Biomedical Engineering Reference
In-Depth Information
unit can flow into the AO unit through holes (20mm in diameter) in shared walls betwwen
Aer1 and Ano1 as well as betwwen Aer2 and Ano2. The working volume of the final settler
was 50L. Detailed description of the proces and operations can reffer to Xia and Liu 2006.
2.2. Anaerobic-anoxic SBR Reactors
Three anaerobic-anoxic SBR reactors used in this study were identical in dimensions with
effective volume of 1.5L and feeding/discharging ratio of 80%. For each SBR reactor, 400mL
sludge was seeded from wasted sludge of the parallel AN/AO process and cultured in the
following 6h-period sequencing operation until a quasi-steady effluent was achieved: feeding
of synthetic wastewater (15min)----anaerobic stage (2h)----sedimentation (30min)----
decanting (15min)----feeding of nitrate solution (15min)----anoxic stages (2h)----
sedimentation (30min)----effluent (15min). Flow rate of feeding and decanting (effluent) were
accurately controlled by peristaltic pumps (Lange, China); magnetic stirrers (Meiyinpu,
China) were used to suspend biomass in anaerobic and anoxic stages. Nitrate concentration at
the beginning of anaerobic stages and DOC concentration at the beginning of anoxic stages
were controlled by washing MLSS of the corresponding above mentioned stages before
starting of their next sequential stages.
COD 8.976 gd
-1
N
2
2.208 gNd
-1
COD 11.472 gd
-1
COD10.608 gd
-1
COD 43.776gd
-1
TN 11.376gd
-1
TP 1.104gd
-1
Wastewater Line
Sludge Line
Aer2
Aer1
Ana2
Settler
COD 23.040 gd
-1
TN 11.088 gd
-1
TP 0. 336 gd
-1
Ana1
Ano1
Ano2
COD 43.776gd
-1
TN 11.376gd
-1
TP 1.104gd
-1
COD 16.401gd
-1
TN 1.148gd
-1
TP 1.497gd
-1
COD 20.448 gd
-1
N
2
.4.272 gNd
-1
COD 7.920 gd
-1
N
2
1.536 gNd
-1
COD 8.832gd
-1
N
2
2.448 gNd
-1
Figure 1. Schematic diagram of the parallel AN/AO process.
2.3. Wastewater and Analysis
Domestic wastewater from Tongji Newly Village Pump Station (Shanghai China) was
used in experimental operations of the parallel AN/AO process; characteristics of the
wastewater were listed in table 1.
