scholarly journals Real Wastewater Treatment Using a Moving Bed and Wastewater-Borne Algal–Bacterial Consortia with a Short Hydraulic Retention Time

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 116
Author(s):  
Donghan Kang ◽  
Keugtae Kim

Algal–bacterial consortium is a promising technology, combined with wastewater treatment plants, because algae produce molecular oxygen for nitrification and organic removal and reduce carbon dioxide emissions. However, algal–bacterial consortia based on suspended growth require a relatively long hydraulic retention time (HRT) of 4 d to 6 d for removal of organic matter and nutrients. For the algal–bacterial consortia in a photobioreactor (PBR) containing a moving bed, the organic matter and nutrient removal and the community structure of algal–bacterial consortia were investigated to determine the performance under a relatively short HRT of 2.5 d. Moving media containing algal–bacterial consortia enhanced the photosynthetic oxygen concentration (0.2 mg dissolved oxygen (DO)·L−1 to 5.9 mg DO·L−1), biochemical oxygen demand removal (88.0% to 97.2%), ammoniacal nitrogen removal (33.8% to 95.3%), total nitrogen removal (61.6% to 87.7%), total phosphate removal (66.4% to 88.7%), algal growth (149.3 mg algae·L−1 to 285.4 mg algae·L−1), and settleability (algae removal efficiency of 20.6% to 71.2%) compared with those of a PBR without moving media (SPBR). Although biomass uptake was the main mechanism for nutrient removal in the SPBR, both biomass uptake and denitrification were the main mechanisms in the PBR with moving media (MBPBR). The bacterial community also changed under the moving media condition. This study shows that moving media might be an essential parameter for PBRs with a short HRT to enhance nutrient removal and settleability.

1995 ◽  
Vol 32 (7) ◽  
pp. 135-142
Author(s):  
E. Görgün ◽  
N. Artan ◽  
D. Orhon ◽  
R. Tasli

Effective nitrogen removal is now required to protect water quality in sensitive coastal areas. This involves a much more difficult treatment process than for conventional domestic sewage as wastewater quantity and quality exhibits severe fluctuations in touristic zones. Activated sludge is currently the most widely used wastewater treatment and may be upgraded as a predenitrification system for nitrogen removal. Interpretation of nitrification and denitrification kinetics reveal a number of useful correlations between significant parameters such as sludge age, C/N ratio, hydraulic retention time, total influent COD. Nitrogen removal potential of predenitrification may be optimized by careful evaluation of wastewater character and the kinetic correlations.


2007 ◽  
Vol 55 (11) ◽  
pp. 165-171 ◽  
Author(s):  
M. Medina ◽  
U. Neis

Algal incorporation into the biomass is important in an innovative wastewater treatment that exploits the symbiosis between bacterial activated sludge and microalgae (Chlorella vulgaris sp. Hamburg). It allows a good and easy algae separation by means of clarification. The effect of process parameters food to microorganisms ratio (F/M) and hydraulic retention time (HRT) on the process performance, evaluated by settleability, microalgae incorporation to biomass and nutrient removal, was studied. HRT hinted at a significant influence in the growth rate of algae, while F/M turned out to be important for stability when algae are incorporated into the biomass. This parameter also affects the total nitrogen removal of the treatment. Stable flocs with incorporated algae and supernatants with low free swimming algae concentrations were obtained at high HRT and low F/M values.


1994 ◽  
Vol 29 (12) ◽  
pp. 185-195 ◽  
Author(s):  
Bjørn Rusten ◽  
Jon G. Siljudalen ◽  
Bjørnar Nordeidet

A new moving bed biofilm reactor (MBBR) has been developed in Norway. The biomass is attached to carrier elements that move freely along with the water in the reactor. It has been demonstrated that existing, high loaded, activated sludge plants can easily be upgraded to nitrogen removing MBBR plants. With chemically enhanced mechanical treatment, full scale tests showed that 80-90% total nitrogen could be removed in a MBBR plant at a total empty bed hydraulic retention time (HRT) of 2.6 hours. The plant was operated in the post-denitrification mode, using methanol as an external carbon source.


1998 ◽  
Vol 33 (2) ◽  
pp. 319-330 ◽  
Author(s):  
Garba Laouali ◽  
Jacques Brisson ◽  
Linda Dumont ◽  
Gilles Vincent

Abstract During the last decades, there has been a growing concern over phosphorus and nitrogen removal in wastewater treatment systems. Excessive loads of these nutrients have been implicated in the eutrophication of water courses. Although effectiveness of constructed reed beds for primary and secondary wastewater treatments is well established, their capacity for nutrient removal is not as well documented, especially under northern temperate climates. We monitored nutrient removal in the experimental reed bed wastewater treatment of the Biosphère de Montréal, a museum entirely devoted to the important role of water in the ecosystem. Over the first 2 years of operation, nutrient removal during plant growing season averaged 60% for total nitrogen, 53% for Kjeldahl nitrogen, 73% for total phosphorus and 94% for phosphate. Removal remains acceptable in winter despite a slight decrease in efficiency. Nitrification-deni-trification appears to be the main mechanism responsible for nitrogen removal, while precipitation and adsorption account for most of the phosphorus removal.


1990 ◽  
Vol 22 (3-4) ◽  
pp. 211-216
Author(s):  
Niels Skov Olesen

In some areas of Denmark nutrient removal is required even for very small wastewater plants, that is down to 500 pe (pe = person equivalents). The goal for the removal is 80% removal of nitrogen and 90% removal of phosphorus, or in terms of concentrations: 8 mg nitrogen/l and 1.2 mg phosphorus/l. The inlet concentrations are typically 40 mg N/l and 10 mg P/l. The paper presents the results from two such plants with a capacity of 800 pe. Phosphorus removal is made by simultaneous precipitation with ferrous sulphate. Nitrogen removal is carried out using the recirculation method. Both plants were originally rotor aerated oxidation ditches. They have been extended with a denitrification reactor and a recirculation pumping station. At present both plants have been in activity for about 3 years and with satisfactory results. Average concentrations of nitrogen (summer) and phosphorus is 7 mg/l and 0.9 mg/l respectively. Nitrogen removal seems to be a practical solution on these small plants. It is,though, sensitive to temperature and highly oxidized rain water. Phosphorus removal seems to be an easily run and relatively non-sensitive technique at least when using simultaneous precipitation.


1992 ◽  
Vol 25 (4-5) ◽  
pp. 203-209 ◽  
Author(s):  
R. Kayser ◽  
G. Stobbe ◽  
M. Werner

At Wolfsburg for a load of 100,000 p.e., the step-feed activated sludge process for nitrogen removal is successfully in operation. Due to the high denitrification potential (BOD:TKN = 5:1) the effluent total nitrogen content can be kept below 10 mg l−1 N; furthermore by some enhanced biological phosphate removal about 80% phosphorus may be removed without any chemicals.


1992 ◽  
Vol 26 (3-4) ◽  
pp. 461-472 ◽  
Author(s):  
O. E. Albertson ◽  
P. Hendricks

A 1630 L/s activated sludge plant at Phoenix was limited to an average rate of 1050 L/s and operated, at 400-600 mg/L MLSS and 0.8-1.3 day solids retention time (SRT) due to bulking sludge and limited clarification capacity. Higher SRTs also produced uncontrolled Nocardia foaming and low dissolved oxygen due to partial nitrification. The City retained the services of a team of consultants to resolve these problems as well as to upgrade the plant to provide nitrification and total nitrogen removal. An anoxic selector design was implemented within the existing basin and the clarifiers were modified to improve inlet design and sludge transport. The modified advanced wastewater treatment (AWT) plant operating at 1450 L/s has averaged an effluent of 7.6 mg/L BOD5, 8.2 mg/L TSS, 1.3 mg/L NH4N, 4.1 mg/L NO3N and 2.9 mg/L TP. Oxygen transfer efficiency has increased about 80% in the nitrification-denitrification (NdeN) mode. The cost of modification/upgrading to AWT was approximately $730,000 and a 400 L/s increase in hydraulic capacity was realized. Upgrading costs were $5.63/m3 ($0.02/gal.)


2011 ◽  
Vol 223 (4) ◽  
pp. 1699-1712 ◽  
Author(s):  
J. Martín-Pascual ◽  
C. López-López ◽  
A. Cerdá ◽  
J. González-López ◽  
E. Hontoria ◽  
...  

2013 ◽  
Vol 67 (7) ◽  
pp. 1481-1489 ◽  
Author(s):  
R. Barat ◽  
J. Serralta ◽  
M. V. Ruano ◽  
E. Jiménez ◽  
J. Ribes ◽  
...  

This paper presents the plant-wide model Biological Nutrient Removal Model No. 2 (BNRM2). Since nitrite was not considered in the BNRM1, and this previous model also failed to accurately simulate the anaerobic digestion because precipitation processes were not considered, an extension of BNRM1 has been developed. This extension comprises all the components and processes required to simulate nitrogen removal via nitrite and the formation of the solids most likely to precipitate in anaerobic digesters. The solids considered in BNRM2 are: struvite, amorphous calcium phosphate, hidroxyapatite, newberite, vivianite, strengite, variscite, and calcium carbonate. With regard to nitrogen removal via nitrite, apart from nitrite oxidizing bacteria two groups of ammonium oxidizing organisms (AOO) have been considered since different sets of kinetic parameters have been reported for the AOO present in activated sludge systems and SHARON (Single reactor system for High activity Ammonium Removal Over Nitrite) reactors. Due to the new processes considered, BNRM2 allows an accurate prediction of wastewater treatment plant performance in wider environmental and operating conditions.


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