Tertiary nitrogen removal for municipal wastewater using a solid-phase denitrifying biofilter with polycaprolactone as the carbon source and filtration medium

2016 ◽  
Vol 93 ◽  
pp. 74-83 ◽  
Author(s):  
Peng Li ◽  
Jiane Zuo ◽  
Yajiao Wang ◽  
Jian Zhao ◽  
Lei Tang ◽  
...  
Keyword(s):  
Carbon Source ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Solid Phase ◽  
Filtration Medium ◽  
Tertiary Nitrogen

scholarly journals Comparison of Clay Ceramsite and Biodegradable Polymers as Carriers in Pack-bed Biofilm Reactor for Nitrate Removal

2019 ◽  
Vol 16 (21) ◽  
pp. 4184
Author(s):  
Qian Zhang ◽  
Xue Chen ◽  
Heng Wu ◽  
Wandong Luo ◽  
Xiangyang Liu ◽  
...  
Keyword(s):  
Carbon Source ◽  
Biodegradable Polymers ◽  
Nitrogen Removal ◽  
Solid Phase ◽  
Biofilm Reactor ◽  
Attractive Alternative ◽  
Low Carbon ◽  
Conventional Process ◽  
Biofilm Carrier ◽  
Denitrification Process

In recent years, there is a trend of low C/N ratio in municipal domestic wastewater, which results in serious problems for nitrogen removal from wastewater. The addition of an external soluble carbon source has been the usual procedure to achieve denitrification. However, the disadvantage of this treatment process is the need of a closed, rather sophisticated and costly process control as well as the risk of overdosing. Solid-phase denitrification using biodegradable polymers as biofilm carrier and carbon source was considered as an attractive alternative for biological denitrification. The start-up time of the novel process using PCL (polycaprolactone) as biofilm carrier and carbon source was comparable with that of conventional process using ceramsite as biofilm carrier and acetate as carbon source. Further, the solid-phase denitrification process showed higher nitrogen removal efficiency under shorter hydraulic retention time (HRT) and low carbon to nitrogen (C/N) ratio since the biofilm was firmly attached to the clear pores on the surface of PCL carriers and in this process bacteria that could degrade PCL carriers to obtain electron donor for denitrification was found. In addition, solid-phase denitrification process had a stronger resistance of shock loading than that in conventional process. This study revealed, for the first time, that the physical properties of the biodegradable polymer played a vital role in denitrification, and the different microbial compositions of the two processes was the main reason for the different denitrification performances under low C/N ratio.

Advanced nitrogen removal via nitrite from municipal wastewater in a pilot-plant sequencing batch reactor

2009 ◽  
Vol 59 (12) ◽  
pp. 2371-2377 ◽  
Author(s):  
Q. Yang ◽  
X. H. Liu ◽  
Y. Z. Peng ◽  
S. Y. Wang ◽  
H. W. Sun ◽  
...  
Keyword(s):  
Carbon Source ◽  
Process Control ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Pilot Plant ◽  
Sequencing Batch Reactor ◽  
Municipal Wastewater ◽  
Batch Reactor ◽  
Nitrite Accumulation ◽  
Advanced Nitrogen Removal

To obtain economically sustainable wastewater treatment, advanced nitrogen removal from municipal wastewater and the feasibility of achieving and stabilizing short-cut nitrification and denitrification were investigated in a pilot-plant sequencing batch reactor (SBR) with a working volume of 54 m3. Advanced nitrogen removal, from summer to winter, with effluent TN lower than 3 mg/L and nitrogen removal efficiency above 98% was successfully achieved in pulsed-feed SBR. Through long-term application of process control in pulsed-feed SBR, nitrite accumulation reached above 95% at normal temperature of 25°C. Even in winter, at the lowest temperature of 13°C, nitrite was still the end production of nitrification and nitrite accumulation was higher than 90%. On the basis of achieving advanced nitrogen removal, short-cut nitrification and denitrification was also successfully achieved. Compare to the pulse-feed SBR with fixed time control, the dosage of carbon source and energy consumption in pulsed-feed SBR with process control were saved about 30% and 15% respectively. In pulsed-feed SBR with process control, nitrogen removal efficiency was greatly improved. Moreover, consumption of power and carbon source was further saved.

Nitrogen Removal in Fixed-Bed Submerged Biofilters without Backwashing

1999 ◽  
Vol 40 (4-5) ◽  
pp. 142-152 ◽  
Author(s):  
R. Canziani ◽  
R. Vismara ◽  
D. Basilico ◽  
L. Zinni
Keyword(s):  
Carbon Source ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Settling Tank ◽  
Fixed Bed ◽  
Organic Load ◽  
Bulk Liquid ◽  
Nitrification Rate ◽  
Recycle Rate ◽  
Hydrolysis Of

The paper reports the findings of four years of pilot-scale research on nitrogen removal in fixed-bed biofilters fed on real raw municipal wastewater. The plant was made of two fixed-bed biofilm reactors in series with an intermediate settling tank from which excess biomass from the first stage was discharged. The first filter was used for carbon removal either with oxygen or nitrates. The second filter was used for nitrification. The average nitrification rate at 20°C was 0.84 gNH4+-N m−2d−1 with 5 mg l−1 dissolved oxygen in the bulk liquid. Temperature dependence was calculated (rn = rn,20° 1,05T-20). The influent organic load strongly affected ammonia oxidation. If the organic loading exceeded 2.5 gCOD m−2 d−1 nitrification rate was reduced by 50%. Denitrification was performed by recycling nitrates back from the second filter and by using sewage itself as carbon source. Denitrification rate showed to be strongly dependent on temperature (rd = rd,20° 1.11T-20) and on the recycle rate. Hydrolysis of the colloidal COD fraction showed a similar dependence on both temperature and recycle rate. Therefore, it has been concluded that the hydrolysis of finely dispersed COD particles can be the limiting step of denitrification in the biofilter when real sewage is used as carbon source.

scholarly journals Optimization of Nitrogen Removal in Solid Carbon Source SND for Treatment of Low-Carbon Municipal Wastewater with RSM Method

Water ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 827
Author(s):  
Liqiu Zhang ◽  
Youwen Huang ◽  
Shugeng Li ◽  
Peifen He ◽  
Dengmin Wang
Keyword(s):  
Carbon Source ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Solid Carbon ◽  
Low Carbon ◽  
Solid Carbon Source

scholarly journals Effects of carbon sources, COD/NO2−-N ratios and temperature on the nitrogen removal performance of the simultaneous partial nitrification, anammox and denitrification (SNAD) biofilm

2017 ◽  
Vol 75 (7) ◽  
pp. 1712-1721 ◽  
Author(s):  
Zhaoming Zheng ◽  
Yun Li ◽  
Jun Li ◽  
Yanzhuo Zhang ◽  
Wei Bian ◽  
...  
Keyword(s):  
Carbon Source ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Inorganic Nitrogen ◽  
Carbon Sources ◽  
Biofilm Reactor ◽  
Partial Nitrification ◽  
Anammox Bacteria ◽  
Coupling Process ◽  
Anammox Activity

The aim of the present work was to evaluate the effects of carbon sources and chemical oxygen demand (COD)/NO2−-N ratios on the anammox–denitrification coupling process of the simultaneous partial nitrification, anammox and denitrification (SNAD) biofilm. Also, the anammox activities of the SNAD biofilm were investigated under different temperature. Kaldnes rings taken from the SNAD biofilm reactor were operated in batch tests to determine the nitrogen removal rates. As a result, with the carbon source of sodium acetate, the appropriate COD/NO2−-N ratios for the anammox–denitrification coupling process were 1 and 2. With the COD/NO2−-N ratios of 1, 2, 3, 4 and 5, the corresponding NO2−-N consumption via anammox was 87.1%, 52.2%, 29.3%, 23.7% and 16.3%, respectively. However, with the carbon source of sodium propionate and glucose, the anammox bacteria was found to perform higher nitrite competitive ability than denitrifiers at the COD/NO2−-N ratio of 5. Also, the SNAD biofilm could perform anammox activity at 15 °C with the nitrogen removal rate of 0.071 kg total inorganic nitrogen per kg volatile suspended solids per day. These results indicated that the SNAD biofilm process might be feasible for the treatment of municipal wastewater at normal temperature.

Enhanced denitrification with methanol at WWTP Zürich-Werdhölzli

1996 ◽  
Vol 33 (12) ◽  
pp. 117-126 ◽  
Author(s):  
I. Purtschert ◽  
H. Siegrist ◽  
W. Gujer
Keyword(s):  
Wastewater Treatment ◽  
Carbon Source ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Yield Coefficient ◽  
Adaptation Period ◽  
Municipal Wastewater Treatment

In coordination with the EU-guidelines the large wastewater treatment plants in Switzerland have to be extended with enhanced nitrogen removal. Due to the existing plant configuration, the low COD/N ratio and dilute wastewater, denitrification supported by an external carbon source instead of extending the plant may be an interesting and cost effective solution for municipal wastewater treatment. At the wastewater treatment plant Zürich-Werdhölzli different experiments were performed with methanol addition to predenitrification from March to July 1994. The aim of this work was to evaluate the use of methanol as an alternative to plant extension to achieve a higher nitrogen removal efficiency. Therefore, two parallel denitrifying lanes were investigated, one served for methanol addition experiments and the other as a control. The effect of oxygen input into the anoxic zone due to influent, return sludge and mixing was investigated, too. The results show that nitrogen removal efficiency can be substantially increased as compared to the reference lane. The adaptation period for methanol degradation was only a few days and the process was relatively stable. Based on total nitrogen in the inflow, the average denitrification was 55% with methanol addition and 35% without methanol. The yield coefficient YCOD was 0.4 g CODX g−1 CODMe. Due to the small net growth rate of the methanol degraders the denitrification capacity is relatively low and nitrate peak loads cannot be fully denitrified. Hence, methanol as a carbon source requires more or less constant dosing. To prevent nitrate limitation, methanol addition should be controlled by the anoxic nitrate concentrations.

Biological nitrogen removal in a step-feed CAST with real-time control treating municipal wastewater

2010 ◽  
Vol 61 (9) ◽  
pp. 2325-2332 ◽  
Author(s):  
Ma Juan ◽  
Peng Chengyao ◽  
Wang Li ◽  
Wang Shuying ◽  
Liu Yang ◽  
...  
Keyword(s):  
Carbon Source ◽  
Real Time ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Nitrification Rate ◽  
Real Time Control ◽  
Time Control ◽  
Characteristic Points ◽  
System Temperature

The performance of a 18 L step-feed cyclic activated sludge technology (CAST) combined with real-time control treating real municipal wastewater was evaluated. The operation strategies employed pH and oxidation reduction potential (ORP) as on-line control parameters, which can control the durations of oxic and anoxic phases flexibly. The obtained results showed that the studied process had achieved advanced and enhanced nitrogen removal by several phases of consecutive oxic/anoxic periods. Total nitrogen in effluent was lower than 2 mg/L and the average TN removal efficiency was higher than 98%, while only requiring small amount of external carbon source. Unexpected characteristic points in pH and ORP profiles denoting the depletion of nitrate were also observed during the last anoxic phase. Denitrification rate was found to be more dependent on the system temperature compared to nitrification rate. Moreover, a stable and efficient phosphorus removal rate above 90% was achieved by using step-feed strategy which enabled the influent carbon source to be fully used and the favourable condition for phosphorus releasing to be created during the anoxic phases.

scholarly journals Riboflavin enhanced denitrification of artificial wastewater under low C/N condition in cold season

BioResources ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 1949-1957
Author(s):  
Jingya Liu ◽  
Jingang Huang ◽  
Binfang Shi ◽  
Kangyin Guo ◽  
Jianping Li ◽  
...  
Keyword(s):  
Carbon Source ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Cold Season ◽  
Utilization Efficiency ◽  
Electron Mediator ◽  
Arduous Task ◽  
Future Work ◽  
Denitrification Process

Nitrogen removal under low C/N ratio in cold season is an arduous task. In this study, riboflavin was used as an eco-friendly electron mediator to improve the denitrification process in an SBR reactor under conditions of low temperature (10 °C to 15 °C) and limited carbon source (C/N ratio = 4.0). The results indicated that riboflavin created a suitable pH in the system for denitrification. Under water temperature of 10 °C to 15 °C, riboflavin (10 mg/L) stimulated the NO3–N and TN removal rate by 16.5%, and 51%, respectively. Riboflavin promoted the utilization efficiency of limited carbon source, driving the denitrification process with low residual acetate as electron donor. The rising cost of riboflavin supplement (10 mg/L) was 0.025 USD per m3 of wastewater. To satisfy the efficient nitrogen removal from municipal wastewater, the optimum C/N ratio and the selection of solid/immobilized redox mediators should be developed in future work.

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