Search or add a thesis

Advanced Search (Beta)
Home > Isolation and Characterization of Coal Solubilizing Microorganisms

Isolation and Characterization of Coal Solubilizing Microorganisms

Thesis Info

Access Option

External Link

Author

Malik, Aneela Younas

Program

PhD

Institute

Quaid-I-Azam University

City

Islamabad

Province

Islamabad.

Country

Pakistan

Thesis Completing Year

2018

Thesis Completion Status

Completed

Subject

Microbiology

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/11257/1/Aneela_Younas_Malik_Microbiology_2018_QAU_PRR.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726530494

Asian Research Index Whatsapp Chanel
Asian Research Index Whatsapp Chanel

Join our Whatsapp Channel to get regular updates.

Similar


Microbial solubilization of coal has been considered as a promising technology to convert raw coal into valuable products. The biological conversion of coal to alternative fuel products can be an efficient and environmentally friendly mean of utilizing the current coal reserves, including those that are difficult to utilize with conventional methods. Understanding the details of microbial coal solubilization leading up to methanogenesis is essential in order to establish new energy production techniques and industrial processes that are cost and energy efficient. The present study was aimed at investigating and exploring the prospects of possible intervention of biotechnological approaches into conventional fuel sciences for the extraction of alternative fuel options like methane. In this regard, seven coal samples, originating from different coal areas of Pakistan, were subjected to detailed chemical analyses including maceral analysis and these indicated that samples belonging to different coal ranks with vitrinite value ranging from 0.27% to 2.13% pointing towards their diverse geological history. To study coal solubilizing potential of aerobic microorganisms, initially a total of 50 different aerobic bacterial and fungal isolates have been isolated from soil, coal and water samples of Salt Range Coal Mines, Chakwal, Pakistan, but on the basis of solubilization potential, only four isolates selected for further study. The intensity of biosolubilization was measured by determining the weight loss of the coal pieces and was observed to be about 25.93% by Pseudomonas sp. AY2, 36.36% by Bacillus sp. AY3 and 50% by Trichoderma sp. AY6 while Phanerochaete sp. AY5 showed maximum coal solubilization potential, i.e. 66.67% in 30 days. Ultraviolet Visible spectrum revealed an increase in the pattern of absorbance of all treated samples as compared to control referring to solubilization. Fourier transform infrared spectroscopy indicated alterations in structure of treated coal in comparison to control coal suggesting breakdown in complex structure of coal. The major absorbance bands in infrared spectroscopy for solubilization product were attributed to carbonyl (1600cm-1), hydroxyl (3450cm-1), cyclane (2925cm-1), ether linkage (1000-1300cm-1), carboxyl (3300-2500cm-1) and side chains of aromatic ring (1000-500cm-1). The presence of microorganisms and surface erosion of coal residues as compared to control samples were observed by scanning electron microscopy, suggested that isolated microorganisms were able to survive in coal for a longer period of time. Therefore, these microorganisms isolated from coal mines have excellent potential for coal solubilization which is considered as a crucial step in coal methanogenesis allowing them to be used successfully for in-situ methane production to meet future energy demands. Coal samples were investigated further for their ability to support microbial methane production in laboratory incubations. For this purpose, bioassay with two different exogenous microorganisms WBC2 (collected from wetlands), and IF (from PRB) were employed. Among all samples, CH sample which is low volatile bituminous coal produced maximum methane 34.9 µmol CH4/g coal with WBC2 consortium, followed by SR (subbituminous coal) with 30.18 µmol CH4/g.Relatively lower methane level was observed with IF consortium, however, maximum concentration observed in case of SR coal was 25.1 µmol CH4/g coal. Acetate accumulated in control incubations where methanogenesis was inhibited, pointing towards acetoclastic pathway and indicated acetate utilization and production during the course of methanogenesis. Methanogenesis inhibited control and bioassay incubations showed nearly same levels of hydrogen, proposed that acetoclastic might be the dominant pathway for methanogenesis. Carbon dioxide and carbon monoxide was produced and consumed during the course of methane production, suggesting their role in complex methanogenic pathway chemistry. Liquid extracts were analyzed through Excitation-Emission Matrix Spectroscopy (EEMS) to obtain qualitative estimates of solubilized coal; these analyses exhibited the release of complex organic moieties. Quantative Polymerase chain reaction analysis for mcrA functional genes suggested microbial quality as well as quantity have significant influence on methane production levels. Therefore, bioassay, suggests an attractive tool for assessing the potential of coal for biogenic methane generation, and provides a platform for studying the mechanisms involved in this economically important activity. Conclusively, the current evidence of Pakistan’s coal potential to be used for cost effective and energy efficient processes particularly the low volatile bituminous coal, would open numerous advantages to the current coal energy infrastructure.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

رام بابو سکسینہ

رام بابو سکسینہ
افسوس ہے دسمبر کے آخری ہفتہ میں جناب رام بابو سکسینہ کاحرکت قلب بند ہوجانے سے بحالت سفر اچانک انتقال ہوگیا۔ موصوف کو اردو زبان وادب کے ساتھ عشق تھااوروہ اس کا بڑا وسیع اورگہرا مطالعہ رکھتے تھے۔یہی وجہ ہے کہ ایک ذمہ دار سرکاری عہدہ کی چند درچند مصروفیتوں کے باوجود انھوں نے ادبِ اردو پرمتعدد ضخیم کتابیں اپنی یادگار چھوڑی ہیں۔ ان کی کتاب ’تاریخ ادبِ اردو‘ کو بڑی مقبولیت حاصل ہوئی، اس موضوع پر یہ کتاب اس پایہ کی ہے کہ ادبِ اردو کاکوئی طالب علم اس سے بے نیاز نہیں ہوسکتا۔اس کے علاوہ’’اردو کے انگریز شعرا‘‘ نامی کتاب انھوں نے بڑی تلاش وجستجواورمحنت سے مرتب کی تھی۔ایک کتاب حال میں ہی’’مرقع شعراء‘‘کے نام سے شائع ہوئی ہے۔سنا ہے کہ دو کتابوں کے مسودے ابھی اورباقی ہیں جو غیر مطبوعہ ہیں،موصوف اب دنیا میں نہیں لیکن اُن کے یہ شاندار ادبی کارنامے اُن کانام زندہ رکھیں گے۔
[جنوری۱۹۵۸ء]

 

Negative Wash-Back of Formative Assessment to Learning in Saudi Higher Education Context

This article reports the wash-back of formative assessment on what students learn, how they learn and the depth of their learning in Saudi higher education context. Previous research indicates that assessment methods affect different aspects of learning either positively or negatively depending on the nature of assessment tasks. Observations indicate a clear association between Saudi students’ learning and how their learning is assessed; so this research was needed to determine how exactly the correlation looked like—positive or negative. The data in this study were collected from Saudi undergraduates by employing a student survey and semi-structured interviews. The survey included Likert scale items of agreement regarding research assignments, quizzes and midterm examinations administered to 250 English-major students. To validate the survey results, sixteen students from different levels with GPA 3 and above were interviewed. The results showed that formative assessment narrowed down the scope of learning materials. The students mostly adopted surface level learning strategies to prepare for formative assessment tasks. Higher order thinking skills were not tested in any of the formative assessment methods. Therefore, it is suggested that assessments tasks should be subjected to thorough validation and moderation. Sound assessment practices should be put in place and practiced judiciously. To achieve these objectives, sustained institutional and departmental professional backing is a prerequisite.

Optical Emission Spectroscopy of N2-H2-Natural Ch4 Mixture Plasmas Generated by Pulsed-Dc for Surface Hardening of Austenitic Stainless Steel

Nitrogen glow discharge plasma is generated by number of power sources and has many applications in material processing such as Nitriding of different metal alloys. The material processing efficiency of the plasma may be enhanced by optimizing the related parameters of the discharge. The concentration of the active nitrogen species in the plasma may depend on various operating conditions such as input power of the discharge, pressure and gas flow rate etc. In order to improve the various excitation and ionization processes occurring in the plasma for the generation of active species, one way is to mix some inert gas in the nitrogen plasma. In the present study the diagnostics of Pulsed-dc generated nitrogen-methane-hydrogen mixture plasma is carried out to analyze the optimum working conditions for its application. Spectroscopic measurements of hydrogen Balmer-β and Balmer-γ line profiles are performed in an abnormal glow region of Pulsed-dc sustained nitrogen-hydrogen- methane plasma for investigating dependencies of their line shapes and intensities on discharge parameters. The excitation temperature Te is determined from Ar-I emission line intensities by using Boltzmann’s plot method of Balmer lines is found to be increased with methane mixing in nitrogen plasma. The electron density is extracted from Stark broadening (FWHM) of the Hβ emission profile. It is found that both the emission intensity and the broadening of the Balmer-β and Balmer-γ lines show significant dependence on the filling pressure in the same manner. However, both the emission intensity and broadening of Hβ line exhibit weak dependence on input power in contrast to the Hγ emission line. The concentration of active species N 2 (C 3 P u ) + + and N 2 ( B 2 S u ) are monitored in terms of the emission intensities of nitrogen bands of the second positive and the first negative systems respectively. The concentration of N 2 (C 3 P u ) active species is appreciably enhanced by methane mixing signifying the role of argon meta-stables in the excitation and dissociation processes. The effect of mixing of methane-hydrogen is studied on the surface nitriding os AISI-304 stainless steel substrate at temperature of 500 0C generated by 50 Hz pulsing source at powers of 300 and 500 watt and filling pressure of 1, 3, 5 mbar at different treated times 1, 2, 3, 4 and 5 hours. The samples are then analyzed for plasma induced changes in their surface properties by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and Vicker’s micro hardness testing. The XRD pattern confirms the formation of expanded austenite phase (γN) resulted by the incorporation of nitrogen as interstitial solid solution in the iron lattice. The EDX spectra show peaks corresponding to elements that are present in the surface of the substrate. It can be noticed that no additional peak corresponding to any impurity element, other than nitrogen, which is supposed to be present owing to nitrogen incorporation in the iron lattice is found in EDX spectra. The effect of ion etching is apparent from the SEM micrograph, which is normally expected during the nitriding process. All the nitrided samples show an increase in surface hardness as compared to that of untreated one. It is revealed that the surface hardness increase significantly with increasing nitriding time. Based upon optical measurement reported here, plasma discharge parameters can be optimized for the production of active species, excitation temperature Te and number density.