scholarly journals Formation and Stability of Nitrifying Granules under High Loading Rates

Author(s):  
Yan-ping Wang ◽  
◽  
Fang-yuan Chen ◽  
Jing-lu Nie ◽  
Ping Ning
Keyword(s):  
2010 ◽  
Vol 101 (8) ◽  
pp. 2700-2705 ◽  
Author(s):  
Jianwei Chen ◽  
Ping Zheng ◽  
Yi Yu ◽  
Chongjian Tang ◽  
Qaisar Mahmood
Keyword(s):  

1983 ◽  
Vol 15 (8-9) ◽  
pp. 359-368 ◽  
Author(s):  
L van den Berg ◽  
K J Kennedy

Cheese whey and a dilute waste from a cheese factory with a Chemical Oxygen Demand of 66,000 and 4,000 mg (COD)/L respectively, were treated at high loading rates in 0.7 to 1.2 L downflow anaerobic stationary fixed film reactors and an upflow sludge bed reactor. In downflow stationary fixed film reactors treating cheese whey, COD removal efficiencies of 97% were achieved at a loading rate of 5 kg COD/m3/day and 92% at a maximum loading rate of 22 kg COD/m3/day. With dairy plant waste, loading rates of up to 15 kg COD/m3/day were possible with COD removal efficiencies averaging 75%, decreasing slightly with increasing loading rates. In an upflow sludge bed reactor the COD removal efficiency of dairy plant waste, decreased from 87% at 5 kg COD/m3/day to 73% at 15 kg COD/m3/day. A stationary fixed film reactor treating a skim milk powder waste (4,000 ppm) could only be operated at up to 10 kg COD/m3/day with a treatment efficiency of 72%. Methane was produced from all wastes at rates corresponding to 0.32 m3 CH4 (0°C, 1 atm) per kg COD removed. Results show that stationary fixed film reactors are capable of treating dairy wastes at high loading rates and high COD removal efficiencies.


2009 ◽  
Vol 43 (1) ◽  
pp. 98-105 ◽  
Author(s):  
Cristiano Nicolella ◽  
Attilio Converti ◽  
Mario Zilli

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2213 ◽  
Author(s):  
Abiodun O. Jegede ◽  
Grietje Zeeman ◽  
Harry Bruning

Chinese dome digesters are usually operated at long hydraulic retention times (HRT) and low influent total solids (TS) concentration because of limited mixing. In this study, a newly optimised Chinese dome digester with a self-agitating mechanism was investigated at a pilot scale (digester volume = 500 L) and compared with a conventional Chinese dome digester (as blank) at 15% influent TS concentration at two retention times (30 and 40 days). The reactors were operated at ambient temperature: 27–33 °C. The average specific methane production, volatile fatty acids and percentage of volatile solids (VS) reduction are 0.16 ± 0.13 and 0.25 ± 0.05L CH4/g VS; 1 ± 0.5 and 0.7 ± 0.3 g/L; and 51 ± 14 and 57 ± 10% at 40 days HRT (day 52–136) for the blank and optimised digester, respectively. At 30 days HRT (day 137–309) the results are 0.19 ± 0.12 and 0.23 ± 0.04 L CH4/g VS; 1.2 ± 0.6 and 0.7 ± 0.3 g/L; and 51 ± 9 and 58 ± 11.6%. Overall, the optimised digester produced 40% more methane than the blank, despite the high loading rates applied. The optimised digester showed superior digestion treatment efficiency and was more stable in terms of VFA concentration than the blank digester, can be therefore operated at high influent TS (15%) concentration.


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