In-process waste

Inadequate housekeeping controls in laboratories, process, or operating areas can result in process waste, leakage, and spillage accumulations that can lead to increased fire losses. Such accumulations are typically from one of several causes ... 

Clement RE, Suter SA,Tosine HM (1989), Chemosphere 18 133-140. Analysis of large volume water samples near chemical dump sites using the aqueous phase liquid extractor (APLE) Hellmann A (1986), Analytik von Oberflachengewassern". Thieme Verlag, Stuttgart Le Bel GL, Williams DT, Ryan JJ, Lau BPY (1986), in Chlorinated Dioxins and Dibenzofurans in Perspective . Evaluation of XAD-2 resin cartridge for concentration/isolation of chlorinated dioxins and furans from drinking water at the parts-per-quadrillion level", p. 329-341, Eds. Rappe C, Choudhary G, Keith LH Lewis Publishers, Chelsea Mahle NH, Lamparski L, NestrickTJ (1989), Chemosphere 18 2257-2261. A method for determination of 2,3,7,8-tetrachlorodibenzo-p-dioxin in processed waste water at the parts per quadrillion level"... 

Carefully evaluate in-process waste generation mechanisms to direct the process designer toward environmentally sound material choices and other P2 options. 

Alpha-particle counting is the most commonly used method for determining plutonium concentrations at low levels in biological samples, as well as in process waste streams, and in soil, water, and air filter samples (Brouns 1980). This method does not distinguish between the different alpha-particle emitters of plutonium (plutonium-236, plutonium-238, plutonium-239, plutonium-240, plutonium- 242), nor does it detect plutonium-241, a beta-particle emitter. 

The waste drum assay system (WDAS) measures the residual small plutonium amounts of in-process wastes in 200 liter drums. The system uses a modified neutron coincidence counter with a counter comprising 60 He tubes ( 20% efficiency) with low background. WDAS applies the add-a-source correction technique that corrects for the effects of the waste matrix on neutrons (Menlove et al. 1993, Menlove 1995). A small Cf source is placed in various positions near the external surface of the sample drum. The changes in the Cf coincidence counting rate provide a matrix correction for the plutonium inside the drum. 

Purification of large volumes of waste air containing mercury in very low concentrations is not effective. In the United States, the upper limit for the emission of mercury in process waste air and hydrogen is 1 kg per day per facility, and for ventilation air it is 1.3 kg per day per facility [18, p. 372], In Western Europe the Parcom Decision 90/3 [109] requires a standard of 2 g Hg/t of chlorine capacity for emissions to the atmosphere from existing plants. 

The overwhelming majority of PVC resin—over 99%—sold for the fabrication of pipe, siding, conduit, and windows eventually becomes salable product. There is very little in-process waste in the pipe and conduit industry if in-process materials are unsuitable for pressure pipe, it can be used in a product ranging from first-grade drain waste and vent to slotted underground drainage pipe. 

Isotopes of curium are also found in waste streams from plutonium-239 production, but in amounts smaller than those of americium. Curium is produced by the beta decay of Am and Am formed by neutron capture in Am and Am. The amount of curium-244 accumulated in process wastes and in unprocessed irradiated fuel elements as of 1985 is estimated at more than 100 kg [5]. Separation and purification of curium and americium is best carried out by the ion-exchange procedures described below (see Section 14.3.5). 

The arsenic and diphenylamine products are separated and purified to become chemicals useful in other industrial proceses. The aqueous hydrochloric acid is cleaned, saturated by addition of gaseous hydrogen chloride, and reused in the process. The minor amounts of arsenic contained in process wastes is processed to arsenic sulfide. 

The two inner layers of the onion diagram in Fig. 1.6 (the reaction and separation and recycle systems) produce process waste. The process waste is waste byproducts, purges, etc. 

Sources of waste in process operations a. Start-up I shutdown in continuous processes... 

In continuous processes, all those sources of process waste associated with start-up and shutdown also apply to product changeover in multiproduct plants. 

Clearly, some of these measures to reduce waste in process operations—such as design for low process inventory—can be taken into consideration at the early stages of design, but many cannot. We should be aware of the problem and do whatever we can in the early stages to prevent problems later. 

Process waste minimization in general terms is a question of... 

The major products of combustion are CO2, water, SO, and NO. The products of combustion are clearly beshminimized by making the process efficient in its use of energy through improved heat recovery and avoiding unnecessary incineration through minimization of process waste. 

In Chap. 10, modification of the process for reducing process waste was considered in detail. It also was concluded that to minimize utility waste, the single most effective measure would be improved heat recovery. The energy-targeting methods presented in Chaps. 6 and 7 maximize heat recovery for a given set of process conditions. However, the process conditions can be changed to improve the heat recovery further. 

Reinforced furan resias have been used for many years in process piping and in underground sewer or waste-disposal systems. With a wide range in pH acceptability and good solvent resistance, furan piping has been a logical choice for many services. 

The catalytic vapor-phase oxidation of propylene is generally carried out in a fixed-bed multitube reactor at near atmospheric pressures and elevated temperatures (ca 350°C) molten salt is used for temperature control. Air is commonly used as the oxygen source and steam is added to suppress the formation of flammable gas mixtures. Operation can be single pass or a recycle stream may be employed. Recent interest has focused on improving process efficiency and minimizing process wastes by defining process improvements that use recycle of process gas streams and/or use of new reaction diluents (20-24). 

Because of its antimicrobial activity, acrolein has found use as an agent to control the growth of microbes in process feed lines, thereby controlling the rates of plugging and corrosion (see Wastes, industrial). 

Nearly every chemical manufacturiag operation requites the use of separation processes to recover and purify the desired product. In most circumstances, the efficiency of the separation process has a significant impact on both the quality and the cost of the product (1). Liquid-phase adsorption has long been used for the removal of contaminants present at low concentrations in process streams. In most cases, the objective is to remove a specific feed component alternatively, the contaminants are not well defined, and the objective is the improvement of feed quality defined by color, taste, odor, and storage stability (2-5) (see Wastes, industrial Water, industrial watertreati nt). 

F. G. Shinskey,/JT andplon Control in Process and Waste Streams, ]o m Wiley Sons, Inc., New York, 1973. 

In a rotary kiln, the burner can produce both thermal and fuel NO, if the fuel contains nitrogen. Many soHd waste streams also contain nitrogen, typically as much as 20 wt %, which contributes to the fuel NO pathway. Key sources of soHd waste fuel nitrogen include plastics, nylons, dyes, and other process wastes. Nylon, for example, is 33 wt % nitrogen. 

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