High-rate nitrification of electronic industry wastewater by using nitrifying granules

2017 ◽  
Vol 76 (11) ◽  
pp. 3171-3180 ◽  
Author(s):  
Yoshiaki Hasebe ◽  
Hiroaki Meguro ◽  
Yuuki Kanai ◽  
Masahiro Eguchi ◽  
Toshifumi Osaka ◽  
...  

Abstract Nitrifying granules have a high sedimentation property and an ability to maintain a large amount of nitrifying bacteria in a reaction tank. Our group has examined the formation process of nitrifying granules and achieved high-rate nitrification for an inorganic synthetic wastewater using these granules. In this research, a pilot-scale test plant with an 850-liter reaction tank was assembled in a semiconductor manufacturing factory in order to conduct a continuous water conduction test using real electronics industry wastewater. The aim was to observe the formation of nitrifying granules and determine the maximum ammonia removal rate. The average granule diameter formed during the experiment was 780 μm and the maximum ammonia removal rate was observed to be 1.5 kgN·m−3·day−1 at 20 °C, which is 2.5–5 times faster than traditional activated sludge methods. A fluorescence in situ hybridization analysis showed that β-proteobacterial ammonia oxidizing bacteria and the Nitrospira-like nitrite-oxidizing bacteria dominate the bacteria population in the granules, and their strong aggregation capacity might confer some benefits to the formation of these nitrifying granules.

2012 ◽  
Vol 65 (3) ◽  
pp. 581-588 ◽  
Author(s):  
Naohiro Kishida ◽  
Goro Saeki ◽  
Satoshi Tsuneda ◽  
Ryuichi Sudo

In this study, the effectiveness of aerobic granular sludge as seed sludge for rapid start-up of nitrifying processes was investigated using a laboratory-scale continuous stirred-tank reactor (CSTR) fed with completely inorganic wastewater which contained a high concentration of ammonia. Even when a large amount of granular biomass was inoculated in the reactor, and the characteristics of influent wastewater were abruptly changed, excess biomass washout was not observed, and biomass concentration was kept high at the start-up period due to high settling ability of the aerobic granular sludge. As a result, an ammonia removal rate immediately increased and reached more than 1.0 kg N/m3/d within 20 days and up to 1.8 kg N/m3/d on day 39. Subsequently, high rate nitritation was stably attained during 100 days. However, nitrite accumulation had been observed for 140 days before attaining complete nitrification to nitrate. Fluorescence in situ hybridization analysis revealed the increase in amount of ammonia-oxidizing bacteria which existed in the outer edge of the granular sludge during the start-up period. This microbial ecological change would make it possible to attain high rate ammonia removal.


2006 ◽  
Vol 53 (3) ◽  
pp. 147-154 ◽  
Author(s):  
S. Tsuneda ◽  
M. Ogiwara ◽  
Y. Ejiri ◽  
A. Hirata

The performance of nitrifying granules, which had been produced in an aerobic upflow fluidised bed (AUFB) reactor, was investigated in various types of ammonia-containing wastewaters. When pure oxygen was supplied to the AUFB reactor with a synthetic wastewater containing a high concentration of ammonia (500 g-N/m3), the ammonia removal rate reached 16.7 kg-N/m3/day with a sustained ammonia removal efficiency of more than 80%. The nitrifying granules possessing a high settling ability could be retained with a high density (approximately 10,000 g-MLSS/m3) in a continuous stirring tank reactor (CSTR) even under a short hydraulic retention time (44 min), which enabled a high-rate and stable nitrification for an inorganic wastewater containing low concentrations of ammonia (50 g-N/m3). Moreover, the nitrifying granules exhibited sufficient performance in the nitrification of real industrial wastewater containing high concentrations of ammonia (1,000–1,400 g-N/m3) and salinity (1.2–2.2%), which was discharged from metal-refinery processes. When the nitrifying granules were used in cooperation with activated sludge to treat domestic wastewater containing organic pollutants as well as ammonia, they fully contributed to nitrification even though a part of activated sludge adhered onto the granule surfaces to form biofilms. These results show the wide applicability of nitrifying granules to various cases in the nitrification step of wastewater treatment plants.


1998 ◽  
Vol 38 (8-9) ◽  
pp. 179-188 ◽  
Author(s):  
K. F. Janning ◽  
X. Le Tallec ◽  
P. Harremoës

Hydrolysis and degradation of particulate organic matter has been isolated and investigated in laboratory scale and pilot scale biofilters. Wastewater was supplied to biofilm reactors in order to accumulate particulates from wastewater in the filter. When synthetic wastewater with no organic matter was supplied to the reactors, hydrolysis of the particulates was the only process occurring. Results from the laboratory scale experiments under aerobic conditions with pre-settled wastewater show that the initial removal rate is high: rV, O2 = 2.1 kg O2/(m3 d) though fast declining towards a much slower rate. A mass balance of carbon (TOC/TIC) shows that only 10% of the accumulated TOC was transformed to TIC during the 12 hour long experiment. The pilot scale hydrolysis experiment was performed in a new type of biofilm reactor - the B2A® biofilter that is characterised by a series of decreasing sized granular media (80-2.5 mm). When hydrolysis experiments were performed on the anoxic pilot biofilter with pre-screened wastewater particulates as carbon source, a rapid (rV, NO3=0.7 kg NO3-N/(m3 d)) and a slowler (rV, NO3 = 0.3 kg NO3-N/(m3 d)) removal rate were observed at an oxygen concentration of 3.5 mg O2/l. It was found that the pilot biofilter could retain significant amounts of particulate organic matter, reducing the porosity of the filter media of an average from 0.35 to 0.11. A mass balance of carbon shows that up to 40% of the total incoming TOC accumulates in the filter at high flow rates. Only up to 15% of the accumulated TOC was transformed to TIC during the 24 hour long experiment.


2004 ◽  
Vol 50 (4) ◽  
pp. 283-290 ◽  
Author(s):  
T. Kanagawa ◽  
H.W. Qi ◽  
T. Okubo ◽  
N. Tokura

The exhaust gas from compost processing plants contains a large amount of ammonia. To treat ammonia gas at high loads, bench-scale experiments were carried out. First, nitrifying bacteria were enriched from soil and immobilized on porous ceramics. The ceramics were packed in an acrylic cylinder (diameter, 100 mm; packed height, 190 mm) and ammonia gas was introduced to the top of the cylinder. The concentration and flow rate of ammonia gas were gradually increased and finally 85 ppm was introduced at a space velocity of 800 h-1 (empty bed residence time (EBRT), 4.5 sec). The ammonia load was 1.0 kg N/m3 day-1. The exhaust contained 1.5-2 ppm of ammonia. Then the packed ceramics were transferred to another acrylic cylinder (diameter, 50 mm; packed height, 800 mm). A high concentration of ammonia gas (1,000 ppm) was introduced at a space velocity of 96 h-1 (ammonia loading, 1.44 kg N/m3 day-1; EBRT, 37.5 sec). The exhaust contained 2 ppm of ammonia (removal rate, 99.8%). The packed bed was washed with water intermittently or continuously, and the wastewater from the cylinder contained a large amount of ammonium and nitrate ions of at a 1:1 ratio. Stoichiometric analysis showed that half of the introduced ammonia was oxidized to nitrate, and the rest was converted to ammonium ion. Thus, ammonia gas was effectively treated at a high load by biofiltration with nitrifying bacteria.


2014 ◽  
Vol 69 (9) ◽  
pp. 1926-1931 ◽  
Author(s):  
F. Hassard ◽  
E. Cartmell ◽  
J. Biddle ◽  
T. Stephenson

The impact of organic loading rate (OLR) on carbonaceous materials and ammonia removal was assessed in bench scale rotating media biofilm reactors treating real wastewater. Media composition influences biofilm structure and therefore performance. Here, plastic mesh, reticulated coarse foam and fine foam media were operated concurrently at OLRs of 15, 35 and 60 g sCOD m−2d−1 in three bench scale shaft mounted advanced reactor technology (SMART) reactors. The sCOD removal rate increased with loading from 6 to 25 g sCOD m−2d−1 (P < 0.001). At 35 g BOD5m−2d−1, more than double the arbitrary OLR limit of normal nitrifying conditions (15 g BOD5m−2d−1); the removal efficiency of NH4-N was 82 ± 5, 27 ± 19 and 39 ± 8% for the mesh, coarse foam and fine foam media, respectively. Increasing the OLR to 35 gm−2d−1 decreased NH4-N removal efficiency to 38 ± 6, 21 ± 4 and 21 ± 6%, respectively. The mesh media achieved the highest stable NH4+-N removal rate of 6.5 ± 1.6 gm−2d−1 at a sCOD loading of 35 g sCOD m−2d−1. Viable bacterial numbers decreased with increasing OLR from 2 × 1010–4 × 109 cells per ml of biofilm from the low to high loading, suggesting an accumulation of inert non-viable biomass with higher OLR. Increasing the OLR in permeable media is of practical benefit for high rate carbonaceous materials and ammonia removal in the pretreatment of wastewater.


2018 ◽  
Author(s):  
Paul Roots ◽  
Yubo Wang ◽  
Alex F. Rosenthal ◽  
James S. Griffin ◽  
Fabrizio Sabba ◽  
...  

AbstractRecent findings show that a subset of bacteria affiliated withNitrospira, a genus known for its importance in nitrite oxidation for biological nutrient removal applications, are capable ofcompleteammoniaoxidation (comammox) to nitrate. Early reports suggested that they were absent or present in low abundance in most activated sludge processes, and thus likely functionally irrelevant. Here we show the accumulation of comammoxNitrospirain a nitrifying sequencing batch reactor operated at low dissolved oxygen (DO) concentrations. Actual mainstream wastewater was used as influent after primary settling and an upstream pre-treatment process for carbon and phosphorus removal. The ammonia removal rate was stable and exceeded that of the treatment plant’s parallel full-scale high DO nitrifying activated sludge reactor. 16S rRNA sequencing showed a steady accumulation ofNitrospirato 53% total abundance and a decline in conventional ammonia oxidizing bacteria to <1% total abundance over 400+ days of operation. After ruling out other known ammonia oxidizers, qPCR confirmed the accumulation of comammoxNitrospirabeginning around day 200, to eventually comprise 94% of all detectedamoAand 4% of total bacteria by day 407. Quantitative fluorescence in-situ hybridization confirmed the increasing trend and high relative abundance ofNitrospira. These results demonstrate that comammox can be metabolically relevant to nitrogen transformation in wastewater treatment, and can even dominate the ammonia oxidizing community. Our results suggest that comammox may be an important functional group in energy efficient nitrification systems designed to operate at low DO levels.


Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3000
Author(s):  
Wujie Xu ◽  
Yu Xu ◽  
Haochang Su ◽  
Xiaojuan Hu ◽  
Keng Yang ◽  
...  

Ammonia is the main pollution factor of the aquatic environment in marine shrimp culture systems. In order to demonstrate the feasibility of the combination of biofloc technology and nitrifying biofilter for the ammonia removal, a 70-day production trial was conducted in a simplified pilot-scale hybrid biofloc-based recirculating aquaculture system (biofloc-RAS) with the intensive culture of Litopenaeus vannamei. Nitrogen dynamics and nitrifying microbial communities were investigated in three replicated systems simultaneously under the conditions of high feed loading and zero water exchange. Along with biofloc development in the culture tank and biofilm formation in the nitrifying biofilter during the trial, nitrification could be fastly and effectively established in the system, which was indicated by the dynamics of total ammonia nitrogen (TAN), NO2–-N, NO3–-N, and total nitrogen (TN) concentrations. Meanwhile, similar nitrifying microorganisms could be found between biofloc and biofilm, despite some differences in abundance, diversity, and composition of ammonia-oxidizing archaea and bacteria and nitrite-oxidizing bacteria. High TAN removal rate could be achieved and was significantly and positively correlated with abundances of these nitrifying microbial communities in both biofloc and biofilm, further indicating that both biofloc and biofilm could contribute highly to nitrification performance of the biofloc-RAS. The results of this study indicate a potential application of the biofloc-RAS in coastal intensive aquaculture.


2005 ◽  
Vol 52 (7) ◽  
pp. 69-75 ◽  
Author(s):  
K.F. Janning ◽  
S.N. Bak ◽  
M. Andersen ◽  
G.H. Kristensen

A new pressurised biofilm reactor (PBR) process with a patented disc system that enables constant biofilm control has been developed to treat concentrated wastewater with respect to easily degradable organic matter under pressures of up to 6 bar. The pressurisation enables a six-fold increase of the O2 saturation level and aeration capacity, which potentially increases the reaction rate of COD as long as O2 is limiting the reaction rate. Experiments performed in a pilot-scale PBR-reactor fed by synthetic wastewater were conducted to verify the potential and kinetics of heterotrophic conversion of O2 and acetate. Under O2-limited conditions the maximum removal rate of O2 and CODf was measured to rA,O2=60 g O2/m2/d and rA,CODf=150 g CODf/m2/d at 70 mg O2/l. Experiments verified that half-order kinetics could be applied but liquid film diffusion apparently influenced the reaction rate considerably. The observed half-order rate constant was experimentally determined to K½A,O2=7.0 (g O2)1/2m−1/2d−1 but this value is underestimated by 15% due to the observed liquid film diffusion. Based on this the intrinsic zero-order reaction rate was estimated at k0f,O2=190 kg O2/m3 biofilm/d when both liquid film and biofilm diffusion were taken into account.


2016 ◽  
Vol 74 (6) ◽  
pp. 1354-1364 ◽  
Author(s):  
Bin Dong ◽  
Jie Tan ◽  
Yang Yang ◽  
Zishan Pang ◽  
Zhongtian Li ◽  
...  

The primary goal of this study is to investigate ammonia removal, abundance of nitrifying bacteria and microbial community structures in a laboratory-scale integrated fixed film activated sludge (IFAS) reactor. The results of Illumina MiSeq sequencing based on 16S rRNA genes showed Proteobacteria and Bacteroidetes were the dominant phyla in both biofilm and suspended sludge samples in the IFAS reactor. The dominant ammonia-oxidizing bacteria (AOB) species was Nitrosomonas and the dominant nitrite-oxidizing bacteria species was Nitrospira. The contribution of biofilm to ammonia removal increased from 4.0 ± 0.9% to 37.0 ± 2% when the temperature decreased from 25 °C to 10 °C. The real-time polymerase chain reaction (PCR) result showed the abundance of AOB in suspended sludge was higher than that in biofilm at the same time. However, nitrification is more dependent on attached growth than on suspended growth in the IFAS reactor at 15 °C and 10 °C and the abundance of AOB in biofilm was also higher than that in suspended sludge. The more robust ammonia removal rate at low temperatures by biofilm contributed to the relatively stable ammonia removal, and biofilm attached on carriers in the IFAS reactor is advantageous for nitrification in low-temperature environment.


2005 ◽  
Vol 51 (11) ◽  
pp. 151-158 ◽  
Author(s):  
H. Nagaoka ◽  
H. Nemoto

Influence of EPS on fouling of intermittent aeration MBR reactor (denitrification MBR) was investigated changing intermittent aeration cycle (10 minute-cycle and 120 minute-cycle) in laboratory-scale reactors using synthetic wastewater. EPS were extracted from bacterial cells using cation resin method and molecular weight fractioning of EPS was conducted using gel chromatography. In both of the reactors, nitrogen removal rate was almost 100% after 50th day although DO concentration was not very high during the aerated phase because of accumulation of nitrifying bacteria in the reactors. In the 120 minutes-cycle reactor, trans-membrane pressure increased more rapidly than in the 10 minutes-cycle reactor. The reason might be that EPS of more than 1000 kDa, which are the main fouling substances, are produced more rapidly in the 120 minute-cycle condition. It was also found that three peaks at around 100 kDa, 500 kDa and 2000 kDa are prominent in EPS in intermittent-aeration MBR irrespective of cycle and higher molecular weight EPS are decomposed to smaller molecular weight EPS on membrane surface.


Sign in / Sign up

Export Citation Format

Share Document