Nitrogen is removed from the synthetic wastewater by simultaneous nitrification and denitrification via nitrite by controlling sludge age in the sequencing batch reactor(SBR).

Sludge loading method and sludge age method are the main calculating methods for the design of activated sludge process,the said 2 design methods lay particular stress on security and conservatism,take experiences as the core factor,the biological reaction mechanism in activated sludge process are not reflected.

According to the characteristic of Spiral up-flow reactor(SUFR)system, the peculiarities of the SUFR system with the longer sludge age are analyzed through test comparison .

Effect of SRT on denitrifying dephosphatation;

An Application of SRT in Design and Operation of A~2/O Process;

Analysis of Effect of SRT on Biological Phosphorus Removal;

MLSS) and shortening sludge retention time(SRT)from 15d to 8d could both control sludge bulking and biological foaming effectively in experiment and actual application practice.

On the basis of which some key factors such as Hydraulic Retention Time(HRT),Dissolved Oxygen(DO),and Sludge Retention Time(SRT) were investigated to figure out their effects on the treatment effectiveness.

Some improvements of traditional operation of Integrated Activated Sludge process have been presented in this paper,on the basis of which some key factors such as length of both phase,hydraulic retention time(HRT),dissolved oxygen(DO),and sludge retention time(SRT) were investigated to figure out their effects on the treatment effectiveness.

Taking the urban wastewater as investigation objective,the influence of stepped operation time,hydraulic retention time (HRT),density of dissolved oxygen(DO),and sludge retention time (SRT) on the efficiency of biological nitrogen removal with integrated activated sludge processing was investigated and,then,several improving measures of the design and operation with this technique were discussed.

Study was made on the Non-Backflow Intermittent Aeration System (NBIAS) to investigate the relation of the sludge retention time and other operational parameters with the removal rate of COD,total nitrogen (TN) and total phosphorus (TP).

Effect of SRT on Minimization of Excess Activated Sludge Production;

Effect of Carbon Source and SRT on Denitrifying Phosphorus Removal;

The results show that extending sludge retention time(SRT) can improve the capability of anaerobic phosphorous release,while total phosphorous removal rate is not influenced by SRT.