Trace elements in corn grown on long-term sludge disposal site. Reply to comments

1976 ◽  
Vol 10 (3) ◽  
pp. 285-285 ◽  
Author(s):  
M. B. Kirkham
Keyword(s):  
Trace Elements ◽  
Disposal Site ◽  
Sludge Disposal

Disposal of Western Fly Ash in the Northern Great Plains

1984 ◽  
Vol 43 ◽  
Author(s):  
Gerald F. Groenewold ◽  
David J. Hassett ◽  
Robert D. Koor ◽  
Oscar E. Manz
Keyword(s):  
Trace Elements ◽  
Fly Ash ◽  
Great Plains ◽  
Disposal Site ◽  
Northern Great Plains ◽  
Fly Ashes ◽  
Toxic Trace Elements ◽  
High Concentrations ◽  
Ash Disposal

AbstractLeachates from western fly ashes are typirally alkaline. Our studies indicate a strong correlation between alkalinity of western fly ash leachate and trace element concentrations. Elements of particular concern include As, Se, and Mo. A base neutralization mechanism is operative in all of the overburden types found at mine disposal sites in western North Dakota. Regional geological similarity suggests that this mechanism is operative throughout the Northern Great Plains. Although the mechanisms of neutralizatioti are speculative, laboratory experiments indicate significant neutralization at all levels of base above background levels. Long-term monitoring of fly ash disposal-sites indicates that alkaline neutralization of fly ash leachate is occurring. Further, field data indicate that toxic trace elements (particularly As and Se) in disposal site leachates decrease in concentration as the pH of the learhate is neutralized. Thus, the intrinsic corditions at Northern Great Plains fly ash disposal sites appear to promote significant attenuation of critical toxic elements found in fly ash leachates. Regardless of the pH, leachates in those settings have high concentrations of sodium and sulfate. Western fly ashes are commonly cementitious. Our studies indicate that fly ashes comnoniy develop significant strength after several months of burial, particularly if emplaced in an unsaturated disposal setting. Once cementitious reactions have occurred, the fly ashes show little potential for leaching. Thus, a combination of intrinsic disposal-site conditions and the cementitious behavior of the fly ashes suggests that surface-mine disposal of western fly ashes in the Northern Great Plains, assuming proper disposal-site selection, may not cause long-term environmental problems associated with toxic trace elements.

Case study on the implementation of deammonification for the process water treatment of Munich WWTPs

2012 ◽  
Vol 65 (10) ◽  
pp. 1895-1902 ◽  
Author(s):  
Rita Hilliges ◽  
Eberhard Steinle ◽  
Bernhard Böhm
Keyword(s):  
Water Treatment ◽  
Operating Costs ◽  
Process Water ◽  
Second Stage ◽  
Sludge Disposal ◽  
Sludge Digestion ◽  
High Investment ◽  
Flow Treatment

The two-staged WWTP ‘Gut Grosslappen’ has a capacity of 2 mio. PE. It comprises a pre-denitrification in the first stage using recirculation from the nitrifying second stage. A residual post-denitrification in a downstream sand filter is required in order to achieve the effluent standards. Presently the process water from sludge digestion is treated separately by nitrification/denitrification. Due to necessary reconstruction of the biological stages, the process water treatment was included in the future overall process concept of the WWTP. A case study was conducted comparing the processes nitritation/denitrititation and deammonification with nitrification/denitrification including their effect on the operational costs of the planned main flow treatment. Besides the different operating costs the investment costs required for the process water treatment played a significant role. Six cases for the process water treatment were compared. As a result, in Munich deammonification can only be recommended for long-term future developments, due to the high investment costs, compared with the nitritation/denitritation alternative realizable in existing tanks. The savings concerning aeration, sludge disposal and chemicals were not sufficient to compensate for the additional investment costs. Due to the specific circumstances in Munich, for the time being the use of existing tanks for nitritation/denitritation proved to be most economical.

Anaerobic digestion of excess activated sludge with ozone pretreatment

2003 ◽  
Vol 47 (12) ◽  
pp. 207-214 ◽  
Author(s):  
R. Goel ◽  
T. Tokutomi ◽  
H. Yasui
Keyword(s):  
Anaerobic Digestion ◽  
Ozone Treatment ◽  
Anaerobic Sludge ◽  
Methane Recovery ◽  
Sludge Disposal ◽  
Ozone Dose ◽  
Significant Difference ◽  
Attractive Option ◽  
Ozone Pretreatment

Source minimization of excess sludge production by economical means can be considered an attractive option to deal with the problem of sludge disposal under strict disposal standards. In this paper long-term operational results for a process that combines the oxidative ozone pretreatment with anaerobic sludge digestion are described. The ozone pretreatment solubilized around 19% and 37% of the solids at 0.015 and 0.05 gO3/gTS ozone dose. The solubilization ratios during ozonation did not show any significant difference for the sludge concentrations ranging from 1.8-2.6%. The TVS concentrations after ozone treatment were observed to be about 3% lower than the feed sludge concentrations suggesting only partial mineralization during ozonation. The ozone pretreatment resulted in improved solid reduction efficiencies during anaerobic digestion leading to higher methane recovery. The TVS removal efficiencies during anaerobic digestion were observed to increase by a maximum of 35-90% depending on the applied ozone dose during ozone pretreatment. The improvement in TVS degradation efficiency at different applied ozone doses correlated well with the extent of solubilization during ozonation. Long-term data also suggested that biomass acclimation to ozonated sludge was necessary before higher degradation efficiencies could be achieved.

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