POWDERED ACTIVATED CARBON WASTEWATER TREATMENT
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| Overview: | The powdereded activated carbon
wastewater treatment system combines biological treatment (such as the
activated sludge process) with adsorption on powdereded activated carbon
(PAC). The technology removes organic contaminants from wastewater and
minimizes the inhibitory effects of process wastewater containing toxic
organic compounds. Mobile powdereded activated carbon wastewater treatment
systems can be furnished as continuous flow or batch treatment systems.
Continuous flow systems come mounted on a mobile trailer, with treatment
capacities from 2,500 to 10,000 gallons per day. Batch operated or
continuous flow package plants can be provided for flows to 100,000 gal/d.
In-ground systems of up to 53,000,000 gal/day are currently in
operation.
Typically, living microorganisms (biomass) and PAC contact wastewaters in an aeration basin (anaerobic systems are also available). Biomass removes biodegradable organic contaminants through biological assimilation, while the carbon physically adsorbs conventional and toxic organics. The degree of removal achieved by the system depends on the influent waste characteristics and the system's operating parameters. Important considerations are biodegradability, absorbability, and concentrations of toxic inorganic compounds, such as heavy metals. Powdereded activated carbon wastewater treatment systems can be adjusted to specific waste stream feeds by varying the concentration of the PAC in the system, adjusting the retention time of the mixed liquor, and adjusting the waste-to-biomass ratio. If necessary, the temperature and the pH of the incoming waste can be adjusted, and nutrients can be added. After the aeration cycle, solids (PAC, with adsorbed organics, biomass, and inert solids) are removed through settling. The removed solids are mostly returned to the aeration tank, with only excess solids being removed. Solids may be regenerated to recover PAC, or may be dewatered and disposed. A two-stage powdereded activated carbon wastewater treatment system may be applied where environmental standards require an even higher degree of treatment. In the first stage aeration basin, a high level of biomass and PAC removes most contaminants. The second stage aeration basin polishes the first stage effluent. The virgin PAC, added just before the second stage, and the counter flow of solids to the first stage increases process efficiency. Excess solids are removed from the first stage and treated as described above. |
| Compliance Benefit: | The use of a powdereded
activated carbon wastewater treatment system can help facilities meet
pretreatment standards for discharges of wastewater to a POTW (40 CFR
403) or meet effluent limits of a NPDES permit (40 CFR 122). In
addition, this treatment process may help facilities meet the requirements
of waste reduction under RCRA, 40 CFR 262, Appendix. Wastewater
treatment units that are covered under a NPDES permit or provide for
pretreatment prior to discharge into a POTW may not need to comply with
requirements for a hazardous waste treatment permit.
The compliance benefits listed here are only meant to be used as a general guideline and are not meant to be strictly interpreted. Actual compliance benefits will vary depending on the factors involved, e.g. the amount of workload involved. |
| Materials Compatibility: | No materials compatibility issues were identified. |
| Safety and Health: | Care should be taken when
handling wastewater polluted with organic substances. They have a high
order of dermal toxicity. Proper personal protection equipment is,
therefore, highly recommended.
Consult your local industrial health specialist, your local health and safety personnel, and the appropriate MSDS prior to implementing any of these technologies. |
| Benefits: | A powdereded activated carbon
wastewater treatment system has been applied for:
The technology can be very useful at Naval installations that have a combined industrial and municipal collection system. powdered activated carbon wastewater treatment systems can treat liquid wastes with a chemical oxygen demand (COD) in excess of 60,000 parts per million (ppm), including toxic volatile organic compounds in excess of 1,000 ppm. Treatability studies have shown that the system can reduce the concentration of specific toxic organic chemicals to below the detection limit. Other benefits of the system include:
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| Disadvantages: |
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| Economic Analysis: | The capital and operating costs
of a powdered activated carbon wastewater treatment system depends on the
influent quality and the effluent standards. The budget level capital cost
estimate for a mobile powdered activated carbon wastewater treatment
system ranges from $100,000 to $300,000. The operational costs range from
less than $0.50 to greater than $1.00 per 1,000 gallons, depending upon a
number of variables. Costs of wastewater treatment vary from one location
to another. Factors determining the wastewater treatment costs are: the
treatment technology used, the flow rate, and the level and type of
contamination. Each Naval activity will have to examine the cost
effectiveness of the treatment technology needed before selecting the
appropriate treatment system.
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| Approving Authority: | Approval is controlled locally
and should be implemented only after engineering approval has been
granted. Major claimant approval is not required.
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| NSN/MSDS: |
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| Points of Contact: | Navy: Mr. Charles Sokol Environmental Engineer, ESC 423 Naval Facilities Engineering Service Center 1100 23rd Avenue Port Hueneme, CA 93043 Phone: (805) 982-5318 DSN: 551-5318 FAX: (805) 982-4832 Email: sokolcw@nfesc.navy.mil |
| Vendors: | This is not meant to be a
complete list, as there are other manufacturers of this type of
equipment.
US Filter, Zimpro Division, Inc. |
| Sources: | None listed
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