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Papers by Mohammad Faisal Umar

Journal of Water Process Engineering, 2022

International Journal of Energy Research, 2022

Journal of Cleaner Production, 2021

Membranes, 2020

Benthic microbial fuel cells (BMFCs) are a kind of microbial fuel cell (MFC), distinguished by th... more Benthic microbial fuel cells (BMFCs) are a kind of microbial fuel cell (MFC), distinguished by the absence of a membrane. BMFCs are an ecofriendly technology with a prominent role in renewable energy harvesting and the bioremediation of organic pollutants through electrogens. Electrogens act as catalysts to increase the rate of reaction in the anodic chamber, acting in electrons transfer to the cathode. This electron transfer towards the anode can either be direct or indirect using exoelectrogens by oxidizing organic matter. The performance of a BMFC also varies with the types of substrates used, which may be sugar molasses, sucrose, rice paddy, etc. This review presents insights into the use of BMFCs for the bioremediation of pollutants and for renewable energy production via different electron pathways.

Emerging Carbon‐Based Nanocomposites for Environmental Applications, 2020

SAŽETAK: Tijekom pandemije COVID-a 19 smanjio se broja pregleda te dijagnostičkih i terapijskih z... more SAŽETAK: Tijekom pandemije COVID-a 19 smanjio se broja pregleda te dijagnostičkih i terapijskih zahvata u bolesnika s kardiovaskularnim bolestima. U nekoliko zemalja zabilježen je porast mortaliteta u iste skupine bolesnika, kako od COVID-a 19, tako i od samih kardiovaskularnih bolesti. Važno je nastaviti liječiti takve bolesnike i spriječiti nedostupnost zdravstvene zaštite zbog subjektivnih ili objektivnih razloga. U tome nam može pomoći i telemedicina, no velik dio odgovornosti ostaje na samim bolesnicima da samokontrolom i redovitim uzimanjem terapije spriječe pogoršanje bolesti. Mi im možemo pomoći olakšavanjem te zadaće (telefonski kontakt, fiksne kombinacije lijekova). Također je važno zdravstvenu zaštitu prilagoditi pandemiji kako bi ta zaštita bila učinkovita i sigurna i za bolesnike i za pružatelje zaštite. SUMMaRY: During the COVID-19 pandemic, there fewer examinations and diagnostic and therapeutic procedures were performed in patients with cardiovascular diseases. In several countries, an increase in mortality has been reported in this group of patients, both from COVID-19 and from cardiovascular diseases. It is important to continue to treat these patients and to prevent the unavailability of health care for subjective or objective reasons. Telemedicine can also help us in this, but much of the responsibility remains with the patients themselves to prevent the disease from getting worse through self-monitoring and regular therapy. We can help them by facilitating this task (telephone contacts, fixed drug combinations). It is also important to adapt healthcare to the pandemic in order to make it effective and safe for both patients and caregivers. KLJUČNE RIJEČI: COVID-19, kardiovaskularne bolesti, mortalitet, zdravstvena zaštita.

Membranes, 2021

Microbial electrosynthesis is a new approach to converting C1 carbon (CO2) to more complex carbon... more Microbial electrosynthesis is a new approach to converting C1 carbon (CO2) to more complex carbon-based products. In the present study, CO2, a potential greenhouse gas, was used as a sole carbon source and reduced to value-added chemicals (acetate, ethanol) with the help of bioelectrochemical reduction in microbial electrosynthesis systems (MES). The performance of MES was studied with varying electrode materials (carbon felt, stainless steel, and cobalt electrodeposited carbon felt). The MES performance was assessed in terms of acetic acid and ethanol production with the help of gas chromatography (GC). The electrochemical characterization of the system was analyzed with chronoamperometry and cyclic voltammetry. The study revealed that the MES operated with hybrid cobalt electrodeposited carbon felt electrode yielded the highest acetic acid (4.4 g/L) concentration followed by carbon felt/stainless steel (3.7 g/L), plain carbon felt (2.2 g/L), and stainless steel (1.87 g/L). The alc...

International Journal of Environmental Research and Public Health, 2021

Anthropogenic activities are largely responsible for the vast amounts of pollutants such as polyc... more Anthropogenic activities are largely responsible for the vast amounts of pollutants such as polycyclic aromatic hydrocarbons, cyanides, phenols, metal derivatives, sulphides, and other chemicals in wastewater. The excess benzene, toluene and xylene (BTX) can cause severe toxicity to living organisms in wastewater. A novel approach to mitigate this problem is the benthic microbial fuel cell (BMFC) setup to produce renewable energy and bio-remediate wastewater aromatic hydrocarbons. Several mechanisms of electrogens have been utilized for the bioremediation of BTX through BMFCs. In the future, BMFCs may be significant for chemical and petrochemical industry wastewater treatment. The distinct factors are considered to evaluate the performance of BMFCs, such as pollutant removal efficiency, power density, and current density, which are discussed by using operating parameters such as, pH, temperature and internal resistance. To further upgrade the BMFC technology, this review summarizes ...

Journal of Hazardous Materials, 2021

Xylene, a recalcitrant compound present in wastewater from activities of petrochemical and chemic... more Xylene, a recalcitrant compound present in wastewater from activities of petrochemical and chemical industries causes chronic problems for living organisms and the environment. Xylene contaminated wastewater may be biodegraded through a benthic microbial fuel cell (BMFC) as seen in this study. Xylene was oxidized into intermediate 3-methyl benzoic acid and entirely converted into non-toxic carbon dioxide. The highest voltage of the BMFC reactor was generated at 410 mV between 23 and 90 days when cell potential was 1 kΩ. The reactor achieved a maximum power density of about 63 mW/m2, and a current of 0.4 mA which was optimized from variable resistance (20 Ω - 1 kΩ). However, the maximum biodegradation efficiency of the BMFC was at 87.8%. The cyclic voltammetry curve helped to determine that the specific capacitance was 0.124 F/g after 30 days of the BMFC operation. Furthermore, the fitting equivalent circuit was observed with the help of Nyquist plot for calculating overall internal resistance of 65.82 Ω on 30th day and 124.5 Ω on 80th day. Staphylococcus edaphicus and Staphylococcus sparophiticus were identified by 16S rRNA sequencing as the dominant species in the control and BMFC electrode, presumably associated with xylene biodegradation.

International Journal of Energy Research, 2020

Nanomaterials, 2020

A novel method of preparing reduced graphene oxide (RGOX) from graphene oxide (GOX) was developed... more A novel method of preparing reduced graphene oxide (RGOX) from graphene oxide (GOX) was developed employing vegetable extract, Chenopodium album, as a reducing and stabilizing agent. Chenopodium album is a green leafy vegetable with a low shelf life, fresh leaves of this vegetable are encouraged to be used due to high water content. The previously modified ‘Hummers method’ has been in practice for the preparation of GOX by using precursor graphite powder. In this study, green synthesis of RGOX was functionally verified by employing FTIR and UV-visible spectroscopy, along with SEM and TEM. Our results demonstrated typical morphology of RGOX stacked in layers that appeared as silky, transparent, and rippled. The antibacterial activity was shown by analyzing minimal inhibitory concentration values, agar diffusion assay, fluorescence techniques. It showed enhanced antibacterial activity against Gram-positive and Gram-negative bacteria in comparison to GOX. It has also been shown that th...

International Journal of Biological Macromolecules, 2019

Oxidative stress plays a central role in the incidence of liver injury. Nuclear factor erythroid ... more Oxidative stress plays a central role in the incidence of liver injury. Nuclear factor erythroid 2-related factor-2 (Nrf2) is a key protein regulator of antioxidant response elements (ARE)-mediated gene expression. Thus, Nrf2 can be regarded as a plausible therapeutic target during liver injury. β-Carotene is implicated as one of the important antioxidant with diverse health benefits. The delivery of β-carotene to the target tissue has been debatable due to its low bioavailability, poor water solubility and instability. Here, a nanocomposite of β-carotene with reduced graphene oxide (βC-rGO) has been developed to demonstrate its pronounced effect in regulating Nrf2 to trigger protection against diethylnitrosamine (DEN)-induced hepatic fibrosis in rats. The rGO and βC-rGO samples were characterised by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. Progress of disease was monitored through ultrasonography, in vitro liver and serum biochemistry (alanine transaminase, aspartate transaminase, alkaline phosphatase, bilirubin, lipid peroxidation, protein carbonyls, superoxide dismutase, catalase, glutathione-S-transferase, Nrf2, vitamin-A, retinol dehydrogenase), histopathology, confocal and ultrastructural studies. In fibrotic animals liver biochemistry was significantly altered along with massive changes in liver anatomy. βC-rGO ameliorates experimental fibrogenesis and restores liver functioning due to increased availability of β-carotene in the liver. It is suggested that βC-rGO nanocomposite promotes cellular antioxidant status via upregulation of Nrf2 protein factor and invigorate hepatic stellate cells (HSCs) through restoring vitamin-A.

Applied Water Science, 2018

In the present work, a novel biosensor (GCE/RGO/PPy/NR) based on the nanocomposite of reduced gra... more In the present work, a novel biosensor (GCE/RGO/PPy/NR) based on the nanocomposite of reduced graphene oxide (RGO), polypyrrole (PPy) immobilized by nitrate reductase (NR) was developed on a glassy carbon electrode (GCE). The conductive nanocomposite (RGO/PPy) was synthesized by in situ oxidative polymerization of pyrrole in the presence of RGO in acidic medium. A facile and green path was employed to synthesize RGO from graphene oxide (GO). This was performed by a novel route using Abelmoschus esculentus vegetable extract as a stabilizing and reducing agent for GO. The composite of reduced graphene oxide and polypyrrole (RGO/PPy) was deposited onto GCE with subsequent deposition of NR enzyme on the GCE/ RGO/PPy to develop GCE/RGO/PPy/NR biosensor. The surface morphology and structural features of the composites were studied by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical behavior and electrocatalytic activity of the biosensor were examined by cyclic voltammetry at different scan rates (20-100 mV s −1) in the synthetic nitrate solution. The developed bio-anode achieved a maximum current density of 4.24 mA cm −2 at a scan rate of 100 mV s −1 for 10 mM sodium nitrate solution.