Macroencapsulation

Applicability Surface encapsulation (macroencapsulation) is appropriate for both organic and inorganic wastes. 

MACRO Macroencapsulation Macroencapsulation is the application of a surface coating material to seal hazardous constituents in place and prevent them from leaching or escaping... 

During a 1996 full-scale demonstration for the U.S. Department of Energy (DOE), Envirocare macroencapsulated approximately 500,000 lb of radioactive elemental lead. Costs were shared between Envirocare and DOE under the terms of the cooperative agreement. Envirocare paid for equipment, supplies, facility construction, facility modihcation, permitting, and personnel... 

Macroencapsulation Physical isolation Coating with a low permeability mixture... 

Solidification refers to techniques that encapsulate the waste, forming a solid material, and does not necessarily involve a chemical interaction between the contaminants and the solidifying additives. The product of solidification, often known as the waste form, may be a monolithic block, a clay-like material, a granular particulate, or some other physical form commonly considered solid. Solidification as applied to fine waste particles, typically 2 mm or less, is termed microencapsulation and that which applies to a large block or container of wastes is termed macroencapsulation [29]. 

Sorption Ion Exchange Encapsulation Microencapsulation Macroencapsulation Embedment... 

D. Singh, A. Wagh, M. Tlustochowicz, and S. Jeong, Phosphate ceramic process for macroencapsulation and stabilization of low-level debris waste, Waste Mgmt, 18 (1998) 135-143. 

Macroencapsulation is used for large objects such as concrete debris that is contaminated, or structural steel that has fixed contamination. The chemical stabilization and microencapsulation work together to immobilize chemical constituents, while the macroencapsulation is used to physically encapsulate large objects. For this reason, we will discuss chemical stabilization and microencapsulation together and address macroencapsulation in a separate section in this chapter. 

Singh et al. [33] patented a macroencapsulation technique in which waste forms are coated with a polymer for successful retention of Cl and NO3. This macroencapsulation of the waste forms reduced the nitrate leaching further in the ANS 16.1 test. Details may be found in Ref. [5]. 

To demonstrate this capabihty, Wagh et al. group worked with Bechtel Jacobs Co., the contractor at Oak Ridge, and conducted a feasibility study. The smdy comprised macroencapsulation of internally contaminated pipe sections [23]. 

The various case studies discussed in this paper demonstrate that CBPCs are a very versatile material for the stabilization of hazardous and radioactive waste streams. CBPCs chemically immobilize and microencapsulate the contaminants, and reduce leaching to levels that meet WAC at DOE sites. They are also suitable for the macroencapsulation of various contaminated objects. 

J. Lichtenwalter and R.S. Seigler, Macroencapsulation of gaseous diffusion plant equipment for burial, Proc. Spectrum Conf., Amer. Nucl. Soc., 2002. 

The inclusion of cells into functional biomaterial scaffolds carries several critical requirements. During and after the macroencapsulation process, cells must remain viable and physiologically functional. It is desirable to encapsulate as many cells as possible and... 

Physical processes macroencapsulation/ containerization, nonchemical microen-capsulation. 

Macroencapsulation Method for Immobilization of Osmium Tetroxide. Macroencapsulation is a technique for entrapping pre-... 

Reservoir systems with rate-controlling membrane Microencapsulation Macroencapsulation Membrane systems... 

Further research examining the transplantation of pancreatic islet cells identifies this approach aimed at curing type 1 diabetes. Unfortunately, the loss of cell function following transplantation presents a major issue. Macroencapsulation of cells in order to isolate and protect them from immune responses have proven unsuccessful, resulting in hypoxic death due to poor diffusion of essential molecules. Nanoencapsulation has been shown to allow for sufficient molecular permeability without significant... 

Another application of smart materials for PPE concerns thermoregulating phase change materials. Based on microencapsulation, macroencapsulation, or solid—solid transition, this technology allows a certain level of on-demand, immediate, and powerless cooling and warming with possible recharge at room temperature. Several fiber, textile, and PPE products are already commercially available, with the addition of a fire-resistant functionality soon to come. 

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