Ramat Raji - Academia.edu (original) (raw)

Papers by Ramat Raji

International Journal of Corrosion and Scale Inhibition, 2019

Corrosion inhibition analysis of Leucaena leucocephala leaves extract (LLE) as an additive incorp... more Corrosion inhibition analysis of Leucaena leucocephala leaves extract (LLE) as an additive incorporated into a commercialized coating to protect mild steel when immersed in seawater has been successfully conducted. The procedures involve the utilization of multiple techniques including Fourier transform infrared spectroscopy (FTIR), ultravioletvisible spectroscopy (UV-Vis), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and scanning electron microscope with energy-dispersive Xray spectroscopy (SEM/EDS). The result of FTIR identified both hydroxyl (-OH) and carbonyl (C=O) groups indicating the presence of phenolic compounds in the extract whereas the analysis obtained from UV-Vis showed a peak absorption spectrum at 268 nm. The electrochemical analysis indicated an excellent inhibition efficiency up to 96.12% for the immersed mild steel coated with 6% of LLE coating. Furthermore, based on the study of polarization, a drastic decrease of corrosion rate at 0.2791 mm/year was observed for the same coating as compared to the uncoated substrate, which was 2.3991 mm/year. The study also confirmed that LLE acts as a mixed type inhibitor, as shown in the polarization curve. The morphological evaluation displayed a smooth and homogenous surface with less salt precipitation for 6% of LLE coating as compared to other types of coating affirming it to be the optimum concentration for this evaluation study.

CRC Press eBooks, Mar 29, 2022

Brazilian Journal of Biological Sciences, 2019

Caves are natural aperture and oligotrophic extreme environment for psychrophilic and psychrotole... more Caves are natural aperture and oligotrophic extreme environment for psychrophilic and psychrotolerant microorganisms. Microorganisms found in caves can be indigenous to the caves or introduced by humans, animals, water flow and wind action. Group of microorganisms found in caves are bacteria, fungi, protozoa, algae and viruses. However, bacteria and fungi are the dominant microorganisms. Cave microorganisms are metabolically diverse and are able to acquire energy independently through photoautotrophic, chemoautotrophic or heterotrophic activities. Different microbial groups also interact in the formation of cave and as part of the biogeochemical cycling of elements. Cave microbiology has allowed the detection of microorganisms with the potentials to produce different biomolecules for industrial, pharmaceutical, environmental and biotechnological purposes.

SN Applied Sciences, 2019

The fifth author's middle name was incorrect in the initial online publication. The original arti... more The fifth author's middle name was incorrect in the initial online publication. The original article has been corrected. Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

CRC Press eBooks, Mar 29, 2022

SN Applied Sciences, 2019

Heavy metals polluted soils have turned out to be a common environmental problem across the globe... more Heavy metals polluted soils have turned out to be a common environmental problem across the globe due to their toxic effects and accumulation through the food chain. Heavy metals have lethal effects on all forms of life. For instance, plants grown on heavy metal polluted soil show a reduction in growth and yields. A surge in anthropogenic activities and industrial operations has substantially increased the level of heavy metal pollution and release into the environment; hence, there is need to remediate these heavy metal pollutants. Biosorption is an efficient, economical, ecofriendly and convenient techniques of remediating heavy metal polluted soils. It is a widely accepted method that utilizes biomaterials such as natural biomass as biosorbents. The current study was based on the biosorption of copper, chromium, cadmium and nickel polluted soil using bacteria and fungi isolated from soil. Bacterial species isolated were Pseudomonas, Bacillus, Micrococcus, Escherichia, Streptococcus, Enterobacter and Staphylococcus while fungi isolated were Aspergillus niger, Penicillium notatum and Aspergillus flavus. The isolated bacteria were screened for potential to biosorb copper and chromium likewise fungi for cadmium and nickel. Biosorption rate was determined using atomic absorption spectrophotometry. Five milliliters each of a-day-old culture of the screened bacteria and fungi was inoculated into 45 ml of nutrient broth (bacteria) and potato dextrose broth (fungi) having concentrations of 5, 10, 15 and 20 ppm, respectively, of copper, chromium, cadmium and nickel. The conical flasks were incubated at a temperature of 37 °C and 28 °C ± 2 for bacteria and fungi, respectively, for a period of 35 days of inoculation. For the bacterial isolates, the highest biosorption rates of chromium (89.67%) and copper (90.89%) by Pseudomonas aeruginosa were observed at 20 ppm on day 21 and 15 ppm on day 14, respectively, while for the fungi isolates, P. notatum showed highest biosorption rate for cadmium at 10 ppm with 77.67%. Aspergillus niger showed highest biosorption rate for nickel with 81.07% after 28 days of incubation. The results of this study revealed the ability of Pseudomonas aeruginosa to biosorb copper and chromium and also A. niger and P. notatum to biosorb cadmium and nickel from the environment and can be developed for the biosorption of soils polluted with copper, chromium, cadmium and nickel.

International Journal of Corrosion and Scale Inhibition, 2019

Corrosion inhibition analysis of Leucaena leucocephala leaves extract (LLE) as an additive incorp... more Corrosion inhibition analysis of Leucaena leucocephala leaves extract (LLE) as an additive incorporated into a commercialized coating to protect mild steel when immersed in seawater has been successfully conducted. The procedures involve the utilization of multiple techniques including Fourier transform infrared spectroscopy (FTIR), ultravioletvisible spectroscopy (UV-Vis), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and scanning electron microscope with energy-dispersive Xray spectroscopy (SEM/EDS). The result of FTIR identified both hydroxyl (-OH) and carbonyl (C=O) groups indicating the presence of phenolic compounds in the extract whereas the analysis obtained from UV-Vis showed a peak absorption spectrum at 268 nm. The electrochemical analysis indicated an excellent inhibition efficiency up to 96.12% for the immersed mild steel coated with 6% of LLE coating. Furthermore, based on the study of polarization, a drastic decrease of corrosion rate at 0.2791 mm/year was observed for the same coating as compared to the uncoated substrate, which was 2.3991 mm/year. The study also confirmed that LLE acts as a mixed type inhibitor, as shown in the polarization curve. The morphological evaluation displayed a smooth and homogenous surface with less salt precipitation for 6% of LLE coating as compared to other types of coating affirming it to be the optimum concentration for this evaluation study.

CRC Press eBooks, Mar 29, 2022

Brazilian Journal of Biological Sciences, 2019

Caves are natural aperture and oligotrophic extreme environment for psychrophilic and psychrotole... more Caves are natural aperture and oligotrophic extreme environment for psychrophilic and psychrotolerant microorganisms. Microorganisms found in caves can be indigenous to the caves or introduced by humans, animals, water flow and wind action. Group of microorganisms found in caves are bacteria, fungi, protozoa, algae and viruses. However, bacteria and fungi are the dominant microorganisms. Cave microorganisms are metabolically diverse and are able to acquire energy independently through photoautotrophic, chemoautotrophic or heterotrophic activities. Different microbial groups also interact in the formation of cave and as part of the biogeochemical cycling of elements. Cave microbiology has allowed the detection of microorganisms with the potentials to produce different biomolecules for industrial, pharmaceutical, environmental and biotechnological purposes.

SN Applied Sciences, 2019

The fifth author's middle name was incorrect in the initial online publication. The original arti... more The fifth author's middle name was incorrect in the initial online publication. The original article has been corrected. Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

CRC Press eBooks, Mar 29, 2022

SN Applied Sciences, 2019

Heavy metals polluted soils have turned out to be a common environmental problem across the globe... more Heavy metals polluted soils have turned out to be a common environmental problem across the globe due to their toxic effects and accumulation through the food chain. Heavy metals have lethal effects on all forms of life. For instance, plants grown on heavy metal polluted soil show a reduction in growth and yields. A surge in anthropogenic activities and industrial operations has substantially increased the level of heavy metal pollution and release into the environment; hence, there is need to remediate these heavy metal pollutants. Biosorption is an efficient, economical, ecofriendly and convenient techniques of remediating heavy metal polluted soils. It is a widely accepted method that utilizes biomaterials such as natural biomass as biosorbents. The current study was based on the biosorption of copper, chromium, cadmium and nickel polluted soil using bacteria and fungi isolated from soil. Bacterial species isolated were Pseudomonas, Bacillus, Micrococcus, Escherichia, Streptococcus, Enterobacter and Staphylococcus while fungi isolated were Aspergillus niger, Penicillium notatum and Aspergillus flavus. The isolated bacteria were screened for potential to biosorb copper and chromium likewise fungi for cadmium and nickel. Biosorption rate was determined using atomic absorption spectrophotometry. Five milliliters each of a-day-old culture of the screened bacteria and fungi was inoculated into 45 ml of nutrient broth (bacteria) and potato dextrose broth (fungi) having concentrations of 5, 10, 15 and 20 ppm, respectively, of copper, chromium, cadmium and nickel. The conical flasks were incubated at a temperature of 37 °C and 28 °C ± 2 for bacteria and fungi, respectively, for a period of 35 days of inoculation. For the bacterial isolates, the highest biosorption rates of chromium (89.67%) and copper (90.89%) by Pseudomonas aeruginosa were observed at 20 ppm on day 21 and 15 ppm on day 14, respectively, while for the fungi isolates, P. notatum showed highest biosorption rate for cadmium at 10 ppm with 77.67%. Aspergillus niger showed highest biosorption rate for nickel with 81.07% after 28 days of incubation. The results of this study revealed the ability of Pseudomonas aeruginosa to biosorb copper and chromium and also A. niger and P. notatum to biosorb cadmium and nickel from the environment and can be developed for the biosorption of soils polluted with copper, chromium, cadmium and nickel.