Pretreatment of wastes

Thermal pretreatment of waste can enhance the biodegradability of hazardous substance. Homogenization/suspension of solid wastes or nondissolved sludges in water will increase the surface of the waste particles and, as result of this, the rate of biodegradation wiU also be increased. 

The advanced integrated solvent extraction and ion exchange systems are designed for the chemical pretreatment of waste retrieved from storage tanks at Department of Energy (DOE) sites (e.g., at INEL, Hanford, Savannah River). 

The building will also contain absorption columns for the pretreatment of waste gases as well as distillation columns for solvent recovery. A generous... 

Transfer of a substance from a solution to a solid phase is called sorption. The most important sorbent used iu waste treatment is activated carbon. Activated carbon can also be applied to pretreatment of waste streams going into other processes in order to improve treatment efficiency and reduce fouling. Activated carbon sorption is most effective for removing from water organic materials that are poorly water-soluble and that have high molecular masses. 

G. J. Lumetta, Pretreatment of Neutralised Cladding Removal Waste Sludge, PNL-9747, BatteUe Pacific Northwest Laboratory, Richland, Wash., 1994. 

Pretreatment of the raw waste gas to remove particulates, adjust temperature and humidify to saturation. 

Most treatment options for detoxifying the hazardous constituents from RCRA facilities must have a uniform feed to the process. However, the media in which hazardous constituents are located are not generally homogeneous. Thus, some form of pretreatment of the waste or waste medium will probably be required to prepare the waste for further treatment by chemical, biological or thermal means. 

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... 

Pretreatment of Industrial Wastes Joint Municipal and Industrial Seminar, 1978 625/4-78-012 ERIC W662 Procedures Manual for Reviewing a POTW Pretreatment Program Submission, October 1983 833/B-83-200 ERIC W137 NTIS PB93-209880. 

All ion-exchange processes produce wastewater from backwash, regeneration and rinse. The proportion of waste depends on the concentration of hardness or to TDS being removed, and can be as high as 15 per cent of the product flow. Any pretreatment has to take this additional flow into account. 

For most smaller operators, the waste water discharge from pretreatment equipment, blowdown receivers, and FSHR equipment typically discharges into a city sewer. Most larger factories, process plants, and power stations, on the other hand, incorporate some form of waste water treatment facility to balance the pH level, remove oils and pre-cipitable solids, or otherwise reduce the contamination load before the discharge of water from the site. 

Cement production demands major amounts of fuel. Energy costs can be upwards of 25% of their turnover. Therefore, many cement kilns in the UK, Belgium, the Netherlands, Switzerland and other countries have started to use pretreated waste streams as a fuel. This not only saves fuel input, but indeed often allows a charge for the treatment of waste. In principle, cement kilns can deal with the following types of waste ... 

A Box-Behnken design was employed to investigate statistically the main and interactive effects of four process variables (reaction time, enzyme to substrate ratio, surfactant addition, and substrate pretreatment) on enzymatic conversion of waste office paper to sugars. A response surface model relating sugar yield to the four variables was developed on the basis of the experimental results. The model could be successfully used to identify the most efficient combination of the four variables for maximizing the extent of sugar production. 

In a previous publication (1) we reported that the pretreatment of fresh fhiit waste using microwave heating ensured a better extraction of pectin, resulting in an increase in the yield of pectin from 10 to 50 %. It was established that this microwave pretreatment ensured retention of the degree of esterification of the extracted pectin, better expressed in citrus peels... 

Givens, S. and Cable, J., Case study—a tale of two industries, pretreatment of confectionary and bakery wastewaters. 1988 Food Processing Waste Conference, presented by the Georgia Tech Research Institute, Atlanta, Georgia, October 31-November 2, 1988. 

In contrast to the reduction of tremors by DFMO, pretreatment of rats with diphenylhydantoin results in exacerbation of chlordecone-induced tremors (Hong et al. 1986 Tilson et al. 1985, 1986b). The mechanism for the exacerbation of the tremors is unknown. Therefore, if persons receiving diphenylhydantoin treatment for epilepsy were exposed to sufficiently high concentrations of chlordecone at a hazardous waste site, increased tremor severity would be likely to occur. 

Biorefineries New catalytic pretreatment of plant materials Valorization, pretreatment or disposal of co-products and wastes from biorefinery by catalytic treatments New and/or improved catalytic processes for chemicals production through the integration of the biorefinery concept and products into the existing chemical production chain New advanced catalytic solutions to reduce waste emissions (solid, air and, especially, water) New catalysts to selectively de-oxygenate products from biomass transformation Catalysts to selectively convert chemicals in complex multicomponent feedstocks New biomimetic catalysts able to operate under mild conditions Small catalytic pyrolysis process to produce stabilized oil for further processing in larger plants... 

Ohrt, J.A. Physicochemical Pretreatment of a Synthetic Industrial Dairy Waste. Lenox Institute of Water Technology Lenox, MA. Masters Thesis (Wang, L.K. Aulenbach, D.B., advisors), 2001 62... 

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