EVALUATION OF TWO-STAGE SUBSURFACE FLOW CONSTRUCTED WETLANDS FOR ABATTOIR WASTEWATER MANAGEMENT

Abattoir wastewater is high in organic content, the waste recovery and treatment facility is expensive and this results in indiscriminate dumping into streams without adequate treatment. The effectiveness of using a two-stage subsurface flow constructed wetland to treat abattoir effluent was examined in this study. Diluted abattoir wastewater from Lafenwa Abattoir, Abeokuta, Ogun State, Nigeria was fed into a two-stage Vegetated Subsurface Bed Constructed Wetlands (VSBCW). The VSBCW consisted of 500 mm deep 10-15 mm diameter granite with 150 mm thick overlay of well graded sand planted with locally available Vetiveria nigritana. Grab samples were collected at selected points along Ogun river and measurement of physico-chemical parameters such as: Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD5), Electrical Conductivity (EC), Total Dissolved Solids (TDS) and Total Suspended Solid (TSS) of the influent and effluent from the VSBCW were carried out. Irrigation with water and diluted abattoir wastewater to examine the variation in plant growth rate was also investigated. The results revealed a pollution load reduction as the wastewater moves away from the discharge point but inadequate to meet the FEPA (1991) standard for wastewater discharge into rivers. The VSBCW was observed to reduce the concentration of BOD5, COD, EC, TDS and TSS in the abattoir wastewater by 88.71, 87.28, 45.72, 56.89 and 72.27 % respectively. The growth rate of the V. nigritana reduced by 1.9% when irrigated with abattoir wastewater. The study revealed that locally available V. nigritana in VSBCW is effective in abattoir wastewater treatment and could be use to curtail the pollution caused by discharge of untreated wastewater into rivers.     &nbsp

Campylobacter jejuni Modulates Reactive Oxygen Species Production and NADPH Oxidase 1 Expression in Human Intestinal Epithelial Cells

Campylobacter jejuni is the major bacterial cause of foodborne gastroenteritis worldwide. Mechanistically, how this pathogen interacts with intrinsic defence machinery of human intestinal epithelial cells (IECs) remains elusive. To address this, we investigated how C. jejuni counteracts the intracellular and extracellular reactive oxygen species (ROS) in IECs. Our work shows that C. jejuni differentially regulates intracellular and extracellular ROS production in human T84 and Caco-2 cells. C. jejuni downregulates the transcription and translation of nicotinamide adenine dinucleotide phosphate (NAPDH) oxidase (NOX1), a key ROS-generating enzyme in IECs and antioxidant defence genes CAT and SOD1. Furthermore, inhibition of NOX1 by diphenylene iodonium (DPI) and siRNA reduced C. jejuni ability to interact, invade, and intracellularly survive within T84 and Caco-2 cells. Collectively, these findings provide mechanistic insight into how C. jejuni modulates the IEC defence machinery

COEFFICIENT OF STATIC FRICTION OF BENISEED FOR MILD STEEL, PLYWOOD, CONCRETE AND GLASS STRUCTURAL SURFACES

In developing processing machines for plant materials, the frictional property of the seed on structural surfaces of Mild steel (MS), Plywood (PW), Concrete (CC) and Glass (GL) is a parameter which needs to be measured. In this study, the static coefficient of friction of two Nigerian beniseed accessions (Yandev-55 and E8) were determined at moisture content levels of 5.3, 10.6, 16.1 and 22.4 per cent (wet basis). These were used as inputs into designing a beniseed oil expeller. A - 2 x 4 factorial experiment in completely randomized was used for the study. The static coefficients of friction between beniseed and the four structural surfaces increased curvilinearly with increase in moisture content irrespective of the surface employed. The result showed that glass has the least value of 0.32 while for mild steel, plywood and concrete, frictional coefficients with beniseed were between 0.39 to 0.59 within the 5.3 and 22.4% moisture content levels. The effect of moisture content is highly significant on the coefficient of frictions of all the tested surfaces.

Wettability alteration in carbonates: the effect of water-soluble carboxylic acids in crude oil

"Reprinted (adapted) with permission from Fathi, S J., Austad, T., Strand S., Puntervold, T. (2010) Wettability alteration in carbonates: the effect of water-soluble carboxylic acids in crude oil. Energy & Fuels 24(5), pp. 2974–2979. Copyright (2010) American Chemical Society. The article forms part of Jafar Fathi's PhD thesis: Water-based enhanced oil recovery (EOR) in carbonate reservoirs : initial wetting condition and wettability alteration by "Smart Water", Stavanger : University of StavangerAcidic components in crude oil influence the wetting condition through their effect on electrostatic interactions with the mineral surfaces. In this paper, we have extracted water-soluble acids from a crude oil with a high acid number (AN) to study the effect of these acidic materials on the wetting condition. The AN for the original oil was 1.8 mg of KOH/g, while the AN for the oil depleted in water-soluble acids was 1.5 mg of KOH/g. Two crude oils have been studied by a chromatographic wettability test and spontaneous imbibition using seawater as imbibing fluid to determine the differences in the wetting condition and oil recovery. In a spontaneous imbibition process at 110 °C, both the imbibition rate and ultimate recovery were higher in the cores saturated with the oil depleted in water-soluble acids. The difference in the imbibition rate and also ultimate recovery indicates that the carboxylic material from the oil depleted in water-soluble acids can be displaced easily compared to the original oil. The difference in wetting properties was also confirmed by chromatographic wettability tests. The water wetness appeared to be lower for the original oil compared to that for the treated oil. These crude oils were also investigated with respect to interfacial intension. Even though the strength of the bonding of carboxylic material onto the calcite surface is mostly dictated by the carboxylic group, the organic structure of the carboxylic material will have an influence on the wettability alteration process as well