Effect of operational conditions on the nitrogen removal in a pilot scale baffled wastewater stabilization ponds under tropical conditions

2011 ◽  
pp. 97-109
Keyword(s):  
Nitrogen Removal ◽  
Pilot Scale ◽  
Operational Conditions ◽  
Stabilization Ponds ◽  
Tropical Conditions ◽  
Wastewater Stabilization Ponds

Understanding the contribution of biofilm in an integrated fixed-film-activated sludge system (IFAS) designed for nitrogen removal

2015 ◽  
Vol 71 (10) ◽  
pp. 1500-1506 ◽  
Author(s):  
P. Moretti ◽  
J. M. Choubert ◽  
J. P. Canler ◽  
O. Petrimaux ◽  
P. Buffiere ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Loading Rate ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Biofilm Growth ◽  
Operational Conditions ◽  
Solids Concentration ◽  
Fixed Film ◽  
Autotrophic Biomass

The objective of this study is to improve knowledge on the integrated fixed-film-activated sludge (IFAS) system designed for nitrogen removal. Biofilm growth and its contribution to nitrification were monitored under various operating conditions in a semi-industrial pilot-scale plant. Nitrification rates were observed in biofilms developed on free-floating media and in activated sludge operated under a low sludge retention time (4 days) and at an ammonia loading rate of 45–70 gNH4-N/kgMLVSS/d. Operational conditions, i.e. oxygen concentration, redox potential, suspended solids concentration, ammonium and nitrates, were monitored continuously in the reactors. High removal efficiencies were observed for carbon and ammonium at high-loading rate. The contribution of biofilm to nitrification was determined as 40–70% of total NOx-N production under the operating conditions tested. Optimal conditions to optimize process compacity were determined. The tested configuration responds especially well to winter and summer nitrification conditions. These results help provide a deeper understanding of how autotrophic biomass evolves through environmental and operational conditions in IFAS systems.

Wastewater Treatment by a Submerged Contact Media Process Using Net Plates

1991 ◽  
Vol 23 (10-12) ◽  
pp. 1853-1862 ◽  
Author(s):  
T. Nambu ◽  
K. Kawarura ◽  
M. Kaneko
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Retention Time ◽  
Municipal Wastewater ◽  
Pilot Scale ◽  
Recycled Water ◽  
Operational Conditions ◽  
Treatment Performance ◽  
Conventional Activated Sludge ◽  
Treated Municipal Wastewater

Wastewater treatment by using a series of bioreactors with submerged net plates, on which microbial growths could be developed, was studied to evaluate its treatment performance and to find suitable operational conditions for sufficient BOD and nitrogen removal. A comprehensive experimental study was carried out by using a bench-scale plant which treated artificial wastewater and a pilot-scale plant which treated municipal wastewater. This process treated well the wastewater with higher pollutant loads in comparison with the conventional activated sludge process. The wastewater containing 200 mg BOD/l was reduced to 20 mg BOD/l at the high BOD loading of 1,94 kg/m3 day and the retention time less than 5 hours. Nitrogen removal could be explained well by an index defined as the product of the water temperature and the retention time. When the ratio, in flow rate, of recycled water to influent was 4 and the index was more than 400, nitrogen removal more than 80 % was obtained.

Energy saving processes for nitrogen removal in organic wastewater from food processing industries in Thailand

2004 ◽  
Vol 50 (6) ◽  
pp. 345-351 ◽  
Author(s):  
N.H. Johansen ◽  
N. Suksawad ◽  
P. Balslev
Keyword(s):  
Process Control ◽  
Energy Saving ◽  
Nitrogen Removal ◽  
Pilot Scale ◽  
Sludge Bulking ◽  
Tropical Conditions ◽  
Additional Process ◽  
Nitrogen Conversion ◽  
Energy Saving Process ◽  
Organic Wastewater

Nitrogen removal from organic wastewater is becoming a demand in developed communities. The use of nitrite as intermediate in the treatment of wastewater has been largely ignored, but is actually a relevant energy saving process compared to conventional nitrification/denitrification using nitrate as intermediate. Full-scale results and pilot-scale results using this process are presented. The process needs some additional process considerations and process control to be utilized. Especially under tropical conditions the nitritation process will round easily, and it must be expected that many AS treatment plants in the food industry already produce NO2-N. This uncontrolled nitrogen conversion can be the main cause for sludge bulking problems. It is expected that sludge bulking problems in many cases can be solved just by changing the process control in order to run a more consequent nitritation. Theoretically this process will decrease the oxygen consumption for oxidation by 25% and the use of carbon source for the reduction will be decreased by 40% compared to the conventional process.

Nitrogen removal in baffled waste stabilization ponds

1996 ◽  
Vol 33 (7) ◽  
pp. 173-181 ◽  
Author(s):  
S. Muttamara ◽  
U. Puetpaiboon
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Plug Flow ◽  
Specific Area ◽  
Pilot Scale ◽  
Bacterial Biofilm ◽  
Waste Stabilization Ponds ◽  
Stabilization Ponds ◽  
N Removal ◽  
Waste Stabilization

This study evaluated nitrogen removal in Baffled Waste Stabilization Ponds (BWSPs) comprising laboratory and pilot-scale ponds with different number of baffles. The aim was to promote the waste stabilization pond practice for wastewater treatment in tropical countries by increasing nitrogen and organic carbon removal efficiency or reducing the land area requirement through the use of baffles which increased the biofilm biomass concentrations. The experiments started with a tracer study to find out the hydraulic characteristics of each pond. It was shown that the dispersion number decreased with increasing flow length and number of baffles which indicated more plug flow conditions. The deviation of actual HRT from theoretical HRT was computed and the flow pattern suggested the existence of an optimum spacing of baffles in BWSP units. The investigations further revealed that more than 65% TN and 90% NH3-N removal efficiencies were achieved at HRT of 5 days in a 6 baffled pond, which corresponds to the specific area of 34.88 m2m3. TN and NH3-N removal increased with increasing number of baffles in the BWSP units. Combined algal/bacterial biofilm grown on the baffles immersed in the ponds showed potential for increasing the extent of nitrification. COD removal increased with higher number of baffles with its maximum removal efficiency at 6 baffles. Compared with normal WSP, BWSP gave higher TN, NH3-N, COD and BOD5 removal efficiency. The effluent SS concentrations from the laboratory-scale 6 baffled pond were less than 20 mg/L at HRT of 3 days or more.

Nitrogen mass balances for pilot-scale biofilm stabilization ponds under tropical conditions

2011 ◽  
Vol 102 (4) ◽  
pp. 3754-3760 ◽  
Author(s):  
M.A. Babu ◽  
N.P. van der Steen ◽  
C.M. Hooijmans ◽  
H.J. Gijzen
Keyword(s):  
Pilot Scale ◽  
Mass Balances ◽  
Stabilization Ponds ◽  
Tropical Conditions

Comparative study of domestic wastewater treatment efficiencies between facultative pond and water spinach pond

1995 ◽  
Vol 32 (3) ◽  
pp. 263-270 ◽  
Author(s):  
Seni Karnchanawong ◽  
Jaras Sanjitt
Keyword(s):  
Growth Rates ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Organic Content ◽  
Water Spinach ◽  
Removal Rates ◽  
Mass Removal ◽  
Loading Rates ◽  
Tropical Conditions ◽  
Average Water

Two pilot-scale studies were comparatively conducted under tropical conditions during December 1992 to September 1993. One study involved facultative ponds(FP) and the others water spinach ponds(SP). Four rectangular concrete ponds, 0.8 m × 2.4 m × 1.1 m (width × length × depth), were employed to treat the Chiang Mai University campus wastewater. Water spinach (Ipomoea aquatica) was planted in two of the ponds. The influent characteristics noted showed a low organic content, i.e. BOD 25.4-29.9 mg/l, with BOD:N ratio around 1:1. The investigations were conducted using the following hydraulic retention times (HRT): 1.6, 2, 2.7, 4, 8 and 16 d. The results showed that the BOD, COD and SS mass removal rates increased as the mass loading rates increased and the SP was significantly more effective in reducing the organic content than the FP. No relationship was found between TN mass removal and the loading rates. However, the TP mass removal rates in the SP and the FP were rather low and were considered to be insignificant. It was observed that SS accumulated in the water spinach root systems which tended to act as a strainer. This process led to plant growth inhibition and finally die-off. The average water spinach growth rates varied from 37 to 107 g wet wt./(m2.d) and no relationship was established between the growth rates and the HRT.

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