The design characteristics of an active waste disposal capsule placed within a saturated groundwater environment is investigated, with the objective of developing a methodology to determine environmentally, technically and economically feasible conditions for its operation. In operation, conditions are created and maintained within and surrounding a containment cell to insure that a potential for convective inflow exists everywhere across an encapsulating barrier which tends to counter the potential for outward dispersion through the barrier. A computer algorithm based on the finite element method has been developed in the BASIC language to aid in the hydraulic analysis. Essentially, it provides a numerical solution to potential flow through porous media for two dimensional anisotropic solution domains of various materials. Data generated from this algorithm for cases of varying geometric material and boundary properties are used to verify and quantify assumed relationships involving critical design parameters which have been developed through dimensional analysis and physical reasoning. An expression describing the concentration profiles developed across the barrier is obtained by solving the one-dimensional convection-dispersion equation for steady conditions within and bounding the capsule barrier. Applying this result to an identified critical point allows conservative barrier design criteria to be developed so that operation of the active capsule results in only negligibly small amounts of contamination escaping through the barrier to the environment. By introducing cost coefficients which are descriptive of various aspects of construction, operation and maintenance of the active capsule, a total cost function is formulated from which, when minimized with respect to various design variables, optimizing criteria are developed. Finally, a predictor-corrector optimization program which incorporates the results of this study is developed and used to investigate an illustrative problem. / M.S.

The author evaluated the applicability of the Environmental Protection Agency's Organic Leachate Model to wastes containing organic solvents and other organic compounds ("non-solvents"), and determined that the model tends to overestimate the leaching of organic solvents and other organic compounds. Furthermore, when evaluated for its ability to predict leaching of organic compounds, the model was found to predict the leaching of organic solvent compounds with some accuracy, with a correlation coefficient (R²) of 0.671 for this subset of the data. The model's ability to predict the leaching of non-solvent organic compounds, however, was found to be poor, yielding an R² of 0.388 for this subset of the data. The author also investigated the effect that organic solvents have on the leaching of other organic compounds in a waste and found that the presence of solvents increases the potential for leaching among the non-solvent compounds. This conclusion was drawn when the average "leachability ratio", or the ratio of leachate concentration to waste concentration for non-solvent compounds in solvent-bearing waste was found to be nearly four times the average leachability ratio for non-solvent compounds in wastes that did not contain organic solvents. Finally, the author modified the Organic Leachate Model to account for the unique properties of organic solvents in an effort to improve the model's accuracy in predicting the leaching of solvents and other compounds in solvent-bearing wastes. The results of this modelling effort produced an improvement in the predictive ability of the model for both solvents and non·solvents, yielding correlation coefficients (R²) of 0.678 for the subset of data represented by organic solvents, and 0.431 for non-solvents) but the improvement was still not sufficient to justify applying the model to non-solvent compounds. / Master of Science

The purpose of this investigation was to evaluate the use of NUCHAR activated carbon and aluminum sulfate as agents for removing a significant amount of color V from the caustic extraction waste of a sulfate pulp process. After a thorough search of the related literature was completed, experimental tests were conducted using activated carbon and aluminum sulfate. Fourteen tests employing activated carbon were made at 25 °C, pH values of waste ranging from 3 to 11.4, carbon content of 0.1 and 0.3 gram per 100 milliliters of waste, and stirring times of 1, 3, 5, 10, 15, and 30 minutes. Treatment of the waste with aluminum sulfate was s conducted at temperatures of 25, 60, 61, and 62 °C, pH values of waste of 6, 7, 8, 9, and 10, and alum additions of 0.6, 0.0, 1.2, and 1.5 grams alum per liter of undiluted waste, Stirring time for these e treatments was 5 minutes at 75 revolutions per minute and 25 minutes at 45 revolutions per minute. Filtration of the sludge from alum coagulation of the caustic waste was performed through a sand bed and by vacuum through filter aid. Filtration through filter aid indicates a greater possibility of development into a workable process. It was concluded from this investigation that NUGHAR CEE-N activated carbon will not remove a significant amount of color free the caustic waste at the above conditions, but alum coagulation of the waste at pH of 6, temperature of 25 °C„ alum dosage of 1.5 gram per liter of waste, and stirring of 5 minutes and 25 minutes at 75 and 45 revolutions per minute, respectively, will decrease the color content of the waste approximately 90 per cent. / Master of Science

With the advent of polyester fibers, disperse dyes, with complex chemical carriers and surfactants have been introduced. These dispersing agents inhibited chemical treatment and passed through biological facilities untreated. Therefore, it was the purpose of this study to ascertain whether chemical treatment with polyelectrolytes could achieve an economical treatment. The study consisted of the evaluation of flocculation performance (turbidity, chemical oxygen demand, and color reductions) for treatments with alum alone and alum with polyelectrolytes. A univariant search technique was used to optimize the flocculation performance with respect to the three parameters, pH, alum concentration, and polyelectrolyte concentration. The results of the alum treatment revealed that the chemical oxygen demand reduction was inadequate, although turbidity and color reductions were sufficient, to permit disposal of the effluent to the stream. When cationic polyelectrolytes were used with alum the results were greatly improved compared to alum. Reductions of turbidity, chemical oxygen demand, and color greater than 80 per cent were attained with two cationic polyelectrolytes. The flocculation performance with anionic polyelectrolytes was inferior to treatment with alum and alum with cationic polyelectrolytes. The floc was faster settling for all polyelectrolyte treatments. The volume of sludge in alum treatment was two to 2.5 times greater than for treatment with polyelectrolytes. Considering the present value determinations, aerated lagoons were the least expensive investment and would be the obvious means of treatment. However, if restrictions such as color reduction were imposed, chemical treatment with polyelectrolytes may be justified. / Master of Science

The feasibility of the excess lime process for color removal from textile dye wastes was evaluated. The lime dosages were optimized by using anionic, cationic, and nonionic polyelectrolytes as coagulant aids. The effect of the process on the removal of organic pollutants was determined. The time interval between coagulant additions was analyzed. Color reductions of at least 94 per cent were obtained by the lime and lime-polyelectrolyte processes. The lime dosage of 980 to 1,060 ppm was decreased by at least 30 per cent using 5 ppm polyelectrolyte dosages. The processes reduced the Total Organic Carbon concentration by 73 per cent approximately, the Chemical Oxygen Demand by 50 per cent, and suspended solids by about 85 to 90 per cent. The excess lime process was more efficient in removing organic matter than the lime-polyelectrolyte processes, and also incurred the least chemical coagulant cost. The excess lime process was most effective at 30 minutes flocculation and 30 minutes settling. The lime-polyelectrolyte processes were more effective when the polyelectrolyte was added after about 30 minutes lime flocculation and settled for 5 minutes. The lime-polyelectrolyte processes produced a floe which settled rapidly. The volume of sludge produced was about 8.1 to 12.8 per cent, resulting in a sludge to supernatant ratio range of 1:7 to 1:11. The lime-polyelectrolyte sludge volumes were usually higher than the lime sludge volumes. / Master of Science

Coagulation studies were conducted to determine an appropriate treatment approach to remove color and organic carbon from the pulp and paper wastes from the Union Camp Corporation, Franklin, Va. Based on a preliminary analysis of the data collected during this research, either alum or ferric chloride may be used to remove color from pulp and paper wastes. An effluent with final residual color less than 5 color units can be generated using PAC treatment after flocculating certain waste streams with alum or ferric chloride. Higher molecular weight organics (above 5K mass units) showed a near complete removal by coagulation. It is expected that alum coagulation would involve a lesser cost in pH adjustment as compared to ferric chloride coagulation. Alum sludge dewatered and thickened more rapidly than the iron sludge; however, after mechanical dewatering, the alum cake had a slightly greater moisture content than the sludge produced after ferric chloride coagulation. / Master of Science

Coarse coal refuse is difficult to reclaim due to high potential acidity and coarse fragment content, low water holding capacity, low fertility, and other problems. Little is known about coal refuse properties, particularly as they relate to revegetation potential. This study was undertaken to determine the physical and chemical properties of composite samples from 27 coal waste piles of varying age. Selected physical and chemical properties varied widely across this sample set. The mean coarse fragment (>2mm) content of these materials was 60%. The average texture of the fine (<2mm) fraction was a sandy loam with 15% clay. The mean water retention difference, between 0.03 MPa and 1.5 MPa of soil moisture tension, on a whole sample basis was 0.08 g water/g refuse. The pH values varied from 8.3 to 3.0, and the older piles generally had lower pH values than the more recent piles. The saturated paste electrical conductivity (EC) was higher in the younger coal waste materials. Total elemental analysis revealed that Si, Al, Fe, and K were the most abundant elements in these materials. The mineralogy of three selected samples was found to be dominated by quartz in the sand and silt fraction and mica in the clay fraction. The physical factor most limiting to plant growth was found to be low water holding capacity. Low pH was found to be the chemical factor most limiting to plant survival. These findings indicate that some refuse piles may be suitable for direct seeding, but many will require heavy lime and/or organic treatments. / Master of Science

In this study, solidification and stabilization processes were evaluated for use as a treatment method for electric arc furnace dust. Specific objectives were (1) to develop a solidified material capable of meeting EPA requirements for heavy metal leaching, and (2) to develop a solidified material that could be used for construction. Results from the studies of the untreated electric arc furnace dust showed that the solubility of cadmium is controlled by the hydroxide species. Lead solubility is more complex because its solubility is controlled by a species other than hydroxide and therefore it is more difficult to predict. Studies also indicated that approximately 1.9% of the composition of the electric arc Furnace dust is made up of lead. This study demonstrated that solidification and. stabilization is a viable treatment process for electric arc. furnace dust. Success in treating the electric arc furnace dust by this method, however, depends upon such factors as the compressive strength of the solidified waste, the amount of electric arc furnace dust incorporated in the concrete, and the ability of the solidified waste to remain intact during the Toxicity Characteristic Leaching Procedure (TCLP). Based on these factors, approximately 165 lb dust/cu yd concrete was determined to be the upper limit on the amount of electric arc furnace dust that can be incorporated in such a system. Efforts to improve the quality of the concrete by the addition of a chelating agent was moderately successful; however, the addition of salts to speed the concrete set times was not successful. A model was developed which predicts the required compressive strength of the solidified dust based upon the amount of electric arc furnace dust that is incorporated in the concrete. The model effectively predicts, without performing the TCLP test, whether the solidified material will meet limits for heavy metal required by the EPA. / Master of Science

No / A predictive modelling technique was employed to estimate wastewater temperatures in sewer pipes. The simplicity of abductive predictive models attracts large numbers of users due to their minimal computation time and limited number of measurable input parameters. Data measured from five sewer pipes over a period of 12 months provide 33,900 training entries and 39,000 evaluation entries to support the models' development. Two simple predictive models for urban upstream combined sewers and large downstream collector sewers were developed. They delivered good correlation between measured and predicted wastewater temperatures proven by their R(2) values of up to 0.98 and root mean square error (RMSE) of the temperature change along the sewer pipe ranging from 0.15 degrees C to 0.33 degrees C. Analysis of a number of potential input parameters indicated that upstream wastewater temperature and downstream in-sewer air temperature were the only input parameters that are needed in the developed models to deliver this level of accuracy.

Call number: LD2668 .T4 1985 R33 / Master of Science