Improving the nitrogen removal efficiency of an A2/O based WWTP by using an on-line Knowledge Based Expert System

2002 ◽  
Vol 36 (8) ◽  
pp. 2109-2123 ◽  
Author(s):  
J.A Baeza ◽  
D Gabriel ◽  
J Lafuente
Keyword(s):  
Expert System ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Knowledge Based ◽  
On Line

On-line control of a SBR system for nitrogen removal from industrial wastewater

2001 ◽  
Vol 43 (3) ◽  
pp. 93-100 ◽  
Author(s):  
G. Andreottola ◽  
P. Foladori ◽  
M. Ragazzi
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Low Cost ◽  
Ammonia Removal ◽  
High Concentration ◽  
Plywood Industry ◽  
On Line ◽  
Pre Treatment ◽  
Study Laboratory ◽  
System Operating

In this study, laboratory-scale experiments were conducted applying the SBR activated sludge process to a wastewater from a wood factory operating on plywood production. Due to the fact that the wastewater is characterised with a high concentration of ammonia, the aim was to evaluate the nitrogen removal process with SBR system operating with a on-line control of ORP, pH and DO. The complete ammonia removal corresponded exactly to the “Ammonia Valley” in the pH versus time graphic. The ammonia removal efficiency in SBR was 99% at 20°C. The denitrification reaction was completed when in the ORP versus time graphic appeared the “Nitrate Knee”. From the experimental results the optimisation of the SBR cycle allowed the doubling of the applied load with respect to a not optimised cycle (performed in the same volume reactor), without a decrease in the removal efficiency. Moreover, the possibility of stopping the aeration just after the appearance of the Ammonia Valley allows an energy saving. The easy operation and the low cost make the SBR system an interesting option for the biological pre-treatment of plywood industry to be discharged into surface water.

Nitrogen Removal in a Real-Time Controlled Sequencing Batch Membrane Bioreactor

2010 ◽  
Vol 5 (3) ◽  
Author(s):  
Cheng-Nan Chang ◽  
Li-Ling Lee ◽  
Han-Hsien Huang ◽  
Ying-Chih Chiu
Keyword(s):  
Real Time ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Synthetic Wastewater ◽  
Real Time Control ◽  
Time Control ◽  
Cake Layer ◽  
On Line ◽  
Solid Liquid ◽  
Solid Liquid Separation

The performance of a real-time controlled Sequencing Batch Membrane Bioreactor (SBMBR) for removing organic matter and nitrogen from synthetic wastewater has been investigated in this study under two specific ammonia loadings of 0.0086 and 0.0045g NH4+-N gVSS−1 day−1. Laboratory results indicate that both COD and DOC removal are greater than 97.5% (w/w) but the major benefit of using membrane for solid-liquid separation is that the effluent can be decanted through the membrane while aeration is continued during the draw stage. With a continued aeration, the sludge cake layer is prevented from forming thus alleviating the membrane clogging problem in addition to significant nitrification activities observed in the draw stage. With adequate aeration in the oxic stage, the nitrogen removal efficiency exceeding 99% can be achieved with the SBMBR system. Furthermore, the SBMBR system has also been used to study the occurrence of ammonia valley and nitrate knee that can be used for real-time control of the biological process. Under appropriate ammonia loading rates, applicable ammonia valley and nitrate knee are detected. The real-time control of the SBMBR can be performed based on on-line ORP and pH measurements.

scholarly journals Start-up Strategies for Anaerobic Ammonia Oxidation (Anammox) in In-Situ Nitrogen Removal from Polluted Groundwater in Rare Earth Mining Areas

2021 ◽  
Vol 13 (8) ◽  
pp. 4591
Author(s):  
Shuanglei Huang ◽  
Daishe Wu
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Ex Situ ◽  
High Concentration ◽  
Low Concentration ◽  
Start Up ◽  
Anammox Activity

The tremendous input of ammonium and rare earth element (REE) ions released by the enormous consumption of (NH4)2SO4 in in situ leaching for ion-adsorption RE mining caused serious ground and surface water contamination. Anaerobic ammonium oxidation (anammox) was a sustainable in situ technology that can reduce this nitrogen pollution. In this research, in situ, semi in situ, and ex situ method of inoculation that included low-concentration (0.02 mg·L−1) and high-concentration (0.10 mg·L−1) lanthanum (La)(III) were adopted to explore effective start-up strategies for starting up anammox reactors seeded with activated sludge and anammox sludge. The reactors were refrigerated for 30 days at 4 °C to investigate the effects of La(III) during a period of low-temperature. The results showed that the in situ and semi in situ enrichment strategies with the addition of La(III) at a low-concentration La(III) addition (0.02 mg·L−1) reduced the length of time required to reactivate the sludge until it reached a state of stable anammox activity and high nitrogen removal efficiency by 60–71 days. The addition of La(III) promoted the formation of sludge floc with a compact structure that enabled it to resist the adverse effects of low temperature and so to maintain a high abundance of AnAOB and microbacterial community diversity of sludge during refrigeration period. The addition of La(III) at a high concentration caused the cellular percentage of AnAOB to decrease from 54.60 ± 6.19% to 17.35 ± 6.69% during the enrichment and reduced nitrogen removal efficiency to an unrecoverable level to post-refrigeration.

Sign in / Sign up

Export Citation Format

Share Document