Mathematical models and bacterial communities for ammonia toxicity in mesophilic anaerobes not acclimated to high concentrations of ammonia

2016 ◽  
Vol 74 (4) ◽  
pp. 935-942 ◽  
Author(s):  
Seyong Park ◽  
Fenghao Cui ◽  
Kyung Mo ◽  
Moonil Kim

In this study, we evaluated ammonia toxicity in mesophilic anaerobic digestion at various pH values and total ammonia nitrogen (TAN) concentrations. We performed anaerobic toxicity assays (ATAs) to evaluate the toxicity effects of TAN and pH on mesophilic anaerobic digestion. Modeling based on the results of the ATAs indicated that the specific methanogenic activity (SMA) decreased by 30% at a TAN concentration higher than 3.0 g/L compared to a TAN concentration of 0 g/L. In addition, the highest SMA for a given TAN level (0.5–10.0 g/L) was observed at a pH of around 7.6. The results of bacterial community analyses showed that the diversity and richness of microorganisms with increasing TAN concentration were decreased. Chloroflexi and Synergistetes were the dominant phyla at TAN concentrations less than 3.0 g/L, and Firmicutes was the dominant phylum at TAN concentrations higher than 3.0 g/L, implying that the ammonia toxicity concentration may influence the kind of dominant species. In conclusion, to start a stable mesophilic anaerobic digestion concerning ammonia toxicity, a TAN concentration less than 3.0 g/L is preferable.

2002 ◽  
Vol 45 (10) ◽  
pp. 113-120 ◽  
Author(s):  
T. Liu ◽  
S. Sung

The inhibition effects of total ammonia nitrogen (TAN) on aceticlastic methanogenic activity using biomass from thermophilic anaerobic reactors were investigated in this study. Anaerobic Toxicity Assays (ATA) were conducted after the biomass was acclimated to different levels of TAN. The TAN background concentrations in the reactors were 400, 1,200, and 3,050 mg/L. The results from ATA showed: 1) high TAN concentrations could cause inhibition of aceticlastic methanogens; 2) biomass acclimated to higher TAN concentrations could alleviate the inhibition effect due to the increase of TAN concentration; 3) the lethal TAN concentration for methanogens was approximately 10,000 mg/L regardless of the background TAN concentration; 4) ATA results also revealed the role played by pH. At a given TAN concentration, methanogenic activity varied with the pH values. The highest methanogenic activity was always observed at a pH of 7.0∼7.5. 5) It was also observed that acclimation could increase the pH tolerance range, which made methanogens less sensitive to pH changes.


2021 ◽  
Vol 2 (2) ◽  
pp. 49-55
Author(s):  
Gunawan Pratama Yoga ◽  
Kristin Noni Riyanti Buraen ◽  
Sutanto Sutanto

Ammonia is one of the nutrient wastes products which can be toxic to all vertebrates, including fish. Usually, ammonia toxicity is expressed as Total Ammonia Nitrogen (TAN, mgN/L). Tambra fish (Tor tambroides) is freshwater fish with important economic value in some areas in Indonesia. According to overfishing and forest degradation, the fish has become threatened. This research aimed to calculate the LC50 value of ammonia to Tambra fish (Tor tambroides) and estimate  NOEC,  LOEC, and MATC values of ammonia to Tambra fish (Tor tambroides). This study was conducted using the static test method with two steps. The first stage is a preliminary test, where the preliminary test is observed for 24 hours With five concentrations excluding control. Whereas in the second stage that is carried out, observation for 96 hours with four concentrations excluding control. The Probit test is Performed to obtain LC50 value results, then proceed with ammonia analysis using the Salicylate Test Kit method. The results showed that ammonia had acute toxicity with LC50-96 hour value of NH4Cl against Tambra fish fry (Tor tambroides) in the amount of 354.615 mg/L. Ammonia caused acute toxicity to Tambra fish fry (Tor tambroides).The LC50-96 hour value was 354.615 mg/L in the form of Total Ammonia Nitrogen (TAN) or it was equivalent to un-ionized Ammonia (NH3) of 9.8937 mg/L, while values of the Lowest Observed Effect Concentration (LOEC) and No Observed Effect Concentration (NOEC) of ammonia on Tambra fish (Tor tambroides) were 578.24 mg/L and 280.18 mg/L, respectively.


2018 ◽  
Vol 7 (3) ◽  
Author(s):  
Fredynanta Saputra ◽  
Sutaryo Sutaryo ◽  
Agung Purnomoadi

Tujuan dari penelitian ini adalah untuk mengetahui pengaruh penggunaan ampas tahu sebagai co-substrat dalam digesti secara anaerob terhadap kecernaan protein, konsentrasi VFA dan total amonia nitrogen. Penelitian dilakukan dengan menggunakan dua buah digester kontinyu dan data dikoleksi selama tiga kali hydraulic retention time (HRT), dimana satu kali HRT setara dengan 25 hari. Data yang diperoleh dibahas dengan metode independent sampel comparison dengan membandingkan variabel hasil pengamatan dari digester satu (tanpa ampas tahu) dan digester dua (penambahan 5% ampas tahu) yang keduanya diencerkan menggunakan air dengan perbandingan 1:1. Hasil dari penelitian ini adalah terdapat adanya perbedaan yang nyata (P<0,05) dari perlakuan yang diterapkan terhadap kecernaan protein, konsentrasi VFA, dan konsentrasi total amonia nitrogen (TAN). Nilai kecernaan protein, konsentrasi VFA dan konsentrasi TAN dari digester 1 dan digester 2 secara berturut turut adalah 36,13% dan 25,71%; 25,39 ml/mol/l dan 11,21 ml/mol/l serta 1959 dan 1675 mg/l. Kesimpulan dari penelitian ini adalah konsentrasi VFA dan TAN yang stabil pada konsentrasi yang relatif rendah pada slurry dari digester 2 dipertengahan dan akhir penelitian mengindikasikan bahwa ampas tahu bisa digunakan sebagai co-subtrat pada feses sapi, namun demikian perlu dilakukan penelitian lebih lanjut untuk mengevaluasi level ampas tahu yang terbaik untuk meningkatkan produksi biogas dari digester biogas berbasis feses sapi.Utilization of Waste from Tofu as Co-Substrate in Biogas ProductionAbstractThe aim of this research was to evaluate the effect of co-substrate of waste of tofu in anaerobic digestion on protein digestibility, VFA concentration, and total ammonia nitrogen. The experiment was performed in two continuously feeding digesters for three hydraulic retention times (HRT) which was a HRT equal to 25 d. The observed data was analysed using independent sample comparison. The treatments were digester 1 as no co-substrat and digester 2 as 5% solid waste from tofu addition which both of them then diluted with tap water at 1:1 ratio. The results of this study showed that there were significant effect (P<0.05) of treatments on protein digestibility, VFA concentration and total ammonia nitrogen. The protein digestibility, VFA concentration and TAN concentration of digester 1 and digester 2 were 36.13 and 25.71%; 25.39 and 11.21 ml/mol/L; 1959 and 1675 mg/L, respectively. As conclusion, a stabil at low concentration of VFA and TAN in the middle and in the end experiment might be used to indicate that waste from tofu is suitable substrate for co-digestion with cow feses, however a further experiment is needed to obtain optimum level of tofu cake to enhance biogas production of digester biogas base on cow feses.•••


2021 ◽  
Vol 43 ◽  
pp. e53009
Author(s):  
Francisco Roberto dos Santos Lima ◽  
Davi de Holanda Cavalcante ◽  
Marcelo Vinícius do Carmo e Sá

The current study aimed at fostering bacterial growth in BFT aquaculture tanks by early Nile tilapia stocking. Control tanks had no tilapia but received daily applications of dry molasses (NT+) or had tilapia but no C:N ratio adjustment (T-). Experimental tanks had tilapia and received daily application of molasses to adjust the C:N ratio of water to 15:1 (T+). The development of bioflocs in NT+ was insignificant as demonstrated by low levels of settleable solids (SS) and total suspended solids (TSS). Total ammonia nitrogen (TAN) was significantly higher in NT+ than in T+. In the C:N-ratio adjusted tanks, the presence of fish shortened the control of TAN in several days. As nitrite declined in T+, it increased in NT+. The final concentrations of TSS in T+, T- and NT+ were 236 ± 29 mg L-1, 100 ± 32 mg L-1, and 40 ± 22 mg L-1, respectively (p < 0.05). It can be concluded that stable nitrifying and heterotrophic bacterial communities could be attained in BFT aquaculture tanks, before the end of the 4th week of culture, if the bacterial growth is fostered by early Nile tilapia stocking.


Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2556
Author(s):  
Huihui Wang ◽  
Zifu Li ◽  
Xiaoqin Zhou ◽  
Xuemei Wang ◽  
Siqi Zuo

This study was performed to investigate the anaerobic digestion feasibility of kitchen waste and blackwater under different scenarios in laboratory tests. According to biochemical methane potential tests, when the kitchen waste to blackwater solid ratio was 1:1, the cumulative methane production reached the highest amount at 313.2 mL/g volatile solids (VSs), which was 26.4% and 29.4% higher than the anaerobic monodigestion of kitchen waste and blackwater, respectively, indicating that the anaerobic codigestion of kitchen waste and blackwater had a synergetic effect. Furthermore, the effect of different initial total ammonia nitrogen concentrations in blackwater on anaerobic digestion was determined based on the above experimental results, thereby proving that reducing the total ammonia nitrogen concentration in blackwater can appropriately improve the efficiency of methane production. Therefore, anaerobic digestion is a suitable method for the biogas production of kitchen waste and blackwater. It is of great significance for the organic waste stream treatment of households in a decentralized scale, especially in rural areas.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bharat Nandkumar Mulay ◽  
Konda Rajasekhar Reddy

Abstract This experimental investigation of a laboratory scale aquaponic system included testing of a biofilter with basil plant as the biofilter part on aquaculture water quality. Irridescent shark was selected as aquaculture species. The biofilter consist of natural biomaterials such as coconut husk, coco peat, and coarse aggregates. The experiment was carried out for three short water recirculation durations of 2, 3, and 4 h/day. The influent and effluent ammonia NH3, total ammonia nitrogen (TAN), nitrites NO2 and nitrates NO3 levels were measured and analysed. The results showed that the biofilter effectively removed NH3 (65 - 71 %), TAN (34 - 58 %), and NO2 (60 - 67 %) from the aquaculture water. The dissolved oxygen (DO) levels were maintained between 3 - 7.0 mg/l during all the recirculation durations. The significance of water recirculation period was assessed by calculating the differences between the means of water quality parameters with a statistical test named one-way analysis of variance (ANNOVA) with significant level P taken as 5 %, i.e., P ≤ 0.5. The effluent mean NH3 levels 0.030 mg/l, 0.033 mg/l, and 0.022 mg/l exhibited significant difference at 4 h/d periods while effluent TAN levels 0.81, 0.77, and 0.77 showed no difference with varying periods.


Aquaculture ◽  
2020 ◽  
Vol 520 ◽  
pp. 734963 ◽  
Author(s):  
Mamoru Oshiki ◽  
Takashi Aizuka ◽  
Hirotoshi Netsu ◽  
Satoshi Oomori ◽  
Akihiro Nagano ◽  
...  

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