Books by Mohammad Boshir Ahmed
As most of the energy in different forms is generated from fossil fuels such as petroleum, coal a... more As most of the energy in different forms is generated from fossil fuels such as petroleum, coal and natural gas, the reserves of them are depleting in the world, especially in Bangladesh it is very fast for natural gas. Furthermore, the burning of fossil fuels causes global worming and environmental problems. To meet the growing demand of energy and to mitigate the global worming and environmental problems, it is time to consider the alternative sources of energy. The woody biomass is one of the sources in Bangladesh. Therefore, the objective of this work is to pyrolyse the different types of woody biomass such as ipil-ipil wood, krishnachura wood, and koroi wood to produce liquid fuels (bio-oil) in order to study the possibility of using them as a renewable energy source. The bio-oil can be used as renewable liquid fuels for power generation as well as for transportation.
The experiments have been carried out at different temperatures ranging from 300 to 500 oC. Relatively bigger particle of the wood (3-4 cm long and 2-3 cm diameter), real size for the practical use, was used. Special emphasis has been given to investigate the effects of heating rate and heating up time of the central mass of the particles on the product distribution. In each experiment, the surface temperature reached to the reactor set temperature immediately while the temperature at the central part was as low as 50 oC. The center temperature gradually increased and reached to the final temperature in 3 to 8 minutes, depending on the wood type and the reactor set temperature. The heating rate and heating up time of the central mass greatly affected the product distribution. It also depended on the wood type. For ipil-ipil wood the heating rate of the central mass was much faster than krishnachura and koroi woods, and thus the heating up time was lower. This was resulted in the higher yield (65%) of bio-oil even at lower reactor temperature (300 oC, particle temperature 450 oC) from ipil-ipil wood. In the case of krishnachura and koroi woods, the bio-oil yields were lower under the same condition. This was because the heating rates of the central parts were much slower. Further development can be done to make the process commercialized.
Conference Presentations by Mohammad Boshir Ahmed
Papers by Mohammad Boshir Ahmed
Journal of Environmental Management, 2017
Concentration of eight heavy metals in the surface and groundwater around Dhaka Export Processing... more Concentration of eight heavy metals in the surface and groundwater around Dhaka Export Processing Zone (DEPZ) industrial area were investigated, and estimated the health risk of theposed to local children and adult residents was determined via ingestion and dermal contact was evaluated using deterministic and probabilistic approaches. Metal concentrations (except Cu, Mn, Ni, and Zn) in Bangshi River water were above the drinking water quality guidelines, while in groundwater were less than the recommended limits. Concentration of metals in surface water decreased as a function of distance. Those eEstimations of noncarcinogenic health risk for surface water revealed that mean hazard index (HI) values of As, Cr, Cu, and Pb for combined pathways (i.e., ingestion and dermal contact) were > 1.0 for both age groups. The estimated risk mainly came from the ingestion pathway. However, the HI values for all the examined metals in groundwater were < 1.0, indicating no possible human health hazard. Deterministically estimated total cancer risk (TCR) via Bangshi River water exceeded the acceptable limit of 1 × 10-4 for adult and children. Although, probabilistically estimated 95th percentile values of TCR exceeded the benchmark, mean TCR values assessed by Monte Carlo simulation were less than 1 × 10-4. Simulated results showed that 20.13 % and 5.43 % values of TCR for surface water were > 1 × 10-4 for adult and children, respectively. Deterministic and probabilistic estimations of cancer risk through exposure to groundwater wereas well below the safety limit. Overall, the population exposed to Bangshi River water remained at carcinogenic and non-carcinogenic health threat and the risk was higher for adults. Sensitivity analysis identified exposure duration (ED) and ingestion rate (IR) of water were as the most relevant variables affecting the probabilistic risk estimation model outcome.
Current opinion in green and sustainable chemistry, Aug 1, 2017
UV filters as emerging contaminants are of great concern and their wide detection in aquatic envi... more UV filters as emerging contaminants are of great concern and their wide detection in aquatic environments indicates their chemical stability and persistence. This review summarized the photolytic and photocatalytic degradation of UV filters in contaminated water. The findings indicated that limited research has been conducted on the photolysis and photocatalysis of UV filters. Photolysis of UV filters through UV irradiation in natural water was a slow process, which was accelerated by the presence of photosensitisers e.g. triplet state of chromaphoric dissolved organic matter (3 CDOM*) and nutrients but reduced by salinity, dissolved organic matter (DOM) and divalent cations. UV Photocatalysis of 4-methylbenzylidene camphor and 2-phenylbenzimidazole-5-sulfonic acid was very effective with 100% removal within 30 min and 90 min using medicated TiO 2 /H 2 O 2 and TiO 2 , respectively. The radiation source, type of catalyst and oxygen content were key factors. Future research should focus on improved understanding of photodegradation pathways and by-products of UV filters.
Bioresource Technology, Dec 1, 2018
The sorptive removal of dissolved organic matter (DOM) in biologically-treated effluent was studi... more The sorptive removal of dissolved organic matter (DOM) in biologically-treated effluent was studied by using multi-walled carbon nanotube (MWCNT), carboxylic functionalised MWCNT (MWCNT-COOH), hydroxyl functionalized MWCNT (MWCNT-OH) and functionalized biochar (fBC). DOM was dominated by hydrophilic fraction (79.6%) with a significantly lower hydrophobic fraction (20.4%). The sorption of hydrophobic DOM was not significantly affected by the sorbent functionality (~10.4% variation) and sorption capacity followed the order of MWCNT > MWCNT-COOH > MWCNT-OH > fBC. In comparison, the sorption of hydrophilic fraction of DOM changed significantly (~37.35% variation) with the change of sorbent functionality with adsorption capacity decreasing as MWCNT-OH > MWCNT-COOH > MWCNT > fBC. Furthermore, the affinity of adsorbents toward a hydrophilic compound (dinitrobenzene), a hydrophobic compound (pyrene) and humic acid was also evaluated to validate the proposed mechanisms. The results provided important insights on the type of sorbents which are most effective to remove different DOM fractions.
Journal of Hazardous Materials, Oct 1, 2018
adsorption coefficient (Kd) normalized against hexadecane-water partition coefficient (KHW) betwe... more adsorption coefficient (Kd) normalized against hexadecane-water partition coefficient (KHW) between HOCs and PHEN indicated strong π-π-EDA interactions. π-π interactions among DNB, PHEN and HOCs were verified by the observed upfield frequency (Hz) shifts using proton nuclear magnetic resonance (1 H NMR) which identified the specific direction of π-π interactions. UV-vis spectra showed charge-transfer bands for π-donors (PHEN and HOCs) with the model π-acceptor (DNB) also demonstrating the role of π-π EDA interactions. The role of π-electron-donor and πelectron-acceptor domains in fBC was identified at different solution pH.
Applied Environmental Research, Aug 8, 2018
He has published more than 20 papers (including 12 as first author) in reputed journals. He has r... more He has published more than 20 papers (including 12 as first author) in reputed journals. He has received several awards including publication awards and award for finalist in NSW Young Water Profession of the Year 2017 awarded by UTS and Australian Water Association, respectively.
Bangladesh Journal of Scientific and Industrial Research, Mar 28, 2016
Objective of this work was to pyrolysis woody biomass. Experiments were carried out at 300 to 500... more Objective of this work was to pyrolysis woody biomass. Experiments were carried out at 300 to 500 o C. Relatively bigger particles were used. Special emphasis was given to investigate the effects of heating rate and heating up time of the central mass of the particles on the product distribution. Surface temperature reached to the reactor set temperature immediately while the temperature at the central part was as low as 50 o C. The center temperature gradually increased to the final temperature within 3 to 8 minutes, depending on the wood types and the reactor set temperature. For ipil-ipil wood the heating rate of the central mass was much faster than krishnachura and koroi woods, and thus the heating up time was lower. Ipil-ipil wood was experienced higher yield (65%) even at lower reactor temperature 300 o C with particle temperature 450 o C. In the case of krishnachura and koroi woods, the bio-oil yields were lower under the same condition due to the heating rates of the central parts were much slower. Further researchon different biomasses may be necessary to demonstrate overall process.
Bangladesh Journal of Scientific and Industrial Research, 1970
The objective of the present work is to install a modified suitable and compatible reactor system... more The objective of the present work is to install a modified suitable and compatible reactor system for the efficient production of renewable liquid fuel (bio-oil) from agro-based bio-mass. This new type of reactor system contains a combustor connected with the upper end of the reactor chamber. The bottom end of the reactor is connected with the bottom part of the combustor by a stainless steel pipe through which hot sand is circulated by the force of air pump. Thus, effective heat transfer from the continuously circulated heated sand as well as efficient biomass conversion into the reactor can be obtained. In this work, jute stick and bagasse abundantly available in Bangladesh were pyrolyzed separately in a continuous feeding circulating fluidized bed reactor at around 500°C for bio-oil production. The total bio-oil yields from bagasse and jute stick were about 69.5 wt% and 68.2 wt% respectively, which are higher than the yields obtained from fixed bed pyrolysis reactor. The total yields of char contents were 19.4 wt% and 21.7wt% after complete pyrolysis of bagasse and jute stick respectively, which are less than that of char yields obtained from fixed bed pyrolysis reactor. Physical and chemical analyses of bio-oils were carried out by conventional methods. The density, viscosity, pH, acid value, water, lignin, solid and ash contents of bio-oils obtained from both jute stick and bagasse were found to be 1.1 g/cc, 3.1 cp, 4.
Processes, Jun 19, 2020
Lignocellulosic biomass is widely grown in many agricultural-based countries. These are typically... more Lignocellulosic biomass is widely grown in many agricultural-based countries. These are typically incinerated or discarded in open spaces, which further may cause severe health and environmental problems. Hence, the proper utilization and conversion of different parts of lignocellulosic biomasses (e.g., corn wastes derived leave, cob, stalk, and husk) into value-added materials could be a promising way of protecting both health and environments. In addition, they have high-potential for myriads applications (e.g., pharmaceuticals, cosmetics, textiles, and so on). In this context, herein, we isolated holocellulose (a mixture of alpha α, beta β, and gamma γ cellulose) from corn waste, and then it was converted into carboxymethyl cellulose (CMC). Subsequently, the prepared CMC was evaluated successfully to be used as a pharmaceutical excipient. Different characterization tools were employed for structural, morphological, and thermal properties of the extracted holocellulose and synthesized CMC. Results showed that the highest yield of CMC was obtained 187.5% along with the highest degree of substitution (DS i.e., 1.83) in a single stage (i.e., size reduction technique) with the lowest particle size of holocellulose (100 µm). This happened due to the use of a single stage instead of multiple stages. Finally, extracted CMC was successfully used as a pharmaceutical excipient with promising results compared to commercially available pharmaceutical-grade CMC.
Catalysts
Developing cost-effective, eco-friendly, efficient, stable, and unique catalytic systems remains ... more Developing cost-effective, eco-friendly, efficient, stable, and unique catalytic systems remains a crucial issue in catalysis. Due to their superior physicochemical and electrochemical properties, exceptional structural characteristics, environmental friendliness, economic productivity, minimal energy demand, and abundant supply, a significant amount of research has been devoted to the development of various doped carbon materials as efficient catalysts. In addition, carbon-based materials (CBMs) with specified doping have lately become significant members of the carbon group, showing promise for a broad range of uses (e.g., catalysis, environmental remediation, critical chemical production, and energy conversion and storage). This study will, therefore, pay attention to the function of heteroatom-based doped and undoped CBMs for catalytical applications and discuss the underlying chemistries of catalysis. According to the findings, doping CBMs may greatly improve their catalytic ac...
Science of The Total Environment, Dec 1, 2017
Biochar and functionalized biochar (fBC-1 and fBC-2) were prepared and applied to remove antibiot... more Biochar and functionalized biochar (fBC-1 and fBC-2) were prepared and applied to remove antibiotic chloramphenicol from deionized water, lake water and synthetic wastewater. Results showed that chloramphenicol removal on biochar was pH dependent and maximum sorption occurred at pH 4.0-4.5. The sorption data of chloramphenicol fitted better with the Langmuir isotherm model than the Freundlich isotherm model with the maximum Langmuir sorption capacity of 233 μM g-1 using fBC-2. Chloramphenicol sorption on fBC-2 followed the trend: deionized water > lake water > synthetic wastewater. The presence of humic acid decreased the sorption distribution coefficient (Kd) while the presence of low ionic strength and soil in solution increased Kd value significantly. The mechanism of sorption on fBC mainly involved electron-donor-acceptor (EDA) interactions at pH < 2.0; formation of charge assisted hydrogen bond (CAHB) and hydrogen bonds in addition to EDA in the pH 4.0-4.5; and CAHB and EDA interactions at pH > 7.0. Additionally, solvent and thermal regeneration of fBC-2 for repeatable applications showed excellent sorption of chloramphenicol under the same condition, due to the creation of a fingerprinting effect in fBC-2. Consequently, fBC-2 can be applied with excellent reusability properties to remove chloramphenicol and other similar organic contaminants.
Bioresource Technology, Aug 1, 2017
Competitive sorption affinity of sulfonamides and chloramphenicol antibiotics toward functionaliz... more Competitive sorption affinity of sulfonamides and chloramphenicol antibiotics toward functionalized biochar for water and wastewater treatment, Bioresource Technology (2017),
Polymers
Over the last decade, researchers have investigated the potential of nano and microfiber scaffold... more Over the last decade, researchers have investigated the potential of nano and microfiber scaffolds to promote wound healing, tissue regeneration, and skin protection. The centrifugal spinning technique is favored over others due to its relatively straightforward mechanism for producing large quantities of fiber. Many polymeric materials have yet to be investigated in search of those with multifunctional properties that would make them attractive in tissue applications. This literature presents the fundamental process of fiber generation, and the effects of fabrication parameters (machine, solution) on the morphologies such as fiber diameter, distribution, alignment, porous features, and mechanical properties. Additionally, a brief discussion is presented on the underlying physics of beaded morphology and continuous fiber formation. Consequently, the study provides an overview of the current advancements in centrifugally spun polymeric fiber-based materials and their morphological fe...
Gels, 2022
There is a great demand for biodegradable hydrogel, and cellulose enriched wastes materials are w... more There is a great demand for biodegradable hydrogel, and cellulose enriched wastes materials are widely used to serve this purpose for various advance applications (e.g., biomedical and environmental). Sugarcane bagasse is cellulose-enriched agro-waste, abundantly grown in Bangladesh. This study aimed to treat sugarcane bagasse-based agro-waste using a sustainable and ecofriendly approach to produce hydrogel with super-swelling capacity for adsorption of copper, chromium, iron ions, methylene blue and drimaren red dyes. To increase the swelling property of hydrogels, copolymerization of hydrophilic monomers is an effective technique. Therefore, this study aimed to prepare hydrogel via free radical graft-copolymerization reaction among acrylamide, methyl methacrylate and treated bagasse in the presence of N,N-methylene-bis-acrylamide as a crosslinker and potassium persulphate as an initiator. To obtain maximum yield, reaction conditions were optimized. It was found that hydrogel obtai...
Current Developments in Biotechnology and Bioengineering, 2020
Abstract The occurrence of different organic micro-pollutants, especially emerging micro-pollutan... more Abstract The occurrence of different organic micro-pollutants, especially emerging micro-pollutants, even at very low concentrations, in the natural environment has raised significant concerns about their negative effect on aquatic ecosystems and human health. Micro-pollutants may present in the natural environment in a complex form and at varying concentrations. Hence, advanced and highly sensitive analytical instruments are required for the accurate and precise qualitative and quantitative identification of micro-pollutants. Analytical approaches used for the identification of micro-pollutants consist of different procedures, such as sample treatment or preparation, separation, and detection by instruments. Several high-end advanced analytical instruments such as triple quadrupole liquid chromatography-mass spectrometry, triple quadrupole gas chromatography-mass spectrometry), nuclear magnetic resonance, etc. are used for the efficient analysis of micro-pollutants depending on the type of analytes. In this regard, the analytical techniques and their limitations involved in the analysis of different micro-pollutants are discussed in this chapter.
Science of The Total Environment, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Background: Welding exposes a lot of gases, fumes and radiant energy that may be potentially haza... more Background: Welding exposes a lot of gases, fumes and radiant energy that may be potentially hazardous for unsafe welder's health. Welding fumes (WFs) are a severe problem among all those exposed. WFs are an intricate composition of metallic oxides, fluorides and silicates that may effect to the progression of various health problems. If a welder inhales such fumes in large quantities over a long period, there is a risk of developing various respiratory system diseases (RSDs). Methods: We developed quantitative frameworks to recognize the genetic effects of WFs on the development of RSDs. We analyzed Gene Expression microarray data from WFs exposed tissues and RSDs including Chronic Bronchitis (CB), Asthma (AS), Pulmonary Edema (PE), Lung Cancer (LC) datasets. We built disease-gene (diseasome) association networks and identified dysregulated signaling and ontological pathways, and protein-protein interaction sub-network using neighborhood-based benchmarking and multilayer networ...
Science of The Total Environment, 2015
Antibiotics as emerging contaminants are of global concern due to the development of antibiotic r... more Antibiotics as emerging contaminants are of global concern due to the development of antibiotic resistant genes potentially causing superbugs. Current wastewater treatment technology cannot sufficiently remove antibiotics from sewage, hence new and low-cost technology is needed. Adsorptive materials have been extensively used for the conditioning, remediation and removal of inorganic and organic hazardous materials, although their application for removing antibiotics has been reported for ∼30 out of 250 antibiotics so far. The literature on the adsorptive removal of antibiotics using different adsorptive materials is summarized and critically reviewed, by comparing different adsorbents with varying physicochemical characteristics. The efficiency for removing antibiotics from water and wastewater by different adsorbents has been evaluated by examining their adsorption coefficient (K d) values. For sulfamethoxazole the different adsorbents followed the trend: biochar (BC) > multi-walled carbon nanotubes (MWCNTs) > graphite > clay minerals, and for tetracycline the adsorptive materials followed the trend: SWCNT > graphite > MWCNT = AC > bentonite = humic substance = clay minerals. The underlying controlling parameters for the adsorption technology have been examined. In addition, the cost of preparing adsorbents has been estimated, which followed the order of BCs < ACs < ion exchange resins < MWCNTs < SWCNTs. The future research challenges on process integration, production and modification of low-cost adsorbents are elaborated.
Processes
Perovskite solar cells (PSCs) have captured the attention of the global energy research community... more Perovskite solar cells (PSCs) have captured the attention of the global energy research community in recent years by showing an exponential augmentation in their performance and stability. The supremacy of the light-harvesting efficiency and wider band gap of perovskite sensitizers have led to these devices being compared with the most outstanding rival silicon-based solar cells. Nevertheless, there are some issues such as their poor lifetime stability, considerable J–V hysteresis, and the toxicity of the conventional constituent materials which restrict their prevalence in the marketplace. The poor stability of PSCs with regard to humidity, UV radiation, oxygen and heat especially limits their industrial application. This review focuses on the in-depth studies of different direct and indirect parameters of PSC device instability. The mechanism for device degradation for several parameters and the complementary materials showing promising results are systematically analyzed. The mai...
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Books by Mohammad Boshir Ahmed
The experiments have been carried out at different temperatures ranging from 300 to 500 oC. Relatively bigger particle of the wood (3-4 cm long and 2-3 cm diameter), real size for the practical use, was used. Special emphasis has been given to investigate the effects of heating rate and heating up time of the central mass of the particles on the product distribution. In each experiment, the surface temperature reached to the reactor set temperature immediately while the temperature at the central part was as low as 50 oC. The center temperature gradually increased and reached to the final temperature in 3 to 8 minutes, depending on the wood type and the reactor set temperature. The heating rate and heating up time of the central mass greatly affected the product distribution. It also depended on the wood type. For ipil-ipil wood the heating rate of the central mass was much faster than krishnachura and koroi woods, and thus the heating up time was lower. This was resulted in the higher yield (65%) of bio-oil even at lower reactor temperature (300 oC, particle temperature 450 oC) from ipil-ipil wood. In the case of krishnachura and koroi woods, the bio-oil yields were lower under the same condition. This was because the heating rates of the central parts were much slower. Further development can be done to make the process commercialized.
Conference Presentations by Mohammad Boshir Ahmed
Papers by Mohammad Boshir Ahmed
The experiments have been carried out at different temperatures ranging from 300 to 500 oC. Relatively bigger particle of the wood (3-4 cm long and 2-3 cm diameter), real size for the practical use, was used. Special emphasis has been given to investigate the effects of heating rate and heating up time of the central mass of the particles on the product distribution. In each experiment, the surface temperature reached to the reactor set temperature immediately while the temperature at the central part was as low as 50 oC. The center temperature gradually increased and reached to the final temperature in 3 to 8 minutes, depending on the wood type and the reactor set temperature. The heating rate and heating up time of the central mass greatly affected the product distribution. It also depended on the wood type. For ipil-ipil wood the heating rate of the central mass was much faster than krishnachura and koroi woods, and thus the heating up time was lower. This was resulted in the higher yield (65%) of bio-oil even at lower reactor temperature (300 oC, particle temperature 450 oC) from ipil-ipil wood. In the case of krishnachura and koroi woods, the bio-oil yields were lower under the same condition. This was because the heating rates of the central parts were much slower. Further development can be done to make the process commercialized.