Factors Affecting Choice of Subspecialisation amongst Orthopaedic Surgery Residents in Southern Nigeria.

Background: As the field of surgery continues to evolve, subspecialty training is fast becoming integral to surgical education. Presently, orthopaedic surgery residents have opportunities to subspecialise in different areas.

Objectives: The aim of this study was to determine the factors affecting the choice of desired subspecialties amongst orthopaedic surgery residents in southern Nigeria.

Assessment of leachable and persistent dissolved organic carbon in sludges and biosolids from municipal wastewater treatment plants.

Environmental regulation of organic pollutants has not kept pace with the growth in the number and diversity of legacy and emerging organic substances now in use. Simpler and cheaper tools and methodologies are needed to quickly assess the organic pollutant risks in waste materials applied to land such as municipal wastewater treatment sludges and biosolids. This study attempts to provide these, using an approach that consists of chemical leaching and analysis of dissolved organic carbon and determination of its biodegradability by measuring persistent dissolved organic carbon.

Cow urine as a source of nutrients for Microbial-Induced Calcite Precipitation in sandy soil.

Microbial Induced Calcite Precipitation (MICP) via biostimulation of urea hydrolysis is a biogeochemical process in which soil indigenous ureolytic microorganisms catalyse the decomposition of urea into ammonium and carbonate ions which, in the presence of calcium, precipitate as calcium carbonate minerals. The environmental conditions created by urine in soil resemble those induced by MICP via urea hydrolysis. Thus, this study assesses the suitability of a waste product, cow urine, as a source of nutrients for MICP.

Road deposited sediment: implications for the performance of filter drains servicing strategic trunk roads.

This study investigates the contribution of road deposited sediment (RDS) to clogging and the operational lifecycle of highway filter drains (HFDs). RDS samples were collected from nine Scottish trunk roads and fractionated into grain size classes to determine their particle size distributions (PSDs). Results show that RDS PSDs, and the percentage of each grain size fraction, are highly variable.

Effect of liquid nitrogen pre-treatment on various types of wool waste fibres for biogas production.

This study investigated the role of liquid nitrogen (LN) in increasing microbial accessibility of wool proteins for biogas production. It involves a mechanical size reduction of four different types of raw wool fibres, namely, Blackface, Bluefaced Leicester, Texel and Scotch Mule, in presence of liquid nitrogen, followed by the determination of the methane production potential of the pre-treated wool fibres. The highest methane yield, 157.

Investigating the removal of some pharmaceutical compounds in hospital wastewater treatment plants operating in Saudi Arabia.

The concentrations of 12 pharmaceutical compounds (atenolol, erythromycin, cyclophosphamide, paracetamol, bezafibrate, carbamazepine, ciprofloxacin, caffeine, clarithromycin, lidocaine, sulfamethoxazole and N-acetylsulfamethoxazol (NACS)) were investigated in the influents and effluents of two hospital wastewater treatment plants (HWWTPs) in Saudi Arabia. The majority of the target analytes were detected in the influent samples apart from bezafibrate, cyclophosphamide, and erythromycin. Caffeine and paracetamol were detected in the influent at particularly high concentrations up to 75 and 12 ug/L, respectively.

Treatment of metal-contaminated wastewater: a comparison of low-cost biosorbents.

This study aimed to identify some optimum adsorption conditions for the use of low-cost adsorbent, seaweed (Ascophyllum nodosum), sawdust and reed plant (Phragmites australis) root, in the treatment of metal contaminated wastewater for the removal of cadmium, chromium and lead. The effect of pH on the absorption capacity of each of these biosorbents was found to be significant and dependent on the metal being removed. Post-adsorption FTIR analysis showed significant binding activities at the nitro NO groups site in all biosorbents, especially for lead.

Modelling start-up performance of anaerobic digestion of saline-rich macro-algae.

Some of the key factors affecting the adaptation of anaerobic digestion processes to increasing levels of salinity were determined in batch tests using brown seaweed as a feedstock. It was found that cultures seeded with non-saline anaerobic inoculum required an adaptation period of up to two months to reach the same level of methane production rate as in those cultures seeded with saline-adapted inoculum. The Anaerobic Digestion Model No.

The impact and mode of action of phenolic compounds extracted from brown seaweed on mixed anaerobic microbial cultures.

Aims: This study discusses the effect of phenolic compounds extracted from brown seaweed (phlorotannins) on mixed microbial cultures found in anaerobic systems.

Methods And Results: Assays were conducted with phloroglucinol as the nonpolymerized form of phlorotannin and with phlorotannins extracted from the brown seaweed Laminaria digitata. Electron micrographs revealed that phlorotannins induce significant extra- and intracellular effects upon cells, with the disruption of cell membranes observed with most micro-organisms.

Modelling sodium inhibition on the anaerobic digestion process.

Sodium is a known process inhibitor in anaerobic systems and impacts on methanogens through an increase of osmotic pressure or complete dehydration of microorganisms. In this study, a combination of experimental and modelling approaches has been employed to determine and simulate sodium inhibition on the anaerobic digestion process. The ADM1, which has been successfully used in modelling anaerobic processes, has been modified to include an extra inhibition function that considers the effect of sodium on acetoclastic methanogens and the impact on biogas production and composition.

Sexual risk behaviour among HIV-positive persons in Kumasi, Ghana.

Objectives: To assess the prevalence and predictors of sexual risk behaviours among HIV-positive individuals in clinical care in Kumasi, Ghana.

Design: Cross-sectional survey of 267 (43 males and 224 females) HIV-positive individuals attending Kumasi South Regional Hospital.

Methods: An interviewer-administered questionnaire was used to asses demographic and health characteristics, HIV/AIDS knowledge, attitudes, and beliefs and sexual risk behaviours.

Stimulation of bioprocesses by ultrasound.

Ultrasound (US) has become a ubiquitous technological process in a large variety of scientific disciplines. However, little information exists on the use of ultrasound to enhance biological processes and/or processing and consequently this paper provides an overview of work reported to date on this topic. This review provides a brief introduction to ultrasound and the history of ultrasound as applied to bioprocesses.

Mangrove vulnerability modelling in parts of Western Niger Delta, Nigeria using satellite images, GIS techniques and Spatial Multi-Criteria Analysis (SMCA).

Mangroves are known for their global environmental and socioeconomic value. Despite their importance, mangrove like other ecosystems is now being threatened by natural and human-induced processes that damage them at alarming rates, thereby diminishing the limited number of existing mangrove vegetation. The development of a spatial vulnerability assessment model that takes into consideration environmental and socioeconomic criteria, in spatial and non-spatial formats has been attempted in this study.

Modelling head losses in granular bed anaerobic baffled reactors at high flows during start-up.

Anaerobic treatment of low strength, high flow wastewaters can only be effective if the technology employed can meet key hydrodynamic requirements: maximising the contact surface area and contact period between the influent substrate and the biomass solids, minimising solid washout from the reactor and minimising the backpressure across the system. Backpressure or head loss is an important hydrodynamic property of gravity-flow packed bed reactors, where the flow is the resultant of frictional forces between the incoming fluid and the solid packing material through which the wastewater percolates. Excessive backpressure caused by high influent flow-rates can reduce the contact surface area and increase the influent head on the upstream side of the biomass bed leading to overflow spills, unstable performance and process failure.

Anaerobic digestion of distillery spent wash: Influence of enzymatic pre-treatment of intact yeast cells.

The potential benefits of enzymatic digestion of intact yeast cells on anaerobic digestion of Scotch whisky distillery spent wash and pot ale were investigated. Various yeast cell wall hydrolytic enzymes were studied based on their effect on dissolution of cell wall glucan and mannoprotein. The synergistic activity of beta-glucanase and protease showed greater than 90% yeast cell digestion at 37 degrees C in 24h.

Comparing the performance of UASB and GRABBR treating low strength wastewaters.

Anaerobic technologies have proved successful in the treatment of various high strength wastewaters with perceptible advantages over aerobic systems. The applicability of anaerobic processes to treat low strength wastewaters has been increasing with the evolution of high-rate reactors capable of achieving high sludge retention time (SRT) when operating at low HRT. However, the performance of these systems can be affected by high variations in flow and wastewater composition.

Investigating the effects of anaerobic and aerobic post-treatment on quality and stability of organic fraction of municipal solid waste as soil amendment.

The use of OFMSW for biogas and compost production is considered as a sustainable strategy in saving valuable landfill space while producing valuable product for soil application. This study examines the effects of anaerobic and aerobic post-treatment of OFMSW on the stability of anaerobic digestate and compost and soil quality using seed germination tests. Anaerobic digestion of OFMSW was carried out for fifteen days after which the residual anaerobic digestate was subjected to aerobic post-treatment for seventy days.

Anaerobic digestion of municipal solid wastes containing variable proportions of waste types.

In many parts of the world there are significant seasonal variations in the production of the main organic wastes, food and green wastes. These waste types display significant differences in their biodegradation rates. This study investigated the options for ensuring process stability during the start up and operation of thermophilic high-solids anaerobic digestion of feedstock composed of varying proportions of food and green wastes.

Structural analysis of anaerobic granules in a phase separated reactor by electron microscopy.

This paper discusses the microbial community structure of anaerobic granules and the effect of phase separation in anaerobic reactor on the characteristics of granules. Electron micrographs revealed that the core of anaerobic granular sludge consists predominantly of Methanosaeta-like cells, a key microorganism in granulation process. Granules in the methanogenic dominant zone of the reactor were stable and densely packed with smooth regular surface.

The performance of a phase separated granular bed bioreactor treating brewery wastewater.

This study presents the performance characteristics of a plug flow phase separated anaerobic granular bed baffled reactor (GRABBR) fed with brewery wastewater at various operating conditions. The reactor achieved chemical oxygen demand (COD) removal of 93-96% with high methane production when operated at organic loading rates (OLRs) of 2.16-13.

Assessment of morphology for anaerobic-granular particles.

This study shows that a proper assessment of granule morphology is fundamental before applying any mathematical derivation or empirical formula based on the shape factor of anaerobic-granular particles to determine granular characteristics. The granular images and size distribution of samples observed in this study revealed two different dimensions along two axes, which characterize these particles as ellipsoids. In the literature, theoretical-settling velocities and particle-size distribution of anaerobic granules have been calculated by assuming granules as spherical-shaped and using the numerical correlation between the size and settling velocity.

Carbon and nitrogen removal in a granular bed baffled reactor.

The application of an anaerobic five compartment granular bed baffled reactor (GRABBR) was investigated with brewery wastewater for combined carbon and nitrate removal, with a separate downstream nitrification unit for converting ammonia to nitrate. The GRABBR was operated at an organic loading rate of 3.57 kg chemical oxygen demand (COD) m(-3) d(-1) and ammoniacal nitrogen (NH4-N) loading rate of 0.

Effect of rapid hydraulic shock loads on the performance of granular bed baffled reactor.

This paper describes the performance of a granular bed baffled reactor when receiving unpredictable hydraulic shock loads, which is a frequent occurrence in industrial wastewater treatment plants. Shock loads were created by rapidly increasing volumetric organic loading rates from 2.5 to 20 kg COD m(-3) d(-1), by decreasing (in a stepwise fashion) hydraulic retention time from 48 hrs to 6 hrs.

Increasing the fertilizer value of palm oil mill sludge: bioaugmentation in nitrification.

Malaysia is essentially an agricultural country and her major polluting effluents have been from agro-based industries of which palm oil and rubber industries together contribute about 80% of the industrial pollution. Palm oil sludge, commonly referred to, as palm oil mill effluent (POME) is brown slurry composed of 4-5% solids, mainly organic, 0.5-1% residual oil, and about 95% water.