Advanced Journal of Environmental Science and Technology

Advanced Journal of Environmental Science and Technology ISSN 2756-3251 Vol. 13 (7), pp.001-013,July, 2022. © International Scholars Journals

Review

Biodegradation alternative in the cleanup of petroleum hydrocarbon pollutants

Anthony I Okoh,

Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa. Email: [email protected]

Accepted 29 May, 2022

Abstract

Extensive petroleum hydrocarbon exploration activities often result in the pollution of the environment, which could lead to disastrous consequences for the biotic and abiotic components of the ecosystem if not restored. Remediation of petroleum-contaminated system could be achieved by either physicochemical or biological methods. However, the attendant negative consequences of the physicochemical approach are currently directing greater attention to the exploitation of the biological alternatives. This paper provides a review of the menace of petroleum hydrocarbon pollution and its biodegradation in the environment with the view of understanding the biodegradation processes for better exploitation in bioremediation challenges.

Key words: Petroleum hydrocarbon, pollution, environment and biodegradation.

Advanced Journal of Environmental Science and Technology ISSN 2756-3251 Vol. 13 (4), pp.001-006,April, 2022. © International Scholars Journals

Full Length Research Paper

Characterization and treatment of sludge from the petroleum industry

Asia, I. O.¹*, Enweani, I. B.² and Eguavoen I. O.¹

^{1 & 1*}Department of Chemistry, Ambrose Alli University, P. M. B. 14 Ekpoma, Edo State Nigeria.

²Department of Microbiology, Ambrose Alli University, P. M. B. 14 Ekpoma, Edo State Nigeria.

Accepted 10 March, 2022

Abstract

Samples of sludge from the petroleum industry were collected and characterized for their pollution characteristics. The solids concentration, pH, temperature, biochemical oxygen demand, chemical oxygen demand, dissolved oxygen, phosphate, nitrogen, conductivity, calcium, magnesium, sodium, potassium, iron, manganese, lead and chromium were determined. The analysis revealed that the mean value of total solids (TS) content, total suspended solids (TSS) and total volatile solids (TVS) were 1987, 1050 and 937 mg/l respectively. The dissolved oxygen (DO) content was 3.7 mg/l. The biological oxygen demand (BOD) and chemical oxygen demand (COD) were 518 and 1345 mg/l, respectively. The total nitrogen and phosphorus contents were 3.4 and 2.3 mg/l respectively. The total bacteria counts were 7.4 x 10⁸/100 ml. All these values exceed those of the standard as set by World Health Organisation (WHO) for potable water. This shows that the sludge has high pollution potentials and so need treatment before disposal. The COD:BOD ratio was 2.60 which indicated that the sludge can undergo biodegradation and suggests that biological method could be used in effecting treatment to the sludge. The high conductivity also indicated that the sludge can be treated by physicochemical method of coagulation and flocculation.

Key words: Petroleum sludge, pollution characteristics, eutrophication, biodegradation, aerobic treatment,physicochemical method.

Advanced Journal of Environmental Science and Technology ISSN 2756-3251 Vol. 13 (2), pp.001-005,February, 2022. © International Scholars Journals

Full Length Research Paper

Petroleum-hydrocarbon utilization by native bacterial population from a wastewater canal Southwest Nigeria

O. A. Ojo

Department of Microbiology, Lagos State University, Badagry Expressway, P.M.B 1087 Apapa, Lagos - Nigeria. E-mail: [email protected], Tel: 234-8055055478.

Accepted 28 January, 2022

Abstract

The application of a consortium of native bacterial species in bioremediation processes has long been desired in Nigeria because they would be cost effective and efficient in terms of acclimation time. Two Nigerian crude oils (Bonny light and Escravos blend) were exposed to the wastewater canal via oil impregnated membrane filters (0.45 µm diameter) for 21 days in a microcosm experiment. Bacterial petroleum-hydrocarbon utilizers were later harvested from both the millipore membrane filters and laboratory biodegradative studies. Some of the striking discoveries made were that pH fluctuations in the reaction flasks were due to microbial activities, microbial enzymes, presence of crude oil degradation metabolites such as organic acids, surfactants and aldehydes. More petroleum-hydrocarbon utilizers were detected at 0 to 15 cm depth than at 15 to30 cm. The petroleum sample with higher fractions of saturated hydrocarbon was biodegraded faster (Bonny light) than the ones with higher fractions of asphaltenes and aromatics (Escravos blend). Escravos blend had C-14 component undegraded after the 3-week oil explosure to the waste water. The physico-chemical properties of the freshwater ecosystem were determined and it supported previous conclusion on the latent self purification capability of the aquatic ecosystem inspite of frequent oil pollution incidents. The mean temperatures of the freshwater ecosystem were within the mesophilic range 27-29°C and the pH of the environment supported acidophilic bacterial consortium. Gas chromatographic profiles of the mineralization process of Bonny light and Escravos blend gave the conclusive evidence for the capability of the native bacterial population to mineralize petroleum hydrocarbons in wastewater, at optimum physico-chemical conditions in the habitat. Petroleum-hydrocarbon utilizers detected included Bacillus megaterium, Pseudomonas putida, Micrococcus luteus, Bacillus brevis, B. punilis and Enterobacter aerogenes.

Key words: Biodegradation, bioremediation, petroleum-hydrocarbon.

Advanced Journal of Environmental Science and Technology ISSN 2756-3251 Vol. 12 (6), pp.001-007, June, 2021. © International Scholars Journals

Full Length Research Paper

Studies on the effect of abattior and industrial effluents on the heavy metals and microbial quality of Aba river in Nigeria

O.U. EZERONYE* and A.O. UBALUA

Department of Biological Sciences, Michael Okpara University of Agriculture, Umudike P.M.B. 7267, Umuahia, Abia state, Nigeria.

Accepted 13 May, 2021

Abstract

Levels of lead, iron, zinc, copper, arsenic, cobalt, chromium, manganese, mercury and cadmium, as well as the microbial profile were determined in water samples from Aba River. Physico-chemical examinations revealed that manganese (0.03 mg/l), zinc (4.81 mg/l) and copper (0.19 mg/l) were below the maximum allowable levels set by the United States Environment Protection Agency (USEPA), while lead (0.064 mg/l), iron (0.81 mg/l), arsenic (0.1 mg/l) chromium (0.006 mg/l) and mercury (0.009 mg/l) were high but not significantly. The implication is that waste assimilation capacity of the river is high, a phenomenon attributable to dilution, sedimentation and depuration. Quantitative examinations of the microorganisms present revealed that as many as 2.05 x 10⁸ viable bacterial (cfu/ml) were present. The predominant bacterial forms include Staphylococcus species, Streptococcus faecalis, Escherichia coli, Salmonella species, Bacillus and Clostridium species implying that the abattoir wastes discharged into the river may have had a significant impact on the river ecosystem.

Key words: Waste assimilation, effluent, low level metals, pollution.

Advanced Journal of Environmental Science and Technology ISSN 2756-3251 Vol. 12 (4), pp.001-007, April, 2021. © International Scholars Journals

Review

Production of Polyhydroxyalkanoates, a bacterial biodegradable polymer

Ojumu, T.V.^1*, Yu, J.² and Solomon, B.O.³

¹Engineering Materials Development Institute, P.M.B 611, Akure, Nigeria.

²Hawaii Natural Energy Institute, University of Hawaii, Honolulu, HI 96822, USA

³Department of Chemical Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria.

Accepted 19 March 2021

Abstract

There has been considerable interest in the development and production of biodegradable polymer to solve the current problem of pollution caused by the continuous use of synthetic polymer of petroleum origin. Polyhydroxyalkanoates (PHAs) are known to be accumulated as intracellular inclusion in some bacteria. The materials properties exhibited by PHAs, ranging from stiff, brittle to rubber-like makes it a close substitute for the synthetic plastic. The high cost of PHAs production has restricted its applications. The possibility of producing this polymer commercially and at comparable cost has been the main focus in this area.

Key words: Polyhydroxyalkanoates, biodegradable polymer, bioplastic, poly(3-hydroxybutyrate), biosynthesis.

Advanced Journal of Environmental Science and Technology ISSN 2756-3251 Vol. 12 (3), pp.001-009, March, 2021. © International Scholars Journals

Full Length Research Paper

Episodic bioavailability of environmental mercury: implications for biotechnological control of mercury pollution

O. A. Ogunseitan

Laboratory for Molecular Ecology, Department of Environmental Analysis and Design, University of California, Irvine, CA 92697-7070. Tel: 949-824-6350, Fax: 949-824-2056 E-mail: [email protected]

Accepted 14 February 2002

Abstract

Perennial wildfires in Africa and other continents contribute an estimated 8 x 10⁵ kg of mercury to the global atmosphere with a residence time of approximately one year. This phenomenon changes the flux of biologically available mercury in natural microbial communities where enzymatic actions, including mercuric reductase and organomercurial lyase activities, underpin the biogeochemical cycling of mercury with repercussions for human exposure to toxic forms of the element. To elucidate the impact of episodic mercury bioavailability on the response of microbial communities, the expression of microbial proteins and nucleic acids in environmental strains of Pseudomonas species were evaluated under various concentrations of mercury ranging from 0 to 500 µM. Routine cultivation of Pseudomonas aeruginosa PU21 containing the 142.5 kb plasmid Rip64 in medium containing 100 µg of Hg⁺⁺/ml (500 µM) exhibited a prolonged lag phase survived by hyper-resistant cells able to grow in medium containing 200 µg of Hg⁺⁺/ml. Nucleic acid analyses showed a distinct mutation in the merA gene encoding for mercuric reductase activity in cells able to grow at elevated mercury concentrations. A similar mutation was detected in the merR locus which serves as the regulator of the mer operon. Mutations were not detected in merC which encodes for a hydrophobic membrane-associated protein implicated in active mercury transport. Protein profiles of cells grown with elevated mercury concentrations were associated with a stable increase in the production of specific polypeptides. In addition, the survival and genetic response of naturally-occurring mercury resistant bacteria inoculated into contaminated environmental samples were monitored in microcosm experiments over a 30 day period. The results suggest that sudden exposure to high concentrations of mercury either decimates the bacterial population or selects for hyper-resistant strains with high level of constitutive expression of active proteins, including mercuric reductase. Methyl mercury was observed to cause a higher level of induction for mercuric reductase than the specific substrate, inorganic mercury. The selection of hyper-resistant strains is potentially useful for biotechnological strategies to control the bioavailability of mercury, and thereby potentially reducing the re-uptake of mercury into vegetation in regions frequently subjected to wildfires.

Key words: Mercury pollution, wildfires, mercuric reductase, organomercurial lyase, proteomics, microorganisms, detoxification.