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Granular activated carbon (GAC) was used in an Anammox process treating synthetic wastewater with the aim of evaluating its use as a growth nucleus to enhance granule formation. In an expanded granular-sludge-bed reactor, granules were formed demonstrating excellent retention characteristics with an average settling velocity of 200 m/h (5 cm/s) over a startup period of only 38 days. The time required for formation of Anammox granules under the experimental conditions in this study, was thus demonstrated to be much shorter than that of others. A genetic analysis of the organisms in the granular bed revealed an abundance of Paenisporosarcina uncultured bacterium similar to other known Anammox bacteria.

The Hydrologic Simulation Program-FORTRAN (HSPF) model is widely used to develop management strategies for water resources and to evaluate the hydrologic effect of various management scenarios. The spatial resolution of the input data used to parameterize HSPF model may induce uncertainty in model outputs. In this study, the impact of spatial resolutions of Digital Elevation Model (DEM) and land use map on the uncertainty of HSPF predicted flow and sediment were evaluated. DEM resolution can affect stream length, watershed area and average slope, whereas land use data resolution can lead to redistribution of land use information. Results showed that finer resolution DEM and land use maps can generate higher flow volumes and sediment loads compared to modelling scenarios using inputs of coarse resolution. The relative change in model performance between the baseline scenario (high-resolution) and scenarios of coarser resolution described uncertainties due to DEM and land use spatial information, and the probability density function of these uncertainties was used to estimate these uncertainties. Modelled flow and sediment uncertainty due to DEM resolution seems to follow a log-normal and a general extreme value distribution respectively, whereas modelled flow and sediment uncertainty due to land use resolution seems to both follow a general extreme value distribution. Overall, results highlight the need for a high-resolution DEM and land use maps in the application of the HSPF model while they provide useful information for reducing the model uncertainties.

Antioxidant defense mechanisms are crucial for plants to survive under stress conditions. We investigated the capacity of a wild fern species, Nephrolepis biserrata, growing in the vicinity of industrial land to accumulate heavy metals, and assessed its antioxidative response under metal stress. The soils in this particular area were highly contaminated with zinc followed by lead and copper. As control, N. biserrata located 10 km away from the industrial area were collected and assessed. N. biserrata from the contaminated sites accumulated metals in their tissues in similar descending order of zinc>lead>copper. The values of bioaccumulation factor between 0 to 0.1 indicate N. biserrata as a moderate accumulator for the tested metals. For the enzymatic antioxidant assays, the activities of catalase and ascorbate peroxidase were significantly higher in N. biserrata from contaminated soil compared to control, while the activity of superoxide dismutase was not differ significantly in plants from both sites. We also detected higher contents of total phenolics and total flavonoids in N. biserrata collected from contaminated site compared to control. Our HPLC analysis revealed higher levels of myricetin and kaempferol in plant samples from the contaminated area. Our study verified the capacity of N. biserrata to scavenge oxygen radicals when exposed to heavy metal stress. Such ability to tolerate stressful condition suggests that the plant is a potential metal phytoremediator. 

Petroleum products are used in different forms in auto-mechanic workshops every day. Spent motor oil disposed-off improperly contains potentially toxic substances which can seep into the water tables and contaminate ground water. This study involved isolation and screening of bacterial species capable of utilizing hydrocarbons from three auto-mechanic workshops in Abeokuta, Ogun State. Total Heterotrophic Bacterial Counts ranged from 1.03 × 10⁶ to 2.81 × 10⁶ CFU/g. Total Oil Degrading Bacterial Counts varied between 4.0 × 10⁵ and 2.01 × 10⁶ CFU/g while Surface Active Bacterial Counts were from 1.2 × 10⁴ to 2.76 × 10⁵ CFU/g. Twenty-four bacteria species capable of utilizing petroleum as a carbon source were isolated from various contaminated soils using enrichment technique. Isolated bacteria include: Bacillus spp., Pseudomonas aeruginosa, Micrococcus spp., Proteus mirabilis, Proteus vulgaris and Enterobacter spp. Redox indicator 2, 6-dichlorophenol indophenol (DCPIP) was used to screen for efficient hydrocarbon (Kerosene, Premium Motor Spirit, and Engine oil) degradation by bacteria. Degradation efficiency was measured by optical density at 600 nm. Micrococcus spp., Proteus mirabilis, and Pseudomonas aeruginosa were found to be the best isolates growing on majority of hydrocarbons due to their high utilization value when growing on the hydrocarbons tested.