Permanence of metals containment in solidified and stabilized wastes /
Despite the increased use of solidification/ stabilization
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1997.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=736823971&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Despite the increased use of solidification/ stabilization remediation technologies, little research has been conducted on the weathering and degradation of solidified and stabilized wastes once the treated materials have been buried. This research was initiated to examine the mineralogical alterations of seven metal-bearing solidified and stabilized wastes that have been landfilled or stored aboveground for up to six years. Although the extent of degradation after six years is considered slight to moderate, mineralogic analyses using optical and electron microscopy, x-ray diffraction, and electron probe microanalyses identified chemical weathering features that include: dissolution of copper, lead, nickel, zinc, and various minerals within the cement micromass; mineralogic zoning of copper, barium, and lead sulfates, phosphates, and oxides; chemical reaction rims around metallic cores of chromium, lead, and zinc; diffusion of cadmium, lead, zinc, iron, and tin into the surrounding cement micromass; and precipitation of various minerals along fracture surfaces and void spaces. Many of the mineralogical changes were promoted by pervasive cracking at macro-, micro-, and submicroscopic scales. Cracking was observed within the cement matrix, as well as within waste aggregates which allowed air, moisture, and groundwater to interact with the treated waste constitutents. Wastes treated with cement, like hardened concrete, are metastable both physically and chemically under ambient conditions of service. Over time, the treated wastes will attempt to reach equilibrium with the surrounding environment. The same environmental concerns that affect the durability of concrete must be considered when evaluating the durability and permanence of cement- stabilized and solidified wastes. Additional long-term studies are needed from controlled sites that include microscopic and submicroscopic site-specific analyses. Such studies cannot be based on leaching and chemistry analyses alone. Regulations for the on-site burial of treated wastes, even after they are rendered nonhazardous, are needed. Burial of cement-based solidified and stabilized wastes in deleterious environmental zones, such as acid or saline soils, as well as fluctuating groundwater systems are not recommended. |
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| Item Description: | Vita. "Major Subject: Soil Science". |
| Physical Description: | xvii, 327 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 160-175. |