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Chemical Precipitation of Phosphate withi a High Rate Bio-oxidation System I. Synthetic Sewage Studies W. A. EBERHARDT, FWPCA Research Fellow J. B. NESBITT, Professor Civil Engineering Department Pennsylvania State University University Park, Pennsylvania INTRODUCTION Be it in research, education, or regulatory policy formation, few areas of water quality management receive the attention presently given the problems and causes of surface water enrichment. Nevertheless, while descriptive examples of eutrophication have been abundantly reported, the associated direct causes have seldom been unequivocally defined. Commonly mentioned in this respect have been increased levels of inorganic nutrients and/or growth factors. Of the former, foremost attention has been directed toward phosphorus. In order of usual importance, phosphorus gains access to surface waters via wastewater (industrial and domestic), runoff, and groundwater. It has been considered likely that in some instances the removal of this nutrient from waste discharges will result in stream concentrations sufficiently low to limit vegetative productivity in accord with Liebig's Law of the Minimum. Accordingly, phosphorus removal methods have been widely investigated. With few exceptions, the processes considered have been tertiary in nature - - a condition conducive to high costs. Recently, Nesbitt (1) reviewed the many proposed schemes and evaluated each on the basis of effluent residual (assuming a stream to waste dilution factor of 9:1, an effluent residual of 0.1 mg P/l or less was considered desirable.) and annual costs. His analyses indicated promise for a non-tertiary scheme utilizing chemical precipitation in conjunction with chemically aided bioflocculation in a short-term activated sludge process. The concept of using iron and aluminum salts simultaneously for cell floc- culation and phosphorus elimination was suggested by Stumm (2) ana later successfully tried on a batch basis by Tenney and Stumm (3). Realizing that biological treatment occurs in two phases, substrate utilization and bioflocculation, they reasoned that by chemically aiding flocculation the initial phase could be accomplished in a "high-rate, low-solids retention unit." The increased treatment costs for phosphorus removal and flocculation would then be partially compensated for by savings from the shortened biological phase. Work apparently of this nature has also been conducted in Switzerland (4). OBJECT AND PROCESS CONSIDERATIONS OF THIS INVESTIGATION It was the object of this research to develop and study the effectiveness of a continuously operated bench scale process combining chemical treatment and activated sludge so as to effect low phosphorus residuals without any sacrifice in biological treatment efficiency. - 100 -
Object Description
Purdue Identification Number | ETRIWC196711 |
Title | Chemical precipitation of phosphate within a high rate bio-oxidation system. I. Synthetic sewage studies |
Author |
Eberhardt, W. A. Nesbitt, John B. |
Date of Original | 1967 |
Conference Title | Proceedings of the 22nd Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://earchives.lib.purdue.edu/u?/engext,14179 |
Extent of Original | p. 100-119 |
Series |
Engineering extension series no. 129 Engineering bulletin v. 52, no. 3 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Date Digitized | 2009-05-20 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 100 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Transcript | Chemical Precipitation of Phosphate withi a High Rate Bio-oxidation System I. Synthetic Sewage Studies W. A. EBERHARDT, FWPCA Research Fellow J. B. NESBITT, Professor Civil Engineering Department Pennsylvania State University University Park, Pennsylvania INTRODUCTION Be it in research, education, or regulatory policy formation, few areas of water quality management receive the attention presently given the problems and causes of surface water enrichment. Nevertheless, while descriptive examples of eutrophication have been abundantly reported, the associated direct causes have seldom been unequivocally defined. Commonly mentioned in this respect have been increased levels of inorganic nutrients and/or growth factors. Of the former, foremost attention has been directed toward phosphorus. In order of usual importance, phosphorus gains access to surface waters via wastewater (industrial and domestic), runoff, and groundwater. It has been considered likely that in some instances the removal of this nutrient from waste discharges will result in stream concentrations sufficiently low to limit vegetative productivity in accord with Liebig's Law of the Minimum. Accordingly, phosphorus removal methods have been widely investigated. With few exceptions, the processes considered have been tertiary in nature - - a condition conducive to high costs. Recently, Nesbitt (1) reviewed the many proposed schemes and evaluated each on the basis of effluent residual (assuming a stream to waste dilution factor of 9:1, an effluent residual of 0.1 mg P/l or less was considered desirable.) and annual costs. His analyses indicated promise for a non-tertiary scheme utilizing chemical precipitation in conjunction with chemically aided bioflocculation in a short-term activated sludge process. The concept of using iron and aluminum salts simultaneously for cell floc- culation and phosphorus elimination was suggested by Stumm (2) ana later successfully tried on a batch basis by Tenney and Stumm (3). Realizing that biological treatment occurs in two phases, substrate utilization and bioflocculation, they reasoned that by chemically aiding flocculation the initial phase could be accomplished in a "high-rate, low-solids retention unit." The increased treatment costs for phosphorus removal and flocculation would then be partially compensated for by savings from the shortened biological phase. Work apparently of this nature has also been conducted in Switzerland (4). OBJECT AND PROCESS CONSIDERATIONS OF THIS INVESTIGATION It was the object of this research to develop and study the effectiveness of a continuously operated bench scale process combining chemical treatment and activated sludge so as to effect low phosphorus residuals without any sacrifice in biological treatment efficiency. - 100 - |
Resolution | 300 ppi |
Color Depth | 8 bit |
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