Biological phosphorus removal in anoxic-aerobic sequencing batch reactor with starch as sole carbon source

2016 ◽  
Vol 75 (1) ◽  
pp. 28-38 ◽  
Author(s):  
Dacheng Luo ◽  
Linjiang Yuan ◽  
Lun Liu ◽  
Lu Chai ◽  
Xin Wang

In traditional biological phosphorus removal (BPR), phosphorus release in anaerobic stage is the prerequisite of phosphorus excessive uptake in aerobic conditions. Moreover, when low molecular weight of the organic substance such as volatile fatty acids (VFAs) is scarce in bulk liquid or anaerobic condition does not exist, phosphate accumulating organisms (PAOs) have difficulty removing phosphorus. However, in this work, phosphorus removal in two anoxic-aerobic sequencing batch reactors (SBRs) was observed when starch was supplied as a sole carbon source. The relations of the BPR with idle period were investigated in the two identical SBRs; the idle times were set to 0.5 hr (R1) and 4 hr (R2), respectively. Results of the study showed that, in the two SBRs, phosphorus concentrations of 0.26–3.11 mg/L in effluent were obtained after aeration when phosphorus concentration in influent was about 8 mg/L. Moreover, lower accumulations/transformations of polyhydroxyalkanoates (PHAs) and higher transformation of glycogen occurred in the SBRs, indicating that glycogen was the main energy source that was different from the traditional mechanism of BPR. Under the different idle time, the phosphorus removal was a little different. In R2, which had a longer idle period, phosphorus release was very obvious just as occurs in a anaerobic–aerobic regime, but there was a special phenomenon of chemical oxygen demand increase, while VFAs had no notable change. It is speculated that PAOs can assimilate organic compounds in the mixed liquor, which were generated from glycolysis by fermentative organisms, coupled with phosphorus release. In R1, which had a very short idle period, anaerobic condition did not exist; phosphorus removal rate reached 63%. It is implied that a new metabolic pathway can occur even without anaerobic phosphorus release when starch is supplied as the sole carbon source.

2019 ◽  
Vol 657 ◽  
pp. 1398-1408 ◽  
Author(s):  
Natalia Rey-Martínez ◽  
Marina Badia-Fabregat ◽  
Albert Guisasola ◽  
Juan Antonio Baeza

2013 ◽  
Vol 864-867 ◽  
pp. 1886-1889
Author(s):  
Xiao Yan Tian ◽  
Liang Wang

Based on An / OSBR, the paper explores the different sludge loading and nitrate concentrations under the conditions of An / OSBR effects of biological phosphorus removal systems.The influent phosphorus concentration constant at 10 ± 0.5mg / L, in order to compare the end of the anaerobic and effluent TP concentration.The results showed that: ①With the increasing of nitrate concentrations , PAOs release phosphorus in the anaerobic reaction zone is decreased, nitrate appears to reduce the synthesis of PHB, which is due to PHB synthesis and denitrification requires a simple carbon source as hydrogen donor, resulting in competition;② With the COD sludge load increases, the effluent TP concentration decreased, when the COD sludge load ≥ 0.46mgCOD/mgMLSS · d, the effluent TP concentrations is less than 1mg / L;③ When the reaction temperature was 25 °C and 15 °C , the releasing phosphorus in anaerobic and COD sludge load have a good correlation,Linear relationship between the two were: y = 0.72 +71.91 x ( 25 °C), y = 2.81 +73.33 x (15 °C);


2012 ◽  
Vol 46 (9) ◽  
pp. 2983-2991 ◽  
Author(s):  
Javier Guerrero ◽  
Carlota Tayà ◽  
Albert Guisasola ◽  
Juan A. Baeza

1985 ◽  
Vol 17 (11-12) ◽  
pp. 297-298 ◽  
Author(s):  
Takao Murakami ◽  
Atsushi Miyairi ◽  
Kazuhiro Tanaka

In Japan various biological phosphorus removal processes have recently been researched by laboratory or pilot plant scale studies and most of them have shown good results. Based on these results, the Japan Sewage Works Agency has conducted a full scale study of the biological phosphorus removal process from June 1982 until February 1983, which was the first full scale operation of this process in Japan. The main purpose of the study was to evaluate phosphorus removal efficiency and also nitrogen removal efficiency of the process and in addition, to ascertain the important operating factors of the process. For the study a treatment train of a large scale sewage treatment plant was remodelled. The aeration tank of 3.825 m3 volume was divided into four equal cells. The whole train including return sludge line was operated entirely independently of the other trains. During the experiment the train was operated under two different modes, Mode 1 and Mode 2. In Mode 1, the train was operated as an A/O process, the first cell of the aeration tank being anaerobic and the other cells oxic. In Mode 2, the train was operated as a Modified Phoredox process. In this case, the first cell was anaerobic, but the second cell was anoxic and nitrified liquor was returned to it from the end of the oxic cells. Mode 1 and Mode 2 were further divided into many ‘runs' and the flow rate varied between 12,550 m3 d−1 and 25,270 m3 d−1 , corresponding to retention times of 7.3 hours and 3.6 hours, respectively. Throughout the experimental period the mean value of influent (primary effluent) total-P concentration was 3.38 mg 1−1 , and that of the final effluent was 0.47 mg 1−1 . A cumulated frequency curve of the data showed that about 93% of measured effluent total-P was below 1.0 mg l−1 . Therefore, it can be concluded that with these influent total-P levels, biological phosphorus removal processes can sufficiently satisfy the effluent standard of 1 mg 1−1 total-P. Even when the process was operated as a Modified Phoredox Process, no obstruction to phosphorus removal because of nitrification was observed and phosphorus removal remained good. However, since the sewage treatment plant treated influent from a combined sewerage system, phosphorus removal was sometimes affected by heavy rainfalls. In such cases phosphorus release in the anaerobic cell was insufficient because of increased influent NOx concentration and accordingly increased denitrification level in the anaerobic cell. Therefore, as a result, enhanced phosphorus uptake in the following cells could not be observed. Higher process stability can be expected if an effective countermeasure to high influent NOx concentration can be made. Influence of flow rate fluctuation on the process was also studied. The treatment train was operated for a week under a daily flow rate fluctuation pattern which ranged between 460 m3 hr−1 and 820 m3 hr−1 . Nevertheless, the effluent total-P concentration showed no increase and stayed constantly lower than 0.5 mg 1−1. The oxidation reduction potential (ORP) was an effective control index to evaluate the degree of phosphorus release in the anaerobic cell. Water temperature did not affect phosphorus release and uptake rates.


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