Bench scale batch experiments were performed on sludges obtained from line neutralization of coal mine drainage in an attempt to alleviate present problems in sludge handling and disposal. Tests were of an exploratory nature and did not afford sufficient data for cost analyses. Ferro Magnetic sludge densification, filter aids, coagulant aids, heating, freeze drying, and coprecipitation of calcium carbonate through addition of CO₂ were tested. Of these, freeze drying, CO₂ addition, and ferro magnetic treatment were shown to be feasible alternatives to present disposal methods. Each of these methods resulted in settled sludge volume reduction of approximately 90% and increases in sludge solids contents of from 0.5 to about 5% after 30 min. settling periods. The ferro magnetic process has the advantages of possible recovery of a useful product, and elimination of costly settling lagoons, but is very sensitive to aluminum and requires a considerable amount of heat. Sludge freezing is the simplest conceptual approach and is apparently effective for any lime produced sludge. The CO₂ addition method offers the possibility of partial recovery and recycling of both CaO and CO₂ through sludge calcination.

Periodic taste and odor at the Cleveland, Ohio Crown Water Treatment Plant prompted investigation of the role microorganisms play in the problem. Fungi, bacteria, and algae collected near the plant intake were studied during June through August 1971. During the three months of sampling, no vertical distribution pattern was noted in quantitative analysis of the phytoplankton. A number of algae, reported to induce taste and odor in water, were identified. Whatever the source of these odors, they were not due to benthic or periphyton algae, but could have been associated with the phytoplankton community as the reported 'Lake Erie odor' coincided with phytoplankton increase.

The introduction of sulfite waste liquors into streams often leads to the development of unsightly masses of biological slime dominated by Sphaerotilus. One approach for controlling the development of Sphaerotilus in streams receiving pulp mill wastes has been to employ biological methods for treating wastes before release into a receiving stream. The study evaluates the slime growth potential of pulp mill wastes treated by various methods of biodegradation. Wastes were tested both before and after secondary treatment in order to determine the type of biodegradable material present in the influent, determine the extent of fermentation during treatment, and the amount of biodegraded fermentable compounds discharged in the effluent. These studies were carried out in an effort to define total carbon, readily fermentable carbon, and to design a reasonably accurate and sensitive method for predicting adequate water quality presently measured by BOD.

Studies were undertaken on a small scale to determine the effect liquid waste artificial iron-rich acid brines had on municipal sewage treatment processes. The brines were devised to simulate concentrates from treatment of acid mine drainage. At very high concentrations, the brines neutralized with lime give virtually complete removal of phosphate from primary effluent, activated sludge effluent, or anaerobic sludge digester decantate. The cost of the iron-rich acid brine produced from acid mine drainage by the reverse osmosis membrane treatment is estimated. Costs of transportation by rail, truck, and pipeline are also shown.

A pilot scale field investigation of the effects of supplemental aeration on waste stabilization lagoons was conducted at Laramie, Wyoming, a low temperature, high altitude area. Both batch and complete mixed experiments were conducted using constant air flows. Loading rates, both hydraulic and process, were varied. The supplemental aeration provided both aeration and mixing, thereby increasing metabolic rates. BOD reductions varied from 72 to 85% under three different loadings, at temperatures of less than 12°C. No settleable solids were found in the effluent from the aerated system. Series operation was demonstrated to have the advantages of damping variations in quality parameters, providing for shock loading, and reducing coliform counts to minimum levels.