Waste treatment application

Contactor design is important in order to maximize the ozone-transfer efficiency and to minimize the net cost for treatment. The three major obstacles to efficient ozone utilization are ozone s relatively low solubility in water, the low concentrations and amounts of ozone produced from ozone generators, and the instability of ozone. Several contacting devices are currently in use including positive-pressure injectors, diffusers, and venturi units. Specific contact systems must be designed for each different application of ozone to wastewater. Further development in this area of gas-liquid contacting needs to be done despite its importance in waste treatment applications. In order to define the appropriate contactor, the following should be specified ... 

Waste water treatment. Supercritical CO2 has been put to use in a variety of industrial waste treatment applications. Clean Harbors Environmental Services, Inc., has used SCCO2 in Baltimore since 1989 to treat wastewater from chemical and pharmaceutical manufacturers. In the process the wastewater is pumped into the top of a 32-ft-high, 2-ft-diameter column, while the CO2 is pumped in from the bottom and percolates up. As the CO2 trowels up it dissolves the organics. CO2 contaminated with organics is at the top of the column, and clean water is at the bottom. The contaminants are incinerated off-site after separation from the CO2 which is recycled. 

Pyrometallurgical treatment The use of heat in furnaces or incinerators to volatilize and remove arsenic or other inorganic contaminants from solid wastes. For millennia prior to waste treatment applications, this smelting technology was used to extract and concentrate valuable elements from ore deposits. 

Food and beverage processing represents an expanding area for process-scale microfiltration. Already in place are clarification systems for wine and beer, sugar, and gelatin, replacing existing practices such as diatomaceous earth filtration. Less attractive economically are miscellaneous waste treatment applications, for which microfiltration is often a sophisticated but expensive alternative. 

Whether the radiation source is a machine-generated e-beam, isotopic gamma rays, or machine-generated x-rays (bremsstrahlung), a continuum of x-rays and electrons is produced as the initial event dissipates its energy in the irradiated medium. This chapter will focus on an e-beam source, as this is the most likely source to be used in a waste-treatment application. It should be noted that most of the comments made here are equally applicable to other sources of radiation. 

The use of the pseudo-first-order dose constant assumes that the removal of solutes is exponential, which is common in waste-treatment applications [10]. For example, the concentration of OH calculated from Eq. (16) for absorbed doses between 1 and 10 kGy is 0.28 to 2.8 mM. Under these conditions the loss of the solutes (at typical solute concentrations in the micromolar range) is pseudo-first-order, with respect to absorbed dose, and can be described by the following ... 

HRP and SBP are quite stable and active at or near room temperature. However, they can be susceptible to inactivation at elevated temperatures, which may be important in certain waste-treatment applications. The stability of enzymes is often first order with time and can be expressed as follows ... 

Aitken MD. Waste treatment applications of enzymes opportunities and obstacles. Chem Eng J 1993 52 B49 B58. 

Because (1 + r — rC) < 1, it is possible to operate the system at dilution rates greater than the maximum growth rate. It is this stability imparted by the cell recycle fermentor system that makes it useful, especially in waste treatment applications. 

The commercial membrane separation processes are offered in the areas of nitrogen production and waste treatment applications (1). Developing membrane applications in oil milling and edible oil processing are (1) solvent recovery, (2) degumming, (3) free fatty acid removal, (4) catalyst recovery, (5) recovery of wash water from second centrifuge, (6) coohng tower water recovery, (7) protein purification, and (8) tocopherol separation. 

This example is a waste treatment application. It is the reaction of ethylchloroacetate with caustic... 

Radioactive waste treatment applications have been reported [3-9] for the laundry wastes from nuclear power plants and mixed laboratory wastes. Another interesting application of reverse osmosis process is in decontamination of boric acid wastes from pressurized heavy water reactors (PHWRs), which allows for the recovery of boric acid, by using the fact that the latter is relatively undissociated and hence wdl pass with water through the membrane while most of the radioactivity is retained [10]. Reverse osmosis was evaluated for treating fuel storage pool water, and for low-level liquid effluents from reprocessing plants. 

Tertiary carbon systems have, in general, performed more successfully than IPCT systems in municipal waste treatment applications. This is due in part to the increased adsorptive loading required of IPCT systems over tertiary units in which the carbon beds are merely polishing filters. Both tertiary and IPCT applications have been beset by design and/or operational difficulties, the majority of which have been mechanical in nature rather than failures in process performance. However, these problems have tended to be more severe in IPCT cases in terms of system impact as well as in fact. In IPCT plants, the carbon system is more central to overall treatment than in tertiary units, hence system failures in the former applications make achievement of discharge permits virtually impossible. 

Membrane Ultraflltratlon Waste Treatment Application for Water Reuse," Proc. Ind. Waste Conf.. Vol. 30, 120-131, 1975. 

Waste Treatment In addition to the waste treatment applications mentioned earlier under ultrafiltration, there are more applications in the removal of organics and inorganics from synfuel wastes, phenolic wastes, organic acid wastes, and pesticides wastes (Siler Bhattacharyya, 1985). 

Marrone, R, Cantwell, S. and Dalton, D. (2005). SCWO system designs for waste treatment Application to chemical weapons destruction, Ind. Eng. Chem. Res., 44, pp. 9030-9039. Brandvold, T. and Kocal, J. (2007). Process for the direct production of methanol from methane, US Patent 7288684 (UOP LLC). 

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