Importance of 2,4,6-Trichloroanisole (TCA) as an odorant in the emissions from anaerobically stabilized dewatered biosolids.

Odours from stabilized biosolids after anaerobic digestion of wastewater sludge can cause local community impact. Apart from the well-known odorants such as sulfur compounds, contributions from other volatile organic compounds (VOCs) to nuisance odours is limited. The presence of compounds with low odour detection thresholds (ODTs) at low concentrations, can present challenges for analytical identification. Thirty-six biosolids samples were taken after anaerobic stabilisation and dewatering at a wastewater treatment plant, Sydney, Australia. Biosolid cake samples were stored outside in loosely covered trays under aerobic conditions, however without interactions with soil microorganisms as it would be in reality. All biosolids cake samples were analysed over a period of 35 days. Emissions were collected onto Tenax TA sorbent tubes using a U.S. EPA flux hood method at storage days 1, 3, 7, 10, 14, 21 and 35. Gas chromatography (GC) coupled with mass spectrometer detector (MSD) and an olfactory detection port (ODP) was used to identify a musty/moldy/earthy type odorant in the biosolids emissions as 2,4,6-trichloroanisole (TCA). Measured odour intensities, classified on a scale from 1 to 4, and odour characters were specified by three ODP assessors. TCA was identified in all biosolid cake emissions. The measured odour intensities of the TCA did not significantly alter as the biosolids were aged, however varied between biosolids cakes. Due to its odour intensity, 85% frequency of detection and its low ODT, which is orders of magnitudes lower than sulfur compounds, TCA should be considered as a potential odorant of concern in biosolids emissions.

Odorous volatile organic compound (VOC) emissions from ageing anaerobically stabilised biosolids.

Opportunities for the beneficial re-use of biosolids are limited by nuisance odour emissions. Volatile organic compounds (VOCs) from anaerobically stabilised biosolids were measured to identify compounds that could contribute to the overall odour character of nuisance emissions. Flux hood sampling and chemical analysis were used to identify VOCs emitted from biosolids as they were stored in ambient conditions. Compounds emitted varied as the biosolid cakes were stored for a period of 50 days. VOCs detected in the biosolids are likely to occur from catchment sources as well as abiotic and biotic generation in the wastewater processing and the biosolids as they are stored. Odour activity values (OAVs) were used to compare odorants. Trimethylamine was the only VOC detected that exceeded the sulfur compounds in terms of OAVs. Other compounds such as limonene, ethyl methyl benzene and acetic acid were detected at concentrations exceeding their olfactory detection limits, however at lower OAVs than sulfur compounds.

Validation of a method for odor sampling on solid area sources.

The aim of this paper is the study and the validation of a method for odor sampling on solid area sources. This aim is achieved by considering a suitable theoretical model that accounts for all the variables involved in the volatilization process of odorous compounds from solids into the atmosphere. The simulation of the emission of odors from a solid surface was achieved by designing a suitable experimental setup and a specific wind tunnel for laboratory tests. The results of the tests show a good correspondence between the theoretical data derived from the adopted model and the experimental data. The verification of the possibility of describing the wind tunnel functioning with a theoretical volatilization model proves the applicability of this device for sampling on solid area sources.

Myocardial structures over the coronary arteries and their branches.

Myocardial bridges over coronary arteries have been investigated in 30 pig's hearts. Such bridges were found in 26 hearts. Such structures were in form of myocardial loops, bridges or tunnels. The bridges were found most often over the posterior interventricular branch.

Clinical evaluation of the Cleon imager.

We have compared bone images from a number of patients using three instruments. In 38 patients, Cleon body images were compared with whole-body rectilinear scans. Cleon images were also compared with scintillation camera images of the trunk or extremities of 31 patients and of the skull of 70 patients. The Cleon was superior to the rectilinear scanner in resolution, lesion detectability, and speed of scanning. The Cleon and gamma camera were comparable in lesion detection, but the Cleon was consdierably faster. Clinical studies and comparative evaluation are presented.

Acute viral hepatitis in adults. Comparison of the radioimmunoassay and counterimmunoelectrophoresis methods of detecting HbsAg.

We compared the radioimmunoassay (RIA) and counterimmunoelectrophoretic (CIE) methods in detecting hepatitis B antigen (HBsAG) in 407 acute and 336 convalescent sera of adults with viral hepatitis. The CIE method demonstrated that 41% of acute and 28% of 14-to 17-day serum specimens were HBsAg-positive. The RIA method demonstrated seropositivity in 60% of acute and 56% of convalescent specimens (P less than .001). Eighty-four percent of coded specimens initially positive for HBsAg by RIA were found to have subtype antigenic determinants d or y; 92% of the HBsAg-negative controls were negative for subtype antigens, confirming the specificity of the RIA test. RIA subtyping data corroborated earlier work with immunodiffusion techniques.