Secondary by-products

When they are released as secondary by-products. One of the most notorious examples is dioxin. 

Although the utility of large-scale cultivation of plant cells) has been well recognized, plant tissue cultivation has not yet been employed industrially for the production of primary or secondary by-products except for a few test processes.10 The underutilization of plant tissue... 

Plasma-driven photocatalysis was performed also for degrading gas-phase toluene (Sun et al., 2007), showing a significant increase in the removal of toluene, while decreasing the number of secondary by-products. It is noteworthy that the decrease in the emission of byproducts could be also due to the loading of the photocatalyst on AC fibers, which could operate through the Adsorb and Shuttle mechanism (Paz, in press). 

The idea of production-integrated environmental protection was implicitly described by A. W. von Hofmann (founder of the Royal College of Chemistry in London) as long ago as 1848 In an ideal chemical factory. .. there is, strictly speaking, no waste but only products (main and secondary by-products). The better a real factory makes use of its waste, the closer...it gets to its ideal, the bigger is the profit [19]. 

The secondary aim is to make use of residues as primary or secondary by-product. Primary by-products are residues that are also generated in a definite production process besides the target product and economically used without prior treatment, i.e. raw materials for other syntheses. Secondary by-products are the resulting residues from a process that are treated outside the considered unit in order to gain immediately usable value-added products. The outside treatment also mostly generates waste materials. Secondary by-products are matures. The main components are considered those mixture components that represent the usable portion of the material. 

The first step in determining the impact of the new air toxics programs is to simply compare the results of the facihty emission inventory to the 10- and 25-ton thresholds. For certain operations, secondary by-products may be chemically created and exist in the effluent discharge stream. H they are triggered for any one or more of the 189 HAPs, then the following provisions need to be evaluated in detail. 

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