Sludge volume reduction

Because the WAO process also aims to reduce sludge volume we will spend more time describing this process under the section dealing with Volume Reduction. The other thermal sludge conditioning method is best-known as sludge pasteurization, and deserves more than just a brief overview. 

Maximum volume reduction. Reduces volume and weight of wet sludge cake by approximately 95 percent, thereby reducing disposal requirements. 

WHAT FINALLY HAPPENS TO SLUDGE AFTER VOLUME REDUCTION... 

Envirobond is a stabilization technology that may be applied in situ or ex situ to treat solids (soils, sediments, wastes, and sludge) contaminated with heavy metals and radionuclides. Envirobond s proprietary blend of chemical additives combine with heavy metals and radionuclides to form an insoluble, stable mass. The Envirobric volume reduction system compacts the stabilized solids into construction-grade bricks. 

Sevenson claims that MAECTITE technology converts heavy metals and radionuclides in soil, groundwater, solid waste, debris, sludges, and other material into nonleachable forms that are stable over geological time spans. They also claim that the technology limits the bioavailability of lead in treated soil and can result in volume reduction with limited mass increase during treatment. 

Sludge washing removes various nonradioactive chemical components from the waste, which can then be treated and disposed of as low-level radioactive waste (LLW). LLW is significantly less expensive and easier to treat and discard than HLW. The ESW process was designed as a volume reduction pretreatment step for vitrification of HLW. 

The real application of this process is the recalcination of lime sludges from water treatment plants, coking of heavy residues and tars from petroleum refinery operations, concentration and volume reduction of liquid, radioactive wastes, and treatment of refinery sludges containing hydrocarbons, phosphorus, and compounds of calcium, magnesium, iron, and aluminum. 

Torpey, W. N., Melbinger, N. R., Reduction of Digested Sludge Volume... 

Without doubt the quantity of Al2(SO g used in the process is by far the most important factor which influences the sludge volume of the freshly formed hydroxide floes. The effect on sludge production of a change of floe structure because of a change of the experimental conditions is thus subsidiary to the influence of the dosage. Of course the floe structure (19 0) plays an important role in the rate of reduction of the sludge because of floe ageing phenomena (21). 

A number of processes are under development for consolidation and volume reduction of the hulls. Melt densification has received much effort, resulting in volume reductions by a factor of 6. Other processes seriously considered are mechanical compaction and consolidation in concrete. In any case, final disposal of consolidated hulls will be similar to that of other HLW. Thus, hulls (and dissolver sludge) will add considerably to the volume of waste eventually to be disposed of with essentially the HLW technology. 

MF may be used to remove these heavy metals provided pretreatment chemicals are added to precipitate the metals to particles of filterable size. The chemical pretreatment step is crucial since it will affect the performance of the membrane and the resultant sludge volume as well as the contaminant removal efficiency. Reduction/oxidation, absorption/oxidation, and/or catalytic reactions are utilized along with pH adjustment to provide the optimum precipitation. Although conventional methods of waste water treatment may use a similar pretreatment chemistry, the final solid/liquid separation by gravity settling is usually not as effective as membrane filtration. 

Chemical volume reduction Reduction of volume of solid wastes through burning (incineration) Mass-fired incinerators, with and without heat recovery, for unprocessed wastes rotary kilns for hazardous/containerized and bulk solid/sludge waste... 

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