Instantaneous amounts of organic carbon, both particulate and dissolved, in a number of freshwaters ranging from unproductive tarns to moderately productive reservoirs were measured by acid-persulfate digestion and infrared absorption. Organic carbon was designated as net seston carbon, filter seston carbon, or dissolved carbon based on filtering techniques. Repeated sampling showed amounts of organic carbon, either dissolved or particulate, fluctuated considerably over short periods of time; the dissolved fraction probably varying less than particulate forms. Almost daily measurements in samples incubated over three week periods also revealed erratic changes, with no clear reduction in total organic carbon. The data have descriptive value, although they cannot, at this time, be related satisfactorily to the general limnological knowledge.

A two volume compilation, review and critique of the literature on biological trickling filter studies and related pollution abatement processes have been made. In the report, the literature review and critical analysis, is divided into: Introduction, definitions, history and background theory of the trickling filter process; Plant design, materials of construction, operation, maintenance and performance; Trickling filter research and development approaches, ecology, and patents, and Applications of trickling filter to specific industrial wastes. Based on the review, several general conclusions were drawn. There is no well-defined theory of design and operation. Much published work was redundant, and European efforts were not readily accepted in the United States, and vice versa. The literature reflects cycles of interest in trickling filters. The process is not applicable to all pollution problems, but its shock survival capabilities and rapid flow-through time are definite advantages which cannot be overlooked in any design of a waste treatment facility. In Vol. 2 a bibliography of 5,665 references relating to biological trickling filters studies is presented. Author references are listed in alphabetical sequence based upon the surname of the author. Anonymous articles are listed after the alphabetical author sequence, according to the alphabetical sequence of the journal, and chronologically within the journal.

Hot waste pickle liquor (ferrous sulfate) as an iron source was successful in precipitating phosphorus from solution in a 115 mgd East Plant of Milwaukee's Jones Island Activated Sludge Wastewater Treatment Plant. An 85 mgd section of the plant receiving the same influent was operated as a control. The East Plant with iron addition, achieved 91.3% removals (0.70 mg/1 P effluent residual), while the control West Plant removed 83.1% (1.4 mg/1 P residual). Comparison of efficiencies of purification, pH, alkalinity, and microscopic examinations of the sludge microorganism indicated that the addition of unneutralized waste pickle liquor did not adversely affect purification processes.

The feasibility of using histochemical and histopathological changes in brook trout, longnose dace and fathead minnows as bioindicators of acid pollution was investigated. Laboratory studies entailed using a gravity flow diluter system. Field studies involved using net traps in polluted streams. Exposure durations were 4-5 days and 28-30 days. Histochemical and cytophotometric analyses were made of gills, Stannius corpuscle, blood, spleen, kidney and liver. The primary mode of acid toxicant action is gill damage which results in impaired respiratory, excretory and liver functions. Short term indices of acid stress include: colloidal iron and aminosalicylic acids (PAS) staining of gills and renal Stannius corpuscles. A useful bioindicator of prolonged acid exposure is decreased azure B-RNA staining of liver cells; this assesses the extent of liver impairment and reflects a reduced tolerance of fish to other toxicants.

The energy budget approach to cooling ponds has been outlined and applied to cooling ponds. Monthly average weather data from 88 stations throughout the U.S. were used to calculate equilibrium temperatures, heat exchange coefficients, and amount of cooling in various sized ponds receiving the effluent from a standard power plant of 1000-mw capacity, both for average and extreme weater conditions. The data for each station is shown on a chart, and the variation of these results across the U S. is depicted by a series of 28 maps of the U.S. with contours connecting equal values of the parameters. The results may also be used to estimate cooling pond performance for other sized power plants. The maps disclose variations across the U.S., on a given date, of up to 55°F in equilibrium temperature, up to 100% difference in heat exchange coefficients, up to 50% difference in heat lost from a given sized pond, and up to 200% difference in the size of a pond necessary to produce an equal cooling effect.