Toxic sludge treatment

Stover, E. L., Fazel, A., and Kincannon, D. F., 1985, Powdered Activated Carbon and Ozone Assisted Activated Sludge Treatment for Removal of Toxic Organic Compounds Science and Engineering, Vol. 7, No. 3, pp. 191-203. 

The toxicity and volume of some deoiled and dewatered sludge can be reduced further through thermal treatment. Thermal sludge treatment units use heat to vaporize the water and volatile components in the feed and leave behind a dry solid residne. The vapors are condensed for separation into hydrocarbon and water components. Noncondensable vapors are either flared or sent to the refinery amine nnit for treatment and nse as refinery fnel gas. 

Processes can be modified to deliver targeted remediation levels. Many different soil contaminants have been treated. These include PCBs, polycyclic aromatic hydrocarbons (PAHs), chlorinated solvents, dioxins, furans, pesticides, hexachlorobenzenes, BTXs, volatiles, and semi volatiles. After treatment, the soils pass all toxicity characterization leachate procedure (TCLP) criteria for replacement or nonhazardous waste landfill disposal. Specific examples of soil and sludge treatment will now be given. Table 3 contains data from several PCB remediation projects. 

B. O Connor, T. Kovacs, S. Gibbons et a/.,...Paper Mill Effluents from Oxygen-activated Sludge Treatment... A Source of Toxicity to Fish, Water Dual. Res. J. Canada, 35(2) 189-200 (2000). 

The Control of Industrial Pollution Water Quality and Health Aspects of the Chemistry and Analysis of Substances of Concern in the Water Cycle The Role of Wastewater Treatment Processes in the Removal of Toxic Pollutants Sewage and Sewage Sludge Treatment The Chemistry of Metal Pollutants in Water Effects of Pollutants on the Aquatic Environment Important Air Pollutants and Their Chemical Analysis Pollutant Pathways and Modelling of Air Pollution Legislation and the Control of Air Pollution Catalyst Systems for Emission Control from Motor Vehicles Evaluating Pollution Effects on Plant Productivity A Cautionary Tale Epidemics of Non-infectious Disease Systems Methods in the Evaluation of Environmental Pollution Problems Organometallic Compounds in the Environment. 

Stover, E. K., A. Eazel, and D. E. Kincannon. 1985. Powdered activated carbon and ozone-assisted activated sludge treatment for removal of toxic organic compounds. Ozone Sci. Eng. 7(3) 191-203 cited in Chem. Abstr. CA 104(14) 115399V. 

In addition to the disposal problems associated widi powdered triclosan, there are also disposal problems associated with triclosan containing organic solvents. Solutions containing up to 2.5% triclosan in ethanol or isopropanol are commonly used for disinfecting medical equipment. Because of the high toxicity of triclosan to bacteria, and the recalcitrance of triclosan in activated sludge treatment systems, disposal of these solutions into sanitary sewers may result in... 

Some fixed equipment including ductwork, piping or waste treatment systems can also be a source of toxic chemical hazards. Ductwork can be coated with residual materials scrubber systems will contain trace toxic materials from the process piping must be adequately purged before work can be safely imdertaken. On-site treatment systems to react solvents, or remove metals can produce toxic sludges and potential exposures. Adequate training and protective equipment will prevent exposure. 

Copper levels are also significantly enhanced as a result of sludge treatment. Sheep are particularly susceptible to copper toxicity but problems do not usually arise, even with sheep, at levels less than 10 ppm in herbage dry matter. Fortunately, it is unusual for grass to contain more than this... 

Wastewater. Phenol is a toxic poUutant to the waterways and has an acute toxicity (- 5 m g/L) to fish. Chlorination of water gives chlorophenols, which impart objectionable odor and taste at 0.01 mg/L. Biochemical degradation is most frequently used to treat wastewater containing phenol. Primary activated sludge, along with secondary biological treatment, reduces phenol content to below 0.1 mg/L (69). 

Yourfacility is involved in chrome plating of metal parts, which produces an aqueous plating waste that is treated on-site to recover chromium sludge. The effluent from the on-site treatment plant, which contains chromium compounds (a listed toxic chemical), is piped to a POTW. The chromium sludge is transferred to an off-site, private ly owned firm tor the recovery of the chromium. 

---