functions t h a t must be performed t o accept, handle, and dispose o f t h e immobilized l o w -a c t i v i t y waste (ILAW) produced by t h e Tank Waste Remediation System (TWRS) p r i v a t e treatment contractors and close t h e f a c i l i t y . functions and t h a t must be met. The functional and performance requirements i n t h i s document provide t h e basis f o r t h e conceptual design o f t h e Tank Waste Remediation System Immobilized Low-Activity Waste disposal f a c i l i t y p r o j e c t (W-520) and provides t r a c e a b i l i t y from t h e program-level requirements t o t h e p r o j e c t design a c t i v i t y .

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There are various criteria concerning hydrocarbons for water needs. Some water users have little concern for dissolved hydrocarbons (e.g., agriculture), and some have strict standards (e.g., drinking water). In general the presence of organic compounds, including hydrocarbons, in water can lead to a buildup of biofilms. Biofilms can be problematic in many situations including drinking water, cooling water, recirculating water, and water used for various other industrial processes. During biofilm formation, the first substances on the surface are not bacteria but trace organics. Almost immediately after the clean pipe surface comes into contact with water, an organic layer deposits on the water/solid interface. These organics form a conditioning layer that neutralizes excessive surface charge and surface free energy that may prevent a bacteria cell from approaching near enough to initiate attachment. In addition, the adsorbed organic molecules often serve as a nutrient source for bacteria. Though there are many criteria, the thrust of this article is on the treatment, including the removal and destruction of hydrocarbons for whatever purpose. It is assumed in this article that the hydrocarbons are dissolved in water, so that technologies such as incineration or decantation will not apply. The focus will be on water‐phase separation and destruction. No economic evaluation is considered. In reality, the trade‐offs would need to be considered, for example, waste disposal costs, electrical cost, and materials.

No abstract

Some of the variables that affect the growth of microorganisms include food/nutrient availability, temperature, pH, biocide concentrations, radiation, makeup water microorganism concentration, and predation. There are practical limitations to the types of activities that can be used to control microorganisms, for example, restricting the use of biocides or pH out of the range of water chemistry requirements. The first substances on a surface during biofilm formation are trace organics (2). Almost immediately after the clean pipe surface comes into contact with water, an organic layer deposits on the water/solid interface (3). These organics form a conditioning layer that neutralizes excessive surface charge and surface free energy that may prevent a bacterial cell from approaching near enough to initiate attachment. In addition, the absorbed organic molecules often serve as a nutrient source for bacteria.