Aquacultural Engineering最新文献

{"title":"Design and optimization of a head-to-tail orientation device for freshwater fry","authors":"Chen Li ,&nbsp;Wei Luo ,&nbsp;Kang Wu ,&nbsp;Junyang Chen ,&nbsp;Musa Abubakar Tadda ,&nbsp;Songming Zhu ,&nbsp;Zhangying Ye ,&nbsp;Jianping Li","doi":"10.1016/j.aquaeng.2024.102433","DOIUrl":"https://doi.org/10.1016/j.aquaeng.2024.102433","url":null,"abstract":"<div><p>The head-to-tail orientation is an important part of the automatic injection of fish vaccines. However, it is characterized by being labour-intensive, with a poor working environment and low working efficiency. To solve the above mentioned problems, a freshwater fry head-to-tail orientation device has been designed. This paper took grass carp fry as the object of the study, described the working principle of the liquid bridge, analyzed the forces at key stages, measured the length and bending radius of the fry, and clarified the main factors affecting the efficiency of orientation. With roller radius, conveyor speed, and inclination angle as test factors and orientation success rate as the test index, single factor analysis and orthogonal testing were carried out on the orientation device to study the influence of each parameter on the test index. The optimal parameter combination was obtained. The test results showed that the highest orientation success rate was achieved when the drum radius was 50 mm, the line speed was 0.8 m/s, and the inclination of the conveyor belt was −6°. The orientation mechanism was experimentally verified with this combination of parameters, and the orientation success rate was 99.5 %. The device was simple in structure and could meet the requirements of the head-to-tail orientation of the mechanized injection of fish fry. It provided a reference and the basis for designing the head-to-tail orientation device for a freshwater fish fry.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"106 ","pages":"Article 102433"},"PeriodicalIF":3.6,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141485711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance of nursery Litopenaeus vannamei post-larvae in a BFT system enriched with Rhizoma coptidis broth","authors":"Jincheng Lao ,&nbsp;Yuqing Chen ,&nbsp;Hongxin Tan ,&nbsp;Wenchang Liu ,&nbsp;Guozhi Luo","doi":"10.1016/j.aquaeng.2024.102430","DOIUrl":"https://doi.org/10.1016/j.aquaeng.2024.102430","url":null,"abstract":"<div><p>The shrimp farming industry has historically been limited by outbreaks of bacterial diseases. The current study aimed to investigate the performance of adding <em>Rhizoma coptidis</em> (<em>R. coptidis</em>), an herbal medicine, to the biofloc system of <em>Litopenaeus vannamei</em> culture. A broth of boiled <em>R. coptidis</em> was added to four experimental groups (C0 (control), C2, C4, and C6, with respective dry weights of 0, 2, 4, and 6 g/L <em>R. coptidis</em>). The results showed that the nitrase and dehydrogenase activities of the biofloc enriched with <em>R. coptidis</em> were enhanced compared to the control group. Shrimp reared in the systems enriched with <em>R. coptidis</em> showed significantly better growth performance, digestion, and immune enzyme activity and a lower food conversion ratio compared to the control group. The mortality rate for Groups C4 and C6 in a Vibrio infection test was less than 50 %, while Group C0 experienced 100 % mortality. There were no significant differences in ammonia or nitrite concentration among the treatment groups. These results suggested better performance of nursery <em>Litopenaeus vannamei</em> post-larvae in BFT systems by enrichment with 4 g/L <em>R. coptidisL</em> broth.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"106 ","pages":"Article 102430"},"PeriodicalIF":3.6,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141482792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Facilities pond aquaculture system construction and the ecological economy analyzed","authors":"Hao Zhu ,&nbsp;Zhao-Jun Gu ,&nbsp;Guo-Feng Cheng ,&nbsp;Xing-Guo Liu ,&nbsp;Rong Tang","doi":"10.1016/j.aquaeng.2024.102435","DOIUrl":"https://doi.org/10.1016/j.aquaeng.2024.102435","url":null,"abstract":"<div><p>Pond aquaculture is the main form of aquaculture worldwide. However, there are problems with water quality being difficult to control, discharge pollution, low production quality, etc. Therefore, an efficient, low-carbon, and controllable pond system should be established. In this paper, we introduce two facilities’ pond systems: a segregated pond aquaculture system (SPA) and a batch pond aquaculture system (BPA). In these two systems, we evaluated a rearing period with bream (<em>Megalobrama amblycephala</em>) and detected ecological and economic indexes such as yield, nitrogen and phosphorus conversion efficiency, and energy utilization efficiency in different aquaculture pond systems. The results showed that the yields of the SPA and BPA were 12.81 % and 74.29 %, respectively, greater than those of traditional ponds. The feed conversion ratios (FCRs) of the BPA and SPA were 1.8 and 2.1, respectively, but those of the traditional ponds were 2.3. The proportions of nitrogen converted to fish in the SPA, BPA, and traditional ponds were 29.67 %, 33.45 %, and 26.19 %, respectively, and the percentages of phosphorus converted to fish in the SPA, BPA and traditional ponds were 53.68 %, 63.38 %, and 52.20 %, respectively. With the production of 1 kg of aquatic products, the utilization of solar and feed energy in the SPA, BPA, and traditional ponds was 60.28 ± 1.12 MJ/kg, 66.59 ±0.26 MJ/kg, and 37.05 ±1.33 MJ/kg, respectively. In addition, the SPA and BPA can also use 60 % less water, reduce wastewater discharge by 80 % and use 35 % less land. These results showed that construction facility pond systems could improve pond aquaculture efficiency and have great development potential.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"106 ","pages":"Article 102435"},"PeriodicalIF":3.6,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141543622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wheat bran addition methods in Pacific white shrimp (Litopenaeus vannamei) biofloc systems","authors":"Apriana Vinasyiam ,&nbsp;Julie Ekasari ,&nbsp;Johan W. Schrama ,&nbsp;Marc C.J. Verdegem ,&nbsp;Fotini Kokou","doi":"10.1016/j.aquaeng.2024.102437","DOIUrl":"https://doi.org/10.1016/j.aquaeng.2024.102437","url":null,"abstract":"<div><p>Incorporating non-starch polysaccharides (NSP) as a slowly degradable carbohydrate source in pelleted feed can simplify biofloc system management, compared to external carbon addition. NSP-containing ingredients like wheat bran synchronizes carbon input with the system organic matter dynamics compared to simple sugars. This study evaluated the effect of two methods of addition of an NSP-rich carbon source, wheat bran, to a Pacific white shrimp (<em>Litopenaeus vannamei</em>) biofloc system; supplementation via feed (wheat bran diet; WBdiet) and direct addition to the water (CONdiet+WB). The amount and composition of the total nutrient input to each mesocosm of the treatments was the same. A digestibility and a growth experiment were carried out separately for 35 and 42 days, respectively. The nutrient digestibility was overall lower in shrimp fed the WBdiet compared to the CONdiet, but without an effect on shrimp final weight, production, and survival. When comparing the methods of addition, neither of the approaches altered the shrimp nutritional quality. As expected, a difference in faecal C:N ratio was observed; 21 vs. 17 for WBdiet and CONdiet, respectively. The difference in faeces composition did not affect biofloc quantity, quality, and chlorophyll-a concentrations, and resulted in comparable water quality and microbial activity. Our study concluded that both NSP-addition methods, either via feed or via the water, were equally effective. When compared to the traditional addition of carbohydrate to the water, supplementing NSP-containing carbon sources via the feed can be a more efficient approach in terms of labour and feeding management practices.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"106 ","pages":"Article 102437"},"PeriodicalIF":3.6,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0144860924000487/pdfft?md5=e55c7c4a4f35bf598e78b9fefc823ef6&pid=1-s2.0-S0144860924000487-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141485702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrodynamic characteristics analysis of series hydraulic cyclone separators for pond aquaculture wastewater purification","authors":"Jun Zhang ,&nbsp;Haowei Liu ,&nbsp;Jingjing Yao ,&nbsp;Shouqi Cao ,&nbsp;Xingguo Liu ,&nbsp;Guofeng Cheng ,&nbsp;Qingsong Hu ,&nbsp;Fang Wang ,&nbsp;Zheng Zhang","doi":"10.1016/j.aquaeng.2024.102436","DOIUrl":"10.1016/j.aquaeng.2024.102436","url":null,"abstract":"<div><p>This study introduces a series of hydraulic cyclone separators designed to efficiently remove sediments and other high-density particulate matter from pond aquaculture wastewater. A three-dimensional two-phase model of these hydraulic cyclone separators was developed using the discrete phase model (DPM) and Reynolds stress turbulence model (RSM) based on numerical simulation theory. The computational fluid dynamics (CFD) method was validated by comparing it with experimental data, and an analysis of the hydrodynamic characteristics of the hydraulic cyclone separators was conducted. Furthermore, the relationships between structural parameters and separation efficiency were examined using Pearson's correlation coefficient. The findings reveal that the length of the first-stage cyclone column significantly influences the tangential velocity distribution within the second-stage cyclone, while the length of the second-stage cyclone column predominantly affects the pressure distribution of the first-stage cyclone. Increasing the column length enhances the overall particulate separation efficiency of the system. Moreover, adjustments in the split ratio of the first-stage cyclone have a notable impact on the tangential velocity and pressure distribution within the second-stage cyclone. Increasing the split ratio proves beneficial in improving the separation efficiency of particulate matter. This study provides valuable insights into the design and optimization of hydraulic cyclone separators, offering a dependable computational model for predicting and understanding their flow behavior and separation performance effectively.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"106 ","pages":"Article 102436"},"PeriodicalIF":3.6,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141408805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing flow uniformity and velocity fields in aquaculture tanks by modifying water inlets and nozzles arrangement: A computational fluid dynamics study","authors":"Milad Mohammadi Moghadam ,&nbsp;Houman Rajabi Islami ,&nbsp;Mojtaba Ezam ,&nbsp;Seyed Abdolmajid Mousavi","doi":"10.1016/j.aquaeng.2024.102431","DOIUrl":"10.1016/j.aquaeng.2024.102431","url":null,"abstract":"<div><p>Ensuring optimal conditions for fish, especially in terms of uniform velocity fields, is crucial for aquaculture systems to attain self-cleaning efficiency in rearing tanks and better fish behavior, which ultimately impacts their survival and growth. The current study presented a full-scale computational fluid dynamics (CFD) model of three types of circular, square and square arc angle tanks used in aquaculture farms to choose the most optimal tank based on the flow uniformity and velocity field. At the next step, the optimal arrangement of the inlet number, inlet location, inlet angle, as well as the number of nozzles on each inlet was reconfigured to create the most optimal tank. The simulations were done using the CFD software FLUENT distributed by the ANSYS Corporation. The software calculates velocities in the tanks by solving the Reynolds-averaged Navier-Stokes equations of continuity and momentum that govern the mean turbulent flow of water. The results illustrated circular and square arc angle tanks had significantly more uniform fluid velocity compared to the square tanks, which the square arc angle tank due to better flow velocity near the wall and space utilization was selected for further rearrangements. Additionally, the implementation of two entrance pipes near the corner of the two parallel walls with an entry angle of 0° in a square arc angle tank resulted in a more consistent water velocity. As the number of inlet nozzles increased to six, the water streamlines became more uniform, suggesting a more consistent water velocity throughout the tank. However, when the number of input nozzles increased to nine, the tension on the nozzle apertures were increased probably due to the decrease of distance between them. Findings of the present study concluded that two inlets in the corner with an entry angle of 0° and six nozzles on each inlet pipe could provide the optimum water velocity in the square arc angle tanks.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"106 ","pages":"Article 102431"},"PeriodicalIF":4.0,"publicationDate":"2024-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141281768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Real-time ammonia estimation in recirculating aquaculture systems: A data assimilation approach","authors":"Alaa Jamal ,&nbsp;Ahmed Nasser ,&nbsp;Jaap van Rijn","doi":"10.1016/j.aquaeng.2024.102432","DOIUrl":"https://doi.org/10.1016/j.aquaeng.2024.102432","url":null,"abstract":"<div><p>Recirculating aquaculture systems offer sustainable fish production but face challenges related to ammonia levels. Ammonia, particularly the un-ionized fraction, NH3, can negatively impact fish growth and health. Traditional ammonia estimation methods, including offline analyses and affordable, yet inaccurate, in-situ measurements, lack the ability to provide reliable real-time insights. Data assimilation combines simulation models and in-situ measurements to provide more accurate estimations. In this study, we demonstrate a novel approach using data assimilation to enhance real-time ammonia estimation in RAS. First, ammonia dynamics are described by forming equations that constitute a simulation model, based on the feeding amounts and the biofilter removal rate parameters. Then, an extended Kalman filter is presented and customized to integrate the simulation model and total ammonia nitrogen measurements for estimating NH3, NH4+, and biofilter parameters. We validated our method through synthetic and laboratory case studies and demonstrated its superior estimation capability as compared to in situ measurements or simulation models. Furthermore, improved ammonia estimation led to improved current and future fish weight estimations, which can be essential for reliable RAS management. The proposed approach facilitates wider adoption of DA in challenging estimations in aquaculture.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"106 ","pages":"Article 102432"},"PeriodicalIF":4.0,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141324838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In situ measurements and simulations of a net cage in currents","authors":"Sihan Gao ,&nbsp;Chunling Wang ,&nbsp;Stig Atle Tuene ,&nbsp;Guoyuan Li ,&nbsp;Houxiang Zhang ,&nbsp;Lars Christian Gansel","doi":"10.1016/j.aquaeng.2024.102429","DOIUrl":"https://doi.org/10.1016/j.aquaeng.2024.102429","url":null,"abstract":"<div><p>Accurate predictions of net cages’ deformation under current loads are vitally important for the welfare of stocked fish and the safety of cage structures. In this study, a scaled cage model was deployed at a fish farm. The incoming flow profile was measured through an Acoustic Doppler Current Profiler (ADCP) with high resolution in the depth direction, and the flow inside the cage was measured through an Acoustic Doppler Vector (ADV). Pressure tags were applied to capture the lifting of the cage under varying current conditions. The incoming flow velocity shows a good correlation with the lifting of the cage, and in general the rate of the cage being lifted by the flow increases with flow speed. However, the flow speed measured inside the cage is much less correlated to the upstream flow and cage deformation. Numerical cage models consisting of truss elements were developed; two flow reduction factors <em>r</em> = 0.9 and 0.8 derived from empirical formulas and measurements inside cages in previous studies were applied. The numerical model with <em>r</em> = 0.8 can predict the cage deformation well, with most relative deviations in the depth directions being less than 15%. The study indicates the feasibility of applying pressure tags with high precision to estimate current-induced cage deformation in situ, especially when a cage is experiencing obvious deformation.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"106 ","pages":"Article 102429"},"PeriodicalIF":4.0,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0144860924000402/pdfft?md5=f3dfe4b07775276057b782b62e58837d&pid=1-s2.0-S0144860924000402-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141298051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing instance segmentation: Leveraging multiscale feature fusion and attention mechanisms for automated fish weight estimation","authors":"Xiaoning Yu ,&nbsp;Jincun Liu ,&nbsp;Jinze Huang ,&nbsp;Feng Zhao ,&nbsp;Yaqian Wang ,&nbsp;Dong An ,&nbsp;Tong Zhang","doi":"10.1016/j.aquaeng.2024.102427","DOIUrl":"10.1016/j.aquaeng.2024.102427","url":null,"abstract":"<div><p>The accurate estimation of fish weight relies on the crucial parameter of individual fish contour features. While instance segmentation proves effective in extracting fish contours, challenges arise from diverse fish postures and reduced image sharpness underwater. Current instance segmentation methods often struggle to effectively balance global and local detailed features, which can result in inaccurate positioning of contour keypoints and consequently limit the accuracy of fish weight estimation. To overcome this, our study introduces a novel instance segmentation network tailored for precise fish contour extraction. The proposed approach incorporates multi-scale feature fusion and an attention mechanism based on the Segmenting Objects by Locations (SOLO) network, referred to as SOLO-MFFA. This paper designs a multi-scale context aggregation module to integrate features with a wider range of receptive fields, augmenting the model's capability to comprehend both local features and global information. At the same time, the introduction of a mixed-domain attention mechanism emphasizes more critical channel features and simultaneously improves the localization accuracy of contour points. Compared with SOLO and its improved model CAM-SOLO on the fish instance segmentation dataset, SOLO-MFFA demonstrated an effective improvement, with a 4.3% and 1.6% increase in mAP (mean Average Precision), respectively. The Decoupled-SOLO-MFFA achieved higher mAP. The visualization results also demonstrate that the contour features extracted in this paper are smoother and more accurately positioned. Additionally, in comparison to other well-known instance segmentation networks, our method has demonstrated significant improvements in both qualitative and quantitative evaluations. Furthermore, the integration of contour features derived from Decoupled-SOLO-MFFA, along with binocular vision, was utilized for the precise estimation of fish perimeter and weight. The findings reveal a strong correlation between the perimeter calculated by Decoupled-SOLO-MFFA and the actual weight, with a notably reduced error in weight estimation. Compared to previous methods, RMSE, MAE, and MAPE of the linear model constructed in this paper decreased by 3.92, 3.19, and 1.4%.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"106 ","pages":"Article 102427"},"PeriodicalIF":4.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141029635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sulphate removal by membrane filtration minimizes the risk of hydrogen sulphide formation in fixed bed biofilters","authors":"Paulo M. Fernandes ,&nbsp;Sanni L. Aalto ,&nbsp;Helga Ø. Åsnes ,&nbsp;Paula Rojas-Tirado ,&nbsp;Åse Åtland ,&nbsp;Carlos O. Letelier-Gordo","doi":"10.1016/j.aquaeng.2024.102426","DOIUrl":"https://doi.org/10.1016/j.aquaeng.2024.102426","url":null,"abstract":"<div><p>Hydrogen sulphide (H₂S) is one of the suspected reasons behind sudden mass fish mortalities in recirculating aquaculture systems (RAS) in recent years. H₂S production in aquaculture systems depends on sulphate and organic matter availability, presence of specific microbial groups, and local anoxic conditions. Specific potential H₂S production hotspots in RAS have been identified within biofilters and in accumulated sludge. Current H₂S control methods have been identified, such as improved hydrodynamics, increasing degassing efficiency, chemical addition of hydrogen peroxide or ozone, but have not been efficient or widespread applied. In this study, a nanomembrane filtration system was installed at a brackish water (mixture of seawater and freshwater to 15 ppt) smolt production site in Norway to remove sulphate ions from the seawater intake line (15 times reduction). The hydrogen sulphide production potential of the nanofiltered seawater mixed with freshwater (n = 3) was compared to an unfiltered seawater and freshwater mixture (15 ppt, n = 3) for 42 days in experimental scale biofilters using industrial fixed bed media. In both treatments, the linear production of H₂S started around the time that bulk water measurements of oxidation-reduction potential (ORP) and dissolved oxygen (DO) dropped below 0 mV and 1 mg/L, respectively. As expected, the highest H₂S concentration was observed in unfiltered water reactors, which also reached the highest concentration faster than filtered-water reactors. A 15 times reduction in initial sulphate levels by the nanofiltration membrane led to overall three times lower H₂S production and delayed the onset of production by two days. Hence, membrane-filtering intake water decreased the risk of H₂S production. A limitation in this study, however, was that sulphate was not completely removed from the intake water, and the next steps should evaluate how increasing the effort of membrane operation to completely remove sulphate affect the dynamics of H₂S production in RAS.</p></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"106 ","pages":"Article 102426"},"PeriodicalIF":4.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0144860924000372/pdfft?md5=87aadcb834e98a66cbf5f2787a1680ab&pid=1-s2.0-S0144860924000372-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140947755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}