scholarly journals Effect of mixed liquor suspended solids (MLSS) on simultaneous nitrification and denitrification in a sequencing batch reactor

Author(s):  
Xi Tian ◽  
Shangli Guo ◽  
Kaicheng Xu ◽  
Chunling Zhao ◽  
Xuefeng Wang ◽  
...  
2016 ◽  
Vol 51 (4) ◽  
pp. 377-387 ◽  
Author(s):  
Kshitij Ranjan ◽  
Shubhrasekhar Chakraborty ◽  
Mohini Verma ◽  
Jawed Iqbal ◽  
R. Naresh Kumar

Sequencing batch reactor (SBR) was assessed for direct co-treatment of old landfill leachate and municipal wastewater for chemical oxygen demand (COD), nutrients and turbidity removal. Nitrogen removal was achieved by sequential nitrification and denitrification under post-anoxic conditions. Initially, SBR operating conditions were optimized by varying hydraulic retention time (HRT) at 20% (v/v) landfill leachate concentration, and results showed that 6 d HRT was suitable for co-treatment. SBR performance was assessed in terms of COD, ammonia, nitrate, phosphate, and turbidity removal efficiency. pH, mixed liquor suspended solids, mixed liquor volatile suspended solids (MLVSS), and sludge volume index were monitored to evaluate stability of SBR. MLVSS indicated that biomass was able to grow even at higher concentrations of old landfill leachate. Ammonia and nitrate removal efficiency was more than 93% and 83%, respectively, whereas COD reduction was in the range of 60–70%. Phosphate and turbidity removal efficiency was 80% and 83%, respectively. Microbial growth kinetic parameters indicated that there was no inhibition of biomass growth up to 20% landfill leachate. The results highlighted that SBR can be used as an initial step for direct co-treatment of landfill leachate and municipal wastewater.


2015 ◽  
Vol 13 (3) ◽  
pp. 746-757 ◽  
Author(s):  
Bei Long ◽  
Chang-zhu Yang ◽  
Wen-hong Pu ◽  
Jia-kuan Yang ◽  
Guo-sheng Jiang ◽  
...  

Mature aerobic granular sludge (AGS) was inoculated for the start-up of a pilot-scale sequencing batch reactor for the treatment of high concentration solvent recovery raffinate (SRR). The proportion of simulated wastewater (SW) (w/w) in the influent gradually decreased to zero during the operation, while volume of SRR gradually increased from zero to 10.84 L. AGS was successfully domesticated after 48 days, which maintained its structure during the operation. The domesticated AGS was orange, irregular, smooth and compact. Sludge volume index (SVI), SV30/SV5, mixed liquor volatile suspended solids/mixed liquor suspended solids (MLVSS/MLSS), extracellular polymeric substances, proteins/polysaccharides, average particle size, granulation rate, specific oxygen utilization rates (SOUR)H and (SOUR)N of AGS were about 38 mL/g, 0.97, 0.52, 39.73 mg/g MLVSS, 1.17, 1.51 mm, 96.66%, 47.40 mg O2/h g volatile suspended solids (VSS) and 8.96 mg O2/h g VSS, respectively. Good removal effect was achieved by the reactor. Finally, the removal rates of chemical oxygen demand (COD), total inorganic nitrogen (TIN), NH4+-N and total phosphorus (TP) were more than 98%, 96%, 97% and 97%, respectively. The result indicated gradually increasing the proportion of real wastewater in influent was a useful domestication method, and the feasibility of AGS for treatment of high C/N ratio industrial wastewater.


2011 ◽  
Vol 183-185 ◽  
pp. 231-235
Author(s):  
Yan Ping Jia ◽  
Lan He Zhang ◽  
Zhi Ling Zhao ◽  
Tao Yang

In this study, a sequencing batch reactor (SBR) was used to treat synthetic wastewater when dissolved oxygen (DO) concentration and temperature were 0.5-1.0mg/L and 30±1°C, respectively. Effect of sludge loading(Ns) on simultaneous nitrification and denitrification (SND) was investigated. The results indicated that removal efficiencies of ammonia nitrogen (NH4+-N), COD and total nitrogen (TN) were all higher than 90%, respectively, when influent NH4+-N and Ns were 35-45mg/L, 0.15kgCOD/(kgMLSS•d) under 7 hours of aeration time and 1 hour of idle time, respectively. Therefore, the SBR has obviously achieved simultaneous nitrification and denitrification.


2011 ◽  
Vol 233-235 ◽  
pp. 600-603
Author(s):  
Gao Shun Qiu ◽  
Ling Feng Qiu ◽  
Yi Ming Chen

The influences of HRT, C/N ratio on simultaneous nitrification and denitrification (SND) and the rule of pH in a sequencing batch reactor (SBR) were investigated while treating low C/N synthetic municipal wastewater. The results showed that the function of SND became more outstanding and the removal rate of TN, NH4+-N was improved greatly by lengthening HRT appropriately; when the C/N increased, the denitrification effect of the simultaneous nitrification and denitrification would be improved; .At the same time, the variation of pH value was well related to ammonia oxidation. So that judgment on the ending of nitrification and denitrification could be based on the inflection point on the varied curve of pH, and thus reducing aeration and mixing time for the purpose of energy saving.


2013 ◽  
Vol 39 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Katarzyna Bernat

Abstract In this study, the dependence between volumetric exchange rate (n) in an SBR (Sequencing Batch Reactor) with a modified cycle and simultaneous nitrification and denitrification (SND) efficiency during the treatment of anaerobic sludge digester supernatant was determined. In the SBR cycle alternating three aeration phases (with limited dissolved oxygen (DO) concentration up to 0.7 mg O2/L) and two mixing phases were applied. The lengths of each aeration and mixing phases were 4 and 5.5 h, respectively. Independently of n, a total removal of ammonium was achieved. However, at n = 0.1 d-1 and n = 0.3 d-1 nitrates were the main product of nitrification, while at n = 0.5 d-1, both nitrates and nitrites occurred in the effluent. Under these operational conditions, despite low COD/N (ca. 4) ratio in the influent, denitrification in activated sludge was observed. A higher denitrification efficiency at n = 0.5 d-1 (51.3%) than at n = 0.1 d-1 (7.8%) indicated that n was a crucial factor influencing SND via nitrite and nitrate in the SBR with a low oxygen concentration in aeration phases.


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