published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

Accurate and detailed costs for individual municipal waste collection, treatment and landfill methods are not readily available. Neither is there a reliable means of comparing between two or more alternative options. However, before improvements to the management and planning of solid waste disposal can be achieved both are required. Currently, comparisons and planning in this field are highly ambiguous, often misleading, with individual operators using widely different accounting conventions and operating standards. The purpose of this work has been to establish accurate comparisons. Initially, detailed financial and technical information \'las collected from numerous operators, and then a standard basis for comparison (the "base case") was derived onto which the costs obtained were adjusted. Cost functions were also generated to interpret component costs fora range of sizes of operation. The economics of five collection methods, four transfer methods, seven bulk transport vehicle types and several landfill disposal variations are considered. For each a detailed appraisal of the component capital and operating costs has been made so as to identify the largest expenditures. The effect of uncertainty on cost estimates was also emphasised and explicitly considered by sensitivity analyses on selected economic and physical parameters. These analyses have indicated those component costs which exert the most significant influence on the total costs, and as such should be the most closely monitored by a waste manager. One notable example is the sensitivity of total landfill costs to leachate treatment. Six case studies are also presented. These are designed to demonstrate the versatility of the cost models derived and also the method developed for unambiguous economic comparison. This research provides a large financial data base on all of the collection, transfer and landfill methods in common use in Britain. Use of this information and the principles for comparison put forward would enable waste managers to incorporate sound financial appraisals into both their operational and forward planning decisions. This should subsequently improve not only the quality of their decisions but ultimately the standard of service they offer too.

The disposal of waste is a growing environmental, political, and economic problem. Low level radioactive waste (LLW) disposal is no exception. The major purposes of this dissertation are to examine the economic tradeoffs which arise in the process of LLW disposal and to derive a framework within which the impact of these tradeoffs on LLW disposal policy can be analyzed. There are two distinct stages in the disposal of LLW--the transportation of the waste from sources to disposal sites and the disposal of the waste. The levels of costs and risks associated with these two stages depend on the number and location of disposal sites. Having more disposal sites results in lower transportation costs and risks but also in greater disposal costs and risks. The tradeoff between transportation costs and risks can also be viewed as a tradeoff between present and future risks. Therefore, an alteration in the spatial distribution of LLW disposal sites necessarily implies a change in the temporal distribution of risks. These tradeoffs are examined in this work through the use of a transportation model to which probabilistic radiation exposure constraints are added. Future (disposal) risks are discounted. The number and capacities of LLW disposal sites are varied in order to derive a series of system costs and corresponding expected cancers. This provides policymakers with a cost vs. cancers possibility function. The marginal cost of reducing cancers by changing the number and location of disposal sites is calculated. A possible policy application of this information is illustrated by comparing these costs to an assumed value of life derived from experimental evidence found in the literature. A tentative conclusion is reached that the current movement toward a system of regional LLW disposal sites may be economically suboptimal.

The concentration of phenols in the soils environment and their fate was studied as a function of five different soil types, six different monohydroxyphenols, and three different municipal landfill leachates media. Concentrations of naturally occurring phenols were also followed for a period of one year in young and old leachates. Methods for analysis of phenols were reviewed for quantitative and qualitative analysis of phenols in landfill leachates. To determine the adsorptive capabilities of the soils used in this study, the isotherm approach was used after the equilibration time of phenols in soils was determined to be five days. Concentrations of phenols varying from 5 ppm to 100 ppm were used to construct isotherm graphs. The soil-phenol isotherm curves conformed very well to the Freundlich equation, indicating multiple adsorption mechanisms and slow equilibration times in the soilsphenols reactions. A statistical analysis of the isotherm data showed %-free iron oxides to be the most important soil characteristic for the adsorption of phenols by all soils; followed by soil pH and % clay in order of significance. High solubility and moderate polarity of phenols also were found to be favorable factors in the adsorption of phenols by soils. Naturally occurring phenols such as cresols disappeared fastèr from soil solutions than synthetic phenols. The reactivities of phenols with MSW leachates increased with the age of the leachates. Very young leachates, having low pH and high TOC levels favored synthetic phenols over naturally occurring phenols to react with. All leachates studied demonstrated an ability to remove from solution one or more of the six phenols used in large quantities over a period of 15 days or less. The overall performance of the leachates used in this study seemed to be a function of the humic acid levels found in them. Levels of naturally occurring phenols in leachates varied from several ppbs to more than 9000 ppbs for a year's period. The highest phenol levels were found in the young phenols and the lowest levels in the old phenols; indicating that pH and TOC concentration determine the amounts of phenols in solution. In column studies of perfusion of leachates through 10 cm of soil materials packed at field densities, no soil was able to stop the migration of phenols for more than 5 to 10 pore volume displacements. Low pH and high TOC levels seemed to play a much larger role in the migration of phenols through soils than the levels of phenols found in the leachates used. The use of phenol enriched deionized water passed through soil columns showed the fact that there is a clear dependency of adsorption of phenol on the flow rate. Slow rates favored adsorption of phenol by all soils studied. The TOC analysis of the effluents from the phenol enriched water-soil columns studies indicated that some mechanisms for the disappearance of phenol from soil solution may have been transformation reactions as well as adsorption reactions. Varying TOC levels with flux seemed to indicate that these reactions are much slower than the adsorption reactions. The use of Cu⁺² saturated soils in an attempt to correlate transformation reactions of phenol with transition metal catalytic properties failed to increase the adsorption and/or transformation of phenol in the soil media. The 4-aminoantipyrine colorimetric method performed well in the analysis of phenols in air unstable leachates. Gas-liquid chromatography using NPGSB+H₃PO₄ on Anakrom A 90/100 mesh was used for the quantitative and qualitative analysis of phenols in leachates.

No description available.

Porous plates delivered calcium chloride at a negative potential to the top of blocks of partially welded (20.1 x 20.1 x 66.6 cm) and densely welded (30.1 x 20.1 x 48.1 cm) tuff with discrete fractures. During infiltration, flux increased through the partially welded block's fracture as the applied suction was lowered to 2.3 cm. The wetting front advanced 66.6 cm in 239 days. Chloride concentration and temporal moments from five tracer tests with 0 to 5 cm of applied suction indicated that preferential fracture flow occurred. Displacement transducer data reflect a decrease in fracture aperture at several months prior to but not during tracer tests. Fracture transmissivities decreased an order of magnitude (6.4 x 10⁻⁹ to 4.2 x 10⁻¹⁰ M²/s) as the applied suction increased from 0 to 5 cm while the tensiometer data indicated a suction of about 20 cm of water within the fracture and matrix. Highest during infiltration to an initially dry block, inflow losses of 3 to 44 percent due to evaporation are the greatest source of error for the constant potential method used.