Microbial Release of Soluble Phosphate in an Activated Sludge Environment

摘要

Batch type laboratory units were used to study the mechanisms and factors that determine the amount of soluble phosphate that will be released from activated sludge during typical plant operation. In addition to studying the effect of typical operational factors such as rate and duration of aeration, organic loading rate, and duration of anaerobiosis, emphasis was placed on determining whether activated sludge phosphate release is primarily a chemical or a biological phenomenon. The experimental results demonstrate that the release of soluble phosphate from activated sludge is basically a biological phenomenon and that it is relatively independent of the chemical environment as measured by pH and ORP, within the normal range of waste treatment operation. Such release is a strong function of parameters that affect cellular metabolism such as D. O. The release of phosphate occurs under both aerobic and anoxic conditions but the amount released during anoxia is considerably greater and it is released much more rapidly. The magnitude and rapidity of release under any conditions is directly proportional to the biological stress imposed on the system. Release during anoxia can be retarded by preceding high aeration rates and significant amounts of organic substrate. (Author)