Permanently reducing environment

In a review of various marine disposal options, Kester et al.(1983) suggested that the best strategy for disposing of contaminated sediments is to isolate them in a permanently reducing environment. Disposal in capped mound deposits above the prevailing sea-floor, disposal in subaqueous depressions and capping deposits... 

Although reducing the corrosivity of the external environment wrould reduce cracking, in this case it is judged that cyclic, operational stresses are predominant. Until the source of the stresses is determined and reduced or eliminated, it is doubtful that a permanent solution can be achieved. 

After the inherent hazards are reduced, layers of protection are frequently used to protect the receptors of the hazard—the public, the environment, workers, other processes, or the process itself (Figure 1.1). In the strictest sense, one could argue that the definition of inherently safer applies only to elimination or reduction of the hazard. In the broad sense, the strength of a layer of protection can be improved by features that are permanent and inseparable from that layer. Thus, layers of protection can be classified into three categories, listed in decreasing order of reliability passive, active, and procedural. A passive layer of protection can be described as inherently safer than an active... 

What do we mean when we speak of an inherently safer chemical process Inherent has been defined as existing in something as a permanent and inseparable element, quality, or attribute (American College Dictionary, 1967). A chemical manufacturing process is inherently safer if it reduces or eliminates the hazards associated with materials and operations used in the process, and this reduction or elimination is permanent and inseparable. To appreciate this definition fully, it is essential to understand the precise meaning of the word hazard. A hazard is defined as a physical or chemical characteristic that has the potential for causing harm to people, the environment, or property (adapted from CCPS, 1992). The key to this definition is that the hazard is intrinsic to the material, or to its conditions of storage or use. Some specific examples of hazards include ... 

The overall protection of human health and the environment by permanently and significantly reducing the volume, toxicity, or mobility of hazardous substance, pollutants, and contaminants... 

Finally, process analytics methods can be used in commercial manufacturing, either as temporary methods for gaining process information or troubleshooting, or as permanent installations for process monitoring and control. The scope of these applications is often more narrowly defined than those in development scenarios. It will be most relevant for manufacturing operations to maintain process robustness and/or reduce variability. Whereas the scientific scope is typically much more limited in permanent installations in production, the practical implementation aspects are typically much more complex than in an R D environment. The elements of safety, convenience, reliability, validation and maintenance are of equal importance for the success of the application in a permanent installation. Some typical attributes of process analytics applications and how they are applied differently in R D and manufacturing are listed in Table 2.1. 

Triton SP-Series surfactants use both a hydrophobe and an ethoxylate chain hydrophile. The surfactants are characterized by nonionic surfactant features such as good detergency, surface activity, and wetting. When the pH of an aqueous solution that contains a Triton SP-Series surfactant is reduced, the bond between the surfactant hydrophobe and hydrophile is permanently destroyed, thus eliminating surfactancy. This product was launched commercially in December 1996 and is currently available. The surfactants cannot be used in highly acidic environments. Other compounds that might be found in the contaminated waste, snch as phosphate, may interfere with the oil/water separation after snrfactant deactivation. All information is from the vendor and has not been independently verified. 

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