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General design, construction, and operation guidelines: Constructed wetlands wastewater treatment systems for small users including individual residences. Second edition
One of the Tennessee Valley Authority`s (TVA`s) major goals is cleanup and protection of the waters of the Tennessee River system. Although great strides have been made, point source and nonpoint source pollution still affect the surface water and groundwater quality in the Tennessee Valley and nationally. Causes of this pollution are poorly operating wastewater treatment systems or the lack of them. Practical solutions are needed, and there is great interest and desire to abate water pollution with effective, simple, reliable and affordable wastewater treatment processes. In recognition of this need, TVA began demonstration of the constructed wetlands technology in 1986 as an alternative to conventional, mechanical processes, especially for small communities. Constructed wetlands can be downsized from municipal systems to small systems, such as for schools, camps and even individual homes.
Date:
May 1, 1993
Creator:
Steiner, G. R. & Watson, J. T.
Object Type:
Report
System:
The UNT Digital Library
Flue gas desulfurization gypsum and fly ash
The Cumberland Fossil Plant (CUF) is located in Stewart County, Tennessee, and began commercial operation in 1972. This is the Tennessee Valley Authority`s newest fossil (coal-burning) steam electric generating plant. Under current operating conditions, the plant burns approximately seven million tons of coal annually. By-products from the combustion of coal are fly ash, approximately 428,000 tons annually, and bottom ash, approximately 115,000 tons annually. Based on historical load and projected ash production rates, a study was initially undertaken to identify feasible alternatives for marketing, utilization and disposal of ash by-products. The preferred alternative to ensure that facilities are planned for all by-products which will potentially be generated at CUF is to plan facilities to handle wet FGD gypsum and dry fly ash. A number of different sites were evaluated for their suitability for development as FGD gypsum and ash storage facilities. LAW Engineering was contracted to conduct onsite explorations of sites to develop information on the general mature of subsurface soil, rock and groundwater conditions in the site areas. Surveys were also conducted on each site to assess the presence of endangered and threatened species, wetlands and floodplains, archaeological and cultural resources, prime farmland and other site characteristics which must …
Date:
May 1, 1992
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Seasonal trends in growth and biomass accumulation of selected nutrients and metals in six species of emergent aquatic macrophytes
Growth and biomass accumulation of selected nutrients and trace metals were monitored for six species of aquatic macrophytes during June, August and November, 1993. Plant species were cultivated in two polyculture treatments, each replicated three times. Polyculture I consisted of Scirpus acutus (hardstem bullrush), Phragmites communes (common reed), and Phalaris arundinacea (canary grass). Polyculture H consisted of Typha spp. (cattail), Scirpus atrovirens (green bullrush), and Scirpus cyperinus (wool grass). Each of the six cells (6 x 9 x 0.6 m), was operated as a gravel-substrate, subsurface-flow wetlands in a continuous recirculating mode. At six week intervals, macro, micro and trace elements were dissolved and added to the sump of the recirculating system. On each of three sampling dates, replicate shoot and root samples were collected, segregated by species and tissue type (roots, rhizomes, stems and leaves), and prepared for gravimetric biomass estimates and chemical analysis. Tissue specific concentrations of N, P, K, Ca, Mg, Fe, Mn, Zn and Cu, were determined on each date for each species and tissue type. Results will be discussed with respect to species specific growth rates, biomass accumulation, and seasonal uptake and translocation of plant nutrients.
Date:
May 1, 1996
Creator:
Behrends, L.L.; Bailey, E.; Bulls, M.J.; Coonrod, H.S. & Sikora, F.J.
Object Type:
Report
System:
The UNT Digital Library
Field performance of erosion resistant materials on boiler induced draft fan blades
The TVA Kingston Fossil Power Plant has nine units and is located near Kingston, Tennessee. Units 1 through 4 have a rating of 148 MW and units 5 through 9 have a rating of 197 MW. Each unit has two induced draft fans manufactured by Westinghouse Electric Corp., Sturtevant Division. A table showing design data for the induced draft fans is located on page 16 of this report. The fan blade design details for units 5 through 9 are shown on pages 11 through 14. There is a mechanical fly ash collector and a small electrostatic precipitator preceding the induced draft fans in the boiler flue gas stream and a large, efficient electrostatic precipitator downstream of these fans. The steam generators and pulverizers were supplied by Combustion Engineering. The average temperature of the flue gas is about 340 degrees Fahrenheit for units 5 through 9. All induced draft fans in the boiler flue gas stream experience erosion from fly ash. When the precipitators and fly ash collectors were new the fan blades would last about three years before they were eroded severely and had to be replaced. Kingston Plant personnel say the fly ash collectors are presently in need of …
Date:
May 1, 1993
Creator:
Karr, O. F.; Brooks, J. B. & Seay, E.
Object Type:
Report
System:
The UNT Digital Library
Biocide By-Products in Aquatic Environments
A three-year program has been conducted to study the chemistry and biological effects of products arising from the low-level chlorination of natural waters. These studies are related to environmental concerns arising from the discharge of chlorine-treated power plant cooling water. The studies have shown that addition of low levels (2 mg/l) of chlorine to natural waters produces haloforms in concentrations which are orders of magnitude lower than the LC{sub 50}'s measured in a number of fresh ana salt water organisms. Chlorination also produces nonhaloform lipophilic organohalogen products in concentrations much lower than the naloforms, although no evidence was obtained which suggested significant olomagnification of these during chronic exposure of juvenile salmon to chlorinated fresh water. No dramatic effects were noted in organisms chronically exposed to chlorinated waters, but changes in general condition were observed.
Date:
May 1, 1981
Creator:
Bean, R. M.; Gibson, C. I. & Anderson, D. R.
Object Type:
Report
System:
The UNT Digital Library
Atmospheric Fluidized Bed Combustion of Municipal Solid Waste: Test Program Results
Air classified municipal solid waste (MSW) was fired in an atmospheric fluidized bed combustor at low excess air to simulate boiler conditions. The 7 ft/sup 2/ combustor at Combustion Power Company's energy laboratory in Menlo Park, CA, incorporates water tubes for heat extraction and recycles elutriated particles to the bed. System operation was stable while firing processed MSW for the duration of a 300-h test. Low excess air, low exhaust gas emissions, and constant bed temperature demonstrated feasibility of steam generation from fluidized bed combustion of MSW. During the 300-h test, combustion efficiency averaged 99%. Excess air was typically 44% while an average bed temperature of 1400/sup 0/F and an average superficial gas velocity of 4.6 fps were maintained. Typical exhaust emission levels were 30 ppM SO/sub 2/, 160 ppM NO/sub x/, 200 ppM CO, and 25 ppM hydrocarbons. No agglomeration of bed material or detrimental change in fluidization properties was experienced. A conceptual design study of a full scale plant to be located at Stanford University was based on process conditions from the 300-h test. The plant would produce 250,000 lb/hr steam at the maximum firing rate of 1000 tons per day (TPD) processed MSW. The average 800 TPD …
Date:
May 1, 1980
Creator:
Preuit, L. C. & Wilson, K B
Object Type:
Article
System:
The UNT Digital Library
Analysis of Uranium Urinalysis and in Vivo Measurement Results From Eleven Participating Uranium Mills
Uranium urinalysis and in vivo examination results obtained from workers at eleven uranium mills between 1978 and 1980 were evaluated. The main purpose was to determine the degree of the mills' compliance with bioassay monitoring recommendations given in the draft NRC Regulatory Guide 8.22 (USNRC 1978). The effect of anticipated changes in the draft regulatory guidance, as expressed to PNL in May 1982, was also studied. Statistical analyses of the data showed that the bioassay results did not reliably meet the limited performance criteria given in the draft regulatory guide. Furthermore, quality control measurements of uranium in urine indicated that detection limits at ..cap alpha.. = ..beta.. = 0.05 ranged from 13 ..mu..g/l to 29 ..mu..g/l, whereas the draft regulatory guidance suggests 5 ..mu..g/l as the detection limit. Recommendations for monitoring frequencies given in the draft guide were not followed consistently from mill to mill. The results of these statistical analyses indicate a need to include performance criteria for accuracy, precision, and confidence in revisions of the draft Regulatory Guide 8.22. Revised guidance should also emphasize the need for each mill to continually test the laboratory performing urinalyses by submitting quality control samples (i.e., blank and spiked urine samples as …
Date:
May 1, 1984
Creator:
Spitz, H. B.; Simpson, J. C. & Aldridge, T. L.
Object Type:
Report
System:
The UNT Digital Library