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Trace Metals and Filamentous Micro-organism Growth JOHN T. PFEFFER, Assistant Professor AZIZ ABU SAMRA, Research Assistant DIANN T. SCHWEGLER, Research Assistant Environmental Health Research Laboratory University of Kansas Lawrence, Kansas INTRODUCTION Ever since the introduction of the activated sludge process, one of the chronic operational problems has been sludge bulking. This is a very general term which basically means a characteristic of the sludge which produces a light, fluffy sludge that has poor settling properties. One of the principal causative agents of sludge bulking is an excessive growth of filamentous micro-organisms. These organisms are present in activated sludges but usually in small numbers, with nonfilamentous bacteria as the predominant growth. The resulting sludge usually has good settling properties. The predomination of the filamentous micro-organisms can be induced by changes in the environment. The causes of these growths are generally attributed to such factors as low pH, low dissolved oxygen, low nitrogen or high carbohydrate concentration. However, correcting the above factors does not always eliminate the predomination of the filamentous micro-organisms. Research in biological waste treatment systems being conducted at the Environmental Health Lab at the University of Kansas has been plagued with the growths of filamentous fungi and actinomycetes. Preliminary indications were that the problem resulted from the absence of certain key trace nutrients in the substrate. Analysis indicated the absence of certain trace metals in the tap water used in the substrate. Additions of the trace metals to the tap water solutions improved the system in many cases. However, this was not always true. Additions of certain metals far in excess of trace quantities were often necessary. These observations led to the conclusions that not only must the metals be present in trace quantities, but that the chemical environment must be such that these metals are soluble. This led to the investigation of the chemical environment as related to solubility and to the growth characteristics of filamentous micro-organisms as related to the presence of the trace metals. This report is concerned with the availability of trace metals and the growth of filamentous fungi. A search of the literature indicates that a considerable amount of research has been conducted on the sludge bulking caused by filamentous micro-organisms. The majority of this work was concentrated on Sphaerotilus. Very little research has been conducted on other micro-organisms producing filamentous growths. Genetelli and Heukelekian (1) indicate that fungi are rarely the cause of sludge bulking, but the most prevalent cause is sphaerotilus. This has been the contention of many investigators. However, there are several papers which report fungi as the cause of problems with sludge bulking (2,3,4,5). There can be no question that Sphaerotilus is responsible for many of the - 608 -
Object Description
Purdue Identification Number | ETRIWC196546 |
Title | Trace metals and filamentous micro-organisms growth |
Author |
Pfeffer, John T. Abu Samra, Aziz Schwegler, Diann T. |
Date of Original | 1965 |
Conference Title | Proceedings of the twentieth Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://earchives.lib.purdue.edu/u?/engext,12162 |
Extent of Original | p. 608-617 |
Series |
Engineering extension series no. 118 Engineering bulletin v. 49, no. 4 |
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 | 2009-05-19 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 608 |
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 | Trace Metals and Filamentous Micro-organism Growth JOHN T. PFEFFER, Assistant Professor AZIZ ABU SAMRA, Research Assistant DIANN T. SCHWEGLER, Research Assistant Environmental Health Research Laboratory University of Kansas Lawrence, Kansas INTRODUCTION Ever since the introduction of the activated sludge process, one of the chronic operational problems has been sludge bulking. This is a very general term which basically means a characteristic of the sludge which produces a light, fluffy sludge that has poor settling properties. One of the principal causative agents of sludge bulking is an excessive growth of filamentous micro-organisms. These organisms are present in activated sludges but usually in small numbers, with nonfilamentous bacteria as the predominant growth. The resulting sludge usually has good settling properties. The predomination of the filamentous micro-organisms can be induced by changes in the environment. The causes of these growths are generally attributed to such factors as low pH, low dissolved oxygen, low nitrogen or high carbohydrate concentration. However, correcting the above factors does not always eliminate the predomination of the filamentous micro-organisms. Research in biological waste treatment systems being conducted at the Environmental Health Lab at the University of Kansas has been plagued with the growths of filamentous fungi and actinomycetes. Preliminary indications were that the problem resulted from the absence of certain key trace nutrients in the substrate. Analysis indicated the absence of certain trace metals in the tap water used in the substrate. Additions of the trace metals to the tap water solutions improved the system in many cases. However, this was not always true. Additions of certain metals far in excess of trace quantities were often necessary. These observations led to the conclusions that not only must the metals be present in trace quantities, but that the chemical environment must be such that these metals are soluble. This led to the investigation of the chemical environment as related to solubility and to the growth characteristics of filamentous micro-organisms as related to the presence of the trace metals. This report is concerned with the availability of trace metals and the growth of filamentous fungi. A search of the literature indicates that a considerable amount of research has been conducted on the sludge bulking caused by filamentous micro-organisms. The majority of this work was concentrated on Sphaerotilus. Very little research has been conducted on other micro-organisms producing filamentous growths. Genetelli and Heukelekian (1) indicate that fungi are rarely the cause of sludge bulking, but the most prevalent cause is sphaerotilus. This has been the contention of many investigators. However, there are several papers which report fungi as the cause of problems with sludge bulking (2,3,4,5). There can be no question that Sphaerotilus is responsible for many of the - 608 - |
Resolution | 300 ppi |
Color Depth | 8 bit |
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