Nitrogen removal during secondary treatment by aquatic systems

2004 ◽  
Vol 48 (11-12) ◽  
pp. 355-361 ◽  
Author(s):  
B. Erol Nalbur ◽  
L. Akça ◽  
H. Bayhan
Keyword(s):  
Nitrogen Removal ◽  
Aquatic Plant ◽  
Loading Rate ◽  
Lemna Minor ◽  
Domestic Wastewater ◽  
Secondary Treatment ◽  
Mass Loading ◽  
Loading Rates ◽  
Hydraulic Loading ◽  
Nitrogen Conversion

Within the context of this study, two lab-scale aquatic plant reactors consisting of duckweed (Lemna minor) ponds, were investigated for the removal of nitrogen forms during the secondary treatment of domestic wastewater. TKN, NH3-N and NO3-N parameters have been measured in both reactors for hydraulic retention times ranging from 3.3 days to 23 days and at various distances from the inlet of reactors. The results were evaluated for hydraulic retention times, hydraulic loading rates and mass loading rates. It was concluded that hydraulic and mass loading parameters were more meaningful than hydraulic retention time. Optimum nitrogen removal values of hydraulic loading rate and mass loading rate were found to be 1.2 cm/day and 90-160 mg TKN/m2-day, respectively. At the higher and lower loading rates, nitrogen removal efficiency was lower than those at optimum conditions. Effluent TKN concentration was around 2.5 to 3.0 mg/l while NH3-N concentration was almost zero at these loading conditions. On the other hand, effluent NO3-N concentrations changed between 7 mg/l to 11 mg/l. When investigating the longitudinal profile, values were reduced rapidly along the reactors. It was concluded that most of the nitrogen conversion occurred at the beginning of the reactor.

scholarly journals Effects of hydraulic loading rate and aeration mode on nitrogen removal and nitrogen functional gene abundances in subsurface wastewater infiltration systems

2017 ◽  
Vol 76 (1) ◽  
pp. 210-218 ◽  
Author(s):  
Yafei Sun ◽  
Jing Pan ◽  
Shiyue Qi ◽  
Hexin Fei
Keyword(s):  
Nitrogen Removal ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Functional Gene ◽  
Intermittent Aeration ◽  
Anaerobic Conditions ◽  
Loading Rates ◽  
Hydraulic Loading ◽  
Artificial Aeration ◽  
Operation Cost

Matrix dissolved oxygen, nitrogen removal and nitrogen functional gene abundances in two artificial aeration modes, continuous aeration (CA) and intermittent aeration (IA), in subsurface wastewater infiltration systems (SWISs) under different hydraulic loading rates (HLRs) were investigated. Aeration not only successfully created aerobic conditions at 50 cm depth, but also did not change anoxic or anaerobic conditions at 80 and 110 cm depths. Meanwhile, aeration significantly enhanced chemical oxygen demand, NH4+-N, and total nitrogen (TN) removal and the enrichment of nitrogen removal functional genes (amoA, nxrA, napA, narG, nirK and qnorB) compared to the non-aerated SWIS, especially for high HLRs. IA SWIS (79.7%–85.8%) had a better performance on TN removal compared with CA SWIS (73.8%–82.2%) when the HLRs ranged from 0.06 to 0.3 m3/(m2 d). Intermittent aeration is a sensible strategy to achieve high HLR, good nitrogen removal performance and comparatively low operation cost for SWISs.

scholarly journals Improvement of organic matter and nutrient removal from domestic wastewater by using intermittent hydraulic rates on earthworm–microorganism biofilters

2020 ◽  
Author(s):  
C. Chicaiza ◽  
L. Huaraca ◽  
C. E. Almeida-Naranjo ◽  
V. H. Guerrero ◽  
C. A. Villamar
Keyword(s):  
Organic Matter ◽  
Redox Potential ◽  
Nutrient Removal ◽  
Loading Rate ◽  
Domestic Wastewater ◽  
Nitrogen And Phosphorus ◽  
Hydraulic Loading Rate ◽  
Loading Rates ◽  
Hydraulic Loading ◽  
Global Performance

Abstract Biofilters based on earthworms–microorganisms represent, particularly in developing countries, an interesting alternative for domestic wastewater treatment due to their easy operation and low cost. However, there are several operational aspects that should be better understood in order to improve their performance. This paper studies the effect of using intermittent hydraulic loading rates to improve organic matter and nutrient removal from domestic wastewater using these biofilters. Three laboratory-scale columns, operating at a 2.5 m3 m−2day−1 hydraulic loading rate, were used. The B1–24 h, B2–8 h, B3–4 h column loading rates indicate that the columns were operated continuously for 24, 8 and 4 h, respectively. Each column (biomass biofilm/earthworms, redox potential, and head loss) and its corresponding operational performance parameters (TCOD, NH4+, NO3−, NO2−, TP) were monitored. The results showed that the B2–8 h intermittent hydraulic loading rate results in the best global performance, with 74%, 57%, and 20% average removal efficiencies for TCOD, nitrogen, and phosphorus, respectively. Moreover, it showed the best biomass growth (biofilm and earthworms), activity (as redox potential changes) and the lowest clogging effects (up to −1.0 cm). The intermittent operation influences the behavior of the earthworm–microorganism biofilters and offers the possibility of optimizing its global performance and achieving a resilient technology.

Coarse filters for pond effluent polishing: comparison of loading rates and grain sizes

2007 ◽  
Vol 55 (11) ◽  
pp. 121-126 ◽  
Author(s):  
M. von Sperling ◽  
J.G.B. de Andrada ◽  
W.R. de Melo Júnior
Keyword(s):  
Loading Rate ◽  
Uasb Reactor ◽  
E Coli ◽  
Effluent Quality ◽  
Loading Rates ◽  
Hydraulic Loading ◽  
Grain Sizes ◽  
Belo Horizonte ◽  
The City ◽  
Rock Size

A system comprising a UASB reactor, shallow polishing ponds and shallow coarse filters, treating actual wastewater from the city of Belo Horizonte, Brazil, has been evaluated. The main focus of the research was to compare grain sizes and hydraulic loading rates in the coarse filters. Two filters operating in parallel were investigated, with the following grain sizes: Filter 1: 3 to 10 cm; Filter 2: 8 to 20 cm. Two hydraulic loading rates were tested: 0.5 and 1.0 m3/m3.d. The filter with the lower rock size had a better performance than the filter with the larger rock size in the removal of SS and, as a consequence, BOD and COD. A better performance was obtained with the hydraulic loading rate of 0.5 m3/m3.d, as compared to the rate of 1.0 m3/m3.d. The effluent quality during the period with the lower loading rate was very good for discharge into water bodies or for agricultural reuse (median effluent concentrations from Filter 1: BOD: 20 mg/L; COD: 106 mg/L; SS: 28 mg/L; E. coli: 528 MPN/100 mL).

Effect of aeration and hydraulic loading rate on nitrogen removal by subsurface infiltration systems

2019 ◽  
Vol 91 (5) ◽  
pp. 399-406
Author(s):  
Fanping Zheng ◽  
Linli Huang ◽  
Jing Pan ◽  
Shiyue Qi ◽  
Chaoquan Tan ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Loading Rate ◽  
Hydraulic Loading Rate ◽  
Hydraulic Loading

scholarly journals Transport effects on hydraulic loading rate and microbial removal performance in biosand filters

2014 ◽  
Vol 12 (4) ◽  
pp. 686-691 ◽  
Author(s):  
Julie Napotnik ◽  
Kristen Jellison
Keyword(s):  
Loading Rate ◽  
E Coli ◽  
Loading Rates ◽  
Hydraulic Loading ◽  
Filter Performance ◽  
Implementation Costs ◽  
Transport Effects ◽  
Biosand Filters ◽  
Microbial Removal ◽  
Potential Negative Consequence

Biosand filters (BSFs) are increasingly designed using smaller and/or lighter casing material in an effort to reduce logistical requirements and implementation costs. The increased portability of a smaller, lighter design presents a potential negative consequence: the ability to move the installed/operational filter by the homeowner and potentially disturb the system. This study investigated the effects of moving and agitation on filter performance, using mature BSFs which had been in use for over nine months prior to the move. Data were analyzed for four replicate filters of three different filter types: the traditional concrete BSF and two plastic bucket (5-gal and 2-gal, respectively; 5-gal bucket = 18.9-L bucket, 2-gal bucket = 7.6-L bucket) BSFs. Filters were moved approximately 1 km and monitored for hydraulic loading rates (HLRs) and Escherichia coli removal for 8 weeks following the move. Moving the filters resulted in reduced HLRs, likely due to sand compaction, but E. coli removal remained high (log10 removal ≥2.8 for all sizes) and increased significantly as compared to data collected prior to the move. The resulting operational implications of moving BSFs are discussed.

Nitrogen Removal in Permeable Woodchip Filters Affected by Hydraulic Loading Rate and Woodchip Ratio

2016 ◽  
Vol 45 (5) ◽  
pp. 1688-1695 ◽  
Author(s):  
Jacob Bruun ◽  
Carl Christian Hoffmann ◽  
Charlotte Kjaergaard
Keyword(s):  
Nitrogen Removal ◽  
Loading Rate ◽  
Hydraulic Loading Rate ◽  
Hydraulic Loading

Evaluation of microbial fuel cell coupled with aeration chamber and bio-cathode for organic matter and nitrogen removal from synthetic domestic wastewater

2009 ◽  
Vol 60 (6) ◽  
pp. 1409-1418 ◽  
Author(s):  
J. Cha ◽  
C. Kim ◽  
S. Choi ◽  
G. Lee ◽  
G. Chen ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Power Density ◽  
Nitrogen Removal ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Removal Rate ◽  
Nitrate Removal ◽  
Domestic Wastewater ◽  
Carbon And Nitrogen

For simultaneous carbon and nitrogen removal via single stream, a microbial fuel cell (MFC) coupled with an aeration chamber and a bio-cathode was investigated. Without catalysts and any additional buffer, the MFC produced electricity continuously and the power density reached 1.3 W/m3 at a loading rate of 1.6 kg COD/m3 d. Simultaneously, the COD and the nitrate removal rate were 1.4 kg COD/m3 d and 67 g NO3-N/m3 d, respectively. When the hydraulic retention time was changed from 6 to 0.75 hours, the power density significantly increased from 0.2 to 10.8 W/m3 due to an increase of cathodic potential. When the aeration chamber was removed and the nitrate was injected into the cathode, the power density increased to 3.7 W/m3. At a high recirculation rate of 10 ml/min, the power density and the nitrate removal rate greatly increased to 34 W/m3 and 294 g NO3−-N/m3 d, respectively.

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