Biodegradation of crude petroleum by bacterial consortia from oil-contaminated soils in Ota, Ogun State, South-Western, Nigeria

Pollution from petroleum products is of public health concern because of its attendant health and environmental impacts. Biodegradation of Bonny light crude petroleum and other selected hydrocarbons by bacteria isolated from soils of three different mechanic workshops in Ota, Ogun State were studied. Species of bacteria were isolated by the enrichmentofthesoilsamplesinminimalsaltmediumsupplementedwith1%(v/v)crude petroleumasthesolecarbonandenergysource.Thepetroleumutilizingbacteriabelonging to the genera Bacillus sp. SB4, Pseudomonas sp. SC8, Serratia sp. SC11, and Acinetobacter sp. SC12 were screened and subjected for oil degradation using turbidity and total viable count,reductioninpHandresidualoilconcentrationasindices.GasChromatographic(GC) analysis was used to analyze the component and percentage of the petroleum utilized. Plasmidcuringandprofilingweredonetodeterminewhethertheabilitytoutilizecarbon isplasmidorchromosomallyencoded.Resultsrevealedthatfourbacteriastrainswereable to utilize petroleum as energy source. The GC fingerprints showed that both the aliphatic and aromatic components of crude petroleum were reduced to varying degree but the nonadecane C19 could not be reduced. Strain SC11 could not reduce anthracene, pyrene, benzo(a)pyrene and chrysene components. Strain SB4 depleted 24 to 57% aliphatics and 20to42%aromaticsandstrainSC8depleted38to67%aliphaticsand30to79%aromatics while strain SC11 depleted 12 to 46% aliphatics and 13 to 29% aromatics. All organisms harbored plasmid which could suggest that petroleum degradation capabilities could be plasmid encoded. This indicates that the petroleum utilizing bacteria are could be used bioremediationofthepetroleumpollutedenvironment

Feasibility analysis of an off-grid photovoltaic-battery energy system for a farm facility

Renewable energy plays a very important role in the improvement and promotion of environmental sustainability in agricultural-related activities. This paper evaluates the techno-economic and environmental benefits of deploying photovoltaic (PV)- battery systems in a livestock farmhouse. For the energy requirements of the farm to be determined, a walkthrough energy audit is conducted on the farmhouse. The farm selected for this study is located in southern Nigeria. The National Renewable Energy Laboratory’s Hybrid Optimization Modeling for Electric Renewable (HOMER) software was adapted for the purpose of the techno-economic analysis. It is found that a standalone PV/battery-powered system in farmhouse applications has higher economic viability when compared to its diesel-powered counterparts in terms of total net present cost (TNPC). A saving of 48% is achievable over the TNPC and Cost of Energy with zero emissions. The results obtained show the numerous benefits of replacing diesel generators with renewable energy sources such as PV-battery systems in farming applications