scholarly journals Nitrogen Removal from Landfill Leachate by Chemical and Biological Treatment: Process Comparison

2017 ◽  
pp. 655-664
Author(s):  
Andrii Butkovskyi ◽  
Karin Jönsson

The efficiency of nitrogen removal from leachate by different chemical and biological methods was explored. The leachate was derived from Filborna landfill (NSR AB, Helsingborg, Sweden) and was characterized as an old leachate with pH = 8.0 and comparatively low concentrations of nitrogen and organic compounds (ca. 150 mg/l NH4-N and 500 mg/l COD). Three treatment processes were tested in lab-scale experiments; combined nitrification and denitrification in a sequencing-batch reactor (SBR), one-reactor nitritation-anammox process in a moving-bed biofilm reactor (MBBR) in sequencing-batch configuration and nitrogen precipitation in the form of magnesium-ammonium-phosphate (MAP). State-of-the-art of these processes is described. The conventional combined nitrification/denitrification process allowed 99% removal of inorganic nitrogen with 23 mg NH4-N/(l·h) being the highest nitrification rate achieved. Aeration during nitrification step and addition of carbon source according to the stoichiometric ratio for denitrification was required, accounting for the operational costs. The nitritation-anammox process also allowed 99% removal of inorganic nitrogen with 3.7 g NH4- N/(m2·d) being the highest process rate achieved while running the reactor at 25°C and pH 8.0. The process is advantageous in comparison with the conventional biological removal process, as oxygen consumption is lower and addition of carbon source is not required. With MAP precipitation at the optimal Mg:N:P ratio (1.2:1:1) only 78% removal of inorganic nitrogen was achieved. The precipitation process led to a significant increase of phosphorous concentrations in the effluent, while external magnesium and phosphorous sources to be added resulted in high process costs. Detailed descriptions of the processes and obtainedresults are given in the article. Comparing the three processes, conclusions are drawn that it is possible to achieve effluent nitrogen requirements (15 mg N/l) by treatment of leachate with both tested biological processes, but not with MAP precipitation. One-reactor nitritation-anammox would require the lowest operational costs, while MAP precipitation – the highest.

2017 ◽  
Vol 75 (7) ◽  
pp. 1712-1721 ◽  
Author(s):  
Zhaoming Zheng ◽  
Yun Li ◽  
Jun Li ◽  
Yanzhuo Zhang ◽  
Wei Bian ◽  
...  

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.


2002 ◽  
Vol 45 (12) ◽  
pp. 189-196 ◽  
Author(s):  
M. Altinbas ◽  
I. Ozturk ◽  
A.F. Aydin

The aim of the study was to investigate ammonia recovery from high strength agro industry effluents involving significant amounts of ammonia, by applying magnesium ammonium phosphate (MAP) precipitation technology. Two types of industrial effluents have been tested in the study. The first plant was an opium alkaloid processing industry and the second one was a baker`s yeast industry. High chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN) and unacceptable dark brown color characterized effluents from both industries. Effluents from the biologically treated opium alkaloid and baker's yeast industries were both applied at the stoichiometric ratio (Mg:NH4:PO4 =1:1:1) and above the stoichiometric ratio (Mg:NH4:PO4 =1.1:1:1.1) to MAP precipitation. NH4 removals of 61-80% were achieved at the pH of 9.2 at the stoichiometric ratio, whereas 83% NH4 removal was obtained at the pH of 9.2 above the stoichiometric ratio. Experimental studies performed on both anaerobically and/or aerobically treated baker`s yeast and opium alkaloid industry effluents have clearly indicated that MAP precipitation was an appropriate treatment option for NH4 removal or struvite recovery from high ammonia content agro industry effluents. Additional ammonia recovery studies were conducted on ozonated and Fenton's oxidation applied effluents and these have also indicated that the amounts of struvite and the quality of MAP precipitate was increased significantly. In this framework, MAP sludge recovered from combined biological and Fenton's oxidation treatment effluents were considered as a more valuable slow release fertilizer for agricultural use.


2003 ◽  
Vol 48 (1) ◽  
pp. 215-223 ◽  
Author(s):  
I. Kabdaşli ◽  
T. Ölmez ◽  
O. Tünay

Nitrogen removal from wastewaters has gained importance in recent years. In this paper protein precipitation and recovery potential of leather tanning industry wastewaters were experimentally evaluated. A protein profile for all sources was prepared. Liming was determined to be the most important protein source. Composite samples were made up to assess the protein precipitation applications. Isoelectric pH precipitation yielded around 50% protein removal between the optimum pH interval of 2.1-3.8. FeCl3 proved to be a very effective means of protein removal providing over 60% efficiency. Polyelectrolyte precipitation did not yield satisfactory results. Magnesium ammonium phosphate precipitation followed by acid precipitation of protein provided 85% ammonia removal in addition to 50% protein removal.


Author(s):  
Qian Zhang ◽  
Xue Chen ◽  
Heng Wu ◽  
Wandong Luo ◽  
Xiangyang Liu ◽  
...  

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.


2017 ◽  
Vol 77 (6) ◽  
pp. 1483-1492 ◽  
Author(s):  
Yue-mei Han ◽  
Feng-xia Liu ◽  
Xiao-fei Xu ◽  
Zhuo Yan ◽  
Zhi-jun Liu

Abstract This study developed a partial nitrification (PN) and anaerobic ammonia oxidation (Anammox) process for treating high-ammonia wastewater using an innovative biofilm system in which ammonia oxidizing bacteria grew on fluidized Kaldnes (K1) carriers and Anammox bacteria grew on fixed acryl resin carriers. The airlift loop biofilm reactor (ALBR) was stably operated for more than 4 months under the following conditions: 35 ± 2 °C, pH 7.5–8.0 and dissolved oxygen (DO) of 0.5–3.5 mg/L. The results showed that the total nitrogen removal efficiency reached a maximum of 75% and the total nitrogen removal loading rate was above 0.4 kg/(d·m3). DO was the most efficient control parameter in the mixed biofilm system, and values below 1.5 mg/L were observed in the riser zone for the PN reaction, while values below 0.8 mg/L were observed in the downer zone for the Anammox reaction. Scanning electron microscopy and Fluorescence In Situ Hybridization images showed that most of the nitrifying bacteria were distributed on the K1 carriers and most of the Anammox bacteria were distributed within the acryl resin carriers. Therefore, the results indicate that the proposed combined biofilm system is easy to operate and efficient for the treatment of high-ammonia wastewater.


2020 ◽  
Vol 82 (7) ◽  
pp. 1272-1284
Author(s):  
Kenta Shinoda ◽  
Rawintra Eamrat ◽  
Yuya Tsutsumi ◽  
Suphatchai Rujakom ◽  
Tippawan Singhopon ◽  
...  

Abstract The anaerobic ammonium oxidation (anammox) process holds great promise for treating nitrogen-contaminated water; stable nitrite-nitrogen (-N) production is significant to anammox performance. In this study, partial hydrogenotrophic denitrification (PHD) was used to stably and efficiently produce -N from nitrate-nitrogen (-N). An investigation of the effects of initial pH on the PHD process revealed that a high -N production efficiency (77.9%) could be ensured by setting an initial pH of 10.5. A combined PHD-anammox process was run for more than three months with maximal ammonium-nitrogen (-N), -N, and total dissolved inorganic nitrogen removal efficiencies of 93.4, 98.0, and 86.9%, respectively. The -N to -N and -N to -N ratios indicated that various bioprocesses were involved in nitrogen removal during the anammox stage, and a 16S rRNA gene amplicon sequencing was performed to further clarify the composition of microbial communities and mechanisms involved in the nitrogen removal process.


2018 ◽  
Vol 79 (5) ◽  
pp. 975-984 ◽  
Author(s):  
Tatsuru Kamei ◽  
Rawintra Eamrat ◽  
Kenta Shinoda ◽  
Yasuhiro Tanaka ◽  
Futaba Kazama

Abstract Nitrate removal during anaerobic ammonium oxidation (anammox) treatment is a concern for optimization of the anammox process. This study demonstrated the applicability and long-term stability of the coupled anammox and hydrogenotrophic denitrification (CAHD) process as an alternative method for nitrate removal. Laboratory-scale fixed bed anammox reactors (FBR) supplied with H2 to support denitrification were operated under two types of synthetic water. The FBRs showed simultaneous NH4-N and NO3-N removal, indicating that the CAHD process can support NO3-N removal during the anammox process. Intermittent H2 supply (e.g. 5 mL/min for a 1-L reactor, 14/6-min on/off cycle) helped maintain the CAHD process without deteriorating its performance under long-term operation and resulted in a nitrogen removal rate of 0.21 kg-N/m3/d and ammonium, nitrate, and dissolved inorganic nitrogen removal efficiencies of 73.4%, 80.4%, and 77%, respectively. The microbial community structure related to the CAHD process was not influenced by changes in influent water quality, and included the anammox bacteria ‘Candidatus Jettenia’ and a Sulfuritalea hydrogenivorans-like species as the dominant bacteria even after long-term reactor operation, suggesting that these bacteria are key to the CAHD process. These results indicate that the CAHD process is a promising method for enhancing the efficiency of anammox process.


Author(s):  
Mehdi Hajsardar ◽  
Seyed Mehdi Borghei ◽  
Amir Hessam Hassani ◽  
Afshin Takdastan

Abstract A series of reactors including a sequencing batch reactor (SBR) and a sequencing batch biofilm reactor (SBBR) were used for nitrogen removal. The aim of this study was simultaneous removal of NH4+-N and NOx–-N from synthetic wastewater. In the novel proposed method, the effluent from SBR was sequentially introduced into SBBR, which contained 0.030 m3 biofilm carriers, so the system operated under a paired sequence of aerobic-anoxic conditions. The effects of different carbon sources and aeration conditions were investigated. A low dissolved oxygen (DO) level in the biofilm depth of the fixed-bed process (SBBR) simulated the anoxic phase conditions. Accordingly, a portion of NH4+-N that was not converted to NO3–-N by the SBR process was converted to NO3–-N in the outer layer of the biofilm in the SBBR process. Further, simultaneous nitrification and denitrification (SND) was achieved in the SBBR where NO2–-N was converted to N2 directly, before NO3–-N conversion (partial nitrification). The level of mixed liquid suspended solids (MLSS) was 2740 mg/l at the start of the experiments. The required carbon source (C: N ratio of 4) was provided by adding an internal carbon source (through step feeding) or ethanol. Firstly, as part of the system (SBR and SBBR), SBR operated at a DO level of 1 mg/l while SBBR operated at a DO concentration of 0.3 mg/l during Run-1. During Run-2, the system operated at the low DO concentration of 0.3 mg/l. When the source of carbon was ethanol, the nitrogen removal rate (RN) was higher than the operation with an internal carbon source. When the reactors were operated at the same DO concentration of 0.3 mg/l, 99.1 % of the ammonium was removed. The NO3–-N produced during the aerobic SBR operation of the novel method was removed in SBBR reactor by 8.3 %. The concentrations of NO3--N and NO2–-N in the SBBR effluent were reduced to 2.5 and 5.5 mg/l, respectively. Also, the total nitrogen (TN) removal efficiency was 97.5 % by adding ethanol at the DO level of 0.3 mg/l. When C:N adjustment was carried out SND efficiency at C:N ratio of 6.5 reached to 99 %. The increasing nitrogen loading rate (NLR) to 0.554 kg N/m3 d decreased SND efficiency to 80.7 %.


2020 ◽  
Vol 81 (5) ◽  
pp. 1071-1079
Author(s):  
Caimeng Wang ◽  
Lirong Lei ◽  
Fangrui Cai ◽  
Youming Li

Abstract In this study, the completely autotrophic nitrogen removal over nitrite (CANON) process was initiated in a sequencing batch biofilm reactor (SBBR). Then the reactor was operated under different IC/N ratios. The total inorganic nitrogen removal efficiency (TINRE) at IC/N ratios of 0.75, 1.0, 1.25, 1.5 and 2.0 were 37.0 ± 11.0%, 58.9 ± 10.2%, 73.9 ± 3.2%, 73.6 ± 1.8% and 72.6 ± 2.0%, respectively. The suitable range of IC/N ratio in this research is 1.25–2.0. The poor nitrogen removal performance at IC/N ratio of 0.75 was due to the lack of growth substrate for AnAOB and low pH simultaneously; at IC/N ratio of 1.0 this was because the substrate concentration was insufficient for fully recovering the AnAOB activities. Microbial analysis indicated that Nitrosomonas, Nitrospira and Candidatus Brocadia were the main ammonium oxidation bacteria (AOB), nitrite oxidation bacteria (NOB) and anammox bacteria (AnAOB), respectively. In addition, at IC ratios of 1.25 or higher, denitrification was promoted with the rise of IC/N ratio, which might be because the change of IC concentrations caused cell lysis of microorganisms and provided organic matter for denitrification.


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