akrima abu bakar | Universiti Teknologi Malaysia - UTM (original) (raw)
Papers by akrima abu bakar
journal of engineering science and technology, 2016
Microbiologically influenced corrosion (MIC) is significant to the presence of microorganisms suc... more Microbiologically influenced corrosion (MIC) is significant to the presence of microorganisms such as sulfate reducing bacteria (SRB) in the deterioration of metallic and non-metallic materials. Bacterial chemical biocides are commonly used to disinfect microorganism effectively. Yet, the practice has some negative impact on the environment since the chemical content may cause pollution. A laboratory experimental investigation was conducted to explore the performance of Ultraviolet (UV) radiation in exterminating SRB as an option to replace biocides usage. The morphologies of the isolated Sg. Ular SRB used in this study were related to Desulfovibrio species. An experimental work was conducted in determining the optimum pH and temperature for the SRB to grow before disinfection purposes. The experimental result showed optimum growth for respective SRB were at pH of 8.5 with temperature recorded at 37°C. UV radiation with wavelength of 254 nm was utilised to disinfect the microorganis...
ARPN journal of engineering and applied sciences, 2016
Carbon steels are commonly used as structural materials of piping systems in oil and gas industry... more Carbon steels are commonly used as structural materials of piping systems in oil and gas industry because of their lower cost and wider availability despite their relatively lower corrosion resistance. This work investigates the preferable growth media for Sulfate Reducing Bacteria to proliferate rapidly and the effect of Microbiologically Influenced Corrosion activity towards carbon steel API 5L X-70 line pipe. Present research work highlighted that the preferred growth medium for ATCC 7757 and BARAM is Modified Baar's and Postgate C for Sg. Ular types of SRB. In addition, the corrosion rate was calculated using data based on metal weight loss experiment. The result confirmed that the corrosion rate in biotic (presence of Sulfate Reducing Bacteria) environment is much higher compared to abiotic environment (absence of Sulfate Reducing Bacteria). The pitting morphology that developed with time due to SRB activity was characterized with Field Emission Scanning Electron Microscopy...
Sulphate-reducing bacteria (SRB) represent themselves as a class of anaerobic bacteria that can r... more Sulphate-reducing bacteria (SRB) represent themselves as a class of anaerobic bacteria that can reduce sulphate to sulphide for obtaining energy. This paper is aimed to detect sulphatereducing bacteria activities using rapid detectable culture media. Two different strains of sulphate-reducing bacteria were used in this study, namely ATCC 7757 and local bacterial strain of SRB isolated from underground sample. Both strains were tested on three recommended culture media of modified Baar‟s, Postgate B and Postgate C. All three medium contained lactic acid which served to be as carbon source. The results showed that modified Baar‟s medium is the best medium for the growth of ATCC 7757 while Postgate C medium is recommended for the local SRB bacterial strain.
Sains Malaysiana, 2020
Microbiologically influenced corrosion (MIC) is capable on weakening the metal's strength, eventu... more Microbiologically influenced corrosion (MIC) is capable on weakening the metal's strength, eventually leads to pipeline leakage, environmental hazard and financial loss. Sulfate reducing bacteria (SRB) is the principal causative organism responsible for external corrosion on steel structures. To date, considerable works have been conducted in Malaysia on the mechanisms of SRB upon MIC on the marine environment instead of underground. Moreover, commercial bacteria strain represents local strain in terms of performance and behavior upon corrosion of steel structure is yet to be proven. Thus, this paper aims to investigate the influence of environmental parameters towards MIC in corroding pipeline. Two types of SRB strain were used designated as SRB ATCC 7757 (commercial) and SRB Sg. Ular (local strain) isolated from Malaysian soil. The behavior of both strains was critically compared by calculating the rate of corrosion upon carbon steel coupons in stipulated environmental parameters. Four influential parameters i.e. pH, temperature, salinity concentration and iron concentration were considered. Collected data presented and analyzed using graphical and statistical analysis, respectively. The results showed the difference of corrosivity between two SRB strains in terms of corrosion behavior upon the X-70 steel coupon. SRB Sg. Ular able to cause severe effects upon steel structure as compared to SRB ATCC 7757 due to its aggressiveness shown by the recorded metal loss data. Thus, future works related to MIC for local environment in particular, should not compromise with the type of SRB strains considered due to differences of performance of the microorganisms onto tested environment and materials.
JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES, 2017
This research is aimed to give an overview of the impact of bio-corrosion on carbon steel grade A... more This research is aimed to give an overview of the impact of bio-corrosion on carbon steel grade API 5L X-70 immersed in growth medium and exposed to SRB consortium. Simulation of anaerobic corrosion conditions was carried out in a laboratory for 28 days. Raw crude oil gathered from the Baram Delta Operation Terminal was cultured in broth number 1249 (Modified Barr's Medium) to study the effect of bacteria growth upon metal loss. Carbon steel coupons grade X70 were cut to approximately 10mm x 20mm x 5mm and immersed in the cultured broth. During the experiment, the planktonic SRB were enumerated using a counting chamber (direct cell count method) under the electronic microscope at 200x magnification. Results indicated that the optimum pH and temperature for the respected SRB consortium genes were 8.5 and 37 °C, respectively. Metal loss of the corrosion specimen was measured and recorded after retrieval from the immersion period in the medium on a weekly basis prior to SRB inoculation for further analysis. The metal loss values supported that SRB activity can increase the metal loss of carbon steel against time of exposure. Additionally, the FESEM image showed the biofilm formations on the corrosion specimen. Thus, the results could conclude that biocorrosion caused by particular local SRB consortium can be considered as a threat to carbon steel pipelines. Besides, the effect of SRB activity and response towards metallic materials in a dynamic environment is an interesting topic to be studied upon in the future.
Environmental technology, Jan 14, 2016
Microbiologically influenced corrosion (MIC) is among the common corrosion types for buried and d... more Microbiologically influenced corrosion (MIC) is among the common corrosion types for buried and deep-water pipelines that result in costly repair and pipeline failure. Sulfate-reducing bacteria (SRB) are commonly known as the culprit of MIC. The aim of this work is to investigate the performance of combination of ultrasound (US) irradiation and ultraviolet (UV) radiation (known as Hybrid soliwave technique, HyST) at pilot scale to inactivate SRB. The influence of different reaction times with respect to US irradiation and UV radiation and synergistic effect toward SRB consortium was tested and discussed. In this research, the effect of HyST treatment toward SRB extermination and corrosion studies of carbon steel coupon upon SRB activity before and after the treatment were performed using weight loss method. The carbon steel coupons immersed in SRB sample were exposed to HyST treatment at different time of exposure. Additionally, Field Emission Scanning Electron Microscopy coupled wi...
Jurnal Teknologi, 2015
Pipelines play an extremely important role in the transportation of gases and liquids over long d... more Pipelines play an extremely important role in the transportation of gases and liquids over long distance throughout the world. Internal corrosion due to microbiologically influenced corrosion (MIC) is one of the major integrity problems in oil and gas industry and is responsible for most of the internal corrosion in transportation pipelines. The presence of microorganisms such as sulfate reducing bacteria (SRB) in pipeline system has raised deep concern within the oil and gas industry. Biocide treatment and cathodic protection are commonly used to control MIC. However, the solution is too expensive and may create environmental problems by being too corrosive. Recently, Ultraviolet (UV) as one of the benign techniques to enhance mitigation of MIC risk in pipeline system has gained interest among researchers. An amount of 100 ml of modified Baar’s medium and 5 ml of Desulfovibrio vulgaris (strain 7577) seeds was grown in 125 ml anaerobic vials with carbon steel grade API 5L-X70 coupon...
Solid State Phenomena, 2015
This study defines the interrelationship between turbidities and cell number counting efficiency ... more This study defines the interrelationship between turbidities and cell number counting efficiency for the growth of one of the microbiologically influenced corrosion (MIC) species in a medium. The metabolism activities during bacteria growth can accelerate the corrosion process and shorten the reliability of pipelines. Thus, the investigation of MIC species’ development and metabolic activities is significant. An experiment was performed on sulfate-reducing bacteria (SRB) that practiced the medium as the substance to grow. Desulfovibrio vulgaris, a strain of SRB, was cultured in a postgate C medium to measure the bacteria survival using two different measurement methods. The medium was modified to pH 7.5 at 37°C and placed in anaerobic vials. During 24 hours of incubation, samples were retrieved, and the value of turbidity and cell numbers was measured. Based on the SRB growth graph pattern, the amount of bacteria cell numbers was increased parallel to the value of the medium’s turbi...
Corrosion is a natural deterioration phenomenon caused by reactions of metals with their environm... more Corrosion is a natural deterioration phenomenon caused by reactions of metals with their environment. It is also a natural spontaneous process with devastating impact towards the infrastructure (Norhazilan et al., 2011; Yahaya, 2011). There is huge challenge to mitigate this delicate phenomenon albeit the fact that it cannot be simply eliminated altogether from the deteriorating infrastructure, although with careful steps, it can be well controlled. This process has enormous financial and safety implications for many industries, including the energy industry. According to NACE International, corrosion is the deterioration of a substance or its properties as a result of an undesirable reaction with the environment (NACE, 2000). It occurs immediately when pure metals or their alloys are exposed to water. There are four components of corrosion in general: anode (defined as the oxidation reaction where corrosion takes place); a half-reaction reduction called cathode; electrolytes such a...
Corrosion is a natural deterioration phenomenon caused by reactions of metals with their environm... more Corrosion is a natural deterioration phenomenon caused by reactions of metals with their environment. It is also a natural spontaneous process with devastating impact towards the infrastructure (Norhazilan et al., 2011; Yahaya, 2011). There is huge challenge to mitigate this delicate phenomenon albeit the fact that it cannot be simply eliminated altogether from the deteriorating infrastructure, although with careful steps, it can be well controlled. This process has enormous financial and safety implications for many industries, including the energy industry. According to NACE International, corrosion is the deterioration of a substance or its properties as a result of an undesirable reaction with the environment (NACE, 2000). It occurs immediately when pure metals or their alloys are exposed to water. There are four components of corrosion in general: anode (defined as the oxidation reaction where corrosion takes place); a half-reaction reduction called cathode; electrolytes such a...
International Journal of Biological Chemistry, 2015
In oil and gas industry, corrosion due to activity of microorganism is one of the main factors, w... more In oil and gas industry, corrosion due to activity of microorganism is one of the main factors, which contribute to catastrophic structural failure. Previous study always linked Sulfate-Reducing Bacteria (SRB) upon the mechanism of Microbiologically Influenced Corrosion (MIC), as the major contributors. In this study, mechanisms of SRB genus D. vulgaris in terms of bacterial growth under influence of environmental factors were investigated. The growth of pure strain ATCC 7757 and SRB isolated from the soil in suspected areas in Peninsular Malaysia were investigated by using turbidity measurement. Results from the study were analyzed statistically to show the significant influence due to various environmental factors. The results agreed that variation of each environmental parameter tested gives strong influence upon bacterial growth for SRB strain individually.
The term of microbiologically influenced corrosion (MIC) was used to designate corrosion due to t... more The term of microbiologically influenced corrosion (MIC) was used to designate corrosion due to the presence and activities of microorganisms, for example those organisms that cannot be seen individually with the unaided human eye, including microalgae, archaea, bacteria, and fungi. The presence of sulphate-reducing bacteria (SRB) is one of the MIC phenomenon and gives great concern to oil and gas industries. Biocides treatments and cathodic protection are commonly used to control the problem. Nevertheless, the solution is too expensive and may create environmental problems by being too corrosive. Ultraviolet is one of benign techniques to enhance the mitigation of MIC risk in pipeline system. An amount of 100 ml of Baar's medium and 5 ml of Desulfovibrio Vulgaris (strain7577) seeds was grown in 125 ml anaerobic vials with carbon steel grade API X70 coupons at the optimum temperature of 37°C and pH 9.5 for twenty two days followed by exposure to ultraviolet for one hour. Results...
Desulfovibrio Vulgaris, a species of Sulphate Reducing Bacteria (SRB) that are mostly found livin... more Desulfovibrio Vulgaris, a species of Sulphate Reducing Bacteria (SRB) that are mostly found living in the absence of oxygen or namely anaerobic condition is an imminent threat to pipeline long-term integrity. Pipeline infrastructure may experience severe metal loss due to corrosion induced by the species and can potentially lead to catastrophic failure. Desulfovibrio Vulgaris (ATCC7757) was cultured in broth number 1249 (Modified Barr's Medium) to study the effect of bacteria growth upon metal loss. The medium was modified to pH 7.0 at 37°C. Carbon steel coupons grade X70 were cut to approximately 10mmx20mmx5mm and kept in anaerobic vials. After 28 days of incubation, samples were retrieved to determine the weight loss of the carbon steel. Based on the weight loss graph pattern, the amount of weight loss significantly depends on the exposure time to the bacteria. The weight lost dramatically increases from day-1 to day-28 to signify the common pattern of corrosion induced by SRB.
Sulphate-reducing bacteria (SRB) represent themselves as a class of anaerobic bacteria that can r... more Sulphate-reducing bacteria (SRB) represent themselves as a class of anaerobic bacteria that can reduce sulphate to sulphide for obtaining energy. This paper is aimed to detect sulphatereducing bacteria activities using rapid detectable culture media. Two different strains of sulphate-reducing bacteria were used in this study, namely ATCC 7757 and local bacterial strain of SRB isolated from underground sample. Both strains were tested on three recommended culture media of modified Baar"s, Postgate B and Postgate C. All three medium contained lactic acid which served to be as carbon source. The results showed that modified Baar"s medium is the best medium for the growth of ATCC 7757 while Postgate C medium is recommended for the local SRB bacterial strain.
Desalination and Water Treatment, 2013
Microbiologically influenced corrosion (MIC) is caused by the presence of sulfate-reducing bacter... more Microbiologically influenced corrosion (MIC) is caused by the presence of sulfate-reducing bacteria (SRB) and is of great concern to the heavy metal industries. Inhibitors and biocides are commonly used to control the problem. Nevertheless, the solutions are too expensive and may create environmental problems by being corrosive to metals. Ultrasound wave exposure is one of the potential alternatives to biocides for the mitigation of MIC risk in pipeline system. In this work, a combination of ultrasound wave and green biocides of glutaraldehyde and ethanol has been proposed to exterminate SRB in a medium. An amount of 100 ml of Desulfovibrio vulgaris (ATCC7757) broth number 1249 was grown in 125 ml anaerobic vials at 37˚C for one day followed by exposure to various mitigation methods. Results from the study show that a combination of ultrasound and biocide can effectively reduce the dosage of biocide during corrosion treatment. The effectiveness of mitigation based on ultrasound-biocide combination is better than the treatment based solely on biocide whereby the extermination of SRB was found 10 times more effective according to the reduction of cell numbers of planktonic's SRB. Ultrasound technique can provide a feasible alternative as an effective assist to chemical inhibitors and biocides for controlling MIC in a more eco-friendly manner.
Solid State Phenomena, 2015
This study investigates how sulfate-reducing bacteria (SRB) influence the process of microbiologi... more This study investigates how sulfate-reducing bacteria (SRB) influence the process of microbiologically induced corrosion (MIC) of carbon steel by measuring corrosion potential using open-circuit potential (OCP) measurements. MIC is mainly influenced by D. Vulgaris, formerly known as D. Desulfuricans, deposited as Spirillum Desulfuricans, which produces D(-)-lactate dehydrogenase. The manufactured strain ATCC 7757 and pure colony of SRB isolated from the Baram and Sg Ular areas in Malaysia were used in this experiment. An evaluation of SRB growth was performed during the test in the inoculated medium anaerobically at 37°C with pH 7.5. The results showed that the corrosion potential E oc in manufactured ATCC was the highest as compared to the SRB isolated from site. These results indicated that ATCC could be the reference to predict the metal corrosion due to high corrosive product of H 2 S generated during metabolic activity.
Journal of Biological Sciences, 2014
Oil and gas pipelines system often fail due to Microbial Induce Corrosion (MIC). During this cent... more Oil and gas pipelines system often fail due to Microbial Induce Corrosion (MIC). During this century, chemical biocide is one of the common treatments to combat MIC. However, this method is costly and further usage of chemical biocides may cause serious environment pollution. In attempt to disinfect Desulfovibrio Vulgaris, a species of Microbial Induce Corrosion (MIC) from oil and gas pipelines, ultraviolet wave is used as a potential alternative method.
This study defines the interrelationship between turbidities and cell number counting efficiency ... more This study defines the interrelationship between turbidities and cell number counting efficiency for the growth of one of the microbiologically influenced corrosion (MIC) species in a medium. The metabolism activities during bacteria growth can accelerate the corrosion process and shorten the reliability of pipelines. Thus, the investigation of MIC species’ development and metabolic activities is significant. An experiment was performed on sulfate-reducing bacteria (SRB) that practiced the medium as the substance to grow. Desulfovibrio vulgaris, a strain of SRB, was cultured in a postgate C medium to measure the bacteria survival using two different measurement methods. The medium was modified to pH 7.5 at 37°C and placed in anaerobic vials. During 24 hours of incubation, samples were retrieved, and the value of turbidity and cell numbers was measured. Based on the SRB growth graph pattern, the amount of bacteria cell numbers was increased parallel to the value of the medium’s turbidity in respect to time. Both values (turbidity and bacteria cell numbers) dramatically increased from hour1 to hour24. The results supported that the turbidity value was positively correlated with bacteria cell numbers.
journal of engineering science and technology, 2016
Microbiologically influenced corrosion (MIC) is significant to the presence of microorganisms suc... more Microbiologically influenced corrosion (MIC) is significant to the presence of microorganisms such as sulfate reducing bacteria (SRB) in the deterioration of metallic and non-metallic materials. Bacterial chemical biocides are commonly used to disinfect microorganism effectively. Yet, the practice has some negative impact on the environment since the chemical content may cause pollution. A laboratory experimental investigation was conducted to explore the performance of Ultraviolet (UV) radiation in exterminating SRB as an option to replace biocides usage. The morphologies of the isolated Sg. Ular SRB used in this study were related to Desulfovibrio species. An experimental work was conducted in determining the optimum pH and temperature for the SRB to grow before disinfection purposes. The experimental result showed optimum growth for respective SRB were at pH of 8.5 with temperature recorded at 37°C. UV radiation with wavelength of 254 nm was utilised to disinfect the microorganis...
ARPN journal of engineering and applied sciences, 2016
Carbon steels are commonly used as structural materials of piping systems in oil and gas industry... more Carbon steels are commonly used as structural materials of piping systems in oil and gas industry because of their lower cost and wider availability despite their relatively lower corrosion resistance. This work investigates the preferable growth media for Sulfate Reducing Bacteria to proliferate rapidly and the effect of Microbiologically Influenced Corrosion activity towards carbon steel API 5L X-70 line pipe. Present research work highlighted that the preferred growth medium for ATCC 7757 and BARAM is Modified Baar's and Postgate C for Sg. Ular types of SRB. In addition, the corrosion rate was calculated using data based on metal weight loss experiment. The result confirmed that the corrosion rate in biotic (presence of Sulfate Reducing Bacteria) environment is much higher compared to abiotic environment (absence of Sulfate Reducing Bacteria). The pitting morphology that developed with time due to SRB activity was characterized with Field Emission Scanning Electron Microscopy...
Sulphate-reducing bacteria (SRB) represent themselves as a class of anaerobic bacteria that can r... more Sulphate-reducing bacteria (SRB) represent themselves as a class of anaerobic bacteria that can reduce sulphate to sulphide for obtaining energy. This paper is aimed to detect sulphatereducing bacteria activities using rapid detectable culture media. Two different strains of sulphate-reducing bacteria were used in this study, namely ATCC 7757 and local bacterial strain of SRB isolated from underground sample. Both strains were tested on three recommended culture media of modified Baar‟s, Postgate B and Postgate C. All three medium contained lactic acid which served to be as carbon source. The results showed that modified Baar‟s medium is the best medium for the growth of ATCC 7757 while Postgate C medium is recommended for the local SRB bacterial strain.
Sains Malaysiana, 2020
Microbiologically influenced corrosion (MIC) is capable on weakening the metal's strength, eventu... more Microbiologically influenced corrosion (MIC) is capable on weakening the metal's strength, eventually leads to pipeline leakage, environmental hazard and financial loss. Sulfate reducing bacteria (SRB) is the principal causative organism responsible for external corrosion on steel structures. To date, considerable works have been conducted in Malaysia on the mechanisms of SRB upon MIC on the marine environment instead of underground. Moreover, commercial bacteria strain represents local strain in terms of performance and behavior upon corrosion of steel structure is yet to be proven. Thus, this paper aims to investigate the influence of environmental parameters towards MIC in corroding pipeline. Two types of SRB strain were used designated as SRB ATCC 7757 (commercial) and SRB Sg. Ular (local strain) isolated from Malaysian soil. The behavior of both strains was critically compared by calculating the rate of corrosion upon carbon steel coupons in stipulated environmental parameters. Four influential parameters i.e. pH, temperature, salinity concentration and iron concentration were considered. Collected data presented and analyzed using graphical and statistical analysis, respectively. The results showed the difference of corrosivity between two SRB strains in terms of corrosion behavior upon the X-70 steel coupon. SRB Sg. Ular able to cause severe effects upon steel structure as compared to SRB ATCC 7757 due to its aggressiveness shown by the recorded metal loss data. Thus, future works related to MIC for local environment in particular, should not compromise with the type of SRB strains considered due to differences of performance of the microorganisms onto tested environment and materials.
JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES, 2017
This research is aimed to give an overview of the impact of bio-corrosion on carbon steel grade A... more This research is aimed to give an overview of the impact of bio-corrosion on carbon steel grade API 5L X-70 immersed in growth medium and exposed to SRB consortium. Simulation of anaerobic corrosion conditions was carried out in a laboratory for 28 days. Raw crude oil gathered from the Baram Delta Operation Terminal was cultured in broth number 1249 (Modified Barr's Medium) to study the effect of bacteria growth upon metal loss. Carbon steel coupons grade X70 were cut to approximately 10mm x 20mm x 5mm and immersed in the cultured broth. During the experiment, the planktonic SRB were enumerated using a counting chamber (direct cell count method) under the electronic microscope at 200x magnification. Results indicated that the optimum pH and temperature for the respected SRB consortium genes were 8.5 and 37 °C, respectively. Metal loss of the corrosion specimen was measured and recorded after retrieval from the immersion period in the medium on a weekly basis prior to SRB inoculation for further analysis. The metal loss values supported that SRB activity can increase the metal loss of carbon steel against time of exposure. Additionally, the FESEM image showed the biofilm formations on the corrosion specimen. Thus, the results could conclude that biocorrosion caused by particular local SRB consortium can be considered as a threat to carbon steel pipelines. Besides, the effect of SRB activity and response towards metallic materials in a dynamic environment is an interesting topic to be studied upon in the future.
Environmental technology, Jan 14, 2016
Microbiologically influenced corrosion (MIC) is among the common corrosion types for buried and d... more Microbiologically influenced corrosion (MIC) is among the common corrosion types for buried and deep-water pipelines that result in costly repair and pipeline failure. Sulfate-reducing bacteria (SRB) are commonly known as the culprit of MIC. The aim of this work is to investigate the performance of combination of ultrasound (US) irradiation and ultraviolet (UV) radiation (known as Hybrid soliwave technique, HyST) at pilot scale to inactivate SRB. The influence of different reaction times with respect to US irradiation and UV radiation and synergistic effect toward SRB consortium was tested and discussed. In this research, the effect of HyST treatment toward SRB extermination and corrosion studies of carbon steel coupon upon SRB activity before and after the treatment were performed using weight loss method. The carbon steel coupons immersed in SRB sample were exposed to HyST treatment at different time of exposure. Additionally, Field Emission Scanning Electron Microscopy coupled wi...
Jurnal Teknologi, 2015
Pipelines play an extremely important role in the transportation of gases and liquids over long d... more Pipelines play an extremely important role in the transportation of gases and liquids over long distance throughout the world. Internal corrosion due to microbiologically influenced corrosion (MIC) is one of the major integrity problems in oil and gas industry and is responsible for most of the internal corrosion in transportation pipelines. The presence of microorganisms such as sulfate reducing bacteria (SRB) in pipeline system has raised deep concern within the oil and gas industry. Biocide treatment and cathodic protection are commonly used to control MIC. However, the solution is too expensive and may create environmental problems by being too corrosive. Recently, Ultraviolet (UV) as one of the benign techniques to enhance mitigation of MIC risk in pipeline system has gained interest among researchers. An amount of 100 ml of modified Baar’s medium and 5 ml of Desulfovibrio vulgaris (strain 7577) seeds was grown in 125 ml anaerobic vials with carbon steel grade API 5L-X70 coupon...
Solid State Phenomena, 2015
This study defines the interrelationship between turbidities and cell number counting efficiency ... more This study defines the interrelationship between turbidities and cell number counting efficiency for the growth of one of the microbiologically influenced corrosion (MIC) species in a medium. The metabolism activities during bacteria growth can accelerate the corrosion process and shorten the reliability of pipelines. Thus, the investigation of MIC species’ development and metabolic activities is significant. An experiment was performed on sulfate-reducing bacteria (SRB) that practiced the medium as the substance to grow. Desulfovibrio vulgaris, a strain of SRB, was cultured in a postgate C medium to measure the bacteria survival using two different measurement methods. The medium was modified to pH 7.5 at 37°C and placed in anaerobic vials. During 24 hours of incubation, samples were retrieved, and the value of turbidity and cell numbers was measured. Based on the SRB growth graph pattern, the amount of bacteria cell numbers was increased parallel to the value of the medium’s turbi...
Corrosion is a natural deterioration phenomenon caused by reactions of metals with their environm... more Corrosion is a natural deterioration phenomenon caused by reactions of metals with their environment. It is also a natural spontaneous process with devastating impact towards the infrastructure (Norhazilan et al., 2011; Yahaya, 2011). There is huge challenge to mitigate this delicate phenomenon albeit the fact that it cannot be simply eliminated altogether from the deteriorating infrastructure, although with careful steps, it can be well controlled. This process has enormous financial and safety implications for many industries, including the energy industry. According to NACE International, corrosion is the deterioration of a substance or its properties as a result of an undesirable reaction with the environment (NACE, 2000). It occurs immediately when pure metals or their alloys are exposed to water. There are four components of corrosion in general: anode (defined as the oxidation reaction where corrosion takes place); a half-reaction reduction called cathode; electrolytes such a...
Corrosion is a natural deterioration phenomenon caused by reactions of metals with their environm... more Corrosion is a natural deterioration phenomenon caused by reactions of metals with their environment. It is also a natural spontaneous process with devastating impact towards the infrastructure (Norhazilan et al., 2011; Yahaya, 2011). There is huge challenge to mitigate this delicate phenomenon albeit the fact that it cannot be simply eliminated altogether from the deteriorating infrastructure, although with careful steps, it can be well controlled. This process has enormous financial and safety implications for many industries, including the energy industry. According to NACE International, corrosion is the deterioration of a substance or its properties as a result of an undesirable reaction with the environment (NACE, 2000). It occurs immediately when pure metals or their alloys are exposed to water. There are four components of corrosion in general: anode (defined as the oxidation reaction where corrosion takes place); a half-reaction reduction called cathode; electrolytes such a...
International Journal of Biological Chemistry, 2015
In oil and gas industry, corrosion due to activity of microorganism is one of the main factors, w... more In oil and gas industry, corrosion due to activity of microorganism is one of the main factors, which contribute to catastrophic structural failure. Previous study always linked Sulfate-Reducing Bacteria (SRB) upon the mechanism of Microbiologically Influenced Corrosion (MIC), as the major contributors. In this study, mechanisms of SRB genus D. vulgaris in terms of bacterial growth under influence of environmental factors were investigated. The growth of pure strain ATCC 7757 and SRB isolated from the soil in suspected areas in Peninsular Malaysia were investigated by using turbidity measurement. Results from the study were analyzed statistically to show the significant influence due to various environmental factors. The results agreed that variation of each environmental parameter tested gives strong influence upon bacterial growth for SRB strain individually.
The term of microbiologically influenced corrosion (MIC) was used to designate corrosion due to t... more The term of microbiologically influenced corrosion (MIC) was used to designate corrosion due to the presence and activities of microorganisms, for example those organisms that cannot be seen individually with the unaided human eye, including microalgae, archaea, bacteria, and fungi. The presence of sulphate-reducing bacteria (SRB) is one of the MIC phenomenon and gives great concern to oil and gas industries. Biocides treatments and cathodic protection are commonly used to control the problem. Nevertheless, the solution is too expensive and may create environmental problems by being too corrosive. Ultraviolet is one of benign techniques to enhance the mitigation of MIC risk in pipeline system. An amount of 100 ml of Baar's medium and 5 ml of Desulfovibrio Vulgaris (strain7577) seeds was grown in 125 ml anaerobic vials with carbon steel grade API X70 coupons at the optimum temperature of 37°C and pH 9.5 for twenty two days followed by exposure to ultraviolet for one hour. Results...
Desulfovibrio Vulgaris, a species of Sulphate Reducing Bacteria (SRB) that are mostly found livin... more Desulfovibrio Vulgaris, a species of Sulphate Reducing Bacteria (SRB) that are mostly found living in the absence of oxygen or namely anaerobic condition is an imminent threat to pipeline long-term integrity. Pipeline infrastructure may experience severe metal loss due to corrosion induced by the species and can potentially lead to catastrophic failure. Desulfovibrio Vulgaris (ATCC7757) was cultured in broth number 1249 (Modified Barr's Medium) to study the effect of bacteria growth upon metal loss. The medium was modified to pH 7.0 at 37°C. Carbon steel coupons grade X70 were cut to approximately 10mmx20mmx5mm and kept in anaerobic vials. After 28 days of incubation, samples were retrieved to determine the weight loss of the carbon steel. Based on the weight loss graph pattern, the amount of weight loss significantly depends on the exposure time to the bacteria. The weight lost dramatically increases from day-1 to day-28 to signify the common pattern of corrosion induced by SRB.
Sulphate-reducing bacteria (SRB) represent themselves as a class of anaerobic bacteria that can r... more Sulphate-reducing bacteria (SRB) represent themselves as a class of anaerobic bacteria that can reduce sulphate to sulphide for obtaining energy. This paper is aimed to detect sulphatereducing bacteria activities using rapid detectable culture media. Two different strains of sulphate-reducing bacteria were used in this study, namely ATCC 7757 and local bacterial strain of SRB isolated from underground sample. Both strains were tested on three recommended culture media of modified Baar"s, Postgate B and Postgate C. All three medium contained lactic acid which served to be as carbon source. The results showed that modified Baar"s medium is the best medium for the growth of ATCC 7757 while Postgate C medium is recommended for the local SRB bacterial strain.
Desalination and Water Treatment, 2013
Microbiologically influenced corrosion (MIC) is caused by the presence of sulfate-reducing bacter... more Microbiologically influenced corrosion (MIC) is caused by the presence of sulfate-reducing bacteria (SRB) and is of great concern to the heavy metal industries. Inhibitors and biocides are commonly used to control the problem. Nevertheless, the solutions are too expensive and may create environmental problems by being corrosive to metals. Ultrasound wave exposure is one of the potential alternatives to biocides for the mitigation of MIC risk in pipeline system. In this work, a combination of ultrasound wave and green biocides of glutaraldehyde and ethanol has been proposed to exterminate SRB in a medium. An amount of 100 ml of Desulfovibrio vulgaris (ATCC7757) broth number 1249 was grown in 125 ml anaerobic vials at 37˚C for one day followed by exposure to various mitigation methods. Results from the study show that a combination of ultrasound and biocide can effectively reduce the dosage of biocide during corrosion treatment. The effectiveness of mitigation based on ultrasound-biocide combination is better than the treatment based solely on biocide whereby the extermination of SRB was found 10 times more effective according to the reduction of cell numbers of planktonic's SRB. Ultrasound technique can provide a feasible alternative as an effective assist to chemical inhibitors and biocides for controlling MIC in a more eco-friendly manner.
Solid State Phenomena, 2015
This study investigates how sulfate-reducing bacteria (SRB) influence the process of microbiologi... more This study investigates how sulfate-reducing bacteria (SRB) influence the process of microbiologically induced corrosion (MIC) of carbon steel by measuring corrosion potential using open-circuit potential (OCP) measurements. MIC is mainly influenced by D. Vulgaris, formerly known as D. Desulfuricans, deposited as Spirillum Desulfuricans, which produces D(-)-lactate dehydrogenase. The manufactured strain ATCC 7757 and pure colony of SRB isolated from the Baram and Sg Ular areas in Malaysia were used in this experiment. An evaluation of SRB growth was performed during the test in the inoculated medium anaerobically at 37°C with pH 7.5. The results showed that the corrosion potential E oc in manufactured ATCC was the highest as compared to the SRB isolated from site. These results indicated that ATCC could be the reference to predict the metal corrosion due to high corrosive product of H 2 S generated during metabolic activity.
Journal of Biological Sciences, 2014
Oil and gas pipelines system often fail due to Microbial Induce Corrosion (MIC). During this cent... more Oil and gas pipelines system often fail due to Microbial Induce Corrosion (MIC). During this century, chemical biocide is one of the common treatments to combat MIC. However, this method is costly and further usage of chemical biocides may cause serious environment pollution. In attempt to disinfect Desulfovibrio Vulgaris, a species of Microbial Induce Corrosion (MIC) from oil and gas pipelines, ultraviolet wave is used as a potential alternative method.
This study defines the interrelationship between turbidities and cell number counting efficiency ... more This study defines the interrelationship between turbidities and cell number counting efficiency for the growth of one of the microbiologically influenced corrosion (MIC) species in a medium. The metabolism activities during bacteria growth can accelerate the corrosion process and shorten the reliability of pipelines. Thus, the investigation of MIC species’ development and metabolic activities is significant. An experiment was performed on sulfate-reducing bacteria (SRB) that practiced the medium as the substance to grow. Desulfovibrio vulgaris, a strain of SRB, was cultured in a postgate C medium to measure the bacteria survival using two different measurement methods. The medium was modified to pH 7.5 at 37°C and placed in anaerobic vials. During 24 hours of incubation, samples were retrieved, and the value of turbidity and cell numbers was measured. Based on the SRB growth graph pattern, the amount of bacteria cell numbers was increased parallel to the value of the medium’s turbidity in respect to time. Both values (turbidity and bacteria cell numbers) dramatically increased from hour1 to hour24. The results supported that the turbidity value was positively correlated with bacteria cell numbers.