Browsing by Author "Awual, Md. Rabiul"

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A Snapshot of Coal-fired Power Generation in Bangladesh
([email protected], 2021-05-26) Islam, Aminul; Ahmed, A. Islam; Ahmed, Mohammad Tofayal; Mondal, Md Alam Hossain; Awual, Md. Rabiul; Monir, Minhaj Uddin; Islam, ,Kamrul
Despite the numerous exemplary efforts taking place to develop sustainable systems of power generation globally, coal will remain an essential and significant part of Bangladesh’s energy generation. The Government of Bangladesh needs to provide a more reliable and transparent power market for citizens to meet Bangladesh’s rising energy demand. Consequently, various coal-based mega projects were undertaken by the Bangladesh government to ensure an affordable and reliable power supply. Half of the targeted electricity was designated to be produced from imported coal. Hence, the development strategy or the reformation of policy in the energy sector may contribute to the current shortcomings in policy approach including inadequate energy infrastructure, regulation and co-ordination issues. This review focuses on the increasing demand for coal, supply issues, socio-environmental requirements and significant coal import to encourage realistic advancement of the energy sector in Bangladesh. Moreover, forecasting the requirement of coal for mega power projects from 2021 to 2041 was highlighted. The water resource supply for coal-based power plants and approaches for reducing CO2 and other emissions were also addressed. Finally, initiatives for fulfilling Sustainable Development Goals in the Bangladesh energy sector were also discussed in this review.
Energy Challenges for a Clean Environment
(Energy Reports, Elsevier, 2021-11) Islam, Aminul; Hossain, Md Biplob; Mondal, Md Alam Hossain; Ahmed, Mohammad Tofayal; Hossain, Md Alam; Monir, Minhaj Uddin; Khan, Mohammad Forrukh Hossain; Islam, Kamrul; Khandaker, Shahjalal; Choudhury, Tasrina Rabia; Awual, Md. Rabiul
A significant progress has been made to increase electricity generation capacity in the country over the last decade. The electricity supply for growing demand is the foremost challenge of the government, as the country move towards the vision of middle-income status by 2021 and high-income by 2041. The energy security is the concern due the running out of gas supply soon. Despite significant progress on energy in recent years, the goal of access to electricity for all would not be attainable without implementation of a consistent national energy policy. Well-coordinated national energy policy is required to achieve sustainable development goals of the country. Priorities for action and regulatory framework of energy need to identify to overcome energy crisis. Long-term energy planning and private financing policy are also crucial to extend the pace of progress in the energy sector. This review provides insights into the energy policies at different sectors, notably coal fired electricity in Bangladesh. The results revealed that the effective and efficient CO2 emission could be reduced from power generating sector by introducing advanced fuel technologies and management system. Besides, higher thermal and mechanical efficiency can be obtained by initiating the combined power cycle systems in energy sector. The achievement in energy sector as well as challenges facing in ensuring sustainable energy is highlighted. The key challenges in the existing legal framework and substantial progress improving energy efficiency are also discussed in this review.
Healthcare Waste in Bangladesh: Current Status, the Impact of COVID-19 and Sustainable Management With Life Cycle and Circular Economy Framework
(Elsevier, 2023-02-09) Dihan, Musfekur Rahman; Nayeem, S.M. Abu; Roy, Hridoy; Islam, Md. Shahinoor; Islam, Aminul; Alsukaibi, Abdulmohsen K.D.; Awual, Md. Rabiul
COVID-19 has accelerated the generation of healthcare (medical) waste throughout the world. Developing countries are the most affected by this hazardous and toxic medical waste due to poor management systems. In recent years, Bangladesh has experienced increasing medical waste generation with estimated growth of 3 % per year. The existing healthcare waste management in Bangladesh is far behind the sustainable waste management concept. To achieve an effective waste management structure, Bangladesh has to implement life cycle assessment (LCA) and circular economy (CE) concepts in this area. However, inadequate data and insufficient research in this field are the primary barriers to the establishment of an efficient medical waste management systen in Bangladesh. This study is introduced as a guidebook containing a comprehensive overview of the medical waste generation scenario, management techniques, Covid-19 impact from treatment to testing and vaccination, and the circular economy concept for sustainable waste management in Bangladesh. The estimated generation of medical waste in Bangladesh without considering the surge due to Covid-19 and other unusual medical emergencies would be approximately 50,000 tons (1.25 kg/bed/day) in 2025, out of which 12,435 tons were predicted to be hazardous waste. However, our calculation estimated that a total of 82,553, 168.4, and 2300 tons of medical waste was generated only from handling of Covid patients, test kits, and vaccination from March 2021 to May 2022. Applicability of existing guidelines, and legislation to handle the current situation and feasibility of LCA on medical waste management system to minimize environmental impact were scrutinized. Incineration with energy recovery and microwave sterilization were found to be the best treatment techniques with minimal environmental impact. A circular economy model with the concept of waste minimizaton, and value recovery was proposed for sustainable medical waste management. This study suggests proper training on healthcare waste management, proposing strict regulations, structured research allocation, and implementation of public-private partnerships to reduce, and control medical waste generation for creating a sustainable medical waste management system in Bangladesh.
Progress in Plasma Doping Semiconductor Photocatalysts for Efficient Pollutant Remediation and Hydrogen Generation
(Elsevier, 2023-09-01) Rahman, Tanzim Ur; Roy, Hridoy; Fariha, Athkia; Shoronika, Afrina Zaman; Al-Mamun, Md. Rashid; Islam, Syed Z.; Islam, Md. Shahinoor; Marwani, Hadi M.; Islam, Aminul; Alsukaibi, Abdulmohsen K.D.; Rahman, Mohammed M.; Awual, Md. Rabiul
In recent years, solar energy-driven photocatalysis materials have drawn significant attention to addressing the global energy and environmental crisis. However, many of the semiconductor photocatalysts are unable to absorb the visible light of the solar spectra due to their wide band gap. The incorporation of a foreign element such as a dopant in the lattice of these photocatalysts was shown to reduce their band gap and enhance visible light absorption. The doping of semiconductors can be performed using several techniques such as sol–gel, hydrothermal, solvothermal, and plasma-based doping. However, plasma-based doping has been considered a highly efficient approach due to the reduction of the band gap to a large extent, enhancement of visible light absorption, and remarkable photocatalytic activities under visible light illumination. The plasma-based doping approach offered many advantages such as high reactivity, process simplicity, scalability, energy efficiency, homogeneous doping, no chemical inventory, low pressure, and low-temperature operation, and flexibility of operation under gas and liquid phase media. Further advancement of plasma-based doping can be achieved through more theoretical studies allowing an in-depth understanding of the mechanisms and interactions of the species involved. This will facilitate the synthesis and application of doped photocatalysts in a cost-effective manner. This review surveyed recent advances in a wide range of semiconductor photocatalysts doped with various dopants using plasma treatment. Various plasma methods for doping semiconductor photocatalysts and their fundamental mechanisms were discussed. The performance characteristics of the plasma-doped photocatalysts were compared to other methods in terms of energy and environmental applications including degradation of environmental contaminants and solar fuel production such as hydrogen production from water splitting using visible light-driven solar energy. Finally, potential future research directions were recommended for the applications of the efficient photocatalysts developed by plasma treatment.
State-of-the-Art in Solar Water Heating (Swh) Systems for Sustainable Solar Energy Utilization: A Comprehensive Review
(Elsevier, 2023-09-30) Al-Mamun, Md. Rashid; Roy, Hridoy; Islam, Md. Shahinoor; Ali, Md. Romzan; Hossain, Md. Ikram; Aly, Mohamed Aly Saad; Khan, Md. Javed Hossain; Marwani, Hadi M; Islam, Aminul; Haque, Enamul; Rahman, Mohammed M; Awual, Md. Rabiul
The solar water-heating (SWH) system is one of the most convenient applications of solar energy, which is considered an available, economical, and environmentally friendly energy source to fulfill the energy demands of the world. In this review, existing SWH systems and design aspects of major components e.g., solar thermal collector, storage tank, heat exchanger, heat transferring fluid, absorber plate, etc. were extensively studied. Recent research to further improve SWH systems and potential practical applications are critically reviewed. Moreover, a relatively new concept in SWH systems, which is using nanofluids in solar collectors as heat transfer fluid has been studied in terms of design criteria for the development of SWH systems. Stationary flat plate collector (FPC) and single-axis tracking compound parabolic collector (CPC) exhibit thermal efficiencies of 45–60 % (operating range: 25–100 °C) and 30–50 % (operating range: 60–300 °C), respectively. The use of thermal stratification structures e.g., diffusers, baffles, membranes, fabrics, etc. is an effective tool to reduce heat losses from the storage tank as well as to harvest the highest energy from the solar collector. Coating of nanomaterials e.g., nickel, copper, etc. was found to reduce the backside heat loss in SWJ systems which eventually increases the thermal performance of the system. Nanofluids consisting of multiwall carbon nanotubes (MWCNTs) and Al2O3 increased the effectiveness of FPC by 28.3 and 35 %, respectively. Moreover, using CuO nanofluids, the collector efficiency of a typical evacuated tube collector (ETC) was increased by up to 12.4 %. Several potential future recommendations for improving the performance of the SWH system were stated.
Sustainable Pollutant Removal and Wastewater Remediation Using TiO2-Based Nanocomposites: A Critical Review
(Elsevier, 2023-07-29) Suhan, Md. Burhan Kabir; Al-Mamun, Md. Rashid; Farzana, Nawshin; Aishee, Sirazam Munira; Islam, Md. Shahinoor; Marwani, Hadi M.; Hasan, Md. Munjur; Asiri, Abdullah M.; Rahman, Mohammed M.; Islam, Aminul; Awual, Md. Rabiul
Rapid industrialization and urbanization emphasized water purification and the production of carbon-neutral fuels. State-of-the-art technology that is low-cost, long-lasting, and easy to implement is required to address these issues. In this context, substantial developments in green synthesis technology have provided a more efficient, effective, and affordable procedure. One possible paradigm worth considering is a circular system that purifies water and produces biomass. Titanium dioxide-based photocatalysts (TPs) can be a great tool due to their outstanding properties, which can be modified for improving photocatalytic activities in various advanced oxidation process applications. In recent years, there has been a significant increase in the attention given to the development of environmentally sustainable TPs. A comprehensive analysis of nearly 300 academic articles in this study has revealed significant shortcomings in effectively utilizing TPs. The primary objective of this paper was to address these gaps that need to be filled in order to ensure the efficient and sustainable utilization of TPs in wastewater treatment. Accordingly, this paper comprehensively reviewed TiO2’s features, including structure, properties, synthesis methods, photocatalytic activities, mechanism, structure modifications, applications, treatment cost analysis, and catalysts reuse in wastewater treatment. Finally, in order to ensure the sustainability of this wastewater treatment technique and achieve the goal of the circular economy, the concept of waste-to-resource has been introduced. The implementation of the aforementioned approach may serve as a valuable means of achieving environmentally sustainable outcomes in the field of wastewater treatment.
Toxic dye removal, remediation, and mechanism with doped SnO2-based nanocomposite photocatalysts: A critical review
(Daffodil International University, 2023-08) Roy, Hridoy; Rahman, Tanzim Ur; Khan, Md. Atquj Jaman Riad; Mamun, Md. Rashid Al-; Islam, Syed Z.; Khaleque, Md. Abdul; Hossain, Md. Ikram; Khan, Md. Zaved Hossain; Islam, Md. Shahinoor; Marwani, Hadi M.; Islam, Aminul; Hasan, Md. Munjur; Awual, Md. Rabiul
Heterogeneous photo catalysis is considered to be a sustainable solution for treating organic pollutants in wastewater. Tin oxide (SnO2) has received immense attention from researchers due to its excellent photocatalytic activity, low cost, thermal stability, and resistance to photo erosion. The structural properties of SnO2, different strategies for doping of SnO2, organic degradation mechanisms, and optimization of operational parameters for enhanced photocatalysis were critically analyzed. Photocatalytic activity of pristine SnO2 was enhanced by doping with metal oxide-based semiconductor materials, metals (transitional and earth), and non-metals. Doped SnO2 exhibits higher photocatalytic efficiency than pristine SnO2 due to the enhanced charge carrier separation, reduced electron-hole pair recombination, higher surface area, and lower band-gap energy. Green synthesized TiO2 doped SnO2 exhibited reduced band gap energy of 2.8 eV, and degraded 96 % MB within 75 min under visible light irradiation. The lowest bandgap energy for transitional metal-doped SnO2 was achieved by Mn-doping on SnO2 with a bandgap of ∼2.48 eV, whereas Cu-SnO2 and pure SnO2 have bandgap energies of 3.67 eV and ∼3.75 eV, respectively. Copper chromite spinel nanoparticles (CuCr2O4) doped SnO2 with a band gap energy of 1.39 eV degraded crystal violet (CV) dye completely at neutral pH. Gadolinium (Gd) doped SnO2 particles showed the highest surface area (58 m2/g) which was almost double the pristine SnO2 particles. The degradation of organic dyes by doped-SnO2 depended on initial pH, catalyst dosage, pollutants concentration, dose, light intensity, etc. For the degradation of cationic dye (MB), approximately 50 % more degradation was found at basic pH than at acidic pH utilizing pristine SnO2 nanoparticles. On the contrary, about 20 % more degradation was found for anionic dye (Congo Red) degradation at acidic pH compared to basic pH. Moreover, optimization of catalyst dosage can result in about 50 % more degradation of pollutants. The ZnS-doped SnO2 photocatalysts have shown an increased rate constant of photocatalytic reaction by 24.5 times when the concentration was reduced from 30 mg/L to 5 mg/L. This review also assessed the future research directions to develop sustainable organic pollutants-based wastewater using SnO2.