scholarly journals Characteristics of Ammonia Removal and Nitrifying Microbial Communities in a Hybrid Biofloc-RAS for Intensive Litopenaeus vannamei Culture: A Pilot-Scale Study

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.

2021 ◽  
Vol 11 (20) ◽  
pp. 9478
Author(s):  
Yishuai Du ◽  
Jianping Xu ◽  
Li Zhou ◽  
Fudi Chen ◽  
Tianlong Qiu ◽  
...  

Designing good recirculating aquaculture systems (RASs) is challenging in shrimp aquaculture. In this study, two sets of RASs were constructed using sea cucumber nursery tanks for rearing Litopenaeus vannamei. Recirculating aquaculture was supported by key technologies such as sewage collection and aeration systems adapted to the rectangular tanks and technologies for the removal of sewage, shrimp shells, and dead individuals. Six-hundred and eighty-five thousand juveniles were selected for rearing in the newly constructed RASs, where the average stocking density was 1013 shrimp/m3. During the recirculating aquaculture period of 53 days, the water temperature of the tanks was 24–31 °C, the salinity was 25–32‰, the pH was 6.4–8.2, the DO was ≥ 4.9 mg/L, the concentration of total ammonia nitrogen (TAN) was maintained between 0.17 and 4.9 mg/L, the concentration of nitrite nitrogen (NO2-N) was between 0.12 and 4.7 mg/L, and the total number of Vibrio bacteria remained between 330 and 9700 cfu/mL. At the end of the experiment, the final average weight of individual shrimp was 13.43 g, and the average yield reached 12.92 kg/m3. The great improvement in growth performance marks a breakthrough in RAS technology of shrimp, and it supports the use of an innovative methodology for the retrofitting and utilization of idle sea cucumber nursery tanks.


2014 ◽  
Vol 1004-1005 ◽  
pp. 1005-1007
Author(s):  
Dong Xia Zhang ◽  
Qi Liu ◽  
Yong Ming Zhang

Aquaculture waste water was a major sewage resource, and recirculating aquaculture is an important mode of aquaculture development. Potassium ferrate is a novel sewage treatment agent and the use of potassium ferrate as a aquaculture recirculating water purification agents had a very important significance in the theoretical and practical application. When the amount of potassium ferrate is 8mg / L, the removal rate of the total number of colonies is 98.8%, the removal rate of COD is 92.16%, 98.78%, and sulfide is 98.42%. For the total amount of ammonia and nitrite also has a certain effect, when the amount of potassium ferrate is 12mg / L, the nitrite removal rate was 44.61%, total ammonia nitrogen removal rate was 23.61%.


Archaea ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Xiaona Ma ◽  
Xingqiang Song ◽  
Xian Li ◽  
Songzhe Fu ◽  
Meng Li ◽  
...  

Microorganisms play an essential role in the performance of constructed wetlands (CWs) for wastewater treatment. However, there has been limited discussion on the characteristics of microbial communities in CWs for treatment of effluents from marine recirculating aquaculture systems (RAS). This study is aimed at characterizing the microbial communities of pilot-scale CWs with Salicornia bigelovii for treatment of saline wastewater from a land-based Atlantic salmon RAS plant located in Northern China. Illumina high-throughput sequencing was employed to identify the profile of microbial communities of three CWs receiving wastewater under different total ammonia nitrogen (TAN) concentrations. Results of this study showed remarkable spatial variations in diversity and composition of microbial communities between roots and substrates in three CWs, with distinct response to different TAN concentrations. In particular, Proteobacteria, Firmicutes, Cyanobacteria, and Bacteroidetes were predominant in roots, while Cyanobacteria, Proteobacteria, Firmicutes, Verrucomicrobia, and Bacteroidetes were prevalent in substrates. Moreover, redundancy analysis indicated that specific functional genera, such as Nitrosopumilus, Vibrio, Pseudoalteromonas, Nitrospina, and Planctomyces, played key roles in the removal of nitrogen/phosphorus pollutants and growth of wetland plants. From a microorganism perspective, the findings of this study could contribute to better understanding of contaminants’ removal mechanism and improved management of CWs for treatment of effluents from land-based marine aquaculture.


2004 ◽  
Vol 50 (6) ◽  
pp. 45-52 ◽  
Author(s):  
J.-L. Vasel ◽  
H. Jupsin ◽  
A.P. Annachhatre

Membrane bioreactors (MBR) have become common in treating municipal wastewaters. Applied to leachates treatment MBR were also successful with pilot scale experiments and full-scale facilities as well. We succeeded previously in designing an efficient nitrificationÐdenitrification process with an ethylene glycol byproduct as carbon source for denitrification. Moreover, an unexpectedly high inert COD removal efficiency was also observed in the full-scale MBR facility thereby making it possible to increase the operating time of the final GAC (Granulated Activated Carbon) adsorber. Since MBR are very sophisticated systems. Simpler and “lower” cost systems can also be considered. For example it is possible to nitrify leachates from sanitary landfill using a simple infiltrationÐpercolation technique with a low energy cost. To validate previously published laboratory experiments, a semi industrial-scale pilot installation was installed at the Montzen landfill site (Belgium). The process is based on infiltrationÐpercolation through a granular bed. This well known process was modified to increase the load, notably by changing the support medium, adding an electric fan that is run intermittently and maintaining temperatures greater than 15°C. The new material is a type of granular calcium carbonate with a large specific surface area. These technical improvements enabled the system to nitrify up to 0.4 kg NH4+-N/m3 of reactor bed per day at a hydraulic load of 0.35 m.d-1, with an ammonia removal rate in the range of 80 to 95%. Despite the high ammonia nitrogen inlet concentrations, this system exhibits remarkable nitrification efficiency. Moreover, these performances are achieved in a batch mode system without recirculation or dilution processes. If complete nitrification is needed, it can be obtained in a second in series of bioreactors. The system can be classified as a low cost process. An international patent is pending. Possible performances of those systems were compared with the usual methods for leachates treatment.


2018 ◽  
Vol 78 (1) ◽  
pp. 49-56
Author(s):  
I. A. Sánchez ◽  
R. K. X. Bastos ◽  
E. A. T. Lana

Abstract In two pilot-scale experiments, fingerlings and juvenile of tilapia were reared in high rate algal pond (HRAP) effluent. The combination of three different total ammonia nitrogen (TAN) surface loading rates (SLR1 = 0.6, SLR2 = 1.2; SLR3 = 2.4 kg TAN·ha−1·d−1) and two fish stocking densities (D1 = 4 and D2 = 8 fish per tank) was evaluated during two 12-week experiments. Fingerlings total weight gain varied from 4.9 to 18.9 g, with the highest value (equivalent to 0.225 g·d−1) being recorded in SLR2-D1 treatment; however, high mortality (up to 67%) was recorded, probably due to sensitivity to ammonia and wide daily temperature variations. At lower water temperatures, juvenile tilapia showed no mortality, but very low weight gain. The fish rearing tanks worked as wastewater polishing units, adding the following approximate average removal figures on top of those achieved at the HRAP: 63% of total Kjeldahl nitrogen; 54% of ammonia nitrogen; 42% of total phosphorus; 37% of chemical oxygen demand; 1.1 log units of Escherichia coli.


Author(s):  
Yu Li ◽  
Leigang Li ◽  
Reham Yasser Farouk ◽  
Yuanyuan Wang

Flocculation can remove large amounts of nitrogen and phosphorus from wastewater, and the resulting nitrogen- and phosphorus-rich floc can be used to produce organic fertilizer. For biogas slurries containing high levels of nitrogen and phosphorus, ordinary flocculants can no longer meet the flocculation requirements. In this study, to fully utilize the advantages of the two flocculants and achieve efficient removal rates of nitrogen and phosphorus from a biogas slurry, chitosan (CTS) and polyaluminum chloride (PAC) were used as a composite flocculation agent to flocculate pig biogas slurries. The response surface method was used to study the effect of PAC added (PACadded) to the composite flocculant (CF), composite flocculant added (CFadded) to the biogas slurry and the pH on flocculation performance, and optimize these three parameters. In the tests, when the PACadded was 6.79 g·100 mL−1CF, the CFadded was 20.05 mL·L−1 biogas slurry and the pH was 7.50, the flocculation performance was the best, with an absorbance of 0.132 at a wavelength of 420 nm. The total phosphorus (TP) concentration was reduced from 214.10 mg·L−1 to 1.38 mg·L−1 for a removal rate of 99.4%. The total ammonia nitrogen (TAN) concentration was reduced from 1568.25 mg·L−1 to 150.27 mg·L−1 for a removal rate of 90.4%. The results showed that the CF could form larger flocs, and had greater adsorption capacity and more stable flocculation performance than ordinary flocculants. Furthermore, the CF could exhibit better chelation, electrical neutralization and bridge adsorption.


2013 ◽  
Vol 664 ◽  
pp. 454-457
Author(s):  
Xiu Juan Yu ◽  
Li Hong Ning

The removal of ammonia nitrogen in simulated wastewater with 90mg/L NH4Cl was researched by ammonia stripping, electrochemical oxidation and the combination of the ammonia stripping and electrochemical oxidation. It is shown that the reduction of ammonia is enlarged with increasing of wastewater’s alkalinity during stripping. And the removal rates of ammonia nitrogen are 2.1% at pH2 and 43.1% at pH7 which is not related to the stripping time. The ammonia removal is higher efficiency in pH12 which is in the range of 45.1% and 61.4% when the stripping time is changed from 40 to 100 min. The removal rate of ammonia nitrogen is increased with the extension of electrolysis time by the way of the electrochemical oxidation. For 100min electrolysis, the ammonia removal in the cathodic and anodic compartments are 55.8% and 86.9%, respectively. Moreover, by using the ammonia stripping and electrochemical oxidation simultaneously, the ammonia removal in the cathodic and anodic compartments are up to 91.8% and 99.8% for 100min, respectively. The combining of the ammonia stripping with electrochemical oxidation technology has obviously synergistic effect in purifying ammonia nitrogen wastewater.


Author(s):  
Sergio Godoy-Olmos ◽  
Ignacio Jauralde ◽  
Raquel Monge-Ortiz ◽  
María C. Milián-Sorribes ◽  
Miguel Jover-Cerdá ◽  
...  

AbstractGilthead sea bream (Sparus aurata) was raised in six individual recirculating aquaculture systems (RAS) whose biofilters’ performance was analyzed. Fish were fed with three different diets (a control diet, a fishmeal-based diet (FM), and a plant meal-based diet (VM)) and with three different feeding strategies (manual feeding to apparent satiation, automatic feeding with restricted ration, and auto-demand feeding). For every combination of diet and feeding strategy, the mean oxygen consumption, ammonia excretion, and ammonia removal rate were determined. Fish fed with the VM diet consumed the most oxygen (20.06 ± 1.80 gO2 consumed kg−1 day−1). There were significant differences in ammonia excretion depending on the protein content and protein efficiency of the diet, as well as depending on feeding strategy, which in turn affected ammonia removal rates. Fish fed by auto-demand feeders led to the highest mean ammonia removal rate (0.10 gN-TAN removed m−2 biofiltration area day−1), while not leading to peaks of high ammonia concentration in water, which preserve fish welfare and growth.


2014 ◽  
Vol 70 (12) ◽  
pp. 2031-2039 ◽  
Author(s):  
Qiuzhuo Zhang ◽  
Chi Ding ◽  
Varenyam Achal ◽  
Dan Shan ◽  
Yang Zhou ◽  
...  

A new integrated water remediation technology, including a floating bed, a buffer zone of floating plants, enclosed ‘water hyacinth’ purification, economic aquatic plants and near-shore aquatic plant purification, was used in Dishui Lake to improve its water quality. A channel of 1,000 m length and 30 m width was selected to implement pilot-scale experiments both in the static period and the continuous water diversion period. The results showed that the new integrated water remediation technology exhibited the highest removal rate for permanganate index in a static period, which achieved 40.6%. The average removal rates of total nitrogen (TN), ammonia nitrogen (NH3-N) and total phosphorus (TP) in a static period were 23.2, 21.6 and 19.1%, respectively. However, it did not exhibit an excellent removal rate for pollutants in the continuous water diversion period. The average removal rates for all pollutants were below 10%. In winter, the new integrated remediation technology showed efficient effects compared to others. The average removal rate for CODMn, TN, NH3-N and TP were 7, 5.3, 7.6 and 6.5%, respectively. Based on our results, the new integrated water remediation technology was highly efficient as a purification system, especially during the static period in winter.


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