Water treatment sludges

As well as the removal of sediment, waterworks may also soften the water, and may use lime for that purpose (as opposed to fixed bed ion exchange), again producing a sludge needing dewatering in a decanter. 

Waste lime slurries are frequently recycled for conversion back to reusable material. Selective recovery of the calcium carbonate from the waste will enable such calcining to be undertaken without the heavy inert load of the unseparated waste. 

For waterworks applications, decanters normally will be operated with polymer addition facilities, at alternative admission points. They will need full erosion protection for the flights, using tiles. They will have some kind of cake baffle, possibly a cone, and a variable speed back-drive, with good differential and torque control. They will be operated with deep neutral ponds, with axial flow (i.e. with flight windows, such that the liquid flows parallel to the axis, rather than around the helical space), and with provision for wash-out prevention at start-up. 

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Metal ore concentrates Fine coal refuse Metal tailings Refinery sludges Wastewater treatment plant sludges Potable water treatment sludges Variable-volume filter press 46-55 81-93"... 

Disposal of solid wastes is a significant problem for the petrochemical industry. Waste solids include water treatment sludge, ashes, fly ash and incinerator residue, plastics, ferrous and nonferrous metals, catalysts, organic chemicals, inorganic chemicals, filter cakes, and viscous solids. 

Meng, X. Korfiatis, G.P. Jing, C. Christodou-latos, C. (2001) Redox transformations of arsenic and iron in water treatment sludge during aging and TCLP extraction. Environ. Sci. Tedin. 35 3476-3481... 

Posttreatment Treatment of soil cake, water treatment, equipment decontamination, storage, disposal, disposal of water treatment sludge, disposal of used personal protective equipment, takedown, demobilization, site restoration, report 22.55... 

Ozone is applied in three-phase systems where a selective ozone reaction, oxidation of residual compounds and/or enhancement of biodegradability is required. It can be used to treat drinking water and waste water, as well as gaseous or solid wastes. Especially in drinking water treatment full-scale applications are common, e. g. for particle removal and disinfection, while in waste water treatment sludge ozonation and the use of catalyst in AOP have been applied occasionally. Current research areas for three-phase ozonation include soil treatment and oxidative regeneration of adsorbers. Ozonation in water-solvent systems is seldom studied on the lab-scale and seems favorable only in special cases. In general, potential still exists for new developments and improvements in ozone applications for gas/watcr/solvent and gas/waler/solid systems. 

Hauptmann, E.G. et al., Strategies for treatment mixtures of bleach plant effluents and waste water treatment sludges by supercritical water oxidation, preprints of papers to be presented at the annual meeting, 80(B), B71-B77, 1994. 

Jing, C., Liu, S. and Meng, X. (2005) Arsenic leachability and speciation in cement immobilized water treatment sludge. Chemosphere, 59(9), 1241-47. 

Solidification/stabilization Refers to reducing the mobility of a contaminant in soils, other solids, or even liquid wastes by mixing them with Portland cement, lime, cement kiln dust, clays, slags, polymers, water treatment sludges, iron-rich gypsum, fly ash, and/or other binders. The process decreases the mobility of contaminants through physical encapsulation (solidification) and chemical bonding between the contaminants and the binders (stabilization). 

EPA OPTS TSCA regulates the use, disposal, and distribution in commerce of process waste water treatment sludges intended for land application from pulp and paper mills employing chlorine or chlorine derivative based bleaching processes (2,3,7,8-TCDD) Yes 40 CFR 744 EPA 1991f... 

Elliott, H. A., Dempsey, B. A., and Maille, M. J. (1990). Content and fractionation of heavy metals in water treatment sludges. J. Environ. Qual. 19, 330-334. 

Flotation Process for Calcium Carbonate Recovery from Water Treatment Sludges... 

H. A. Dawson, Flotation process used for calcium carbonate recovery from water treatment sludges. Water Treatment Plant Design. Ann Arbor Science, MI, 1979, pp. 105-124. 

Waste water treatment sludges generated in the production of creosote... 

Waste-water treatment sludges resulting from the manufacture of RDX are classified as hazardous wastes and are subject to EPA regulations (EPA 1990a). For more information on regulations that apply to RDX, see Chapter 7. 

Sewage and water-treatment sludges are reported on a dry basis because of their high water content... 

Several methods have been successful in specific applications. Freezing and thawing has been used with sewage sludge, water treatment sludge and some radioactive sludges... 

Innocenti, P. (1988). Techniques for handling water treatment sludge. Opflow 14(2), 1. 

Uses Dispersant for pigments, paints, emulsion polymerization, water treatment, sludge conditioning, agric., cosmetics, industrial cleaners, large particle suspensions binder, emulsion stabilizer, film-former, vise, control agent in cosmetics Alcoquest 125 [Alco]... 

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