Download or read book Contamination of Groundwater by Heavy Metals from the Land Disposal of Fly Ash Technical Progress Report June 1 1977 March 31 1978 written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A study has been undertaken on a specific ponded fly ash disposal site to determine the degree of subsurface leaching of various ionic forms, especially heavy metals. The location is the site of the Michigan City generating station of the Northern Indiana Public Service Company, Michigan City, Indiana. The present ash ponding system consists of two primary ash ponds (volume of each 16.5 million gallons) which are loaded alternately, i.e., when one is in service the other is allowed to dry for the removal operation. The ash is sluiced to the ponds in a concentrated slurry. After primary and secondary settling the water is brought back for further ash sluicing. A constant elevation is maintained in the ponds at approximately 31.5 feet above the surface of Lake Michigan. The system cannot be considered closed because of losses due to evaporation and subsurface leaching. The station produces 340 to 400 tons of fly ash per day when operating at full capacity. A typical pond cycle requires six to nine months between removal periods. Observation wells were installed at various locations. Typically, the chemical composition of the groundwater varied with both time in the pond cycle as well as distance from the pond. Heavy metal concentrations decreased rapidly from the rather high levels found in the pond but a smaller peak concentration occurred some 100 meters from the pond after which the concentration decreased to rather low levels. The dominant mechanisms of attenuation are adsorption of metals onto hydrous oxides of iron and manganese and precipitation of various solid phases.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1984 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contamination of Groundwater by Heavy Metals from the Land Disposal of Fly Ash Technical Progress Report September 1 1976 May 31 1977 written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Field studies were conducted at the fly ash disposal site of a 735 MW coal-fired power plant. Disposal consisted of ponding the ash followed by eventual removal and ultimate deposition as fill. Several sampling wells were made in order to monitor the groundwater quality. Trace metals analyzed include As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn. Results indicated that trace metals are released to the groundwater from the pond at generally low levels. Increased concentrations several times the normal levels were observed when the pond first began the filling cycle and again when maintenance procedures brought about a large fly ash loading in a short time. Metals were found to accumulate in soils at the point of confluence of the pond seepage water with the natural groundwater which was high in dissolved carbonate. Deposition as carbonates and adsorption of metals onto the higher levels of hydrous iron and manganese oxides were considered responsible for this. Effective control strategies, if deemed necessary, would include pH adjustment of pond water with lime or limestone, lining of ponds with natural or chemical materials, and relocation to a more environmentally suitable site.
Download or read book Fossil Energy Update written by and published by . This book was released on 1978 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contamination of Groundwater by Heavy Metals from the Land Disposal of Fly Ash Technical Progress Report June 1 1976 August 31 1976 written by and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A useful method of differentiating surface from total heavy metals associated with fly ash is selective extraction for those metal oxide sinks (Fe, Al, Mn) with which the heavy metals have become associated. This association is important in defining the release of the metals in aqueous environments. This desorption, as well as subsequent adsorption onto local soil matter is pH dependent, lower pH values favoring greater release or less adsorption in the system. Another aspect of trace metal chemistry is solubility, which generally decreases with increasing pH. In view of this pH dependency, it would appear that the more critical case of potential contamination of water resources is that of the acid fly ashes, i.e., those where iron oxide deposits control the pH of the system. The problem could be reduced by maintaining the ash in a neutral or alkaline environment, although at extremely high pH values (approximately 12) the desorbtive tendency of most metals increased slightly. Even at neutral pH values, soluble complexes may increase the concentration of a given metal in excess of solubility. The average percentage of metals released for all fly ashes studied from their surface sinks at pH = 9 were cadmium--17 percent, lead--8 percent, chromium--6 percent, copper--1 percent, and zinc less than 1 percent. Another important factor is the absolute amount of metal on the surface. For instance, even though copper is released very little at neutral pH's, surface concentrations up to 200 .mu.g/g of fly ash were found.
Download or read book Contamination of Groundwater by Heavy Metals from the Land Disposal of Fly Ash Technical Progress Report June 1 1975 February 29 1976 As Ca Cd Cr Cu Fe Hg Pb Zn written by and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Major emphasis was placed on laboratory evaluations of heavy metal associations with fly ash. Data are presented showing that most fly ashes contain considerable amounts of As, Ca, Cd, Cr, Cu, Fe, Hg, Pb, and Zn. Desorption studies suggest that pH and the presence of various heavy metal sinks on the ash particle surface (notably hydrous iron oxides) play significant roles in the release of these metals into solution. Adsorption studies using natural ash leachate/soil systems and vertical soil columns give quantitative estimates (through the use of adsorption isotherms) of the degree of attenuation of the heavy metals. Results verify the importance of solution pH and iron oxide concentration. In general the element cadmium shows the least tendency toward sorbing onto local solid phases while lead is sorbed to the greatest extent. Among soil types, organic peat was the most effective in removing metals while silica was least effective.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1978-11 with total page 794 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1980 with total page 982 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.
Download or read book Environment Reporter written by and published by . This book was released on 1980 with total page 1280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contamination of Groundwater by Heavy Metals from the Land Disposal of Fly Ash Final Report written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Information is provided on laboratory and field research to assess the aquatic effects and extent of release, migration, and attenuation of trace metals from fly ash into subsurface soil environments for a typical disposal regime. Those metals analyzed were arsenic, cadmium, chromium, copper, lead, mercury, nickel, and zinc. Laboratory studies indicated that the major effects of fly ash in water were pH alterations, which could be either acidic or basic, and comparatively high proportions of trace metals released from the ash surface, controlled largely by pH. Field studies confirmed the continued importance of pH in defining the attenuation of the metals by the soil but also suggested that pSO4, ionic strength, and soil chemical parameters, such as iron and manganese content, could not be ignored. Theoretical thermodynamic analysis in concert with field data indicated that both adsorption onto soil phases and precipitation of metal phases occurred, the dominant attenuation mechanism depending upon the specific metal and soil conditions.
Download or read book Environmental Pollution Control written by and published by . This book was released on 1978 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contamination of Groundwater by Heavy Metals from the Land Disposal of Fly Ash written by T. L. Theis and published by . This book was released on 1975 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrochemical and Geophysical Investigation of the Effects of Fly ash Disposal on Groundwater written by Douglas S. Cherkauer and published by . This book was released on 1980 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index Keyword A L written by and published by . This book was released on 1984 with total page 1092 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Environment Index written by and published by . This book was released on 1979 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environment Abstracts written by and published by . This book was released on 1978 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt:
