School of Physical Sciences

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Open Access
Adsorption and corrosion-inhibiting effect of dacryodis edulis extract on low-carbon-steel corrosion in acidic media
(Elsevier Inc, 2010-09-01) Oguzie, E. E.; Enenebeaku, C. K.; Akalezi, C. O.; Okoro, S. C.; Ayuk, A. A.; Ejike, E. N.
The inhibition of low-carbon-steel corrosion in 1 M HCl and 0.5 M H2SO4 by extracts of Dacryodis edulis (DE) was investigated using gravimetric and electrochemical techniques. DE extract was found to inhibit the uniform and localized corrosion of carbon steel in the acidic media, affecting both the cathodic and anodic partial reactions. The corrosion process was inhibited by adsorption of the extracted organic mat ter onto the steel surface in a concentration-dependent manner and involved both protonated and molec ular species. Molecular dynamics simulations were performed to illustrate the process of adsorption of some specific components of the extract
Open Access
Adsorption and corrosion-inhibiting effect of dacryodis edulis extract on low-carbon-steel corrosion in acidic media
(Elsevier Inc., 2010) Oguzie, E. E.; Enenebeaku, C. K.; Akalezi, C. O.; Okoro, S. C.; Ayuk, A. A.; Ejike, E. N.
The inhibition of low-carbon-steel corrosion in 1 M HCl and 0.5 M H2SO4 by extracts of Dacryodis edulis(DE) was investigated using gravimetric and electrochemical techniques. DE extract was found to inhibit the uniform and localized corrosion of carbon steel in the acidic media, affecting both the cathodic and anodic partial reactions. The corrosion process was inhibited by adsorption of the extracted organic mat ter onto the steel surface in a concentration-dependent manner and involved both protonated and molec ular species. Molecular dynamics simulations were performed to illustrate the process of adsorption of some specific components of the extract.
Open Access
Adsorptive removal of methylene blue from aqueous solution using agricultural waste: Equilibrium, kinetic and thermodynamic studies
(U. P., 2015) Enenebeaku, K. Conrad; Okorocha, J. Nnaemeka; Akalezi, O. Chris
The potential of raw corn cobs (RCC) powder, for the removal of methylene blue (MB) dye from aqueous solution was investigated. The adsorbent was characterized by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were studied to observe their effects in the dye adsorption process. The optimum conditions for the adsorption of MB onto the adsorbent (RCC) was found to be: contact time (30mins), pH (10.0) and temperature (343K) for an initial MB dye concentration of 100mg/l and adsorbent dose 1.0g. The experimental equilibrium adsorption data fitted best and well to the Freundlich and Halsey isotherm models. The maximum adsorption capacity was found to be 18.28mg/g. The kinetic data conformed to the pseudo-second-order kinetic model, suggesting that the rate limiting step may be chemisorptions. Adsorption mechanism was investigated with intra-particle diffusion model and it indicated that intra-particle diffusion was not the rate determining step. Thermodynamic quantities such as Gibbs free energy (∆G0), enthalpy (∆H0) andentropy (∆S0) were evaluated. The negative values of ∆G0 and the positive value of ∆H0 obtained indicated the spontaneous and endothermic nature of the adsorption process while the positive ∆S0 value obtained indicated increased randomness during the adsorption process.
Open Access
Ammonia variations in Owerri metropolis and ecological impact
(Conscientia Beam, 2020-04-15) Nnadozie, C. F.; Nkwoada, A. U.; Akagha, C. I.
Ammonia emissions inventory is rarely reported in Nigeria and when at high levels is toxic to animals including humans. It is instructive to evaluate the levels of ammonia in metropolitan area as a priority to promote a clearer understanding of its distribution and interaction. The study investigated the levels of ammonia in different parts of Owerri Metropolis and its ecological impact. Ambient atmospheric NH3 concentrations have been measured for Owerri metropolis, away from point sources, for a period of three consecutive months in 2018 calendar year. Measured lowest mean NH3 concentrations have been in August at 0.04633 mg/L, which exceeded the critical loads and occupation exposure limits. There has been no significant change in the spatial variation in NH3 concentrations between the months albeit different locations varied significantly. The ecosystems where lichens and bryophytes are key species within the studied area may be under threat from loss of biodiversity while levels of human exposure to NH3 are completely unacceptable and require reducing and controlling measures. Hence, excess ammonia will induce elevated nitrification and denitrification driving higher greenhouse gas emissions
Open Access
An experimental investigation of pristine barite adsorption on sodium oleate and sodium palmitate
(Science Publishing Group, 2018) Nwoko, Christopher Ikpe Amadi; Nkwoada, Amarachi Udoka; Okoji, Josephine,; Opah, Solomon
Characterization of the pristine barite mineral was established using a scanning electron microscope (SEM) and Fourier Transform Infra-Red (FTIR). Barite was applied for sodium oleate and sodium palmitate adsorption in aqueous solutions. Equilibrium adsorption data were fitted into two adsorption isotherms, three kinetic models and thermodynamic study. The concentration of the ion and pH in the solution proved to be a controlling factor in the adsorption process. Sodium oleate and sodium palmitate soaps adsorbed strongly onto the barite mineral at pH 9 and a temperature of 293k. They result was affected by the high bulk density and chemical resistance nature of barite indicated by successive increase in dosage amount. The effect of concentration and time typically gave a C-type adsorption isotherm. Adsorptive isotherm showed that sodium palmitate adsorption over natural barite was better described by the Langmuir adsorption isotherm while oleate desorption gave a good fitting with Freundlich isotherm. The adsorptive kinetics of sodium palmitate fitted well into pseudo 1st order and 2nd order kinetics. Intra particle diffusion was not the rate-determining step. Thermodynamic study showed a physiosorption that was exothermic. Hence the findings showed that pristine barite absorbs at optimum pH and temperature of 9 and 293k.
Open Access
Antibacterial activity and identification of metabolites from the semi-purified fraction of chrysophyllum albidum leaf (African Star Apple)
(U. P., 2020) Azih, Ifeanyi; Ijezie, Magnus; Ugariogu, Sylvester N.; Akalezi, Christogonus O.
The medicinal uses of natural products especially medicinal plants have increased tremendously due to the multidrug resistance of some microorganisms and due to the availability and affordability of these plants. This study was aimed at the identification of metabolites from the fractions of Chrysophyllum albidium and their antibacterial activity. The phytochemical analysis and antibacterial analysis were done using standard methods; Harborne and Agar-disc diffusion methods, respectively. The metabolite identification was done using infra-red (IR) and gas chromatography – mass spectrometry (GC-MS). The preliminary result of the antibacterbial screening showed that the neutral metabolite possessed the highest antibacterial activity and was then chosen for the IR and GC-MS study and purified using preparative thin layer chromatography. Various fractions were obtained from the chromatographic purification and in particular N3 fraction demonstrated the highest antibacterial activity against the test microbes with the zones of inhibition indicated against the test organism as follows: Streptococcus spp (18 mm), Staphylococcus aureus (20 mm), Salmonella typhi (25 mm), Escherichia coli (20 mm) and no inhibition zone against Enterobacter cloacae. The results confirm that the plant has some antibacterial activity.
Open Access
Antimicrobial analysis and structural elucidation of active compounds of nauclea latifolia stem extract (Pin Cushion Tree)
(Open Science, 2012-06-12) Ijoma, K. I.; Ajiwe, V. I. E.; Alisa, C. O.
Antimicrobial analysis and structural elucidation were carried out on the purified stem extract of Nauclea latifolia. The Harbone method was used for the extraction. The extracts were separated using a combination of column chromatography and thin layer chromatography, which gave rise to the isolation of two fractions; these fractions were further purified using recrystallization. The melting point of each pure fraction was determined. The purified extracts were subjected to structural elucidation using various spectroscopic techniques which include; FTIR, UV, H1 NMR, C13 NMR, DEPT1350, COSY, TOCSY, HMBC and HSQC. The spectral analysis suggested the presence of Myristic acid and Palmitoleic acid. The antimicrobial analysis (anti fungal and anti bacterial analysis) using the punched agar diffusion method was carried out on the isolated fractions comparatively with a standard drug Funbact-A cream (a broad spectrum antibiotic). A total of thirteen test organisms were used for this analysis amongst which were ten bacteria test organism and three fungi test organisms. The results from the average diameter zones of inhibition, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentrations (MFC) showed that all the fractions were all active on the entire test organism with zones of inhibition ranging from 10mm-26mm comparatively. None of these fractions showed similar anti microbial effect as the standard drug Funbact-A cream but individually could serve as antimicrobial to diseases caused by these test organisms from their MIC, MBC and MFC
Open Access
Antioxidant activity and phenolic content of Okoubaka aubrevillei (Anunuebe) fruit pychnobotrya nitida (Osu) leaf extracts
(David Publishing, 2022) Alisa, Christopher O.; Okoye, Edith N.; Okeke, Peter C.; Anyadogh-Nwadike, Sylvia O.; Agwaramgbo, Lovell; Doyle, Jailen
The antioxidant activity and the total phenolic content of Okoubaka aubrevillei (Anunuebe) and Pychnobotrya nitida (Osu) plant extracts were investigated in this study to justify their ethno medicinal importance. The antioxidant activity of crude extracts of both plants was investigated using the scavenging effect on DPPH (2, 2-Diphenyl-1-Picrylhydrazyl Radical) assay, while the total phenolic content was determined by the Folin-Ciocalteu reagent method. When compared to standard drug vitamin C at various concentrations, both extracts exhibited potent antioxidant activity that increased with increasing concentration of extracts. The high positive linear correlation between the antioxidant capacity and the total phenolic content suggests that the antioxidant capacity of both plants can be largely attributed to their phenolic compounds. Based on these findings, O. aubrevillei fruit and P. nitida leaf could be potential natural antioxidant sources for preventing free radical-induced diseases.
Open Access
Application of aqueous extracts of coffee senna for control of mild steel corrosion in acidic environments
(Springer, 2012-07-16) Akalezi, Chris O.; Enenebaku, Conrad K.; Oguzie, Emeka E.
Background: The inhibitive effect of the aqueous extract of Coffee senna (CS) on the corrosion of mild steel in 1 MHCl and 0.5 M H2SO4 solutions was investigated by weight loss measurement as well as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. Result: The extract was found to efficiently inhibit the corrosion process in both environments and inhibition efficiency increased with extract concentration as well as rise in temperature. Data from electrochemical measurements suggest that the extract functioned by adsorption of the organic matter on the metal/corrodent interface, inhibiting both the anodic and cathodic half reactions of the corrosion process. Adsorption of the extract organic matter was approximated by the Langmuir isotherm. The adsorption behavior of selected organicconstituents of the extract on the metal surface was assessed at the molecular level, in the framework of the density functional theory. Conclusion: This study clearly shows the potentials of CS extract for control of mild steel corrosion in acidic environment.
Open Access
Application of geographic information system (GIS) in composite land capability index mapping of a developing country (A case study of Enugu area, South -Eastern, Nigeria,
(U. P., 2011) Onunkwo, A. A.; Ibeneme, S. I.; Onyekuru, S. O.; Uzoije, A. P.
Enugu, the area under study is experiencing a high rate of population growth. Problems of housing, on employment, waste disposals and the general lowering of standard of living are always associated with over population. It has therefore become necessary to map out areas of residential, industrial and waste disposal land use for future utilization. Land capability index mapping using geographic information system(GIS) is one of the appropriate tools for solving these impending problems. Land capability index mapping of Enugu environs in composite form has been undertaken using Arc view 3.2 academic, excel statistical software and GIS Authcard software. A total of 12 land use determinants have been selected as the thematic data layers and the basic factors influencing the choice of waste, residential and industrial land use. These themes which are in map form are slope, water table, surface and subsurface water conditions, elevation, geology, soil, drainage and geo-structural stability(fault, erosion, landslide and flooding). These maps have been scanned, geo-referenced , digitized and polygonized using authcard drawing capacities to convert them to vector formats and later exported to arc view software environment for analysis. The thematic layers were weighted using the criteria obtained from fieldwork, laboratory and literature surveys. The thematic layers were further subjected to overlays using the arcview software overlay model builder. The operation yields layers showing areas of preferred waste disposal, residential and industrial landuse options in a map form. Three different maps of land use options(waste, industrial and residence) were produced. Areas of varying suitability were isolated, 3 each for waste, residence and industry, indicating suitable, low suitability and unsuitable areas respectively. The three land use maps were superimposed to obtain a single one appropriate for purposes of urban environmental planning.
Open Access
Attenuation kinetics and desorption performance of artocarpus altilis seed husk for Co (II), Pb (II) and Zn (II) Ions
(U. P., 2018) Akpomie, Kovo Godfrey; Eluke, Linda Obiageli; Ajiwe, Vincent Ishmael Egbulefu; Alisa, Christopher Onyemeziri
The potential of Bread Fruit (artocarpus altilis) Seed Husk (BFSH) as low cost biosorbent for the removal of Pb (II), Zn (II) and Co (II) ions from aqueous solution was investigated. The adsorbent was characterized by the Fourier Transform InfraRed (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). Batch methodology was utilized to determine the effect of pH, metal ion concentration, adsorbent dose, contact time and temperature on biosorption. Data generated were fitted into appropriate isotherm, kinetic and thermodynamic models. The effect of pH showed an increase in adsorption of metals with increase in pH and an optimum pH of 5.0 was obtained for Pb (II), while 6.0 were obtained for Co (II) and Zn (II) ions biosorption. An equilibrium sorption contact time of 30, 40 and 60 min was obtained for Co (II), Zn (II) and Pb (II) ions respectively. The biosorption of metal ions was in the order Co (II) > Pb (II) > Zn (II). In general the Freundlich model provided a better fit than the Langmuir, Tempkin and Dubinin-Radushkevich isotherm models with R2 values greater than 0.9. The pseudo first order kinetic model was applicable in the adsorption of Pb (II) and Zn (II) ions while the pseudo-second-order model provided the best fit for Co (II) ion adsorption. The adsorption mechanism was found to be controlled by the liquid film diffusion model (R2>0.9) rather than the intraparticle diffusion model (R2<0.9). Thermodynamics revealed a spontaneous, feasible, exothermic physisorption process and over 60% of the metal ions were desorbed using 0.1M HCl and 0.1M NaOH as eluent. The results showed that BFSH could be utilized as low-cost adsorbent for the removal of toxic heavy metals from solution.
Open Access
Bioassay-guided isolation, purification and charaterization of antimicrobial compound from acidic metabolite of piper umbellatum seed extract
(Canadian Center of Science and Education, 2014) Ejele, A. E.; Akalezi, C. I.; Iwu, I. C.; Ukiwe, L. N.; Enenebaku, C. K.; Ngwu, S. U.
The antimicrobial potential of ethanol extract of Piper umbellatum seeds and its acidic, basic and neutral metabolites were evaluated using the disc diffusion method. The results showed that the acidic and neutral metabolites exhibited greater antibiotic activities against the tested microorganisms; Coliform bacilli, Salmonella typhi and Staphylococcus aureus and gave inhibition zone diameters greater than 28 mm against both C. bacilli and S. aureus. These results were interpreted in terms of differences in phytochemical composition of these metabolites and indicated that an effective anti-Staphylococcal drug could be developed from P. umbellatum extract for chemotherapy of diseases caused by S. aureus, which is known all over the world to develop resistance to most potent antibiotic drugs. Chromatographic purification of the acidic metabolite gave five fractions whose antimicrobial potential against some pathogens was evaluated and compared with Amoxil (a positive standard antimicrobial drug). The results showed that all the chromatographic fractions possessed inhibitory activities against the tested microbes. Spectroscopic analysis of IR, 1H– and 13C–NMR data suggested that the active principle in acidic metabolite of P. umbellatum could be Naringin, a naturally occurring polyphenol and antibiotic drug.
Open Access
Characterization of selected honey in SouthEast Nigeria: Theoretical translation
(U. P., 2017) Nwoko, C. I. A.; Nkwoada, A. U.; Ubeh, E. O.; Njoku, A.
With the vast honey bee species producing honey for international export and consumption in Nigeria, there is need for theoretical translation of quality assessment and characterization of honey for human consumption. The physicochemical and mineral contents of some selected honey in the five South east geopolitical states of Nigeria was performed for above mentioned application. The results were evaluated with 3D plot to identify the statistical significance of the parameters analyzed. The levels of glucose and fructose were accepted by codex alimentation standard and rejected samples B, C, and G. A correlation of similar botanical origin was demonstrated in sample B, C and G and similarly observed in their moisture content been > 21%. The pH and electrical conductivity showed no significant variation. The codex hydroxyl methyl furfural standard identified samples B, E and L to be “aged honey” or falsified honey in circulation. The 3D plot showed the significant variation of hydroxyl methyl furfural content of samples. A hypothesis was observed when the samples and previously analyzed Nigerian samples were compared; metal concentration levels of Group 1 elements > Group 2 > transition metals in Nigerian honey and formed an identification trend.
Open Access
Chemical and medicinal properties of xylopia aethiopica harvested from the South Eastern Nigeria
(U. P., 2022-01-30) Iwu, Irenus Chinonye; Ukaoma, Adanna A.; Alisa, Christopher; Ali, Bilah; Obiagwu, Ifeoma; Onu, Lynda Uchenna; Anozie, Remigius Chukwudi
The characterization of chemical and medicinal properties of the leaf of Xylopia aethiopica was carried out with the aid of Shimazu Japan Gas Chromatography 5890-11 and GC-MS QP 2010 Plus Shimazu Japan. The chromatogram revealed 34 peaks which yielded 34 compounds with their molecular weights, structures and formulars elucidated. Initial phytochemical examination revealed the presence of alkaloid 4.3%, flavonoids 5.1%, properties. saponins 4.89%, tannin 2.2%s, cardiac glycosides and steriods. Antimicrobial determination revealed activity against selected human pathogens: Pseudomonas aeruginosa 10mm, Staphylococcus aureus 20mm, Streptococcus specie 22mm ,Aspergillus niger 16mm, Mucor specie 18mm and but was resistant to Klebsiella pneumonia. Most of the compounds identified in the leaf extract such as phytol.Vitamin E, Squalene, Caryophyllene oxide ans Isoaromadendrene epoxide has proven anti-cancer, anti-tumors, anti-inflammatory antioxidant and anti-arthritic properties
Open Access
Chemical interactions of synthetic and natural remediating agents with crude oil on agricultural soil
(Pelaga Research Library, 2014) Ogukwe, Cynthia E.; Oze, Gabriel O.; Enenebeaku, Conrad E.; Akalezi, Chris O.
Altered chemical system of an Agricultural Soil resulting from crude oil spillage was subjected to NPK fertilizer and compost manure for remediation. The effect of the remediating agents was observed in-situ by examining the soil parameters before, during and after the interactions. An Ultraviolet(UV) Spectrophotometer V180 was used for the evaluation of the Total Hydrocarbon content of the soil. Remediated state of 92.5% TPH reduction, pH, moisture balance and soil restoration was achieved with a combination of 150g NPK fertilizer and 150g compost manure per meter square (300g remediating agent /m2) plot of land, after seven weeks of application.
Open Access
Chemo-remediation of crude oil polluted soils obtained from recent polluted site in oil producing environs in Rivers State Nigeria
(eSciPub, 2019) Iwu, Irenus Chinonye; Onu, Uchenna Lynda; Nkwoada, Amarachi; Onwumere, Fidelis
The chemo- remediation of crude oil polluted soils from recent pollution sites in oil producing environs in River state was carried out by both in vivo and in vitro methods using macro-soil nutrients ( Nitrate, Phosphate and Potassium) as index for remediation. The soil samples were labeled A, B, C, D1 to D6, sample A was obtained from pollution free site used as a control.Sample C was crude oil polluted soil not treated with surfactant, sample B was crude oil polluted soil leached with surfactant and not mineralized. Samples D1-D6 were polluted soil samples, leached with surfactant and mineralized with fertilizer. The samples were leached with linear alkyl benzene sulphonate (LABS) and later mineralized with Nitrate, Phosphate and Potassium (N.P.K) fertilizer and returned to the site of excavation to fallow for four months. The samples were later re-excavated and taken to the laboratory for analysis. Nitrate and phosphate contents were obtained with the aid of spectrum lab 725 UV visible spectrophotometer and potassium content was determined by use of a flame photometer. Results showed that sample A had nitrate concentration of 330ppm, sample B had concentration of 21ppm, sample C had a concentration of 54ppm while samples D-D6 had concentrations ranging from300ppm to 420ppm.Similarly, The phosphate concentrations were 68.50ppm, 17.00ppn, 28.00ppm and 48.80-136.40ppm for sample A, B, C.D1-D6 respectively. The potassium concentrations were not different as concentrations of 46ppm, 12ppm, 28ppm and 38ppm-64ppm was recorded for samples A, B, C, and D1-D6 respectively. These results revealed that crude oils not only renders soils unusable but also destroys the nutrient availability in soils. The soils can therefore quickly be reclaimed by leaching them with surfactants and mineralizing them with adequate inorganic fertilizer.
Open Access
Corrosion inhibiting effect of aframomum melegueta extracts and adsorption characteristics of the active constituents on mild steel in acidic media
(Taylor & Francis Group, LLC, 2013) Oguzie, E. E.; Iheabunike, Z. O.; Oguzie, K. L.; Ogukwe, C. E.; Chidiebere, M. A.; Enenebeaku, C. K.; Akalezi, C. O.
The extract from the seeds of Aframomum melegueta (AM) was investigated as corrosion inhibitor for mild steel in aerated 1M HCl and 0.5M H2SO4 solutions using gravimetric and electrochemical techniques. AM extract was found to inhibit both the cathodic and anodic partial reactions of the corrosion process, via adsorption of the organic matter on the metal/solution interface, as described by the Langmuir as well as Flory-Huggins adsorption isotherms. Corrosion rates in all systems studied increased with rise in temperature. Increasing the temperature of the system enhanced inhibition efficiency of AM extract in 1M HCl, but decreased efficiency in 0.5M H2SO4. Molecular dynamics simulations were performed to theoretically illustrate the electronic structure and adsorption behaviour of the active constituents of the seeds of Aframomum melegueta; paradol (1-(4-Hydroxy-3-methoxyphenyl)decan-3-one) and shogaol ((E)-1-(4-Hydroxy-3- methoxyphenyl)dec-4-en-3-one) in order to theoretically evaluate their contributions to the corrosion inhibiting action of the extract.
Open Access
Corrosion inhibition and adsorption behavior of methionine on mild steel in sulfuric acid and synergistic effect of iodide ion
(Elsevier Inc., 2007) Oguzie, E. E.; Li, Y.; Wang, F. H.
The corrosion inhibition of mild steel in sulfuric acid by methionine (MTI) was investigated using electrochemical techniques. The effect of KI additives on corrosion inhibition efficiency was also studied. The results reveal that MTI inhibited the corrosion reaction by adsorption onto the metal/solution interface. Inhibition efficiency increased with MTI concentration and synergistically increased in the presence of KI, with an opti mum[KI]/[MTI] ratio of 5/5, due to stabilization of adsorbed MTI cations as revealed by AFM surface morphological images. Potentiodynamic polarization data suggest that the compound functioned via a mixed-inhibition mechanism. This observation was further corroborated by the fit of the experimental adsorption data to the Temkin and Langmuir isotherms. The inhibition mechanism has been discussed vis-à-vis the presence of both nitrogen and sulfur atoms in the MTI molecule
Open Access
Corrosion inhibition and adsorption of Anthocleista djalonesis leaf extract on the acid corrosion of mild steel
(U. P., 2012) Ogukwe, C. E.; Akalezi, C. O.; Chidiebere, M. A.; Oguzie, K. L.; Iheabunike, Z. O.; Oguzie, E. E.
Aqueous extracts of the leaves of Anthocleista djalonesis (AD) have been investigated as non toxic corrosion inhibitors for mild steel in acidic environments (1 M HCl and 0.5 M H2SO4, respectively). Corrosion rates were evaluated at 30 oC using the weight loss, electrochemical impedance spectroscopy and potentiodynamic polarization techniques. AD extract was found to inhibit mild steel corrosion in both acidic media via adsorption of the extract organic matter on the metal/solution interface. Polarization data indicate that the extract functioned via a mixed inhibition mechanism, affecting both the cathodic and anodic partial reactions of the corrosion process. Molecular dynamics (MD) simulations were performed to illustrate the adsorption process of some specific components of the extract.
Open Access
Corrosion inhibition of aluminium in acidic and alkaline media by Sansevieria trifasciata extract
(Elsevier Ltd, 2007) Oguzie, E. E.
The inhibitive action of leaf extracts of Sansevieria trifasciata on aluminium corrosion in 2 M HCl and 2 M KOH solutions was studied using the gasometric technique. The results indicate that the extract functioned as a good inhibitor in both environments and inhibition efficiency increased with concentration. Synergistic effects increased the inhibition efficiency in the presence of halide additives. Temperature studies revealed a decrease in efficiency with rise in temperature and corrosion activation energies increased in the presence of the extract. A mechanism of physical adsorption is proposed for the inhibition behaviour. The adsorption characteristics of the inhibitor were approxi mated by Freundlich isotherm