Harrison Ifeanyichukwu Atagana

Biodegradation of PAHs by fungi in contaminated-soil containing cadmium and nickel ions

The study investigated the degradation of the polycyclic aromatic hydrocarbons (PAH) benzo(a)anthracene, benzo(a) fluoranthene, benzo(a) pyrene, chrysene and phenanthrene in a soil that was sterilized and inoculated with the nonligninolytic fungi, Fusarium flocciferum and Trichoderma spp. and the ligninolytic fungi, Trametes versicolor and Pleurotus ostreatus in the presence of cadmium (Cd) and nickel (Ni) during a ten week incubation period. The soil pH was initially 5.3 and after amendment increased to 7.0. The fungi degraded the tested PAHs between 21 and 93% by the end of the tenth week. The fungi degraded the less-soluble PAHs containing five or six aromatic rings more slowly than those containing fewer aromatic rings. Although the presence of cadmium and nickel in the soil affected the activity of the enzymes produced by the fungi, no significant decrease in PAH degradation was found in the contaminated soil containing 50 or 100 mg kg -1 of Cd and Ni. However, at 300 and 500 mg kg -1 , degradation of the PAHs by the fungi was impaired and the severity of the impairments increased with the increase in the concentrations of Cd and Ni. This was probably due to the lack of the activities of some enzymes such as Mn-dependent peroxidase, which could have resulted from the poor colonization of the fungi at these concentrations.

The Potential of Chromolaena Odorata (L) to Decontaminate Used Engine Oil Impacted Soil Under Greenhouse Conditions

This study reports on the use of Chromolaena odorata (L) R.M. King and H. Robinson, an Asteraceae (compositae) and an invasive alien weed in Africa for the remediation of soil contaminated with used engine oil. Used engine oil from a motor service garage was used to artificially contaminate soil taken from a garden to give total petroleum hydrocarbon (TPH) of between 1 and 40 g kg−1. Chromolaena odorata (L), propagated by stem cuttings were transplanted into the contaminated soil and watered just enough to keep the soil at about 70% water holding capacity for 90 day. A set of control experiments containing 40 g kg−1 used engine oil but without plants was set up. All experiments were set up in triplicates. Although the plants in the experiments containing higher than 30 g kg−1 used engine oil showed relatively slower growth (fewer branches and leaves, and shorter in height) compared to those containing lower concentrations, the plants in all the experiments continued to grow until the end of the 90 day period. Residual TPH after 90 days showed that between 21 and 100% of oil was lost from the planted soil while only 11.5% was lost in the control, which did not contain plants during the same period. Analysis of plant tissues showed that both shoot and root tissues contained detectable levels of TPH and selected PAHs were also detectable. Biomass accumulation by Chromolaena odorata was affected adversely by concentrations of oil higher than 20g kg−1. Results of germination rates and germination energy measurements showed that Chromolaena odorata was able to reduce the toxicity of the contaminated soil after 90 days as compared to soils containing freshly contaminated soil.

Biological degradation of oil sludge: A review of the current state of development

Oil sludge is a thick viscous mixture of sediments, water, oil and hydrocarbons, encountered during crude oil refining, cleaning of oil storage vessels and waste treatment. Polycyclic aromatic hydrocarbons (PAHs), which are components of crude oil sludge, constitute serious environmental concerns, as many of them are cytotoxic, mutagenic and potentially carcinogenic. Improper management and disposal of oil sludge causes environmental pollution. The adverse effects of oil sludge on soil ecology and fertility have been of growing interest among environmental scientist and an important consideration in the development of efficient technologies for remediation of contaminated land, with a view to making such land available for further use. Oil sludge can be treated by several methods such as physical, chemical and biological processes. The biological processes are mostly cost effective and environmentally friendly, as they are easy to design and implement, as such they are more acceptable to the public. Compost, the product of biological breakdown of organic matter is a rich source of hydrocarbon-degrading microorganisms such as bacteria and fungi. These microorganisms can degrade the oil sludge to less toxic compounds such as carbon dioxide, water and salts. Compost bioremediation, the application of composting in remediation of contaminated environment, is beginning to gain popularity among remediation scientists. The success or failure of compost bioremediation depends on a number of factors such as nutrients, pH, moisture, aeration and temperature within the compost pile. The bioavailability and biodegradability of the substrate to the degrading microorganisms also contributes to the success of the bioremediation process. This is a review on the biological remediation technologies employed in the treatment oil sludge. It further assesses the feasibility of using compost technology for the treatment of oil sludge, as a better, faster and more cost effective option.

Biological Degradation of Crude Oil Refinery Sludge with Commercial Surfactant and Sewage Sludge by Co-Composting

This study determined the potential of surfactant and sewage sludge in enhancing degradation of oil sludge. A mixture of oil sludge, surfactant, and sewage sludge was co-composted for 24 weeks in the laboratory. Physical and chemical parameters in the compost were measured every four weeks. Isolated microorganisms were characterized by molecular techniques. The pH in all experiments remained between 8 and 6.4. CO2 evolution reached 5503 µg/dwt/day by the twenty-fourth week. The dominant bacterial species were Acinectobacter, Rodococcus, mycobacterium, Pseudomonas, Bacillus, Arthrobacter, and Staphylococcus species and fungi were Pleurotus, Penicillium, and Aspergillus sp. TPH was reduced by 92% in the sewage sludge and surfactant treatment, 75 and 81% in other treatments, and 44.2% in the control. PAH concentrations were reduced by between 75 and 100%. The results indicate that a careful application of surfactant and sewage sludge could enhance oil sludge degradation in a compost system.

Managing physicochemical parameters in compost systems to enhance degradation of petroleum wastes from a sludge dam

3on wooden pallets overlaid with nylon fibre sheets. Temperature, moisture, electrical conductivity (EC), pH, total carbon, total N, heterotrophs and respiration of compost microorganisms were monitored in each pile. Moisture was maintained at between 60 and 70% field capacity. Temperatures reached a mean of 63°C in the compost containing manure and sawdust. The C:N ratio of composts changed significantly during the composting process, reaching 100:41 (sawdust+manure) 100:39 (hay+manure) and 100:31 (woodchips+manure). Respiration of compost organisms rose from 1490 to 3850 CO2 (µg)/dwt/day in the sawdust+manure compost. Total petroleum hydrocarbons (TPH) decreased by between 52 and 66% in the composts and concentrations of selected polycyclic aromatic hydrocarbons (PAH) by between 78 and 100%. The Bacillus, Pseudomonas, Arthrobacter and Staphylococcus species were predominant in all the experiments and all temperature regimes.

Identification and Characterisation of Oil Sludge Degrading Bacteria Isolated from Compost

Abstract Compounds present in oil sludge such as polycyclic aromatic hydrocarbons (PAHs) are known to be cytotoxic, mutagenic and potentially carcinogenic. Microorganisms including bacteria and fungi have been reported to degrade oil sludge components to innocuous compounds such as carbon dioxide, water and salts. In the present study, we isolated different bacteria with PAH-degrading capabilities from compost prepared from oil sludge and animal manures. These bacteria were isolated on a mineral base medium and mineral salt agar plates. A total of 31 morphologically distinct isolates were carefully selected from 5 different compost treatments for identification using polymerase chain reaction (PCR) of the 16S rRNA gene with specific primers (universal forward 16S-P1 PCR and reverse 16S-P2 PCR). The amplicons were sequenced and sequences were compared with the known nucleotides from the GenBank. The phylogenetic analyses of the isolates showed that they belong to 3 different clades; Firmicutes, Proteobacteria and Actinobacteria. These bacteria identified were closely related to the genera Bacillus, Arthrobacter, Staphylococcus, Brevibacterium, Variovorax, Paenibacillus, Ralstonia and Geobacillus. The results showed that Bacillus species were predominant in all composts. Based on the results of the degradation of the PAHs in the composts and results of previous studies on bacterial degradation of hydrocarbons in oil, the characteristics of these bacterial isolates suggests that they may be responsible for the breakdown of PAHs of different molecular weights in the composts. Thus, they may be potentially useful for bioremediation of oil sludge during compost bioremediation.

Physiological responses and expression of Mnsuperoxide dismutase mRNA in Phascolosoma esculenta exposed to benzo(a)pyrene (BaP)

cDNA encoding Mn-superoxide dismutase (MnSOD) and 18S rRNA of Phascolosoma esculenta were cloned in this study. The partial MnSOD cDNA obtained consisted of 411 bp, encoded a protein of 137 amino acids and contained a MnSOD signature (DVWEHAYY). Physiological activity responses and expression of MnSOD mRNA in P. Esculenta exposed to benzo(a)pyrene (BaP) for 4, 24, 48 , 96, 168 and 336 h were also studied, and results indicate that P. Esculenta showed a strong ability to resist BaP stress. The expression levels of MnSOD mRNA were highest at 4 h of exposure, while the physiological activity levels of MnSOD were highest at 96 h, but then returned to baseline levels. The different response rates indicated that there was a very intricate regulating mechanism that prevents the damaging effects of the oxidative stress imposed by BaP. This result suggests that the expression of MnSOD mRNA in P. Esculenta in a short time can be used as a sensitive biomarker to alarm an early acute BaP contamination. Key words : Phascolosoma esculenta , benzo(a)pyrene (BaP), Mn-superoxide dismutase (MnSOD), gene expression, physiological activity.

Profiling of plants at petroleum contaminated site for phytoremediation

ABSTRACT The paucity of information in the literature on the characteristics of plants that could be used for phytoremediation of petroleum hydrocarbons (PHC)-contaminated sites was the principal reason for this study. The aim of the study was to identify indigenous plants growing in PHC-impacted soil in Umuahia in eastern-Nigeria that have the ability to phytoremediate soils contaminated with hydrocarbons under tropical monsoon climate conditions. A total of 28 native plant species from different families growing in and around hydrocarbon-impacted soil in the vicinity of vandalized pipelines carrying petroleum products were collected and studied for their ability to grow in a hydrocarbon-impacted soil and remove the PHC from the impacted soil. Some of the plants demonstrated the ability to grow in soil with high levels of the total petroleum hydrocarbons (TPH), which shows that they may be tolerant to hydrocarbons in soil and could potentially phytoremediate a hydrocarbon-contaminated soil. Chromolaena odorata, Aspilia africana, Chloris barbata, Pasparlum vaginatum, Bryophyllum pinnatum, Paspalum scrobiculatum, Cosmos bipinnatus, Eragrostis atrovirens, Cyperus rotundus, and Uvaria chamae showed tendencies to phytoremediate contaminated soil. By using bioaccumulation coefficient (BAC) as a measure of phytoremediation, results showed that C. odorata, A. africana, and U. chamae demonstrated the highest potentials to phytodegrade hydrocarbons in soil.

Compost bioremediation of oil refinery sludge by using different manures in a laboratory condition

I the Eastern Desert of Egypt, some banded iron and volcanogenic massive sulfide ores have been considered auriferous based on their assay results, though all available information indicate that gold, if presents, is epigenetic in these deposits. Au anomalies in fresh BIF samples are completely absent (assaying tens of BIF samples from different locations in the Egyptian Eastern Desert gave no gold concentrations). Even where subjected to pervasive metasomatism, gold values in the Neoporterozoic BIF deposits are consistently nil. If reported in the BIF, gold is confined to auriferous quartz veins along prominent fault/shear structures (e.g., Abu Marawat BIF). The banded iron ores are associated with Au-quartz veins only where sheared and tectonized. A single evidence for the syn-genetic origin of occasional Au in the Egyptian BIFs is completely missing. Stratabound gold deposits in the Egyptian basement are suggested on basis of assaying results of some samples while no comprehensive genetic studies were done. This will remain a big problem of scientific credibility of the classification suggested by Botros (OGR 2004). Accidental gold traces in some Egyptian massive sulfide ores can be related to post-formation circulating metamorphic/hydrothermal fluids. On the other side, the majority of the discrete gold occurrences in the Eastern Desert are of mesothermal vein-type, either related to fault/shear zones, or confined to peripheries of small granitoid massifs in regional transpression/transcurrent systems. Gold could have been leached from various lithologic units (i.e. volcanic/volcaniclastic or mafic/ultrmafic rocks in depth) or derived from late-orogenic granitoid magamas. Alternatively, hot magmatic intrusions could have aided convection of metamorphic±meteoric, low salinity aqueous-carbonic fluids and thus effectively dissolved, transported, and deposited gold in zones of dilation.The present study deals with detailed geochemical and mineralogical studies of the coastal plain sediments formed along the shoreline of the Arabian Gulf area, Kuwait. These deposits are mainly fluviomarine and beach sands. The coastal plain deposits of the central Kuwait shoreline zone were found to consist of average medium-grained sand. The sand composed, on average of about 90% sand, and about 10% or less is mud, and has a unimodal distribution with a mode of medium sand (1-2 ф). The sediments consists mainly quartz, Feldspar, clay minerals with carbonate minerals (detritus calcite and dolomite) and rock fragments (chart). The mineralogy of the clay fractions of the sediments is dominated by illite, palygorskite, mixed layer illite-montmorillonite with minor amounts of chlorite and Kaolinite. Heavy minerals are concentrated in the very fine sand fraction and are dominated by opaque minerals, and non opaque minerals which represented by amphiboles, pyroxenes, epidotes, dolomite, zircon, tourmaline, rutile, garnet and other which represented by Staurolite, Kyanite, Andalusite and Sillimenite as a trace amounts. The chemical analysis for the detrital amphibole grains from sandstone of coastal plain sediments shows the following features; the grains which have (Na + K) 0.50 its composition have wide variation and on the (Na + K) -Al IV diagram can be characterized two association: Association 1 which characterized by low amount of AlIV and low amount of (Na + K), by comparing the chemical composition of this association and the chemical composition of amphibole grains from older basement rock, can, these association may be derived from metamorphic source rocks and association 2 which characterized by high amount of Al IV and low amount of (Na + K), which may be derived from volcanic source rocks.T effect of long period ground motions on structure seismic responses has become an important consideration because of the increasing number of long-period buildings such as base-isolated structures and high-rise buildings. As a reliable anti-seismic technology, base isolation is used in many research programs to minimize seismic response of nuclear power plants (NPPs), which are a kind of critical constructions and any damage of them could lead to severe disasters. However, long period ground motion effects on isolated structures are not considered in these researches. In this paper, a representative multi-particle model of NPPs is built and lead-rubber bearing is considered as isolation system. Several classic long period and ordinary ground motions are chosen to investigate their characteristics of time domain and frequency domain, and the comparison analysis well explain the response differences of isolated NPPs under long period ground motions and ordinary ground motions. According to the comparison of acceleration responses, displacement responses and shear force responses of these two kinds earthquake, time-domain analysis is carried out using the NPPs model with and without isolation system. It is observed that seismic responses of superstructures could be reduced more effectively under ordinary ground motions than with long period motions input, and isolation layer displacements are larger with long period ground motions action. Seismic safety of nuclear power plants could be enhanced effectively by isolation system, and influences of long period ground motions on it should be considered carefully in further isolation design.S pollution and water pollution are posing a big threat today. With the multiplying population and progress of urban civilization, pollution caused by petroleum products and their wastes is increasing in logarithmic manner. In bioremediation of petroleum compound process in the environment, bacteria have been shown to be relatively more successful in breaking down the higher molecular weight compounds. The n-alkanes are generally considered the most readily degrading components in petroleum mixture. The hydrocarbons are broken by a series of enzyme mediated reactions. First it is mono terminal attack and oxygen serves as an external electron acceptor, while an organic component of the contaminating substance functions as the electron donor or energy source. The general pathway involves sequential formation of an alcohol, an aldehyde and a fatty acid. These organisms carry out their normal life processes using these contaminants as their source of nutrients. Metabolic processes of these organisms are capable of using chemical contaminants as energy source, rendering the contaminants harmless or less toxic in most cases. This review provides an outline of the occurrence of PAHs in the environment and the ability of bacteria to degrade the compound, including pathways for PAHs degradation by these organisms.The effects of emerging environmental problems associated with climate change and human-induced land cover change often directly impede livelihoods of the rural population in Africa. Erratic rainfalls, flooding, forest cover loss, and land degradation are causing unstable agricultural yields and incomes. Earth Observation (EO) has the potential to monitor landscape dynamics in relation to climate or human-induced environmental effects. Moreover, EO can provide seamless and integrative, that is multi-data and multi-scale, geospatial monitoring solutions that are of particular use within data scarce environments. This paper illustrates examples, possibilities and future perspectives from current EO research to address emerging environmental issues in Africa. Two experimental EO examples from eastern Africa are presented; (1) a multi-sensor approach to map vegetation productivity decline over eastern Africa, and (2) an integrative (multi-data) approach to map the spatial distribution of flowering plants at a local to landscape scale. In the first example, vegetation productivity decline, mapped at a regional scale using time-series of 250-meter MODIS NDVI imagery (from 2001 to 2012), is related to very high resolution (VHR) imagery in Google Earth. The MODIS-based productivity data could be effectively linked to land transformation processes (i.e. “deforestation”) using the multi-date VHR imagery. Climate-induced change could be largely disentangled from the human-induced change using rainfall trends derived from passive radar satellite observations. In the second example, the spatial distribution and abundance of flowering plants are mapped for a local site in Kenya using 0.6-meter hyperspectral data. The locations of flowering plants were verified in the field using a Smartphone geo-tagging. The up-scaling potential of the hyperspectral derived flowering map to a multi-spectral Worldview-2 image was probed. The results are instigated for the quantification of pollination effects in Africa and to sustain healthy honey bee colonies. Multi-sensor and multi-scale monitoring of environmental effects in Africa is effectively possible given that adaptable and ‘intelligent’ data integration models or techniques are used.