Riverine macroinvertebrate responses to chlorine and chlorinated sewage effluents - acute chlorine tolerances of Baetis harrisoni (Ephemeroptera) from two rivers in KwaZulu-Natal, South Africa

Chlorine is widely used in South African sewage treatment works, and despite its volatility is likely to have a considerable impact on riverine ecosystems. This paper considers the results of acute (96 h) toxicity responses to chlorine of riverine mayfly nymphs Baetis harrisoni collected from the small, relatively uncontaminated suburban Westville Stream, KwaZulu-Natal and from the more severely impacted Umbilo River, which flows through the industrial area of Pinetown, KwaZulu-Natal, South Africa. The 96 h LC5

Roles of polyurethane foam in aerobic moving and fixed bed bioreactors

The aim of this study was to investigate the performance of sponge as an active mobile carrier for attachedgrowth biomass in three typical types of aerobic bioreactors to treat a high strength synthetic wastewater. The results show that sponge thickness deteriorated the organic and nutrient removal and 1 cm is the optimumthickness for fixed-bed sponge biofilter (SBF). The sponge volume had significant impact on phosphorus removal rather than organic or nitrogen removal, and 20% volume of sponge could achieve 100% T-P removal within 3 h in a sponge batch reactor (SBR). When sponge coupled with submerged membrane bioreactor (SMBR), the single system show outstanding ammonium (100% at filtration flux of 10 and 15 L/m2 h) and phosphorus (>91% at all fluxes range) removal with optimum pH range of 6-7. © 2009 Elsevier Ltd

Concepts towards a novel integrated assessment methodology of urban water reuse

Traditional supplies of large volumes of water and wastewater disposal technologies have offered a linear solution, thus intensifying environmental stress. In addition, provision of urban infrastructure especially any major augmentations are often the impractical or economically prohibitive. Urban water cycle should be viewed as an interactive and coordinated approach involving: • Available water resources, • Appropriate treatment technology producing fit for purpose water quality, and • Ascertaining long term balance between environmental, social and economic issues. Implementation of integrated water reuse scheme requires major paradigm shift within a number of technical (science, technology and knowledge) and non-technical (socio-cultural, economic, environment) dimensions. There are number of questions that arise from this scenario: • How to make decisions regarding selection, design, implementation and operation of any recycling scheme? • What knowledge is necessary to improve decision-making process? • How to assess and compare performance of the scheme? • What are the parameters for uniform evaluation process? The aim of this paper is to introduce a new concept for integrated assessment methodology that can be applied for urban water reuse schemes. The conceptual assessment methodology relies on decision that treatment technology represents a leading theme and is supported by selection of socio-economic and environmental factors, thus enabling holistic evaluation and quantification of the outcomes. © 2009 Desalination Publications

Characterization of Corrosion in Aluminum Alloys Using Nuclear Magnetic Resonance

With an ever increasing emphasis on extending the life of both military and commercial aircraft, it is critical to have nondestructive evaluation (NDE) methods capable of detecting corrosion in its earliest stages of formation. The consequences of corrosion left undetected are material thinning and a subsequent reduction in strength. Conventional NDE methods such as ultrasonics, eddy current and radiography are capable of detecting the resultant exfoliation caused by corrosion; however, some material loss must occur before reliable detection can be made using the referenced methods

Roles of sponge sizes and membrane types in a single stage sponge-submerged membrane bioreactor for improving nutrient removal from wastewater for reuse

Sponge not only can reduce membrane fouling by means of mechanical cleaning and maintain a balance of suspended-attached microorganisms in submerged membrane bioreactor (SMBR), but also can enhance dissolved organic matter and nutrient removal. This study investigated the performance of three different sizes of sponge (S28-30/45R, S28-30/60R and S28-30/90R) associated with continuous aerated SMBR. A laboratory-scale single stage sponge-SMBR (SSMBR) showed high performance for removing dissolved organic matter (>96%) and PO4-P (>98.8), while coarse sponges such as S28-30/45R, S28-30/60R could achieve more than 99% removal of NH4-N. When three-size sponges (S28-30/45R, S28-30/60R and S28-30/90R) were mixed at a ratio of 1:1:1 and in conjunction with two kinds of membranes (0.1 μm hollow fiber and 2 μm nonwoven), the SSMBR system has proved its generic merits of superior treated effluent quality and less membrane fouling. The NH4-N and PO4-P removal were found excellent, which were more than 99.8% and over 99% respectively. Molecular weight distribution also indicated that major fractions of organic matter could be successfully removed by SSMBR. © 2009 Elsevier B.V. All rights reserved

Delayed biliary duet obstruction after orthotopic liver transplantation

After orthotopic liver transplantation and biliary reconstruction by cholecystoduodenostomy, four of 40 patients developed delayed obstruction of the cystic duct. The recipients had the clinical syndrome of fulminating cholangitis with jaundice, fever, leukocytosis, toxemia, and bacteremia. All four patients died; of the four, two patients died despite late reoperation and re-establishment of bile drainage by choledochoenterostomy. In all four cases, a factor contributing to the biliary obstruction may have been infection of the extrahepatic biliary ducts with or without ulceration, and in three of the livers, there was evidence of infection of the ducts with CMV. If cholecystoduodenostomy is used in future cases, prompt re-exploration and conversion to choledochoenterostomy should be considered if the diagnosis of duct obstruction, cholangitis, and persistent bacteremia are made. © 1972

Solitary Esophageal Varix Simulating a Neoplasm

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73070/1/j.1440-1673.1988.tb02785.x.pd