Chemical flocculability of sludge organisms in response to growth conditions

✍ Scribed by Yeun C. Wu

• Publisher: John Wiley and Sons
• Year: 1978
• Tongue: English
• Weight: 698 KB
• Volume: 20
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/bit.260200505

✦ Synopsis

Abstract

The effect of waste characteristics on the removal of suspended solids and soluble phosphorus by alum, Al~2~(SO~4~)~3~·18H~2~O, was investigated in an activated sludge system with no cellular recycle. Under the conditions presently studied, it was found that sludge organisms grown in nitrogen‐ and phosphorus‐restricted media possess exceptionally large capsules and produce a higher surface electric charge per unit of fry weight. Chemical demand for separation of these capsulated cells is obviously higher than those solids cultivated under a well‐balanced nutrient condition. For phosphorus removal, the molar ratio of Al^+3^:P is a function of the initial concentrations of soluble phosphorus and suspended solids in solution. The relationship between percent phosphorus removal and the quantity of chemical coagulent used shows nonstoichiometric relationship; that is, the required molar ratio of Al^+3^:P is always greater than one and directly depends upon the content of suspended solids in the flocculated media. Moreover, the present study indicated that chemical separation of dispersed microorganisms occurred following phosphorus removal.