Organic content

A U.S. EPA study (41) showed that soil vapor extraction (SVE) is an effective treatment for removing volatile contaminants from the vadose zone. Sandy soils are more effectively treated than clay or soils with higher organic content because higher air flows are possible in sand and clays—organic soils tend to adsorb or retain more contaminants. Removal of volatiles is rapid in the initial phase of treatment and thereafter decreases rapidly thereafter-an important consideration in the design of air emissions control over the life of the project. 

It is important to identify volatile organic carbon (VOC) and the presence of specific priority poUutants, ia additioa to the total organic content. The... 

In several cases, such as shellfish areas and aquatic reserves, the usual water quaUty parameters do not apply because they are nonspecific as to detrimental effects on aquatic life. Eor example, COD is an overall measure of organic content, but it does not differentiate between toxic and nontoxic organics. In these cases, a species diversity index has been employed as related to either free-floating or benthic organisms. The index indicates the overall condition to the aquatic environment. It is related to the number of species in the sample. The higher the species diversity index, the more productive the aquatic system. The species diversity index is computed by the equation K- = (S — 1)/logjg I, where S is the number of species and /the total number of individual organisms counted. 

High purity sulfur with low ash and organic content is desirable. If the raw sulfur is in soHd form, it is first melted and filtered or otherwise treated for purification. Liquid sulfur must be handled between the melting point (132°C) and about 150°C to avoid its pecuflar high viscosity range (see Sulfur). 

The HCl gas is absorbed in water to produce 30—40% HCl solution. If the HCl must meet a very low organic content specification, a charcoal bed is used ahead of the HCl absorber, or the aqueous HCl solution product is treated with charcoal. Alternatively, the reactor gas can be compressed and passed to a distillation column with anhydrous 100% Hquid HCl as the distillate the organic materials are the bottoms and are recirculated to the process. Any noncondensible gas present in the HCl feed stream is vented from the distillation system and scmbbed with water. 

Suspended solids, organic content, nitrogen (all forms), phosphorus pH, and inorganic metals including arsenic, harium, cadmium, chromium, copper, lead, mercury, selenium, silver, sodium, and zinc. 

Example. The Pechini method for fuel cell electrode preparation. La, Ba, Mn niU ates - - CgHgO — citrate complex - - C2FI6O2 — gel. Metal nitrates are complexed with citric acid, and then heated with ethylene glycol to form a transparent gel. This is then heated to 600 K to decompose the organic content and then to temperatures between 1000 and 1300K to produce tire oxide powder. The oxide materials prepared from the liquid metal-organic procedures usually have a more uniform particle size, and under the best circumstances, this can be less than one micron. Hence these particles are much more easily sintered at lower temperatures than for the powders produced by tire other methods. 

Washing of samples to determine water soluble fraction or for ashing to determine organic content... 

Halogen, sulphur, nitrogen content Ash content Analysis of ash Organic content by BOD, COD, PV or total carbon methods completed... 

If a waste is a mixture of water and organic liquid, you must report it as wastewater unless the organic content exceeds 50 percent. Slurries and sludges containing water must be reported as solid waste if they contain appreciable amounts of dissolved solids, or solids that may settle, such that the viscosity or density of the waste is considerably different from that of process wastewater. 

As a first step in the selection process, the applicability of the various solidification/ stabilization processes for specific contaminants can be determined using Table 12. Since these waste treatment systems vary widely in their applicability, cost, and pretreatment requirements, many are limited as to the types of waste that can be economically processed. Waste characteristics such as organic content, inorganic content, viscosity and... 

Applicability Pozzolanic processes are suitable for high-volume, low-toxicity wastes containing radioactive materials or heavy metals with an organic content below 10 percent. 

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