Effluent treatment incineration

Treat the effluent using incineration, biplogical digestion, etc. to a form suitable for discharge to the environment, called end-of -pipe treatment. 

Question 5 ("Is combustion with air the only chemistry intended at your facility ") can be answered YES in this case, assuming the "facility" being addressed is limited to the incinerator system. Due to the great number of combustion systems in operation, many other resources are available for ensuring safe design and operation of the combustion part of the incinerator facility. However, it should be noted that many combustors now have effluent treatment systems, such as selective catalytic reduction (SCR) systems, that involve intentional chemistry beyond the combustion reaction. 

Secondary wastes are generated from the collection, treatment, incineration, or disposal of hazardous wastes, such as sludges, sediments, effluents, leachates, and air emissions. These secondary wastes may also contain hazardous substances and must be treated or disposed of properly to prevent secondary pollution of underground water, surface water, soil, or air. 

Without incineration, SW costs would drop to 29/metric ton ( 27/ton) or 44/m ( 34/yd ). The cost figures were developed as order of magnitude estimates (4-50 to 30%). Costs for permitting and regulatory expenses were not included and effluent treatment and disposal for BATS and SBR were assumed not to be required (D10460Z, pp. 19, 22). 

The patent literature claims that olefins can be partially oxidized to epoxides (73) or hydroxy epoxides (74) and alcohols may be oxidized to ketones or aldehydes (75) using various metal ion-exchanged zeolites. In the examples given, the selectivities or conversion levels to the desired products are not particularly attractive. Metal ion-exchanged zeolites do, however, appear to be quite useful catalysts for effluent treatment. For example, Cu2+X and Cu2+Y are claimed to be good catalysts for the total oxidation (incineration) of chlorinated organic compounds (76). 

Solid wastes represent the ultimate in mill residues and include the accumulated refuse of the mill and the sludges from primary and secondary effluent treatment. There is difficulty in removing water from the secondary sludge the primary and secondary sludges often are mixed to aid in water removal, which is important if the sludge is to be incinerated for disposal. The sludges from pulp and paper mills are handled mostly as landfill, and sometimes, if not toxic, they are spread for agricultural purposes. 

I Extraction of the PT eatalyst into water is the commonly used technique for PT catalysts that are soluble in water. Incineration of the extraeted PT catalysts is the preferred method of disposal, though oxidation in biooxidation ponds dedicated to PTC processes is justified in some cases. Water effluent treatment is important as quats and crown ethers are toxic for marine life. 

For many years your plant on the Texas Gulf Coast has produced tetrahydrofuran (THF) for use as a synthetic fiber intermediate. The reaction is carried out in water solution, producing a crude THF which also contains lower aliphatic alcohols as byproducts plus some gamma-butyrolactone (GBL), which is an unreacted intermediate. The THF is purified in a three-column distillation train. The impurities have been incinerated or sent with the water to the biological effluent treatment system. 

These off-spec products will have to be recycled, purified, sold at lower price, or disposed of through effluent treatment units/incinerators. 

Effluent Treatment and Disposal - Two process streams are produced by the filtration unit. The permeate is considered to be essentially free of contaminants and is assumed to meet standards appropriate for discharge to a POTW. The concentrate is the reduced-volume portion of the waste stream containing the enriched contaminants. This stream would require further treatment such as biological degradation, incineration, fuel-blending, or some other process appropriate to the type and concentration of contaminants. 

The need to meet environmental regulations can affect processing costs. Undesirable air emissions may have to be eliminated and Hquid effluents and soHd residues treated and disposed of by incineration or/and landfilling. It is possible for biomass conversion processes that utilize waste feedstocks to combine waste disposal and treatment with energy and/or biofuel production so that credits can be taken for negative feedstock costs and tipping or receiving fees. 

Gaseous vent streams from the different unit operations may contain traces (or more) of HCl, CO, methane, ethylene, chlorine, and vinyl chloride. These can sometimes be treated chemically, or a specific chemical value can be recovered by scmbbing, sorption, or other method when economically justified. Eor objectionable components in the vent streams, however, the common treatment method is either incineration or catalytic combustion, followed by removal of HCl from the effluent gas. 

A fluid-bed incinerator uses hot sand as a heat reservoir for dewatering the sludge and combusting the organics. The turbulence created By the incoming air and the sand suspension requires the effluent gases to be treated in a wet scrubber prior to final discharge. The ash is removed from the scrubber water by a cyclone separator. The scrubber water is normally returned to the treatment process and diluted with the total plant effluent. The ash is normally buried. 

Calculate the mass or weight of chemical in the wastestream being treated by multiplying the concentration (by weight) of the chemical in the wastestream by the flow rate. In most cases, the percent removal compares the treated effluent to the influent for the particular type of wastestream. However, for some treatment methods, such as Incineration or solidification of wastewater, the percent removal of the chemical from the influent wastestream would be reported as 100 percent because the wastestream does not exist in a comparable form after treatment. Some of the treatments (e.g., fuel blending and evaporation) do not destroy, chemically convert, or physically remove the chemical from its wastestream. For these treatment methods, an efficiency of zero must be reported. 

Waste treatment prior to disposal may introduce phase changes which result in quite different pollution control considerations. For example, the gases generated by incineration of a solid waste can be scrubbed with liquid in order to meet an acceptable discharge criterion hence, in addition to ash for disposal, a liquid effluent stream is produced and requires treatment. Other waste treatment processes may result in the liberation of flammable or toxic gaseous emissions as exemplified in Table 16.5. 

In the scenario for the controlled landfill site the treatment of effluent from the site by sewage treatment and the incineration of the sludge are taken into account. An additional scenario is made for an uncontrolled landfill site, assuming DEHP emissions. However, in an uncontrolled landfill site not only DEHP will emit from the site but also other toxic releases like heavy metals. So the results presented for the uncontrolled landfill site are an underestimation. For a more realistic assessment of impacts related to the uncontrolled landfill of PVC, additional estimates are necessary for the emissions of (toxic) releases. As a consequence, the impact assessment score for human and aquatic ecotoxicity for the uncontrolled landfill site will increase. The relative contribution of DEHP to these scores will decrease because also other emissions which are in the present assumptions are now lacking, like heavy metals, will contribute to the score. 

Hexachloroethane may also be released to air during combustion and incineration of chlorinated wastes, from hazardous waste sites, and in small amounts during chlorination of sewage effluent prior to discharge and chlorination of raw water during drinking water treatment (Gordon et al. 1991 Howard 1989). 

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