The authors contend that sludge freezing can be a practical process for dewatering when done at the right rate with a sludge that has been adequately prepared.A MAJORITY of water plants now dispose of waste solids by return ing them to surface waters,1 and better treatment and disposal methods are needed. One method offering possible improvement, which was studied and used in England on a plant scale, is sludge freezing.Doe and others 2 found this process to be quite effective for dewatering alum sludge.

The air basin between the Mississippi River and the bluff in Illinois is of particular interest for this report. The autumnal temperature profiles were measured by a wiresonde. Each day through September and October had an inversion at dawn and/or dusk. During the entire three months, inversions 5° or more occurred at dawn 64% of the mornings, those 10° or more occurred 45% of the mornings; and those 1 5°o ccurred 23% of the mornings. Under intense inversions, the topography holds cool air in the basin like water in a saucer, and currents within this 200-ft air layer comprise a quasi-closed circulation system. A frequent pattern of air circulation involves a northwestward surface drift in the basin, with a southwest wind aloft and an updraft over St. Louis. This forms a horizontal semi-vortex along the river, concentrating the heavier particulates near East St. Louis and Granite City. Multiple evidence showed this pattern to exist one morning among four. Business interests would use the basin for industrial expansion, but air resource planners prefer to keep new air pollution sources out of this low land.

This article discusses methods of detection and characterization that are the most effective currently available for the complete identification of many of the compounds occurring in water supplies. They include: carbon adsorption method; liquid‐liquid extraction; paper chromatography; fluorescent spectroscopy; gas chromatography; thin‐layer chromatography; and, radioactivity.

A study on the importance of the presence of taste‐ and odor‐causing materials in the Missouri River was recognized by representatives of industries and municipalities, resulting in the formation of the Missouri River Pollution Monitoring Committee. This committee furnished materials of taste and odor significance for study in the sanitary engineering laboratories of Washington University in St. Louis. The study of these organic materials of taste and odor significance is presented in this article, including study techniques presently used to characterize these organic substances. Results indicate the following: carbon filters are a good tool for the study of organics of taste and odor significance; infrared spectroscopy is useful in proving other methods of characterization; and, characterization through the use of biological degradation studies is important in determining the persistence of organic material having taste and odor significance.

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