of 28 child care centers (CCCs) located in different parts of Singapore. The O3concentrations ranged from 0.1 to 11.95 parts per billion (ppb) in indoor and from 3.2 to 21.7 ppb in outdoor environments during the study period. It was found that, among the CCCs investigated in this study, air-conditioned CCCs and those located in close proximity to traffic emissions had significantly lower O3concentrations indoors.
- Published
- 2007
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31. Health risk assessment of occupational exposure to particulate-phase polycyclic aromatic hydrocarbons associated with Chinese, Malay and Indian cooking
- Author
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Wei See, Siao, Karthikeyan, Sathrugnan, and Balasubramanian, Rajasekhar
- Abstract
Food cooking using liquefied petroleum gas (LPG) has received considerable attention in recent years since it is an important source of particulate air pollution in indoor environments for non-smokers. Exposure to organic compounds such as polycyclic aromatic hydrocarbons (PAHs) contained in particles is of particular health concern since some of these compounds are suspected carcinogens. It is therefore necessary to chemically characterize the airborne particles emitted from gas cooking to assess their possible health impacts. In this work, the levels of fine particulate matter (PM2.5) and 16 priority PAHs were determined in three different ethnic commercial kitchens, specifically Chinese, Malay and Indian food stalls, where distinctive cooking methods were employed. The mass concentrations of PM2.5and PAHs, and the fraction of PAHs in PM2.5were the highest at the Malay stall (245.3 μg m−3, 609.0 ng m−3, and 0.25%, respectively), followed by the Chinese stall (201.6 μg m−3, 141.0 ng m−3, and 0.07%), and the Indian stall (186.9 μg m−3, 37.9 ng m−3, and 0.02%). This difference in the levels of particulate pollution among the three stalls may be attributed to the different cooking methods employed at the food stalls, the amount of food cooked, and the cooking time, although the most sensitive parameter appears to be the predominant cooking method used. Frying processes, especially deep-frying, produce more air pollutants, possibly due to the high oil temperatures used in such operations. Furthermore, it is found that frying, be it deep-frying at the Malay stall or stir-frying at the Chinese stall, gave rise to an abundance of higher molecular weight PAHs such as benzo[b]fluoranthene, indeno[1,2,3-cd]pyrene and benzo[g,h,i]perylene whereas low-temperature cooking, such as simmering at the Indian stall, has a higher concentration of lower molecular weight PAHs. In addition, the correlation matrices and diagnostic ratios of PAHs were calculated to determine the markers of gas cooking. To evaluate the potential health threat due to inhalation exposure from the indoor particulate pollution, excess lifetime cancer risk (ELCR) was also calculated for an exposed individual. The findings suggest that cooking fumes in the three commercial kitchens pose adverse health effects.
- Published
- 2006
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32. Rapid Extraction of Water Soluble Organic Compounds from Airborne Particulate Matter
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Karthikeyan, Sathrugnan and Balasubramanian, Rajasekhar
- Abstract
Water soluble organic compounds (WSOC) in airborne particulate matter (PM) have received considerable attention in recent years due to their abundance and their importance in atmospheric processes. The analysis of WSOC is necessary for quantifying the relative contribution of individual organic compounds to the total WSOC mass. In the present work, we evaluated the performance of a microwave-assisted extraction (MAE) method for the determination of WSOC in PM and compared the data with those of a conventional ultrasonic extraction (USE). The experimental results showed that the MAE method requires a shorter extraction time (5 min) compared to USE. The isolated water-soluble organic fraction of PM was subsequently analyzed using ion chromatography (IC) for low molecular weight organic acids. The rapid MAE method was used in conjunction with IC for the analysis of organic acids in PM samples, collected from different sources.
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- 2005
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33. Personal exposure to airborne particles in transport micro-environments and potential health impacts: A tale of two cities.
- Author
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Tran, Phuong T.M., Nguyen, Teron, and Balasubramanian, Rajasekhar
- Subjects
CHOICE of transportation ,PARTICULATE matter ,CARBON-black ,LIFE expectancy ,PARTICLES ,RAILROAD commuter service - Abstract
• Personal exposure to PM 2.5 and BC in Danang(Vietnam) and Singapore was assessed. • Exposure to PM 2.5 and BC by commuters was much higher in Danang than Singapore. • Exposure to PM 2.5 and BC in homes should also be considered. • Heavy-duty vehicles and motorcycles are the major contributors to PM in both cities. • Health effects of motorized transport can be avoided by switching to active mobility. The present study investigated the personal exposure (PE) of commuters to fine particles (PM 2.5) and black carbon (BC) in two cities: Singapore and Danang (Vietnam) with different socio-economic conditions. The PE measurement was conducted during a multimodal round trip from Singapore to Danang and back with various on-road transport modes in urban micro-environments within each city by using portable devices. Real-time assessment of PE revealed that more than 60% of the integrated inhaled dose of PM 2.5 by commuters to occurred at airport concourses and transit micro-environments to/from the aeroplane by apron bus. Whereas for BC, the transit by apron bus made a major contribution (> 50%) to the total integrated exposure. The PE to PM 2.5 and BC in transport micro-environments was an order of magnitude higher in Danang compared to Singapore while using various on-road modes of transport in each city. Elevated concentrations of airborne particles in Singapore and Danang were significantly contributed by heavy-duty diesel vehicles and motorcycles, respectively. Moreover, a reduction in years of life expectancy is likely to occur among urban commuters while using motorized transport compared to active mobility (cycling). [ABSTRACT FROM AUTHOR]
- Published
- 2020
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34. Efficient removal of bisphenol A and disinfection of waterborne pathogens by boron/nitrogen codoped graphene aerogels via the synergy of adsorption and photocatalysis under visible light.
- Author
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Jiang, Yiqun, Chowdhury, Shamik, and Balasubramanian, Rajasekhar
- Subjects
PHOTOCATALYSIS ,VISIBLE spectra ,BISPHENOL A ,AEROGELS ,POLLUTANTS ,ADSORPTION (Chemistry) ,NITROGEN ,BORON - Abstract
• B/N codoped graphene aerogels (BNGAs) are prepared by one-pot hydrothermal method. • BNGAs can effectively photodegrade bisphenol A under visible light. • Over 88 % total organic carbon is removed by BNGAs within 3 h. • BNGAs can also remove pathogens such as Escherichia coli. • BNGAs can be recycled and reused repeatedly with no significant loss in efficiency. It is widely acknowledged that doping of carbon materials by multi-elements with different electronegativities can result in unique electron-donor properties and novel functionalities because of the strong synergistic interaction among the dopant atoms. In this study, boron and nitrogen codoped graphene aerogels (BNGAs) are synthesized and their photocatalytic activity towards decomposition of bisphenol A (BPA) under visible light irradiation is systematically examined. The BPA molecules are rapidly adsorbed onto the 3D interconnected pore system of the BNGAs under dark conditions, and eventually mineralized upon exposure to visible light, indicating the synergy between adsorption-enrichment and photocatalysis during degradation of BPA. Notably, almost 96 % of BPA is removed and over 88 % of total organic carbon is eliminated by the as-prepared BNGAs. More importantly, the BNGAs can retain approximately 92 % of their initial activity even after repeated cycling. In addition, the BNGAs display great potential for the disinfection of harmful pathogens like Escherichia coli , with a photocatalytic decontamination rate of 1.2 × 10
3 CFU h−1 g cat−1 . In view of their attractive multi-functional performance, the as-developed BNGAs merit further consideration for eliminating emerging organic contaminants and pathogens from freshwater sources. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
35. Insights into characteristics of light absorbing carbonaceous aerosols over an urban location in Southeast Asia.
- Author
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Adam, Max Gerrit, Chiang, Andrew Wei Jie, and Balasubramanian, Rajasekhar
- Subjects
CARBONACEOUS aerosols ,HOT spots (Pollution) ,BIOMASS burning ,AIR pollution ,CARBON-black ,LIGHT absorption - Abstract
Light absorbing carbonaceous aerosols (LACA) consisting of black carbon (BC) and brown carbon (BrC) have received considerable attention because of their climate and health implications, but their sources, characteristics and fates remain unclear in Southeast Asia (SEA). In this study, we investigated spatio-temporal characteristics of LACA, their radiative properties and potential sources in Singapore under different weather conditions. Hourly BC concentrations, measured from May 2017 to March 2018, ranged from 0.31 μg/m
3 to 14.37 μg/m3 with the mean value being 2.44 ± 1.51 μg/m3 . High mass concentrations of BC were observed during the south-west monsoon (SWM, 2.60 ± 1.56 μg/m3 ) while relatively low mass concentrations were recorded during the north-east monsoon (NEM, 1.68 ± 0.96 μg/m3 ). There was a shift in the Absorption Ångström exponent (AAE) from 1.1 to 1.4 when the origin of LACA changed from fossil fuel (FF) to biomass burning (BB) combustion. This shift is attributed to the presence of secondary BrC in LACA, derived from transboundary BB emissions during the SWM. Lower AAE values were observed when local traffic emissions were dominant during the NEM. This explanation is supported by measurements of water-soluble organic carbon (WSOC) in LACA and the corresponding AAE values determined at 365 nm using a UV–vis spectrophotometer. The AAE values, indicative of the presence of brown carbon (BrC), showed that photochemically aged LACA contribute to an enhancement in the light absorption of aerosols. In addition, spatio-temporal characteristics of BC in the intra-urban environment of Singapore were investigated across diverse outdoor and indoor microenvironments. High variability of BC was evident across these microenvironments. Several air pollution hotspots with elevated BC concentrations were identified. Overall, the results stress a need to control anthropogenic emissions of BC and BrC in order to mitigate near-term climate change impacts and provide health benefits. Image 1 • Black carbon showed diurnal and seasonal variations due to changes in its sources. • Presence of both primary and secondary brown carbon was observed. • Light absorption by brown carbon is linked with the composition of organics. • Contributions from biomass burning to BC and BrC dominated during the dry season. • Key sources of BC in Singapore were construction sites, temples and bus stops. This paper provides insights into the concentration levels, diurnal variations, sources and radiative properties of carbonaceous aerosols over an urban environment in Southeast Asia. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
36. Efficient removal of bisphenol A and disinfection of waterborne pathogens by boron/nitrogen codoped graphene aerogels via the synergy of adsorption and photocatalysis under visible light
- Author
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Jiang, Yiqun, Chowdhury, Shamik, and Balasubramanian, Rajasekhar
- Published
- 2020
- Full Text
- View/download PDF
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