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Sample records for adsorbent recirculating system

  1. Equipment review: The molecular adsorbents recirculating system (MARS®)

    OpenAIRE

    Boyle, Martin; Kurtovic, Jelica; Bihari, David; Riordan, Stephen; Steiner, Christian

    2004-01-01

    The molecular adsorbents recirculating system (MARS®) is a form of artificial liver support that has the potential to remove substantial quantities of albumin-bound toxins that have been postulated to contribute to the pathogenesis of liver cell damage, haemodynamic instability and multi-organ failure in patients with acute liver failure (ALF) and acute-on-chronic liver failure (AoCLF). These toxins include fatty acids, bile acids, tryptophan, bilirubin, aromatic amino acids and nitric oxide....

  2. Fulminant hepatic failure following marijuana drug abuse: Molecular adsorbent recirculation system therapy

    OpenAIRE

    Swarnalatha, G.; Pai, S.; Ram, R.; Dakshinamurty, K. V.

    2013-01-01

    Marijuana is used for psychoactive and recreational purpose. We report a case of fulminant hepatic failure following marijuana drug abuse who recovered following artificial support systems for acute liver failure. There is no published literature of management of marijuana intoxication with molecular adsorbent recirculation system (MARS). MARS is effective and safe in patients with fulminant hepatic failure following marijuana intoxication.

  3. Extracorporeal albumin dialysis with the molecular adsorbent recirculating system in acute-on-chronic liver failure

    DEFF Research Database (Denmark)

    Bañares, Rafael; Nevens, Frederik; Larsen, Fin Stolze;

    2013-01-01

    Acute-on-chronic liver failure (ACLF) is a frequent cause of death in cirrhosis. Albumin dialysis with the molecular adsorbent recirculating system (MARS) decreases retained substances and improves hemodynamics and hepatic encephalopathy (HE). However, its survival impact is unknown. In all, 189...

  4. Liver Dysfunction Supportive Therapies - From Therapeutic Plasmapheresis to Molecular Adsorbent Recirculating System

    OpenAIRE

    C. Stefanutti; Novelli, G.; Morabito, V.; S. Di Giacomo; Labbadia, G.

    2010-01-01

    Background: Because of the scarcity of donor organs, liver support strategies are being developed with the aim of either supporting patients with borderline functional liver cell mass until an appropriate organ becomes available for transplantation. Up until ten years ago Therapeutic Plasmapheresis (TPE) and Continuous Renal Replacement Therapy (CRRT) were the main treatment used. Currently, non-biological systems include Molecular Adsorbent Recirculating System (MARS) which is not only used ...

  5. Thromboelastography to Monitor Clotting/Bleeding Complications in Patients Treated with the Molecular Adsorbent Recirculating System

    OpenAIRE

    Schuepbach, Reto A; Renner, Eberhard L; Beat Müllhaupt; Marco Maggiorini; Markus Béchir; Stover, John F.; Reto Stocker; Jörg Bösiger; Bachli, Esther B.

    2011-01-01

    Background. The Molecular Adsorbent Recirculating System (MARS) has been shown to clear albumin-bound toxins from patients with liver failure but might cause bleeding complications potentially obscuring survival benefits. We hypothesized that monitoring clotting parameters and bed-side thromboelastography allows to reduce bleeding complications. Methods. Retrospective analysis of 25 MARS sessions during which clotting parameters were monitored by a standardized protocol. Results. During MARS ...

  6. Continuous molecular adsorbent recirculating system treatment in 69 patients listed for liver transplantation

    OpenAIRE

    Olin, Per; Hausken, John; Foss, Aksel; Karlsen, Tom Hemming; Melum, Espen; Haugaa, Håkon

    2015-01-01

    Abstract Objective. The molecular adsorbent recirculating system (MARS) is used to purify blood from albumin-bound toxins in patients with liver failure. However, the application of MARS has not demonstrated improved survival in randomized clinical trials and the clinical utility has not been finally established. In our department, the use of MARS is now restricted to the most critically ill patients with acute or acute on chronic liver failure. Material and methods. Since 2005, we have treat...

  7. Meta-analysis of survival with the molecular adsorbent recirculating system for liver failure

    OpenAIRE

    He, Guo-Lin; Feng, Lei; Duan, Chong-Yang; Hu, Xiang; Zhou, Chen-Jie; CHENG Yuan; Pan, Ming-Xin; Gao, Yi

    2015-01-01

    This study aims to assess the treatment effects of the molecular adsorbent recirculating system (MARS) in patients with acute and acute-on-chronic liver failure. We searched MEDLINE, EMBASE, and the Cochrane Controlled Trials Registry database between January 1966 and January 2014. We included randomized controlled trials, which compared the treatment effects of MARS with standard medical treatment. Study quality assessed according to Consolidated Standards of Reporting Trials (CONSORT) crite...

  8. Thromboelastography to Monitor Clotting/Bleeding Complications in Patients Treated with the Molecular Adsorbent Recirculating System

    Directory of Open Access Journals (Sweden)

    Esther B. Bachli

    2011-01-01

    Full Text Available Background. The Molecular Adsorbent Recirculating System (MARS has been shown to clear albumin-bound toxins from patients with liver failure but might cause bleeding complications potentially obscuring survival benefits. We hypothesized that monitoring clotting parameters and bed-side thromboelastography allows to reduce bleeding complications. Methods. Retrospective analysis of 25 MARS sessions during which clotting parameters were monitored by a standardized protocol. Results. During MARS therapy median INR increased significantly from 1.7 to 1.9 platelet count and fibrinogen content decreased significantly from 57 fL−1 to 42 fL−1 and 2.1 g/L to 1.5 g/L. Nine relevant complications occurred: the MARS system clotted 6 times 3 times we observed hemorrhages. Absent thrombocytopenia and elevated plasma fibrinogen predicted clotting of the MARS system (ROC 0.94 and 0.82. Fibrinolysis, detected by thromboelastography, uniquely predicted bleeding events. Conclusion. Bed-side thromboelastography and close monitoring of coagulation parameters can predict and, therefore, help prevent bleeding complications during MARS therapy.

  9. Meta-analysis of survival with the molecular adsorbent recirculating system for liver failure.

    Science.gov (United States)

    He, Guo-Lin; Feng, Lei; Duan, Chong-Yang; Hu, Xiang; Zhou, Chen-Jie; Cheng, Yuan; Pan, Ming-Xin; Gao, Yi

    2015-01-01

    This study aims to assess the treatment effects of the molecular adsorbent recirculating system (MARS) in patients with acute and acute-on-chronic liver failure. We searched MEDLINE, EMBASE, and the Cochrane Controlled Trials Registry database between January 1966 and January 2014. We included randomized controlled trials, which compared the treatment effects of MARS with standard medical treatment. Study quality assessed according to Consolidated Standards of Reporting Trials (CONSORT) criteria. The risk ratio was used as the effect-size measure according to a fixed-effects model. The search strategy revealed 72 clinical studies, 10 of which were randomized controlled trials that met the criteria and were included. Four addressed ALF (93 patients) and six addressed AOCLF (453 patients). The mean CONSORT score was 15 (range 10-20). By meta-analysis, MARS significantly improved survival in ALF (risk ratio 0.61; 95% CI 0.38, 0.97; P = 0.04). There was no significant survival benefit in AOCLF (risk ratio 0.88; 95% CI 0.74, 1.06; P = 0.16). MARS significantly improved survival in patients with acute liver failure, however, there is no evidence that it improved survival in patients with acute-on-chronic liver failure. In conclusion, the present meta-analysis indicates that MARS therapy can improve survival in patients with ALF. It is necessary to develop MARS treatment because of the increasing demand for liver transplantation and the risk of liver failure. PMID:26770295

  10. Survival predictors in patients treated with a molecular adsorbent recirculating system

    Institute of Scientific and Technical Information of China (English)

    Taru Kantola; Anna-Maria Koivusalo; Satu Parmanen; Krister Hockerstedt; Helena Isoniemi

    2009-01-01

    AIM: To identify prognostic factors for survival in patients with liver failure treated with a molecular adsorbent recirculating system (MARS). METHODS: MARS is a liver-assisting device that has been used in the treatment of liver failure to enable native liver recovery, and as a bridge to liver transplantation (LTX). We analyzed the 1-year outcomes of 188 patients treated with MARS, from 2001 to 2007, in an intensive care unit specializing in liver disease. Demographic, clinical and laboratory parameters were recorded before and after each treatment. One-year survival and the number of LTXs were recorded. Logistic regression analysis was performed to determine factors predicting survival. RESULTS: The study included 113 patients with acute liver failure (ALF), 62 with acute-on-chronic liver failure (AOCLF), 11 with graft failure (GF), and six with miscellaneous liver failure. LTX was performed for 29% of patients with ALF, 18% with AOCLF and 55% with GF. The overall 1-year survival rate was 74% for ALF,27% for AOCLF, and 73% for GF. The poorest survival rate, 6%, was noted in non-transplanted patients with alcohol-related AOCLF and cirrhosis, whereas, patients with enlarged and steatotic liver had 55% survival. The etiology of liver failure was the most important predictor of survival (P < 0.0001). Other prognostic factors were encephalopathy (P = 0.001) in paracetamol-related ALF, coagulation factors (P = 0.049) and encephalopathy (P = 0.064) in non-paracetamol-related toxic ALF, and alanine aminotransferase (P = 0.013) and factor V levels (P = 0.022) in ALF of unknown etiology. CONCLUSION: The etiology of liver disease was the most important prognostic factor. MARS treatment appears to be ineffective in AOCLF with end-stage cirrhosis without an LTX option.

  11. Experience of Treatments of Amanita phalloides-Induced Fulminant Liver Failure with Molecular Adsorbent Recirculating System and Therapeutic Plasma Exchange.

    Science.gov (United States)

    Zhang, Jicheng; Zhang, Ying; Peng, Zhiyong; Maberry, Donald; Feng, Xueqiang; Bian, Pengfei; Ma, Wenjuan; Wang, Chunting; Qin, Chengyong

    2014-01-01

    Ingestion of the mushroom containing Amanita phalloides can induce fulminant liver failure and death. There are no specific antidotes. Blood purifications, such as molecular adsorbent recirculating system (MARS) and therapeutic plasma exchange (TPE), are potential therapies. However, the extent to which these technologies avert the deleterious effects of amatoxins remains controversial; the optimal intensity, duration, and initiation criteria have not been determined yet. This study aimed to retrospectively observe the effects of MARS and TPE on nine patients with A. phalloides-induced fulminant liver failure. The survival rate for the nine patients was 66.7%. Both TPE and MARS might remove toxins and improve liver functions. However, a single session of TPE produced immediately greater improvements in alanine aminotransferase (-60% vs. -16.3%), aspartate aminotransferase (-47.6% vs. -15.4%), and total bilirubin (-37.3% vs. -17.1%) (compared with the values of pretreatment, all p MARS compared with MARS. Early intervention may be more effective than delayed therapy. Additionally, the presence of severe liver failure and renal failure indicated worse outcome. Although these findings are promising, additional case-controlled, randomized studies are required to confirm our results. PMID:24727538

  12. Experience with molecular adsorbent recirculating system treatment in 20 children listed for high-urgency liver transplantation.

    Science.gov (United States)

    Lexmond, Willem S; Van Dael, Carin M L; Scheenstra, René; Goorhuis, Joanne F; Sieders, Egbert; Verkade, Henkjan J; Van Rheenen, Patrick F; Kömhoff, Martin

    2015-03-01

    For more than 10 years, children at our national center for pediatric liver transplantation (LT) have been treated with Molecular Adsorbent Recirculating System (MARS) liver dialysis as a bridging therapy to high-urgency LT. Treatment was reserved for 20 patients with the highest degrees of hepatic encephalopathy (HE; median grade = 3.5). Death from neurological sequelae was considered imminent for these patients, and this was further reflected in significantly higher international normalized ratios and ammonia levels and worse prognostic liver indices (Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease scores and liver injury units) in comparison with 32 wait-listed patients who did not receive MARS dialysis. MARS therapy was generally well tolerated, with a reduction in thrombocytes and hemorrhaging as the most common side effects. HE improvement was documented in 30% of the treated patients, but progression to grade IV encephalopathy occurred in 45% of the patients despite the treatment. Serum ammonia, bilirubin, bile acid, and creatinine levels significantly decreased during treatment. Eighty percent of MARS-treated patients survived to undergo LT, and their survival was equivalent to that of non-MARS-treated patients with severe liver failure (69%, P = 0.52). The heterogeneity between MARS-treated patients and non-MARS-treated patients in our cohort precluded a statistical evaluation of a benefit from MARS for patient survival. Our data demonstrate the safety of MARS even in the most severely ill patients awaiting LT, but strategies that promote the more rapid and widespread availability of high-quality donor organs remain of critical importance for improving patient survival in cases of severe acute liver failure. PMID:25366362

  13. Addition of Molecular Adsorbent Recirculating System (MARS® Albumin Dialysis for the Preoperative Management of Jaundiced Patients with Hilar Cholangiocarcinoma

    Directory of Open Access Journals (Sweden)

    Jean-Marc Regimbeau

    2013-09-01

    Full Text Available The preoperative management of hilar cholangiocarcinoma (HC with jaundice focuses on decreasing the total serum bilirubin level (SBL by performing preoperative biliary drainage (PBD. However, it takes about 6-8 weeks for the SBL to fall at a sufficient extent. The objective of this preliminary study was to evaluate the impact of Molecular Adsorbent Recirculating System (MARS® dialysis (in association with PBD on SBL decrease. From January 2010 to January 2011, we prospectively selected all jaundiced patients admitted to our university hospital for resectable HC and requiring PBD prior to major hepatectomy. The PBD was followed by 3 sessions of MARS dialysis over a period of 72 h. A total of 10 patients with HC were screened and two of them were included (Bismuth-Corlette stage IIIa, gender ratio 1, median age 68 years. The initial SBL in the two patients was 328 and 242 μmol/l, respectively. After three MARS dialysis sessions, the SBL had fallen by 30 and 52%, respectively. After the end of each session, there was a SBL rebound of about 10 μmol/l. The MARS decreased the serum creatinine level, the platelet count and the prothrombin index, but did not modify the serum albumin level. Pruritus disappeared after one and two sessions, respectively. MARS-related morbidity included hypotension (n = 1, tachycardia (n = 1, thrombocytopenia (n = 2 and anaemia (n = 1. When combined with PBD, MARS dialysis appears to accelerate the decrease in SBL and thus may enable earlier surgery. This hypothesis must be validated in a larger study.

  14. Therapeutic application of molecular adsorbents recirculating system in various pathogenic MODS/MOF patients

    Institute of Scientific and Technical Information of China (English)

    LUO Hong-tao; GUO Li-min; WU Min; LIU Quan-mei; WANG Min-min

    2005-01-01

    @@ Multiple organ dysfunction syndrome (MODS) or multiple organ failure (MOF) is a syndrome which is frequently related to shock and sepsis, and has been described as the most common cause of death in the noncoronary critical care unit. The potential pathogenesis of the septic and systemic inflammatory response syndrome (SIRS) response has been increasingly associated with the development and aggravation of MODS or MOF. And studies in this respect have also demonstrated that there is a higher risk of mortality associated with some specific organ systems when they are dysfunctional, thus leading to the failures of the liver, brain, lung, and kidney.1 The liver interacts with many other organ systems, and liver dysfunction may act collectively in the production of organ system dysfunction, thus finally ending up with MODS.2

  15. Extracorporeal detoxification for hepatic failure using molecular adsorbent recirculating system: depurative efficiency and clinical results in a long-term follow-up.

    Science.gov (United States)

    Donati, Gabriele; La Manna, Gaetano; Cianciolo, Giuseppe; Grandinetti, Valeria; Carretta, Elisa; Cappuccilli, Maria; Panicali, Laura; Iorio, Mario; Piscaglia, Fabio; Bolondi, Luigi; Colì, Luigi; Stefoni, Sergio

    2014-02-01

    Acute liver failure and acute-on-chronic liver failure still show a poor prognosis. The molecular adsorbent recirculating system (MARS) has been extensively used as the most promising detoxifying therapy for patients with these conditions. Sixty-four patients with life-threatening liver failure were selected, and 269 MARS treatments were carried out as a bridge for orthotopic liver transplantation (OLT) or for liver function recovery. All patients were grouped according to the aim of MARS therapy. Group A consisted of 47 patients treated for liver function recovery (median age 59 years, range 23-82). Group B consisted of 11 patients on the waiting list who underwent OLT (median age 47 years, range 32-62). Group C consisted of 6 patients on the waiting list who did not undergo OLT (median age 45.5 years, range 36-54, P = 0.001). MARS depurative efficiency in terms of liver toxins, cytokines, and growth factors was assessed together with the clinical outcome of the patients during a 1-year follow-up. Total bilirubin reduction rate per session (RRs) for each MARS session was 23% (range 17-29); direct bilirubin RRs was 28% (21-35), and indirect bilirubin RRs was 8% (3-21). Ammonia RRs was 34% (12-86). Conjugated cholic acid RRs was 58% (48-61); chenodeoxycholic acid RRs was 34% (18-48). No differences were found between groups. Hepatocyte growth factor (HGF) values on starting MARS were 4.1 ng/mL (1.9-7.9) versus 7.9 ng/mL (3.2-14.1) at MARS end (P MARS sessions and the ΔHGF proved protective factors. Kaplan-Meier survival analysis was also used; after 12 months, 21.3% of patients in Group A survived, while 90.9% were alive in Group B and 16.7% in Group C (log rank = 0.002). In conclusion, MARS was clinically well tolerated by all patients and significantly reduced hepatic toxins. Better survival rates were linked to an OLT program, but patients' clinical characteristics on starting MARS therapy were the main factors predicting survival. The role of HGF

  16. Liver support therapy with molecular adsorbents recirculating system in liver failure:a summary of 252 cases from 14 centers in China

    Institute of Scientific and Technical Information of China (English)

    WANG Min-min; HU Xiao-bin; LUO Hong-tao; LIU Yi-he; WANG Wen-ya; CHEN Shi-jun; YE Qi-fa; YANG Yi-jun; CHEN Shi-bin; ZHOU Xin-min; GUO Li-min; ZHANG Yue-xin; DING Xiao-qiang

    2008-01-01

    Background A liver support therapy,named molecular adsorbents recirculating system (MARS),has been used for more than 700 liver failure patients in China.We made here a summary to evaluate the effects of MARS treatment in different applications with emphasis on hepatitis B virus (HBV) based liver failure.Methods This report analyzed data of 252 patients (mean age (44.9±12.7) years) in three groups:acute severe hepatitis (ASH),subacute severe hepatitis (SSH) and chronic severe hepatitis (CSH).The largest group was CSH (156 patients,61.9%),and 188 patients (74.6%,188/252) were infected with HBV.Results MARS treatments were associated with significant reduction of albumin bound toxins and water-soluble toxins.Most of the patients showed a positive response with a significant improvement of multiple organ function substantiated by a significant increase in prothrombin time activity (PTA) and median arterial pressure (MAP).There was a decrease in hepatic encephalopathy (HE) grade and Child-Turcotte-Pugh (CTP) scale.Thirty-nine of 188 HBV patients (20.7%) dropped out of the commendatory consecutive therapy ending with lower survival of 43.6% while the rest of the 149 patients had a survival rate of 62.4%.Survival within the ASH and SSH groups were 81.2% and 75.0%,respectively.In the CSH group,end stage patients were predominant (65/151,43%),whereas the early and middle stage patients had a better prognosis:early stage survival,including orthotopic liver transplantation (OLT) survival of 91.7%,middle stage survival of 75%,end stage survival of 33.8%.Conclusions MARS continues to be the most favorable extracorporeal treatment for liver support therapy in China for a wide range of conditions,including the majority of hepatitis B related liver failure conditions.The appropriate application of MARS for the right indications and stage of hepatic failure,as well as the fulfillment of prescribed treatments,will lead to the optimal therapeutic result.

  17. BWR recirculation pump diagnostic expert system

    International Nuclear Information System (INIS)

    At General Electric (GE), an on-line expert system to support maintenance decisions for BWR recirculation pumps for nuclear power plants has been developed. This diagnostic expert system is an interactive on-line system that furnishes diagnostic information concerning BWR recirculation pump operational problems. It effectively provides the recirculation pump diagnostic expertise in the plant control room continuously 24 hours a day. The expert system is interfaced to an on-line monitoring system, which uses existing plant sensors to acquire non-safety related data in real time. The expert system correlates and evaluates process data and vibration data by applying expert rules to determine the condition of a BWR recirculation pump system by applying knowledge based rules. Any diagnosis will be automatically displayed, indicating which pump may have a problem, the category of the problem, and the degree of concern expressed by the validity index and color hierarchy. The rules incorporate the expert knowledge from various technical sources such as plant experience, engineering principles, and published reports. These rules are installed in IF-THEN formats and the resulting truth values are also expressed in fuzzy terms and a certainty factor called a validity index. This GE Recirculation Pump Expert System uses industry-standard software, hardware, and network access to provide flexible interfaces with other possible data acquisition systems. Gensym G2 Real-Time Expert System is used for the expert shell and provides the graphical user interface, knowledge base, and inference engine capabilities. (author)

  18. Preoperational test report, recirculation condenser cooling systems

    International Nuclear Information System (INIS)

    This represents a preoperational test report for Recirculation Condenser Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The four system provide condenser cooling water for vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102. Each system consists of a valved piping loop, a pair of redundant recirculation pumps, a closed-loop evaporative cooling tower, and supporting instrumentation; equipment is located outside the farm on concrete slabs. Piping is routed to the each ventilation condenser inside the farm via below-grade concrete trenches. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System

  19. Preoperational test report, recirculation condenser cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Recirculation Condenser Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The four system provide condenser cooling water for vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102. Each system consists of a valved piping loop, a pair of redundant recirculation pumps, a closed-loop evaporative cooling tower, and supporting instrumentation; equipment is located outside the farm on concrete slabs. Piping is routed to the each ventilation condenser inside the farm via below-grade concrete trenches. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  20. Re-circulating linac vacuum system

    International Nuclear Information System (INIS)

    The vacuum system for a proposed 2.5 GeV, 10ΜA recirculating linac synchrotron light source [1] is readily achievable with conventional vacuum hardware and established fabrication processes. Some of the difficult technical challenges associated with synchrotron light source storage rings are sidestepped by the relatively low beam current and short beam lifetime requirements of a re-circulating linac. This minimal lifetime requirement leads directly to relatively high limits on the background gas pressure through much of the facility. The 10ΜA average beam current produces very little synchrotron radiation induced gas desorption and thus the need for an ante-chamber in the vacuum chamber is eliminated. In the arc bend magnets, and the insertion devices, the vacuum chamber dimensions can be selected to balance the coherent synchrotron radiation and resistive wall wakefield effects, while maintaining the modest limits on the gas pressure and minimal outgassing

  1. Preoperational test report, recirculation ventilation systems

    International Nuclear Information System (INIS)

    This represents a preoperational test report for Recirculation Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102 and supports the ability to exhaust air from each tank. Each system consists of a valved piping loop, a fan, condenser, and moisture separator; equipment is located inside each respective tank farm in its own hardened building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System

  2. Exhaust gas recirculation system for an internal combustion engine

    Science.gov (United States)

    Wu, Ko-Jen

    2013-05-21

    An exhaust gas recirculation system for an internal combustion engine comprises an exhaust driven turbocharger having a low pressure turbine outlet in fluid communication with an exhaust gas conduit. The turbocharger also includes a low pressure compressor intake and a high pressure compressor outlet in communication with an intake air conduit. An exhaust gas recirculation conduit fluidly communicates with the exhaust gas conduit to divert a portion of exhaust gas to a low pressure exhaust gas recirculation branch extending between the exhaust gas recirculation conduit and an engine intake system for delivery of exhaust gas thereto. A high pressure exhaust gas recirculation branch extends between the exhaust gas recirculation conduit and the compressor intake and delivers exhaust gas to the compressor for mixing with a compressed intake charge for delivery to the intake system.

  3. Filter System Performance in a Tilapia Recirculating System

    OpenAIRE

    Cristian Savin; Benone Păsărin; Marilena Talpeş; Gabriel Hoha; Magdalena Tenciu; Elpida Paltenea; Elena Mocanu; Adrian Gruber

    2012-01-01

    It is known that recirculating aquaculture systems, although has some advantages, production costs resulting from these production systems are quite high and is mainly due to the filtration system of technological water. Tilapia is one of the most important species in world aquaculture, the second production after carp, because of the advantages it has being reared in any production system: ponds, net-pens, cages, raceways, recirculating systems. Aim of this study was to evaluate the performa...

  4. Production of market size pikeperch (Sander lucioperca) in a pilot recirculation system

    NARCIS (Netherlands)

    Schram, E.; Philipsen, E.

    2003-01-01

    A pilot recirculation system was designed and constructed to investigate the production characteristics of pikeperch in recirculation systems. The design is based on a recirculation system for eel production.

  5. Development of recirculating RF pulse compression system

    International Nuclear Information System (INIS)

    An RF pulse compression technique using recirculating resonant cavity is under development for accelerating energy reinforcement for KEK B-factory. Cavity design and fabrication of cold model are described. (author)

  6. Modeling of TAN in recirculating aquaculture systems by AQUASIM

    DEFF Research Database (Denmark)

    Arvin, Erik; Pedersen, Lars-Flemming

    2011-01-01

    Modeling of total ammonium nitrogen (TAN) in recirculating aquaculture systems (RAS) contribute to identifying and quantifying the most important processes and their relative contribution to removal of TAN. AQUASIM is a flexible modular simulation system for water quality in natural and technical...... systems developed by EAWAG (Reichert, 1994). AQUASIM allows simulating complex biological, chemical and physical processes in standardized hydraulic systems. We used AQUASIM to model the steady state TAN concentrations in 12 experimental recirculating aquaculture systems (RAS) operated by DTU AQUA in...

  7. Technical and economical feasibility of a rotifer recirculation system

    OpenAIRE

    Suantika, G.; Dhert, P.; Sweetman, E.; O'Brien, E; Sorgeloos, P

    2005-01-01

    A feasibility study was performed on the use of a recirculation system for the mass culturing of rotifers at industrial level. Rotifer culture systems with a culture volume of 750 l were operated at three different stocking densities (3000, 5000 and 7000 individuals ml-1) in a completely closed recirculation system. At all operating rotifer densities, a reliable production of 2.2 billion rotifers could be obtained on a daily basis during 3 weeks. Excellent water quality was maintained by the ...

  8. In-tank aeration, a necessary compliment of loaded systems in an airlift recirculating aquaculture system

    Science.gov (United States)

    Water treatment components in recirculating aquaculture systems in generally address solids removal, nitrification, circulation, aeration, and degasification. Airlift pumps in a recirculating aquaculture system can address water circulation, aeration, and degasification. Recent data indicates oxygen...

  9. Filter System Performance in a Tilapia Recirculating System

    Directory of Open Access Journals (Sweden)

    Cristian Savin

    2012-10-01

    Full Text Available It is known that recirculating aquaculture systems, although has some advantages, production costs resulting from these production systems are quite high and is mainly due to the filtration system of technological water. Tilapia is one of the most important species in world aquaculture, the second production after carp, because of the advantages it has being reared in any production system: ponds, net-pens, cages, raceways, recirculating systems. Aim of this study was to evaluate the performance of a filter system in a tilapia recirculating system. Experiments were conducted during October – December 2011, during which feeding was done only with feed, Nutra category, ageappropriate granulation. Main physical – chemical parameters of technological water were monitored, pH, dissolved oxygen, nitrite, ammonia and ammonium, both the water entry in the filter and the exit from the filter. Filtration efficiency varied from 2-3% and up to 50-60%, mainly due to rapid loading of the filter and its need for cleaning.

  10. Selection оf Parameters for System of Diesel Engine Exhaust Gas Recirculation

    Directory of Open Access Journals (Sweden)

    G. M. Kukharionok

    2014-01-01

    Full Text Available The paper presents research results of various methods for recirculation of diesel engine exhaust gases. An influence of recirculation parameters on economic and ecological diesel engine characteristics has been evaluated in the paper. The paper considers an influence of turbocharger configuration on the intensity of gas recirculation. Specific features of the recirculation system operation in dynamic modes have been shown in the paper. The paper provides recommendations for selection of a diesel engine exhaust gas recirculation system.

  11. Microorganisms in recirculating aquaculture systems and their management

    NARCIS (Netherlands)

    Rurangwa, E.; Verdegem, M.C.J.

    2015-01-01

    Recirculation aquaculture systems (RASs) are increasingly considered as production systems of the future with a minimum ecological impact for the production of aquatic food. To maintain a good water quality and to produce quality and healthy fishery products, the systems depend on a diverse microbia

  12. An Inexpensive Recirculating Aquaculture System with Multiple Use Capabilities.

    Science.gov (United States)

    Scurlock, Gerald Don, Jr.; Cook, S. Bradford; Scurlock, Carrie Ann

    1999-01-01

    Describes the construction of an inexpensive recirculating aquaculture system that can hold up to 46 pounds of fish, invertebrates, and mussels for classroom use. The system is versatile, requires little maintenance, and can be used for both teaching and research purposes. (WRM)

  13. Low-head saltwater recirculating aquaculture systems utilized for juvenile red drum production

    Science.gov (United States)

    Recirculating aquaculture systems reuse water with mechanical and biological treatment between each use and thus require wastewater treatment techniques for continuous waste removal. However, the traditional techniques and equipment utilized in recirculating aquaculture systems are expensive. The d...

  14. Impact of heparin on coagulation index during the therapy of molecular adsorbent recirculating system in patients with liver failure%肝素在分子吸附再循环治疗肝衰竭中的应用及对凝血指标的影响

    Institute of Scientific and Technical Information of China (English)

    袁素娥; 周阳; 谭德明; 李丹; 周涛; 谢群英; 范娟

    2011-01-01

    目的:观察分子吸附再循环系统(molecular adsorbent recirculating system,MARS)治疗肝衰竭时无肝素和肝素循环对患者凝血指标的影响,评价2种抗凝技术的安全性.方法:对174例凝血酶原活动度(PTA)≤40%的肝衰竭患者按随机分组原则进行前瞻性实验性研究.根据抗凝方式不同分为无肝素组92例次,肝素组82例次.选择治疗0,0.5,1,2,3,4,5,6h共8个时间点动态观察凝血指标变化,统计管路/滤器凝血、出血等不良事件的发生情况.结果:2组之间凝血酶原时间(PT),PTA,国际标准化数值(INR)差异无统计学意义(P>0.05).肝素组使用首剂抗凝后激活部分凝血活酶时间(APTT)、凝血酶时间(TT)迅速升高,30 min即达峰值,无肝素组略有上升,2组治疗中各时间点均数比较差异有统计学意义(P<0.05).肝素组纤维蛋白原(Fbg)曲线趋于平稳,无肝素组逐步下降,在治疗的2.5h出现交互,差异有统计学意义(P=0.001).肝素组2例(2.44%)术后严重出血,无肝素组1例(1.09%)Ⅲ级凝血治疗中断.结论:血液与MARS循环管路接触时发生Fbg吸附,抗凝支持可减少吸附.PTA≤40%肝衰竭患者MARS治疗前应根据凝血参数、弥散性血管内凝血(DIC)检测、临床症状等综合评估凝血状态,高凝期选择肝素循环有助于MARS顺利完成的同时改善高凝状态,防治DIC;低凝期选择无肝素循环能有效避免出血,理论上可通过降低血液中类肝素样物质等改善患者凝血机制.%Objective To investigate the impact of coagulative parameters on different anti-coagulation systems in molecular adsorbent recirculating system ( MARS) in subjects with liver failure, and to evaluate the safety of different anticoagulation methods. Methods A prospective experimental observation was designed. According to anticoagulation methods, 174 MARS treatment sessions for 146 patients with liver failure and prothrombin time activity percentage (PTA)≤40% were

  15. Investigation of induced recirculation during planned ventilation system maintenance

    OpenAIRE

    Pritchard, C.J.; Scott, D F; Noll, J.D.; Voss, B.; Leonis, D.

    2014-01-01

    The Office of Mine Safety and Health Research (OMSHR) investigated ways to increase mine airflow to underground metal/nonmetal (M/NM) mine working areas to improve miners’ health and safety. One of those areas is controlled recirculation. Because the quantity of mine air often cannot be increased, reusing part of the ventilating air can be an effective alternative, if implemented properly, until the capacity of the present system is improved. The additional airflow can be used to provide effe...

  16. Fuzzy Logic Controller based on geothermal recirculating aquaculture system

    OpenAIRE

    Hanaa M. Farghally; Doaa M. Atia; Hanaa T. El-madany; Faten H. Fahmy

    2014-01-01

    One of the most common uses of geothermal heat is in recirculation aquaculture systems (RAS) where the water temperature is accurately controlled for optimum growing conditions for sustainable and intensive rearing of marine and freshwater fish. This paper presents a design for RAS rearing tank and brazed heat exchanger to be used with geothermal energy as a source of heating water. The heat losses from the RAS tank are calculated using Geo Heat Center Software. Then a plate type heat exchang...

  17. Particle size distribution in the tilapia Recirculating Aquaculture System

    OpenAIRE

    Stokic, Jelena

    2012-01-01

    This study was to evaluate methods for measuring and describing particle size distribution from three different spots in Tilapia recirculating system at University of Life Ccience in Ås, Norway. For this purpose serial filtration over different mesh size and parallel filtration over different mesh size methods were compared. Water samples were taken from before drum filter, after drum filter and after bio-filter (MBBR) and filtrated through eight different mesh size classes and calculated in ...

  18. THE BIOECONOMICS OF RECIRCULATING AQUACULTURE SYSTEMS

    OpenAIRE

    Richard F. KAZMIERCZAK, Jr.; Caffey, Rex H.

    1996-01-01

    The goal of this study was to produce a detailed aquaculture production model incorporating constraints unique to closed system culture and to conduct a formal economic analysis of closed system operation. Results generated by this model indicate that less than perfect management ability can eliminate the normal advantages associated with using high protein feed. While higher protein levels produce faster growth, and for this reason are often used in the industry, the increased direct feed co...

  19. Solid waste reduction of closed recirculated aquaculture systems by secondary culture of detritivorous organisms

    OpenAIRE

    Bischoff, Adrian A.

    2007-01-01

    Conventional production systems used in aquaculture such as ponds, raceways, net cages or recirculating systems have in common that they release large amounts of feed nutrients either in dissolved or particulate form. The efficient removal of suspended solids is a key factor for the successful operation of recirculating aquaculture systems (RAS). The here presented thesis utilised the solid wastes from modern aquaculture recirculating system for carnivorous fish for the secondary production o...

  20. Considerations upon energetic efficiency of a recirculating aquatic system (RAS) for super intensive fish culture

    OpenAIRE

    Petru David; Augustin Pop; Valentin Popovici

    2009-01-01

    The efficiency of the aquaculture using recirculating systems depends on many factors among which the most important it is the energy consumption of the system. To assure a high levelenergy conservation in an aquatic recirculating system, the intensity of water recirculation must be maximized, but this leads to a increasing of the consumed energy for water circulation. That is why is required a rigorous analysis for the energetic consumption for a system of this type and establishment of opti...

  1. Control methodologies based on geothermal recirculating aquaculture system

    International Nuclear Information System (INIS)

    One of the most common uses of geothermal heat is in RAS (recirculation aquaculture systems) where the water temperature is accurately controlled for optimum growing conditions for sustainable and intensive rearing of marine and freshwater fish. This paper presents a design for RAS rearing tank and plate type heat exchanger to be used with geothermal energy as a source of heating water. A well at Umm Huweitat on the Red Sea is used as a source of geothermal energy. The heat losses from the RAS tank are calculated using Geo Heat Center Software. Then a plate type heat exchanger is designed using the epsilon–NTU (number of transfer units) analysis method. For optimal growth and abundance of production, a different techniques of control system are applied to control the water temperature. The total system is built in MATLAB/SIMULINK to study the overall performance of control unit. Finally, a comparison between PI, Fuzzy-PID, and Fuzzy Logic Control has been done. - Highlights: • Design recirculating aquaculture system using geothermal energy. • Design a PI controller for water temperature control. • Design a Fuzzy logic controller for water temperature control. • Design a Fuzzy-PID controller for water temperature control. • Comparison between different control systems

  2. Continuous hydroponic wheat production using a recirculating system

    Science.gov (United States)

    Mackowiak, C. L.; Owens, L. P.; Hinkle, C. R.; Prince, R. P.

    1989-01-01

    Continuous crop production, where plants of various ages are growing simultaneously in a single recirculating nutrient solution, is a possible alternative to batch production in a Controlled Ecological Life Support System. A study was conducted at John F. Kennedy Space Center where 8 trays (0.24 sq m per tray) of Triticum aestivum L. Yecora Rojo were grown simultaneously in a growth chamber at 23 C, 65 percent relative humidity, 1000 ppm CO2, continuous light, with a continuous flow, thin film nutrient delivery system. The same modified Hoagland nutrient solution was recirculated through the plant trays from an 80 L reservoir throughout the study. It was maintained by periodic addition of water and nutrients based on chemical analyses of the solution. The study was conducted for 216 days, during which 24 trays of wheat were consecutively planted (one every 9 days), 16 of which were grown to maturity and harvested. The remaining 8 trays were harvested on day 216. Grain yields averaged 520 g m(exp -2), and had an average edible biomass of 32 percent. Consecutive yields were unaffected by nutrient solution age. It was concluded that continual wheat production will work in this system over an extended period of time. Certain micronutrient deficiencies and toxicities posed problems and must be addressed in future continuous production systems.

  3. The Effect of Effluent Recirculation in a Semi-Continuous Two-Stage Anaerobic Digestion System

    OpenAIRE

    Karthik Rajendran; Azam Jeihanipour; Taherzadeh, Mohammad J.; Solmaz Aslanzadeh

    2013-01-01

    The effect of recirculation in increasing organic loading rate (OLR) and decreasing hydraulic retention time (HRT) in a semi-continuous two-stage anaerobic digestion system using stirred tank reactor (CSTR) and an upflow anaerobic sludge bed (UASB) was evaluated. Two-parallel processes were in operation for 100 days, one with recirculation (closed system) and the other without recirculation (open system). For this purpose, two structurally different carbohydrate-based substrates were used; st...

  4. Evaluation of a rainbow trout (Oncorhynchus mikyss) culture water recirculating system

    OpenAIRE

    Iván Sánchez O; Wilmer Sanguino O.; Ariel Gómez C.; Roberto García C

    2015-01-01

    ABSTRACTObjective. To evaluate a water recirculation system for rainbow trout fish cultures at the recirculating laboratory of the Aquaculture Engineering Production Program of University of Nariño. Materials and Methods. 324 rainbow trout (Oncorhynchus mikyss) fries were cultured in 12 plastic tanks with a capacity of 250 L in an aquaculture recirculating system the treatment system of which was made up by a conventional sedimentation tank, a fixed stand upflow biofilter with recycled PVC tu...

  5. Exergetic performance analysis of a recirculating aquaculture system

    Energy Technology Data Exchange (ETDEWEB)

    Kucuk, Haydar [Mechanical Engineering Department, Guemueshane University, 29000 Guemueshane (Turkey); Midilli, Adnan [Energy Division, Mechanical Engineering Department. Nigde University, 51000 Nigde (Turkey); Oezdemir, Atilla; Cakmak, Eyuep [Central Fisheries Research Institute, Ministry of Agricultural and Rural Affairs, Trabzon (Turkey); Dincer, Ibrahim [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ont. (Canada)

    2010-05-15

    This paper examines exergetic aspects of a Recirculation Aquaculture System (RAS) for Black Sea trout (Salmo trutta labrax) fingerling rearing at the Trabzon Central Fisheries Research Institute, Turkey. In its thermodynamic analysis, each component of the RAS is treated as a steady-state steady flow system and its exergetic efficiencies are studied. In addition, the following parameters are measured and recorded in experiments: the mass flow rates, inlet and outlet temperatures and of the system components, surrounding temperatures, and electrical work utilized by the components in the RAS. Based on these experimental data, inlet and outlet exergy values, exergy losses, and exergetic efficiencies of each component in the system are determined to assess their performance. Moreover, the overall system exergy efficiency is determined. The results show that exergy efficiencies of the system components are highly affected by varying input exergy flows as a function of the surrounding temperature and chiller's operating period. (author)

  6. Microbial diversity of biological filters in recirculating aquaculture systems.

    Science.gov (United States)

    Schreier, Harold J; Mirzoyan, Natella; Saito, Keiko

    2010-06-01

    Development of environmentally sustainable farming of marine and freshwater species using recirculating aquaculture systems (RASs) requires a complete understanding of the biological component involved in wastewater treatment. This component integrates biofilters composed of microbial communities whose structure, dynamics, and activities are responsible for system success. Engineering highly efficient, environmentally sound, disease-free, and economically viable systems necessitates a thorough knowledge of microbial processes involved in all facets of RAS biofilters and has only recently been the focus of comprehensive studies. These studies have included the application of molecular tools to characterize community diversity and have identified key processes useful for improving system performance. In this paper we summarize the current understanding of the microbial diversity and physiology of RAS biofilters and discuss directions for future studies. PMID:20371171

  7. Fuzzy Logic Controller based on geothermal recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    Hanaa M. Farghally

    2014-01-01

    Full Text Available One of the most common uses of geothermal heat is in recirculation aquaculture systems (RAS where the water temperature is accurately controlled for optimum growing conditions for sustainable and intensive rearing of marine and freshwater fish. This paper presents a design for RAS rearing tank and brazed heat exchanger to be used with geothermal energy as a source of heating water. The heat losses from the RAS tank are calculated using Geo Heat Center Software. Then a plate type heat exchanger is designed using the epsilon – NTU analysis method. For optimal growth and abundance of production, a Fuzzy Logic control (FLC system is applied to control the water temperature (29 °C. A FLC system has several advantages over conventional techniques; relatively simple, fast, adaptive, and its response is better and faster at all atmospheric conditions. Finally, the total system is built in MATLAB/SIMULINK to study the overall performance of control unit.

  8. Unit process engineering for water quality control and biosecurity in marine water recirculating systems

    Science.gov (United States)

    High-intensity systems that treat and recirculate water must maintain a culture environment that can sustain near optimum fish health and growth at the design carrying capacity. Water recirculating systems that use centralized treatment systems can benefit from the economies of scale to decrease th...

  9. Orbital tomography for highly symmetric adsorbate systems

    Science.gov (United States)

    Stadtmüller, B.; Willenbockel, M.; Reinisch, E. M.; Ules, T.; Bocquet, F. C.; Soubatch, S.; Puschnig, P.; Koller, G.; Ramsey, M. G.; Tautz, F. S.; Kumpf, C.

    2012-10-01

    Orbital tomography is a new and very powerful tool to analyze the angular distribution of a photoemission spectroscopy experiment. It was successfully used for organic adsorbate systems to identify (and consequently deconvolute) the contributions of specific molecular orbitals to the photoemission data. The technique was so far limited to surfaces with low symmetry like fcc(110) oriented surfaces, owing to the small number of rotational domains that occur on such surfaces. In this letter we overcome this limitation and present an orbital tomography study of a 3,4,9,10-perylene-tetra-carboxylic-dianhydride (PTCDA) monolayer film adsorbed on Ag(111). Although this system exhibits twelve differently oriented molecules, the angular resolved photoemission data still allow a meaningful analysis of the different local density of states and reveal different electronic structures for symmetrically inequivalent molecules. We also discuss the precision of the orbital tomography technique in terms of counting statistics and linear regression fitting algorithm. Our results demonstrate that orbital tomography is not limited to low-symmetry surfaces, a finding which makes a broad field of complex adsorbate systems accessible to this powerful technique.

  10. Microscreen effects on water quality in replicated recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Fernandes, Paulo; Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg

    2015-01-01

    This study investigated the effects of three microscreen mesh sizes (100, 60 and 20 μm) on water quality and rainbow trout (Oncorhynchus mykiss) performance compared to a control group without microscreens, in triplicated recirculating aquaculture systems (RAS). Operational conditions were kept....... Fish performed similarly in all treatments. Preliminary screening of trout gills did not reveal any pathological changes related to microscreen filtration and the resulting water quality. Biofilter performance was also unaffected, with 0′-order nitrification rates (k0a) being equivalent for all twelve...... increased β-values. Particulate parameters reached steady-state in all treatment groups having microscreens at the end of the trial. The time to reach equilibrium seemingly increased with increasing mesh size but the three treatment groups (100, 60 and 20 μm) did not significantly differ at the end of the...

  11. The evaluation of oxygen and carbon dioxide transfer associated with airlifts in recirculating aquaculture systems

    Science.gov (United States)

    Airlifts in recirculating aquaculture systems (RAS) provide aeration, degasification, and water circulation. They allow the simplification of systems, and if designed properly, can reduce the capital costs and minimize operation and maintenance associated with alternative pumping systems. In order t...

  12. Power plant including an exhaust gas recirculation system for injecting recirculated exhaust gases in the fuel and compressed air of a gas turbine engine

    Science.gov (United States)

    Anand, Ashok Kumar; Nagarjuna Reddy, Thirumala Reddy; Shaffer, Jason Brian; York, William David

    2014-05-13

    A power plant is provided and includes a gas turbine engine having a combustor in which compressed gas and fuel are mixed and combusted, first and second supply lines respectively coupled to the combustor and respectively configured to supply the compressed gas and the fuel to the combustor and an exhaust gas recirculation (EGR) system to re-circulate exhaust gas produced by the gas turbine engine toward the combustor. The EGR system is coupled to the first and second supply lines and configured to combine first and second portions of the re-circulated exhaust gas with the compressed gas and the fuel at the first and second supply lines, respectively.

  13. Performance of the prototype gas recirculation system with built-in RGA for INO RPC system

    International Nuclear Information System (INIS)

    An open loop gas recovery and recirculation system has been developed for the INO RPC system. The gas mixture coming from RPC exhaust is first desiccated by passing through molecular sieve (3 Å+4 Å). Subsequent scrubbing over basic active alumina removes toxic and acidic contaminants. The Isobutane and Freon are then separated by diffusion and liquefied by fractional condensation by cooling up to -26∘C. A Residual Gas Analyser (RGA) is being used in the loop to study the performance of the recirculation system. The results of the RGA analysis will be discussed.

  14. NUTRIENTS DYNIMIC IN AN AQUAPONIC RECIRCULATING SYSTEM FOR STURGEON AND LETTUCE (LACTUCA SATIVA) PRODUCTION

    OpenAIRE

    LORENA SFETCU; Cristea, V.; L. OPREA

    2013-01-01

    Aquaponics are modern production systems, which integrate the aquaculture technology with hydroponic systems (vegetable production without soil) with a goal of fructification of residual nutrients resulted from metabolic activity of fish biomass as high quality vegetable biomass sealable as ecological products. In the present study, as a first step in aquaponic recirculating systems evaluation, the authors aim to compare two types of recirculating systems: classical (hereby noted with RAS) an...

  15. Risk Analysis of Tilapia Recirculating Aquaculture Systems: A Monte Carlo Simulation Approach

    OpenAIRE

    Kodra, Bledar

    2007-01-01

    Risk Analysis of Tilapia Recirculating Aquaculture Systems: A Monte Carlo Simulation Approach Bledar Kodra (ABSTRACT) The purpose of this study is to modify an existing static analytical model developed for a Re-circulating Aquaculture Systems through incorporation of risk considerations to evaluate the economic viability of the system. In addition the objective of this analysis is to provide a well documented risk based analytical system so that individuals (investors/lenders) c...

  16. Closed recirculating system for shrimp-mollusk polyculture

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This paper deals with a new system of aquaculture, i.e., a closed recirculating system for shrimp-mollusk polyculture. The culture system consisted of several shrimp ponds, a mollusk water-purifying pond and a reservoir. During the production cycle, water circulated between the shrimp and mollusk ponds, and the reservoir compensated for water loss from seepage and evaporation. Constricted tagelus, Sinonovacula constricta, was selected as the cultured mollusk, and Pacific white shrimp, Litopenaeus vannamei, as the cultured shrimp. The main managing measures during the production cycle were: setting and using the aerators; introducing the probiotic products timely into the shrimp ponds; adopting a "pen-closing" method for controlling shrimp viral epidemics; setting the flow diversion barriers in the mollusk pond to keep the circulating water flowing through the pond along a sine-like curve and serve as substrate for biofilm; no direct feeding was necessary for the cultured mollusk until the co-cultured shrimp was harvested; natural foods in the water from the shrimp ponds was used for their foods. Two sets of the system were used in the experiment in 2002 and satisfactory results were achieved. The average yield of the shrimp was 11 943.5 kg/hm2, and that of the mollusk was 16 965kg/hm2. After converting the mollusk yield into shrimp yield at their market price ratio, the food coefficient of the entire system averaged at as low as 0.81. The water quality in the ponds was maintained at a desirable level and no viral epidemics were discovered during the production cycle.

  17. Closed recirculating system for shrimp-mollusk polyculture

    Science.gov (United States)

    Wu, Xiongfei; Zhao, Zhidong; Li, Deshang; Chang, Kangmei; Tong, Zhuanshang; Si, Liegang; Xu, Kaichong; Ge, Bailin

    2005-12-01

    This paper deals with a new system of aquaculture, i.e., a closed recirculating system for shrimp-mollusk polyculture. The culture system consisted of several shrimp ponds, a mollusk water-purifying pond and a reservoir. During the production cycle, water circulated between the shrimp and mollusk ponds, and the reservoir compensated for water loss from seepage and evaporation. Constricted tagelus, Sinonovacula constricta, was selected as the cultured mollusk, and Pacific white shrimp, Litopenaeus vannamei, as the cultured shrimp. The main managing measures during the production cycle were: setting and using the aerators; introducting the probiotic products timely into the shrimp ponds; adopting a “pen-closing” method for controlling shrimp viral epidemics; setting the flow diversion barriers in the mollusk pond to keep the circulating water flowing through the pond along a sine-like curve and serve as substrate for biofilm; no direct feeding was necessary for the cultured mollusk until the co-cultured shrimp was harvested; natural foods in the water from the shrimp ponds was used for their foods. Two sets of the system were used in the experiment in 2002 and satisfactory results were achieved. The average yield of the shrimp was 11 943.5 kg/hm2, and that of the mollusk was 16 965 kg/hm2. After converting the mollusk yield into shrimp yield at their market price ratio, the food coefficient of the entire system averaged at as low as 0.81. The water quality in the ponds was maintained at a desirable level and no viral epidemics were discovered during the production cycle.

  18. KE basin recirculation/skimmer/IX systems restart acceptance test report

    International Nuclear Information System (INIS)

    The 105 KE Basin Recirculation System and Skimmer Loop have been upgraded to provide the flexibility to run the Ion Exchange Modules on either system to support spent fuel removal for the Spent Nuclear Fuel Project. This Acceptance Test Report Provides the documentation of the leak Testing for the construction work associated with the IXM inlet and outlet piping, places the cartridge filters back in service and provides the functional testing of the IXM's on the recirculation and skimmer systems

  19. The Presence of Pathogenic Bacteria in Recirculating Aquaculture System Biofilms and their Response to Various Sanitizers

    OpenAIRE

    King, Robin K.

    2001-01-01

    THE PRESENCE OF BACTERIAL PATHOGENS IN BIOFILMS OF RECIRCULATING AQUACULTURE SYSTEMS AND THEIR RESPONSE TO VARIOUS SANITIZERS Robin K. King ABSTRACT Recirculating aquaculture offers a prospect for successful fish farming, but this form of aquaculture presents a great potential for pathogenic microorganisms to become established in the system through the formation of biofilms. Biofilms are capable of forming on all aquaculture system components, incorporating the various microflor...

  20. Considerations upon energetic efficiency of a recirculating aquatic system (RAS for super intensive fish culture

    Directory of Open Access Journals (Sweden)

    Petru David

    2009-04-01

    Full Text Available The efficiency of the aquaculture using recirculating systems depends on many factors among which the most important it is the energy consumption of the system. To assure a high levelenergy conservation in an aquatic recirculating system, the intensity of water recirculation must be maximized, but this leads to a increasing of the consumed energy for water circulation. That is why is required a rigorous analysis for the energetic consumption for a system of this type and establishment of optimum solutions to minimize the consumption. This paperwork presents a detailed analysis of the energy consumption for a recirculating aquatic system for fish breeding, as well as considerations and solutions for optimization of the energy consumption.

  1. Theoretical Insight of Physical Adsorption for a Single Component Adsorbent + Adsorbate System: II. The Henry Region

    KAUST Repository

    Chakraborty, Anutosh

    2009-07-07

    The Henry coefficients of a single component adsorbent + adsorbate system are calculated from experimentally measured adsorption isotherm data, from which the heat of adsorption at zero coverage is evaluated. The first part of the papers relates to the development of thermodynamic property surfaces for a single-component adsorbent + adsorbate system1 (Chakraborty, A.; Saha, B. B.; Ng, K. C.; Koyama, S.; Srinivasan, K. Langmuir 2009, 25, 2204). A thermodynamic framework is presented to capture the relationship between the specific surface area (Ai) and the energy factor, and the surface structural and the surface energy heterogeneity distribution factors are analyzed. Using the outlined approach, the maximum possible amount of adsorbate uptake has been evaluated and compared with experimental data. It is found that the adsorbents with higher specific surface areas tend to possess lower heat of adsorption (ΔH°) at the Henry regime. In this paper, we have established the definitive relation between Ai and ΔH° for (i) carbonaceous materials, metal organic frameworks (MOFs), carbon nanotubes, zeolites + hydrogen, and (ii) activated carbons + methane systems. The proposed theoretical framework of At and AH0 provides valuable guides for researchers in developing advanced porous adsorbents for methane and hydrogen uptake. © 2009 American Chemical Society.

  2. Simultaneous methanogenesis and denitrification of aniline wastewater by using anaerobic-aerobic biofilm system with recirculation

    International Nuclear Information System (INIS)

    Wastewater containing highly concentrated nitrogenous and aromatic compounds, such as aniline, is difficult to degrade and very toxic to microorganisms, especially to nitrifier. In order to remove both carbon and nitrogen from aniline wastewater, recently two biofilm reactors equipped with anaerobic-aerobic cycle and internal recirculation have demonstrated some potential in treating the wastewater. In such system, ammonification, methanogenesis and denitrification reactions occurred simultaneously in one anaerobic reactor, followed by COD removal and nitrification in the aerobic reactor. The effect of recirculation ratio on COD and nitrogen removal using such reactor arrangement was therefore investigated in the present work. The results showed that recirculation had little impact on the overall COD removal or denitrification activity in the anaerobic reactor at any tested ratio, 96-98% of overall COD removal efficiency was achieved with a final effluent COD value below 200 mg/L. But nitrification and TN removal were strongly affected by recirculation. The nitrification rate reached a maximum of 0.48 kg N/(m3 d) at recirculation ratio of 1 and complete nitrification was achieved at the recirculation ratios over 2. TN removal efficiency increased continuously and a sharp reduction of sludge production in the system was observed with increasing recirculation.

  3. Dietary carbohydrate composition can change waste production and biofilter load in recirculating aquaculture systems

    NARCIS (Netherlands)

    Meriac, A.; Eding, E.H.; Schrama, J.W.; Kamstra, A.; Verreth, J.A.J.

    2014-01-01

    This study investigated the effect of dietary carbohydrate composition on the production, recovery and degradability of fecal waste from rainbow trout (Oncorhynchus mykiss) in recirculating aquaculture systems (RAS). Dietary carbohydrate composition was altered by substituting starch with non-starch

  4. Ozonation followed by ultraviolet irradiation provides effective bacteria inactivation in a freshwater recirculating system

    Science.gov (United States)

    Recirculating aquaculture systems may require an internal disinfection process to control population growth of pathogens and heterotrophic bacteria. Ozonation and ultraviolet (UV) irradiation are two technologies that have been used to treat relatively large aquaculture flows, including flows withi...

  5. Application of airlift technology in recirculation aquaculture systems

    Science.gov (United States)

    Marine hatcheries implementing recirculating aquaculture technology require pristine water quality and must be designed to provide a disease free environment as much as possible to limit disease transmission. Given the aggressive nature of a variety of marine pathogens, design considerations with re...

  6. Optimization of recirculating laminar air flow in operating room air conditioning systems

    Directory of Open Access Journals (Sweden)

    Enver Yalcin

    2016-04-01

    Full Text Available The laminar flow air-conditioning system with 100% fresh air is used in almost all operating rooms without discrimination in Turkey. The laminar flow device which is working with 100% fresh air should be absolutely used in Type 1A operating rooms. However, there is not mandatory to use of 100% fresh air for Type 1B defined as places performed simpler operation. Compared with recirculating laminar flow, energy needs of the laminar flow with 100 % fresh air has been emerged about 40% more than re-circulated air flow. Therefore, when a recirculating laminar flow device is operated instead of laminar flow system with 100% fresh air in the Type 1B operating room, annual energy consumption will be reduced. In this study, in an operating room with recirculating laminar flow, optimal conditions have been investigated in order to obtain laminar flow form by analyzing velocity distributions at various supply velocities by using computational fluid dynamics method (CFD.

  7. Dietary carbohydrates and denitrification in recirculating aquaculture systems

    OpenAIRE

    Meriac, A.

    2014-01-01

    Due to overfishing of global fish stocks and increasing fish meal prices, plant ingredients are being increasingly used as an alternative source of protein in fish feeds. However, the inclusion of unpurified plant ingredients will also increase the content of fibers in feeds. Fibers are nearly indigestible and will therefore increase solid waste production in aquaculture. This solid waste can be used to as a carbon source for denitrification to control nitrate levels in recirculating aquacult...

  8. Ornithinimicrobium tianjinense sp. nov., isolated from a recirculating aquaculture system.

    Science.gov (United States)

    Liu, Liang-Zi; Liu, Ying; Chen, Zhu; Liu, Hong-Can; Zhou, Yu-Guang; Liu, Zhi-Pei

    2013-12-01

    A Gram-positive, strictly aerobic and heterotrophic, non-spore-forming actinobacterium (strain B2(T)) isolated from a recirculating aquaculture system was studied for its taxonomic position. Strain B2(T) formed a rudimentary substrate-mycelium that fragmented into short rod-shaped to coccoid cells (0.5 µm×0.5-2.2 µm or 0.5-1.0 µm in diameter). Colonies were yellow, smooth, circular and 1.5-2.0 mm in diameter after incubation on TSA for 3 days at 30 °C. Strain B2(T) grew at 20-40 °C (optimal, 30 °C) and pH 5.5-9.5 (optimal, 6.5-7.0) and in the presence of 0-9% (w/v) NaCl (optimal, 1%). The predominant menaquinone of strain B2(T) was MK-8(H4). The cell-wall peptidoglycan of strain B2(T) contained the amino acids ornithine, glutamic acid, alanine, glycine and aspartic acid. The major polar lipids were phosphatidylglycerol and diphosphatidylglycerol. The major fatty acids were iso-C15 : 0, iso-C16 : 0 and summed feature 9. Its DNA G+C content was 68.3 mol% (Tm). Analysis of 16S rRNA gene sequences indicated that strain B2(T) was related phylogenetically to members of the genus Ornithinimicrobium with highest similarity (96.6 %) to Ornithinimicrobium kibberense DSM 17687(T), followed by Ornithinimicrobium humiphilum DSM 12362(T) (96.3 %), Ornithinimicrobium pekingense LW6(T) (96.2%) and Ornithinimicrobium murale 01-Gi-040(T) (94.8%). On basis of phenotypic, chemotaxonomic and phylogenetic data, it was concluded that strain B2(T) represents a novel species of the genus Ornithinimicrobium, for which the name Ornithinimicrobium tianjinense sp. nov. is proposed. The type strain is B2(T) ( =CGMCC 1.12160(T) =JCM 18464(T)). PMID:23907216

  9. High rate algal pond treatment for water reuse in a marine fish recirculation system: Water purification and fish health

    OpenAIRE

    Metaxa, Elisabeta; Deviller, Genevieve; Pagand, P; Alliaume, C; Casellas, C.; Blancheton, Jean-Paul

    2006-01-01

    Regardless of the degree of closure of a recirculation system, effluents are produced and replacement water is needed, which limits the possibility of locating a seawater production system away from the shoreline. At the Palavas Ifremer station, in the south of France, a High Rate Algal Pond (HRAP) was operated during several years to treat the effluent from a recirculating aquaculture system before reusing it. The effect of the HRAP-treated water on the recirculation system and on the fish w...

  10. Long term/low dose formalin exposure to small-scale recirculation aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg; Nielsen, Jeppe L.;

    2010-01-01

    Repetitive long term formalin application at low dose was investigated to determine the effect on formaldehyde removal rate, biofilter nitrification and the microbial composition in small-scale recirculation aquaculture biofilters. Six pilot-scale recirculation aquaculture systems holding rainbow.......9%, whereas Nitrobacter sp. was not detected. The relative abundances of AOB and NOB in the untreated system were generally higher compared to the system exposed to formalin. Low dose formalin in recirculated aquaculture systems proved to be a possible treatment strategy, as the effect on nitrification was...... were positively correlated to the amount and frequency of formalin treatment. In systems with regularly low formalin dosage, the formaldehyde removal rate increased up to tenfold from 0.19 +/- 0.05 to 1.81 +/- 0.13 mg/(L h). Biofilter nitrification was not impaired in systems treated with formalin on a...

  11. NUTRIENTS DYNIMIC IN AN AQUAPONIC RECIRCULATING SYSTEM FOR STURGEON AND LETTUCE (LACTUCA SATIVA PRODUCTION

    Directory of Open Access Journals (Sweden)

    LORENA SFETCU

    2013-12-01

    Full Text Available Aquaponics are modern production systems, which integrate the aquaculture technology with hydroponic systems (vegetable production without soil with a goal of fructification of residual nutrients resulted from metabolic activity of fish biomass as high quality vegetable biomass sealable as ecological products. In the present study, as a first step in aquaponic recirculating systems evaluation, the authors aim to compare two types of recirculating systems: classical (hereby noted with RAS and integrated/aquaponic (RAS_A regarding water quality parameters generally, and TAN (total ammonia nitrogen production and transformation, particularly.

  12. Implementation of Exhaust Gas Recirculation for Double Stage Waste Heat Recovery System on Large Container Vessel

    DEFF Research Database (Denmark)

    Andreasen, Morten; Marissal, Matthieu; Sørensen, Kim;

    2014-01-01

    Concerned to push ships to have a lower impact on the environment, the International Maritime Organization are implementing stricter regulation of NOx and SOx emissions, called Tier III, within emission control areas (ECAs). Waste Heat Recovery Systems (WHRS) on container ships consist of...... recovering some of the waste heat from the exhaust gas. This heat is converted into electrical energy used on-board instead of using auxiliary engines. Exhaust Gas Recirculation (EGR) systems, are recirculating a part of the exhaust gas through the engine combustion chamber to reduce emissions. WHRS combined...

  13. Flow, aeration, and carbon dioxide transfer rates for airlifts used in recirculating aquaculture systems

    Science.gov (United States)

    Airlift pumping systems reduce the electrical costs of moving water in a recirculating aquaculture system and can be concurrently designed to aerate water and remove carbon dioxide. This study determined the water flow, oxygen transfer, and CO2 removal rates for water using airlift technology in a 1...

  14. Nitrate removal effectiveness of fluidized sulfur-based autotrophic denitrification biofilters for recirculating aquaculture systems

    Science.gov (United States)

    There is a need to develop practical methods to reduce nitrate -nitrogen loads from recirculating aqua-culture systems to facilitate increased food protein production simultaneously with attainment of water quality goals. The most common wastewater denitrification treatment systems utilize methanol-...

  15. Temporary cooling system for critical loads during Recirculation Cooling Water (RCW) system outage

    International Nuclear Information System (INIS)

    As part of the Point Lepreau Refurbishment Project, Recirculation Cooling Water (RCW) system will be shutdown for maintenance activity. During the RCW outage, alternate cooling flow for critical heat loads such as Spent Fuel Bay (SFB), D2O vapour dryers and Instrument Air Compressor Coolers will be provided through a temporary cooling system to remove approximately 3MW of heat. This paper describes a practical strategy to build in the temporary cooling system for this project. Major equipment involved, piping modifications required and system reliability analysis are also addressed. (author)

  16. Evaluation of a rainbow trout (Oncorhynchus mikyss culture water recirculating system

    Directory of Open Access Journals (Sweden)

    Iván Sánchez O.

    2014-09-01

    Full Text Available Objective. To evaluate a water recirculation system for rainbow trout fish cultures at the recirculating laboratory of the Aquaculture Engineering Production Program of University of Nariño. Materials and Methods. 324 rainbow trout (Oncorhynchus mikyss fries were cultured in 12 plastic tanks with a capacity of 250 L in an aquaculture recirculating system the treatment system of which was made up by a conventional sedimentation tank, a fixed stand upflow biofilter with recycled PVC tube pieces and a natural degassing system; the sedimentation unit effluent was pumped up to a reservoir tank using a 2 HP centrifugal pump after being subject to gravity through the biofilter and to be then distributed to the 12 culture units to which a constant amount of air from a blower was injected. Results. The water treatment system removed 31% of total suspended solids, 9.5% of total ammonia nitrogen, and increased dissolved oxygen to the final effluent in 6.5%. An increase of 305% in biomass was calculated during 75 days, the mortality percentage registered throughout the study period was 4.9%. Conclusions. The water treatment system maintained the physicochemical water quality parameters within the values recommended for the species. The increase in weight and size, food conversion, mortality and biomass production reported normal values for rainbow trout fish culture in recirculating systems.

  17. Use of planted biofilters in integrated recirculating aquaculture-hydroponics systems in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Trang, N.T.D.; Brix, Hans

    2014-01-01

    The feasibility of using planted biofilters for purification of recirculated aquaculture water in the Mekong Delta of Vietnam was assessed. The plant trenches were able to clean tilapia aquaculture water and to maintain good water quality in the fish tanks without renewal of the water. NH4-N was ...... rates of 725 kg N and 234 kg P ha-1 year-1. This research demonstrates that integrated recirculating aquaculture-hydroponics (aquaponics) systems provide significant water savings and nutrient recycling as compared with traditional fish ponds. © 2012 John Wiley & Sons Ltd....

  18. The Effect of Effluent Recirculation in a Semi-Continuous Two-Stage Anaerobic Digestion System

    Directory of Open Access Journals (Sweden)

    Karthik Rajendran

    2013-06-01

    Full Text Available The effect of recirculation in increasing organic loading rate (OLR and decreasing hydraulic retention time (HRT in a semi-continuous two-stage anaerobic digestion system using stirred tank reactor (CSTR and an upflow anaerobic sludge bed (UASB was evaluated. Two-parallel processes were in operation for 100 days, one with recirculation (closed system and the other without recirculation (open system. For this purpose, two structurally different carbohydrate-based substrates were used; starch and cotton. The digestion of starch and cotton in the closed system resulted in production of 91% and 80% of the theoretical methane yield during the first 60 days. In contrast, in the open system the methane yield was decreased to 82% and 56% of the theoretical value, for starch and cotton, respectively. The OLR could successfully be increased to 4 gVS/L/day for cotton and 10 gVS/L/day for starch. It is concluded that the recirculation supports the microorganisms for effective hydrolysis of polyhydrocarbons in CSTR and to preserve the nutrients in the system at higher OLRs, thereby improving the overall performance and stability of the process.

  19. The accumulation of substances in Recirculating Aquaculture Systems (RAS) affects embryonic and larval development in common carp Cyprinus carpio

    NARCIS (Netherlands)

    Martins, C.I.; Pristin, M.G.; Ende, S.S.W.; Eding, E.H.; Verreth, J.A.J.

    2009-01-01

    The accumulation of substances in Recirculating Aquaculture Systems (RAS) may impair the growth and welfare of fish. To test the severity of contaminants accumulated in RAS, early-life stages of fish were used. Ultrafiltered water from two Recirculating Aquaculture Systems (RAS), one RAS with a high

  20. Membrane biological reactor treatment of a saline backwash flow from a recirculating aquaculture system

    Science.gov (United States)

    A recirculating aquaculture system (RAS) can minimize water use, allowing fish production in regions where water is scarce and also placing the waterborne wastes into a concentrated and relatively small volume of effluent. The RAS effluent generated during clarifier backwash is usually small in vol...

  1. Investigation of proper modeling of very dense granular flows in the recirculation system of CFBs

    Institute of Scientific and Technical Information of China (English)

    Aristeidis Nikolopoulos; Nikos Nikolopoulos; Nikos Varveris; Sotirios Karellas; Panagiotis Grammelis; Emmanuel Kakaras

    2012-01-01

    The aim of this paper is the development of new models and/or the improvement of existing numerical models,used for simulating granular flow in CFB (circulating fluidized bed) recirculation systems.Most recent models follow the TFM (two-fluid model) methodology,but they cannot effectively simulate the inter-particle friction forces in the recirculation system,because the respective stress tensor does not incorporate compressibility of flow due to change of effective particle density.As a consequence,the induced normal and shear stresses are not modeled appropriately during the flow of the granular phase in the CFB recirculation system.The failure of conventional models,such as that of von Mises/Coulomb,is mainly caused by false approximation of the yield criterion which is not applicable to the CFB recirculation system.The present work adopts an alternative yield function,used for the first time in TFM Eulerian modeling.The proposed model is based on the Pitman-Schaeffer-Gray-Stiles yield criterion.Both the temporal deformation of the solid granular phase and the repose angle that the granular phase forms are more accurately simulated by this model.The numerical results of the proposed model agree well with experimental data,implying that frictional forces are efficiently simulated by the new model.

  2. Experimental Bleaching of a Reef-Building Coral Using a Simplified Recirculating Laboratory Exposure System

    Science.gov (United States)

    Determining stressor-response relationships in reef building corals is a critical need for researchers because of global declines in coral reef ecosystems. A simplified recirculating coral exposure system for laboratory testing of a diversity of species and morphologies of reef b...

  3. Observations on side-swimming rainbow trout Oncorhynchus mykiss in water recirculation aquaculture systems

    Science.gov (United States)

    During a controlled 6-month study using six replicated water recirculation aquaculture systems (WRAS), it was observed that rainbow trout Oncorhynchus mykiss in all WRAS exhibited a higher-than-normal prevalence of side-swimming (i.e. controlled, forward swimming, but with misaligned orientation suc...

  4. Solids removal from a coldwater recirculating system - comparison of swirl separator and radial-flow settlers

    Science.gov (United States)

    Solids removal across two settling devices, i.e., a swirl separator and a radial-flow settler, and across a microscreen drum filter was evaluated in a fully recirculating system containing a single 150 m3 'Cornell-type' dual-drain tank during the production of food-size Arctic char and rainbow trout...

  5. Disinfection of water in recirculating aquaculture systems with peracetic acid (PAA)

    Science.gov (United States)

    The disinfection behaviour of peracetic acid (PAA) in recirculating aquaculture systems (RAS) was investigated. Peracetic acid is a strong oxidizing agent found in various concentrations in different products. Three Wofasteril PAA products (E400 (c), Lspecical; AC 150) were tested in vitro for the...

  6. Geosmin causes off-flavour in arctic charr in recirculating aquaculture systems

    Science.gov (United States)

    The “earthy” and “muddy” off-flavors in pond-reared fish are due to the presence of geosmin or 2-methylisoborneol (MIB) in the flesh of the fish. Similar off-flavors have been reported in fish raised in recirculating aquaculture systems (RAS); however, little information is available regarding the ...

  7. Low-head recirculating aquaculture system for juvenile red drum production

    Science.gov (United States)

    The USDA Agricultural Research Service and the Center for Aquaculture and Stock Enhancement at Harbor Branch Oceanographic Institute-FAU (HBOI-FAU) are collaborating to evaluate low-head recirculating aquaculture system designs to intensively produce red drum juveniles as part of the Florida Fish an...

  8. Theoretical Insight of Physical Adsorption for a Single-Component Adsorbent + Adsorbate System: I. Thermodynamic Property Surfaces

    KAUST Repository

    Chakraborty, Anutosh

    2009-02-17

    Thermodynamic property surfaces for a single-component adsorbent + adsorbate system are derived and developed from the viewpoint of classical thermodynamics, thermodynamic requirements of chemical equilibrium, Gibbs law, and Maxwell relations. They enable us to compute the entropy and enthalpy of the adsorbed phase, the isosteric heat of adsorption, specific heat capacity, and the adsorbed phase volume thoroughly. These equations are very simple and easy to handle for calculating the energetic performances of any adsorption system. We have shown here that the derived thermodynamic formulations fill up the information gap with respect to the state of adsorbed phase to dispel the confusion as to what is the actual state of the adsorbed phase. We have also discussed and established the temperature-entropy diagrams of (i) CaCl 2-in-silica gel + water system for cooling applications, and (ii) activated carbon (Maxsorb III) + methane system for gas storage. © Copyright 2009 American Chemical Society.

  9. A Comparative Analysis of Three Biofilter Types Treating Wastewater Produced in Recirculating Aquaculture Systems

    OpenAIRE

    Hall, Antar Gamble

    1999-01-01

    Nine recirculating systems at the Virginia Tech Aquaculture Center were placed on line and stocked with yellow perch, Perca flavescens, fingerlings. Fish were stocked at a density of approximately 455 fish m-3. Biofilter types were the only factor differing among system designs and were an upflow pulsed bed bead filter, packed tower trickling filter and a rotating biological contactor (RBC). After stocking, systems were allowed to acclimate using ammonia excreted by the yellow perch. Foll...

  10. A COMPARATIVE ANALYSIS OF THREE BIOFILTER TYPES TREATING WASTEWATER PRODUCED IN RECIRCULATING AQUACULTURE SYSTEMS

    OpenAIRE

    Hall, Antar Gamble

    2000-01-01

    Nine recirculating systems at the Virginia Tech Aquaculture Center were placed on line and stocked with yellow perch, Perca flavescens, fingerlings. Fish were stocked at a density of approximately 455 fish m-3. Biofilter types were the only factor differing among system designs and were an upflow pulsed bed bead filter, packed tower trickling filter and a rotating biological contactor (RBC). After stocking, systems were allowed to acclimate using ammonia excreted by the yellow perch. Foll...

  11. Water chemistry characterization and component performance of a recirculating aquaculture system producing hybrid striped bass

    OpenAIRE

    Easter, Christopher

    1992-01-01

    Eight identical and independent pilot scale recirculating aquaculture production systems were populated with fingerling hybrid striped bass (Morone chrysops female x Morone saxatilis male). Three population densities were established with two replicates at 132 fishlm3 and three replicates each at 66 and 33 fishlm3. Water chemistry and water quality characteristics were monitored throughout the 228 day growth trial for all eight systems. A system component performance analys...

  12. Daily micro particle distribution of an experimental recirculating aquaculture system – A case study

    DEFF Research Database (Denmark)

    Fernandes, Paulo; Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg

    2014-01-01

    The particle size distribution (PSD) in a recirculating aquaculture system (RAS) was investigated duringa 24-h cycle. PSD was analyzed in water sampled at several locations in a recirculation loop containing a60-m drum filter, a submerged fixed-bed biofilter and a trickling filter.In relation to...... total counts, the system was dominated by micro-particles with particles smaller than20 m comprising >94% of the distribution in all samples. However, the system presented a substantialvolumetric influence of larger particles, reflected by a PSD derivate ˇ-value of 3.40 ± 0.18. Overall ˇ......-valuesthroughout the compartments (p = 0.584) and experimental period (p = 0.217) were not significantlydifferent, although specific components seemed to marginally affect the PSD.A high internal water turnover rate (one system passage every 50 min) promoted the rapid removalof large particles from the system...

  13. A ZigBee Wireless Sensor Network for Monitoring an Aquaculture Recirculating System

    OpenAIRE

    Francisco J. Espinosa-Faller; Guillermo E. Rendón-Rodríguez

    2012-01-01

    A ZigBee wireless sensor network was developed for monitoring an experimental aquaculture recirculating system.Temperature, dissolved oxygen, water and air pressure as well as electric current sensors were included in the setup.The high fish densities required in these systems to become economically viable present a case where sensornetworks can be applied to preserve a healthy livestock and to reduce the risk of failures that end up in the loss ofproduction. Modules for reading and transmitt...

  14. Probiotic effects on cobia Rachycentron canadum larvae reared in a recirculating aquaculture system

    OpenAIRE

    M. Angélica Garrido-Pereira; Michael Schwarz; Brendan Delbos; Ricardo V. Rodrigues; Luis Romano; Luís Sampaio

    2014-01-01

    Cobia (Rachycentron canadum) is a marine finfish with good potential for mariculture. This study analyzes the effects of probiotic Bacillus spp. on the performance of cobia larvae reared in a recirculating aquaculture system (RAS). Larvae were stocked into two independent RAS for 26 days after hatching. One of the systems (Probiotic treatment) received the addition of a commercial probiotic consisting of B. subtilis, B. licheniformis and B. pumilus directly into the water and by live feed. Su...

  15. Water quality in recirculating aquaculture systems (ras) for arctic charr (salvelinus alpinus L.) culture.

    OpenAIRE

    Isla Molleda , M.

    2008-01-01

    Recirculating aquaculture systems (RAS) for fish culture have been used for more than three decades. The interest in RAS is due to their have advantages such as greatly reduced land and water requirements in places where the water resources are limited; but the RAS have also disadvantages like the deterioration of the water quality if the water treatment processes within the system are not controlled properly. The water quality problems in RAS were associated with low DO and high fish waste m...

  16. Purification Performance and Production of a Re-circulating Pond Aquaculture System Based on Paddy Field

    OpenAIRE

    Gu Li; Shi-yang Zhang; Ling Tao; Xiao-li Li; Jing-hua Song; Chun-xue Zhang; Jian-qiang Zhu

    2012-01-01

    Developing improved aquaculture systems with a more efficient use of water and less environmental impact is becoming a crying need. A re-circulating aquaculture system consisting of paddy field and fish pond is a new culture mode due to aquaculture combing with agriculture. The present study focused on the purification capacity of the paddy field on nitrogen, phosphorus and organic matter, the fluctuation trend of water quality conditions during the whole rearing process and the culture effic...

  17. New developments in recirculating aquaculture systems in Europe: A perspective on environmental sustainability

    OpenAIRE

    Martins, C. I. M.; Eding, E.H.; Verdegem, M.C.J.; Heinsbroek, L.T.N.; Schneider, O.(Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland); Blancheton, Jean-Paul; Roque d'Orbcastel, Emmanuelle; Verreth, J.A.J.

    2010-01-01

    The dual objective of sustainable aquaculture, i.e., to produce food while sustaining natural resources is achieved only when production systems with a minimum ecological impact are used. Recirculating aquaculture systems (RASs) provide opportunities to reduce water usage and to improve waste management and nutrient recycling. RAS makes intensive fish production compatible with environmental sustainability. This review aims to summarize the most recent developments within RAS that have contri...

  18. A ZigBee Wireless Sensor Network for Monitoring an Aquaculture Recirculating System

    Directory of Open Access Journals (Sweden)

    Francisco J. Espinosa-Faller

    2012-06-01

    Full Text Available A ZigBee wireless sensor network was developed for monitoring an experimental aquaculture recirculating system.Temperature, dissolved oxygen, water and air pressure as well as electric current sensors were included in the setup.The high fish densities required in these systems to become economically viable present a case where sensornetworks can be applied to preserve a healthy livestock and to reduce the risk of failures that end up in the loss ofproduction. Modules for reading and transmitting sensor values through a ZigBee wireless network were developedand tested. The modules were installed in an aquaculture recirculating system to transmit sensor values to thenetwork coordinator. A monitoring program was created in order to display and store sensor values and to comparethem with reference limits. An alert is emitted in case reference limits have been reached. E-mail and an SMSmessage alert can also be sent to the cellular phone of the system administrator, so immediate action can be taken. Aweb interface allows Internet access to the sensor values. The present work demonstrates the applicability of ZigBeewireless sensor network technology to aquaculture recirculating systems.

  19. The potential use of constructed wetlands in a recirculating aquaculture system for shrimp culture

    International Nuclear Information System (INIS)

    Constructed wetlands improved water qualities and consequently increased the shrimp growth and survival in a recirculating system. - A pilot-scale constructed wetland unit, consisting of free water surface (FWS) and subsurface flow (SF) constructed wetlands arranged in series, was integrated into an outdoor recirculating aquaculture system (RAS) for culturing Pacific white shrimp (Litopenaeus vannamei). This study evaluated the performance of the wetland unit in treating the recirculating wastewater and examined the effect of improvement in water quality of the culture tank on the growth and survival of shrimp postlarvae. During an 80-day culture period, the wetland unit operated at a mean hydraulic loading rate of 0.3 m/day and effectively reduced the influent concentrations of 5-day biochemical oxygen demand (BOD5, 24%), suspended solids (SS, 71%), chlorophyll a (chl-a, 88%), total ammonium (TAN, 57%), nitrite nitrogen (NO2-N, 90%) and nitrate nitrogen (NO3-N, 68%). Phosphate (PO4-P) reduction was the least efficient (5.4%). The concentrations of SS, Chl-a, turbidity and NO3-N in the culture tank water in RAS were significantly (P≤0.05) lower than those in a control aquaculture system (CAS) that simulated static pond culture without wetland treatment. However, no significant difference (P≤0.05) in BOD5, TAN and NO2-N was found between the two systems. At the end of the study, the harvest results showed that shrimp weight and survival rate in the RAS (3.8±1.8 g/shrimp and 90%) significantly (P≤0.01) exceeded those in the CAS (2.3±1.5 g/shrimp and 71%). This study concludes that constructed wetlands can improve the water quality and provide a good culture environment, consequently increasing the shrimp growth and survival without water exchange, in a recirculating system

  20. The potential use of constructed wetlands in a recirculating aquaculture system for shrimp culture

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y.-F.; Jing, S.-R.; Lee, D.-Y

    2003-05-01

    Constructed wetlands improved water qualities and consequently increased the shrimp growth and survival in a recirculating system. - A pilot-scale constructed wetland unit, consisting of free water surface (FWS) and subsurface flow (SF) constructed wetlands arranged in series, was integrated into an outdoor recirculating aquaculture system (RAS) for culturing Pacific white shrimp (Litopenaeus vannamei). This study evaluated the performance of the wetland unit in treating the recirculating wastewater and examined the effect of improvement in water quality of the culture tank on the growth and survival of shrimp postlarvae. During an 80-day culture period, the wetland unit operated at a mean hydraulic loading rate of 0.3 m/day and effectively reduced the influent concentrations of 5-day biochemical oxygen demand (BOD{sub 5}, 24%), suspended solids (SS, 71%), chlorophyll a (chl-a, 88%), total ammonium (TAN, 57%), nitrite nitrogen (NO{sub 2}-N, 90%) and nitrate nitrogen (NO{sub 3}-N, 68%). Phosphate (PO{sub 4}-P) reduction was the least efficient (5.4%). The concentrations of SS, Chl-a, turbidity and NO{sub 3}-N in the culture tank water in RAS were significantly (P{<=}0.05) lower than those in a control aquaculture system (CAS) that simulated static pond culture without wetland treatment. However, no significant difference (P{<=}0.05) in BOD{sub 5}, TAN and NO{sub 2}-N was found between the two systems. At the end of the study, the harvest results showed that shrimp weight and survival rate in the RAS (3.8{+-}1.8 g/shrimp and 90%) significantly (P{<=}0.01) exceeded those in the CAS (2.3{+-}1.5 g/shrimp and 71%). This study concludes that constructed wetlands can improve the water quality and provide a good culture environment, consequently increasing the shrimp growth and survival without water exchange, in a recirculating system.

  1. Low-dose hydrogen peroxide application in closed recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Good, C.; Pedersen, Per Bovbjerg

    2012-01-01

    The aim of the present work was to simulate water treatment practices with hydrogen peroxide (HP) in recirculating aquaculture systems (RAS). Six identical 1,700-L pilot-scale RAS were divided into two experimental groups based on daily feed allocation and operated under constant conditions for a...... for RAS and contradict prevailing notions that HP cannot be used safely in RAS that employ biofiltration. The development of effective new HP treatment protocols for recirculating aquaculture could reduce the current dependence on formalin to improve water quality and control parasitic loads...... period of 3 months. The organic and nitrogenous loadings of the systems differed fourfold between the two groups and were achieved by predefined constant daily feed loads and constant additions of water. The fixed cumulative feed burden was 1.6 × 103 mg feed/L in the low-intensity RAS and 6.3 × 103 mg...

  2. Performance of an in-situ rotating biological contactor in a recirculating aquaculture system.

    Science.gov (United States)

    Marin, P; Donoso-Bravo, A; Campos, J L; Ruiz-Filippi, G; Chamy, R

    2011-01-01

    The start-up and activation of a nitrifying rotating biological contactor (RBC) and its performance inside a culture tank of rainbow trout were studied. First, in a lab-scale operation, the system was fed with a synthetic medium containing a high ammonia concentration (567 mg NH(4)(+)-N L(-1)) and operated at a high hydraulic retention time (HRT) (6.5 days) to minimize the wash-out of the biomass and promote the biofilm formation. Then, both inlet ammonia concentration and HRT were decreased in order to obtain operational conditions similar to those of the culture tank. During this period, the RBC was able to treat an ammonia loading rate (ALR) of 0.64 g N-NH(4)(+) L(-1) d(-1) with a removal efficiency within 70-100%. Pilot-scale experiments were carried out in culture tanks of rainbow trout. The operation of a recirculating system with the RBC unit was compared with a recirculating system without biological treatment and with a flow-through system. The use of this in-situ nitrifying unit allowed working at a recirculation ratio of 90% without negative effects on either growth or the condition factor of fishes. Up to 70% of ammonia generated was removed and a removal rate of 1.41 g NH(4)(+)-N m(-2) d(-1) was reached. PMID:22156125

  3. Foam fractionation efficiency of a vacuum airlift—Application to particulate matter removal in recirculating systems

    OpenAIRE

    Barrut, Bertrand; Blancheton, Jean-Paul; Callier, Myriam; Champagne, Jean-yves; Grasmick, Alain

    2013-01-01

    The accumulation of particulate organic matter (POM) in recirculating aquaculture systems (RAS) has become an important issue with the intensification of finfish production. The objective of this study was to assess the foam fractionation efficiency of a vacuum airlift in different conditions (POM concentrations, airflow rates, bubble sizes, water renewal rates and feed addition). In sea water, the vacuum airlift allowed removing 20% of the initial POM concentration per hour (foam fractionati...

  4. Experimental Bleaching of a Reef-Building Coral Using a Simplified Recirculating Laboratory Exposure System

    OpenAIRE

    Mace G. Barron; Cheryl J. McGill; Lee A. Courtney; Marcovich, Dragoslav T

    2010-01-01

    Determining stressor-response relationships in reef building corals continues to be a critical research need due to global declines in coral reef ecosystems and projected declines for the future. A simplified recirculating coral exposure system was coupled to a solar simulator to allow laboratory testing of a diversity of species and morphologies of reef building corals under ecologically relevant conditions of temperature and solar radiation. Combinations of lamps and attenuating filters al...

  5. Observations on Side-Swimming Rainbow Trout in Water Recirculation Aquaculture Systems

    OpenAIRE

    Good, Christopher; Davidson, John; Kinman, Christin; Kenney, P. Brett; Bæverfjord, Grete; Summerfelt, Steven

    2014-01-01

    Abstract During a controlled 6-month study using six replicated water recirculation aquaculture systems (WRASs), it was observed that Rainbow Trout Oncorhynchus mykiss in all WRASs exhibited a higher-than-normal prevalence of side swimming (i.e., controlled, forward swimming but with misaligned orientation such that the fish's sagittal axis is approximately parallel to the horizontal plane). To further our understanding of this abnormality, a substudy was conducted wherein side swimmers and n...

  6. Identification and quantification of suspended solids and their effects in modern marine recirculation systems

    OpenAIRE

    Orellana, Jaime

    2007-01-01

    Die effiziente Entfernung von im Wasser suspendierten, partikulären Feststoffen ist ein Schlüsselfaktor für den erfolgreichen Betrieb von Kreislaufanlagen. In der vorliegenden Arbeit wurden die Feststoffe in einem Kreislaufsystem (Recirculating Aquaculture System, RAS) für Fische (Wolfsbarsch, Dicentrarchus labrax) qualitativ und quantitativ analysiert, wobei insbesondere die Größenverteilung der Feststoffe und die Rückhaltung in den mechanischen Filtereinheiten. Die Untersuchungen dienten de...

  7. Denitrification of Recirculating Aquaculture System Waters Using an Upflow Biofilter and a Fermented Substrate

    OpenAIRE

    Phillips, Jennifer Brooke

    1997-01-01

    The ability of an upflow, denitrifying biofilter using a fermentation generated carbon source to treat the high nitrate concentrations typically seen in recirculating aquaculture systems was studied using a synthetic nitrate wastewater supplied at two nitrate loadings, 1.13 and 2.52 kg NO3-N/m3/day. A supplemental carbon source was provided primarily through the fermentation of fish food which generated volatile fatty acids (VFA) in the form of acetic, propionic, isobutyric, n-butyric, 2-me...

  8. Phylogenetic characterization of the heterotrophic bacterial communities inhabiting a marine recirculating aquaculture system

    OpenAIRE

    Michaud, L; Lo Giudice, A; Troussellier, Marc; Smedile, F; Bruni, V.; Blancheton, J. P.

    2009-01-01

    Aims: The aim of the present work was to characterize the heterotrophic bacterial community of a marine recirculating aquaculture system (RAS). Methods and Results: An experimental RAS was sampled for the rearing water (RW) and inside the biofilter. Samples were analysed for bacterial abundances, community structure and composition by using a combination of culture-dependent and -independent techniques. The most represented species detected among biofilter clones was Pseudomonas stutzeri, whi...

  9. Assessement of Growth Performances of Juvenile Sterlet Acipenser ruthenus Raised in a Recirculating Aquaculture System (RAS)

    OpenAIRE

    Mărioara Nicula; Zoltan-Tibor Szelei; Nicolae Pacala; Marian Bura; Eliza Simiz; Silvia Erina; Marian Hotea; Adela Marcu

    2015-01-01

    The study was conducted within the recirculating aquaculture system for sturgeon rearing in Herneacova village, Timis County, on a population of juvenile sterlet (Acipenser ruthenus) aged between 346-431 days. Specimens were housed in five round tanks (Ø=3 m, V=6 m3, h=100 cm) and fed with commercial extruded pellets (3 mm granulation, 48% CP, and 10% EE). Fish from each tank were individually weighed and measured once every two weeks. Bioproductive indices such body weight gain (BW), specifi...

  10. The technical development and application of a recirculating aquaculture respirometer system (RARS) for fish metabolism studies

    OpenAIRE

    Stiller, Kevin Torben

    2016-01-01

    In dieser Arbeit wurde ein Recirculating Aquaculture Respirometre System (RARS) technisch entwickelt und die Einsatzmöglichkeiten in verschiedenen metabolischen Studien an Fischen unter Einbeziehung der Futtermittelverwertung evaluiert. Kapitel 1 stellt das RARS und die eingebauten online Messgeräte vor. Die Funktionalität des RARS wurde durch einige Beispielmessungen an Regenbogenforellen (Oncorhynchus mykiss) und Steinbutt, (Scophthalmus maximus) gezeigt. Im Kapitel 2 wurden über 8 W...

  11. An economic analysis of the use of recirculating aquaculture systems in the production of Tilapia

    OpenAIRE

    Appiah-Kubi, Frank

    2012-01-01

    An economic analysis of tilapia production was conducted using a recirculating aquaculture system facility, situated at the Norwegian University of Life Science (UMB). The goals were; (1) to evaluate and estimate the operational cost involved and from this, estimate the breakeven cost, (2) identify and describe the constraints unique to the RAS, (3) to perform financial feasibility of a (hypothetical) scale-up production, and (4) to conduct sensitivity analysis on some variables to highlight ...

  12. Conditioning of broodstock of tiger grouper, Epinephelus fuscoguttatus, in a recirculating aquaculture system

    OpenAIRE

    Saleem Mustafa; Mohd. Hafizzie Hajini; Shigeharu Senoo; Annita Yong Seok Kian

    2015-01-01

    Closing the cycle of commercial species of fish in a recirculating aquaculture system is gaining importance for a number of practical advantages. Founder broodstock originating from the wild population is conditioned to live in hatchery tanks under suitable environmental and feeding conditions and is induced to breed. The juveniles are grown to maturity and facilitated to spawn in captivity to close the life cycle in the hatchery. This experiment was carried out on tiger grouper (Epinephelus ...

  13. Integrated exhaust gas recirculation and charge cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Ko-Jen

    2013-12-10

    An intake system for an internal combustion engine comprises an exhaust driven turbocharger configured to deliver compressed intake charge, comprising exhaust gas from the exhaust system and ambient air, through an intake charge conduit and to cylinders of the internal combustion engine. An intake charge cooler is in fluid communication with the intake charge conduit. A cooling system, independent of the cooling system for the internal combustion engine, is in fluid communication with the intake charge cooler through a cooling system conduit. A coolant pump delivers a low temperature cooling medium from the cooling system to and through the intake charge cooler for the transfer of heat from the compressed intake charge thereto. A low temperature cooler receives the heated cooling medium through the cooling system conduit for the transfer or heat therefrom.

  14. Duckweed Lemna minor (Liliopsida, Lemnaceae as a natural biofilter in brackish and fresh closed recirculating systems

    Directory of Open Access Journals (Sweden)

    Tharwat S. Nashashibi

    2012-12-01

    Full Text Available This study attempted to assess the potential use of common duckweed Lemna minor asnatural biofilter in brackish closed recirculating systems of 4 g/L salinity and to evaluate the effect ofsalinities in the ranges of 1-7 g L-1 on the duckweed’s ammonium NH4 +1uptake. Furthermore thepossibility of nitrification as a second mechanism of nitrogen removal in closed recirculating systems wasinvestigated. Three closed recirculating systems each having 20 mixed Oreochromis niloticus were used.Duckweed L. minor and fresh water were added in system 1, fresh water only in system 2, and duckweedwith brackish water in system 3. Ammonium NH4 +1and nitrate NO3-1 were tested periodically in eachsystem during a 1.5 month period. Another three experiments were run in parallel using aquariumsincubated with 60.00 g fresh weight L. minor at salinities in the ranges of 1-7 g L-1 for two weeks.Aquariums were exposed directly to sunlight in experiment 1 and 3, and were placed in the dark inexperiment 2. The nitrogen source in experiment 1 and 2 was 100 mg L-1 of NH4Cl, and 280 mg L-1 ofNH4Cl in experiment 3. NH4 +1and NO3-1 levels were monitored as above. L. minor managed to reduce theaverage NH4 +1levels to 0.5 mg L-1, 0.43 mg L-1below the standard recommended levels in both brackishand fresh water systems, respectively. Ammonium NH4 +1 uptake was coupled with nitrate NO3-1 uptakeunder favorable conditions of sunlight. Salinity in the ranges from 1-7 g L-1 enhanced ammonium NH4 +1uptake (r = 0.8819, p = 0.023 without affecting nitrate NO3-1 uptake or any observed mortality of theduckweed. Nitrification was a second mechanism of nitrogen removal in a closed recirculating system,but it was affected by salinity and light. Average ammonium NH4 +1of 51.8 mg L-1 was toxic to L. minorand death was observed within a week in experiment 3. The duckweed L. minor was an efficient naturalbiofilter in both brackish and fresh water closed recirculating systems.

  15. Advanced Horizontal Well Recirculation Systems for Geothermal Energy Recovery in Sedimentary and Crystalline Formations

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, Mike S. [Terralog Technologies USA, Inc., Calgary (Canada); Detwiler, Russell L. [Terralog Technologies USA, Inc., Calgary (Canada); Lao, Kang [Terralog Technologies USA, Inc., Calgary (Canada); Serajian, Vahid [Terralog Technologies USA, Inc., Calgary (Canada); Elkhoury, Jean [Terralog Technologies USA, Inc., Calgary (Canada); Diessl, Julia [Terralog Technologies USA, Inc., Calgary (Canada); White, Nicky [Terralog Technologies USA, Inc., Calgary (Canada)

    2012-12-13

    There is increased recognition that geothermal energy resources are more widespread than previously thought, with potential for providing a significant amount of sustainable clean energy worldwide. Recent advances in drilling, completion, and production technology from the oil and gas industry can now be applied to unlock vast new geothermal resources, with some estimates for potential electricity generation from geothermal energy now on the order of 2 million megawatts. The primary objectives of this DOE research effort are to develop and document optimum design configurations and operating practices to produce geothermal power from hot permeable sedimentary and crystalline formations using advanced horizontal well recirculation systems. During Phase I of this research project Terralog Technologies USA and The University of California, Irvine (UCI), have completed preliminary investigations and documentation of advanced design concepts for paired horizontal well recirculation systems, optimally configured for geothermal energy recovery in permeable sedimentary and crystalline formations of varying structure and material properties. We have also identified significant geologic resources appropriate for application of such technology. The main challenge for such recirculation systems is to optimize both the design configuration and the operating practices for cost-effective geothermal energy recovery. These will be strongly influenced by sedimentary formation properties, including thickness and dip, temperature, thermal conductivity, heat capacity, permeability, and porosity; and by working fluid properties.

  16. STUDIES REGARDING THE PRESENCE OF THE PATHOGENS BACTERIA INTO A RECIRCULATING SYSTEM OF BELUGA STURGEON INTENSIVE REARING

    Directory of Open Access Journals (Sweden)

    ANGELICA DOCAN

    2013-12-01

    Full Text Available Recirculating aquaculture offers good potential for successful fish farming since is often independent of environmental conditions. Maintaining healthy fish in a recirculating system involves establishing adequate dissolved oxygen levels, removal of solid wastes, and sufficient ammonia nitrification to assure optimal rearing conditions. Neglecting these, the fish immune system will depress, the facultative pathogen germs will be able to provoke important disease outbreaks into cultured biomass, as was happened in our recirculating pilot system. In this study are presented the pathological aspects registered to the beluga sturgeon of 1 year, reared into our recirculating pilot system, pathological aspects generated by a haemorrhagic bacterial septicaemia which was manifested in the conditions of low concentrations of DO. The disease was diagnosed to the affected fish through anatomopathological and clinical exam, haematological exam and microbiological exam.

  17. Microbial communities of recirculating aquaculture facilities: interaction between heterotrophic and autotrophic bacteria and the system itself

    OpenAIRE

    Michaud, Luigi

    2007-01-01

    Les systèmes d'aquaculture en circuit recirculé (Recirculating Aquaculture Systems, RAS) peuvent être considérés comme une alternative à la technologie de l'aquaculture en milieu ouvert et en bassins (en consommant moins d'eau pour un même rendement de production) ou peuvent être intégrés dans une chaîne de production avec des systèmes d'enclos en filet. L'intérêt des RAS est dû à leurs avantages intrinsèques comme la réduction des besoins en surface et en eau, le haut niveau de contrôle e...

  18. STUDIES REGARDING THE PRESENCE OF THE PATHOGENS BACTERIA INTO A RECIRCULATING SYSTEM OF BELUGA STURGEON INTENSIVE REARING

    OpenAIRE

    ANGELICA DOCAN; IULIA GRECU; LORENA SFETCU; I. VASILEAN; Cristea, V.

    2013-01-01

    Recirculating aquaculture offers good potential for successful fish farming since is often independent of environmental conditions. Maintaining healthy fish in a recirculating system involves establishing adequate dissolved oxygen levels, removal of solid wastes, and sufficient ammonia nitrification to assure optimal rearing conditions. Neglecting these, the fish immune system will depress, the facultative pathogen germs will be able to provoke important disease outbreaks into cultured biomas...

  19. Internal dust recirculation system for a fluidized bed heat exchanger

    Science.gov (United States)

    Gamble, Robert L.; Garcia-Mallol, Juan A.

    1981-01-01

    A fluidized bed heat exchanger in which air is passed through a bed of particulate material containing fuel disposed in a housing. A steam/water natural circulation system is provided in a heat exchange relation to the bed and includes a steam drum disposed adjacent the bed and a tube bank extending between the steam drum and a water drum. The tube bank is located in the path of the effluent gases exiting from the bed and a baffle system is provided to separate the solid particulate matter from the effluent gases. The particulate matter is collected and injected back into the fluidized bed.

  20. Intensive larval rearing of Macrobrachium rosenbergii in recirculating system

    OpenAIRE

    AQUACOP

    1983-01-01

    Growing ponds for the freshwater prawn Macrobrachium rosenbergii are most of the time far from the seat and good quality fresh or sea water may also be in short supply seasonally. With an open system with water exchange every day the hatcheries have to be located near the sea whereas closed systems allow to set free from environmeneal conditions, and have been developed in Tahiti (Centre Océanologique du Pacifique) in collaboration with the ORERO (Office de la Recherche et de l'Exploitation d...

  1. Development of high temperature adsorbent in PWR primary system

    International Nuclear Information System (INIS)

    Radiation exposure reduction in PWR is one of the most important problems to be solved. We have developed a high temperature Co adsorbent (HTA), which could be directly applied under primary reactor coolant conditions. This adsorbent was Fe-Ti-O system ceramics, and was fabricated to a suitable form for using in a packed column. Through those experiments of adsorption tests, compatibility tests, leaching tests and hot loop tests, it was found that HTA had superior adsorption capability to not only Co and Ni-ion but also many other transition metal ions. And it was also found that HTA was compatible with high temperature water, as well as advantageous for its waste solidification. Based on the experimental results, dose reduction effect was evaluated by a computer code. From this evaluation, it was found that more than 50 % dose reduction could be expected, when an advanced reactor coolant clean-up (RCC) system with HTA would be realized. (author)

  2. Reliability analysis of air recirculation and-refrigeration systems of Angra-1 reactor containment

    International Nuclear Information System (INIS)

    A reliability analysis of the air refrigeration and recirculation containment systems (ARRCS) of Angra-1 nuclear power plants, were done. The fault tree analysis was used. The failure primary data were taken out of Wash-1400 and IEEE. These data were processed by these following computer codes : Prep-Kitt, Sample, Trebil, Cressex and Streusl for the two stages of ARRCS operation. The design bases accident studied was a LOCA (loss of coolant). The component that more contribution give to the non-availability of ARRCS is the motor of the ARRCS. (E.G.)

  3. Mathematical modelling of nutrient balance of a goldfish (Carassius auratus Linn.) recirculating aquaculture system (GRAS)

    OpenAIRE

    Sudeep Puthravilakom Sadasivan Nair; Sanjib Moulick; Chanchal Kumar Mukherjee; Mohd Tanveer

    2010-01-01

    In the present study, a goldfish (Carassius auratus Linn.) recirculating aquaculture system (GRAS) has been developed. The GRAS consisted of a culture tank, a screen filter and a foam fractionator for removal of particulate and dissolved solids and a trickling filter for conversion of ammonium- and nitrite-nitrogen to relatively harmless nitrate-nitrogen. The culture of goldfish at a stocking density of 1.08 kg/m3 was continued for a period of two and half months. Based on mass balance analys...

  4. The influence of pellets quality on the growth of sterlet, in recirculating aquaculture system

    OpenAIRE

    Corina Sion; Petronela G. Călin; Lucian Oprea; Aurelia Nica; Gianina M. Băcanu

    2011-01-01

    The paper presents some aspects regarding the influence of food quality on the breeding of sterlet, Acipenser ruthenus Linnaeus, 1758, in a recirculating aquaculture system (RAS). The experiment took place over 30 days, in four pilot breeding units type aquaria of 300 liters in volume. Two kind of variants were compared, with repetition, V1 with 46% crude protein and V2 with 30% crude protein, respectively. The stocking density was of 14 fish/unit. The same feeding level of 8 g/kg metabolic w...

  5. Nitrification in brackish water recirculating aquaculture system integrated with activated packed bed bioreactor.

    Science.gov (United States)

    Rejish Kumar, V J; Joseph, Valsamma; Philip, Rosamma; Bright Singh, I S

    2010-01-01

    Recirculation aquaculture systems (RAS) depend on nitrifying biofilters for the maintenance of water quality, increased biosecurity and environmental sustainability. To satisfy these requirements a packed bed bioreactor (PBBR) activated with indigenous nitrifying bacterial consortia has been developed and commercialized for operation under different salinities for instant nitrification in shrimp and prawn hatchery systems. In the present study the nitrification efficiency of the bioreactor was tested in a laboratory level recirculating aquaculture system for the rearing of Penaeus monodon for a period of two months under higher feeding rates and no water exchange. Rapid setting up of nitrification was observed during the operation, as the volumetric total ammonia nitrogen removal rates (VTR) increased with total ammonia nitrogen (TAN) production in the system. The average Volumetric TAN Removal Rates (VTR) at the feeding rate of 160 g/day from 54-60th days of culture was 0.1533+/-0.0045 kg TAN/m(3)/day. The regression between VTR and TAN explained 86% variability in VTR (P<0.001). The laboratory level RAS demonstrated here showed high performance both in terms of shrimp biomass yield and nitrification and environmental quality maintenance. Fluorescent in-situ Hybridization analysis of the reactor biofilm ensured the presence of autotrophic nitrifier groups such as Nitrosococcus mobilis lineage, Nitrobacter spp and phylum Nitrospira, the constituent members present in the original consortia used for activating the reactors. This showed the stability of the consortia on long term operation. PMID:20150717

  6. The potential use of constructed wetlands in a recirculating aquaculture system for shrimp culture.

    Science.gov (United States)

    Lin, Ying-Feng; Jing, Shuh-Ren; Lee, Der-Yuan

    2003-01-01

    A pilot-scale constructed wetland unit, consisting of free water surface (FWS) and subsurface flow (SF) constructed wetlands arranged in series, was integrated into an outdoor recirculating aquaculture system (RAS) for culturing Pacific white shrimp (Litopenaeus vannamei). This study evaluated the performance of the wetland unit in treating the recirculating wastewater and examined the effect of improvement in water quality of the culture tank on the growth and survival of shrimp postlarvae. During an 80-day culture period, the wetland unit operated at a mean hydraulic loading rate of 0.3 m/day and effectively reduced the influent concentrations of 5-day biochemical oxygen demand (BOD5, 24%), suspended solids (SS, 71%), chlorophyll a (chl-a, 88%), total ammonium (TAN, 57%), nitrite nitrogen (NO2-N, 90%) and nitrate nitrogen (NO3-N, 68%). Phosphate (PO4-P) reduction was the least efficient (5.4%). The concentrations of SS, Chl-a, turbidity and NO3-N in the culture tank water in RAS were significantly (Paquaculture system (CAS) that simulated static pond culture without wetland treatment. However, no significant difference (Psystems. At the end of the study, the harvest results showed that shrimp weight and survival rate in the RAS (3.8 +/-1.8 g/shrimp and 90%) significantly (Precirculating system. PMID:12663210

  7. 2-Methylisoborneol and geosmin uptake by organic sludge derived from a recirculating aquaculture system.

    Science.gov (United States)

    Guttman, Lior; van Rijn, Jaap

    2009-02-01

    In a previous study on a recirculating fish culture system, levels of geosmin and 2-methylisoborneol were found to decrease when culture water was recirculated through the anaerobic sludge digestion treatment stage of the system. This finding led us to the present study in which the geosmin and 2-methylisoborneol removal capacity of the sludge derived from this treatment stage was examined in vitro. It was found that reduction of off-flavor compounds by the sludge was mediated by both chemical/physical sorption and biological degradation. At geosmin and 2-methylisoborneol concentrations within the range of those experienced in fish culture systems, chemical/physical sorption by the sludge was found to account for a 93% reduction in geosmin and a 79% reduction in 2-methylisoborneol from the overlying water within 48h of incubation. Combined with the biological degradation taking place in the sludge, a complete removal of these compounds from the water phase occurred within 9 days of incubation. By means of repeated washing of the geosmin and 2-methylisoborneol contaminate sludge with clean water, relatively small amounts of these compounds were released from the sludge, a possible indication for the fact that absorption, rather than adsorption, underlies the chemical/physical removal process. PMID:18986667

  8. Corrosion products, activity transport and deposition in boiling water reactor recirculation systems

    International Nuclear Information System (INIS)

    The deposition of activated corrosion products in the recirculation loops of Boiling Water Reactors produces increased radiation levels which lead to a corresponding increase in personnel radiation dose during shut down and maintenance. The major part of this dose rate is due to cobalt-60. The following areas are discussed in detail: - the origins of the corrosion products and of cobalt-59 in the reactor feedwaters, - the consolidation of the cobalt in the fuel pin deposits (activation), - the release and transport of cobalt-60, - the build-up of cobalt-60 in the corrosion products in the recirculation loops. Existing models of the build-up of circuit radioactivity are discussed and the operating experiences from selected reactors are summarised. Corrosion chemistry aspects of the cobalt build-up in the primary circuit have already been studied on a broad basis and are continuing to be researched in a number of centers. The crystal chemistry of chromium-nickel steel corrosion products poses a number of yet unanswered questions. There are major loopholes associated with the understanding of activation processes of cobalt deposited on the fuel pins and in the mass transfer of cobalt-60. For these processes, the most important influence stems from factors associated with colloid chemistry. Accumulation of data from different BWRs contributes little to the understanding of the activity build-up. However, there are examples that the problem of activity build-up can be kept under control. Although many details for a quantitative understanding are still missing, the most important correlations are visible. The activity build-up in the BWR recirculation systems cannot be kept low by a single measure. Rather a whole series of measures is necessary, which influences not only cobalt-60 deposition but also plant and operation costs. (author) 26 figs., 13 tabs., 90 refs

  9. MATHEMATICAL MODEL OF MECHANICAL SYSTEM WITH ROLLER-RECIRCULATING MECHANISM ON BASIS OF RAUSES EQUATIONS

    Directory of Open Access Journals (Sweden)

    I. O. Lapanovich

    2015-01-01

    Full Text Available Roller-recirculating mechanisms have found wide application in engineering. Design peculiarities of these mechanisms permit not only to transform one type of motion to another but also to control an actuator in the process of operational motions.  Analysis and synthesis of transitional processes of such system are possible only on the basis of correct dynamic and mathematical model. The paper of the paper is  to develop a mathematical model of roller-recirculating  mechanisms transforming a rotary motion to a reciprocating one. The dynamic model of the considered mechanism is  presented by the system of two generalized links of reduction, forming non-holonomic kinematics pair that admits two independent motions with two requirements of non-integrated connections. While formulating motion equations equations of non-holonomic mechanics in the form of Rauses equation have been used. The Rauses equation is a combination of Lagranzhs methods of generalized coordinates and indeterminate multipliers. As a result of it a mathematical model of the investigated object is obtained in the form of  two differential equations with variable factors.

  10. Assessement of Growth Performances of Juvenile Sterlet Acipenser ruthenus Raised in a Recirculating Aquaculture System (RAS

    Directory of Open Access Journals (Sweden)

    Mărioara Nicula

    2015-10-01

    Full Text Available The study was conducted within the recirculating aquaculture system for sturgeon rearing in Herneacova village, Timis County, on a population of juvenile sterlet (Acipenser ruthenus aged between 346-431 days. Specimens were housed in five round tanks (Ø=3 m, V=6 m3, h=100 cm and fed with commercial extruded pellets (3 mm granulation, 48% CP, and 10% EE. Fish from each tank were individually weighed and measured once every two weeks. Bioproductive indices such body weight gain (BW, specific growth rate (SGR, and feed conversion ratio (FCR were calculated at the end of an 85 days experimental period. Statistical analysis was performed using the SPPS IBM 22 and Minitab 16 software. Data were reported as Mean±Sx at a significant level of p<0.05. Testing differences between means was realized by ANOVA completed with post-hoc Tukey test. The results obtained indicate that the growth performance of juvenile Acipenser ruthenus seems to be similar and even better than that of other sturgeons species reared in recirculating aquaculture system.

  11. Determination of oxytetracycline residues in matrixes from a freshwater recirculating aquaculture system.

    Science.gov (United States)

    Carson, Mary C; Bullock, Graham; Bebak-Williams, Julie

    2002-01-01

    This paper describes related procedures to determine the amount of oxytetracycline (OTC) present in trout tissue (muscle with skin attached), biofilter sand, sediment, and tank water from a recirculating aquaculture system. OTC was extracted from the matrixes by different techniques, depending on complexity of the matrix and desired OTC detection level in that matrix. Listed in order of increasing complexity, OTC was extracted from tank water by dilution with acidic buffer containing ethylenediaminetetraacetic acid (EDTA); from biofilter sand by shaking with 0.1 N HCl; from sediment by homogenization and shaking with buffer/EDTA; and from ground trout by homogenization and shaking with buffer/EDTA (twice), with further cleanup and concentration of the extract on a polymeric solid-phase extraction cartridge. The 4 procedures all used the same reversed-phase gradient chromatography on a polymeric column with UV detection at 350 nm. The lower limit of detection (estimated) and upper limit of validation for each of these 4 matrixes were 0.04-4.0 microg/g (ppm; trout), 0.03-20 ppm (biofilter sand), 1-6000 ppm (sediment), and 0.003-10 ppm (water). Recoveries ranged from 82 to 108%, with relative standard deviation recirculating aquaculture system. PMID:11990017

  12. Performance of Nile tilapia Oreochromis niloticus fingerlings in a hyper-intensive recirculating aquaculture system with low water exchange

    OpenAIRE

    M Gullian-Klanian; C Arámburu-Adame

    2013-01-01

    The aim of this paper was evaluate the performance of Nile tilapia fingerlings (Oreochromis niloticus) raised at hyper intensive stocking density in a recirculating aquaculture system (RAS) with minimum water replacing. The experimental system was performed in a single-batch nursery system to obtain 50 g fish size in 60 days. Fish (2.07 ± 0.04 g) were stocked in triplicate at 400 (T1), 500 (T2) and 600 (T3) fish m-3 (0.84, 1.05, 1.22 kg m-3). RAS functioned with 12,000 L of recirculating wate...

  13. Continuous vapour adsorption cooling system with three adsorber beds

    International Nuclear Information System (INIS)

    In this paper, the design of a new solar operated adsorption cooling system with two identical small and one large adsorber beds, which is capable of producing cold continuously, has been proposed. In this system, cold energy is stored in the form of refrigerant in a separate refrigerant storage tank at ambient temperature. Silica gel–water is used as a working pair and system is driven by solar energy. The operating principle is described in details and its thermodynamic transient analysis is presented. Effect of COP and SCE for different adsorbent mass and adsorption/desorption time of smaller beds are discussed. Recommended mass and number of cycles of operation for smaller beds to attain continuous cooling with average COP and SCE of 0.63 and 337.5 kJ/kg, respectively are also discussed, at a generation, condenser and evaporator temperatures of 368 K, 303 K and 283 K, respectively. - Highlights: • A three-bed silica gel–water continuous adsorption cooling system is analyzed. • Cold energy is stored in the form of liquid refrigerant at ambient temperature. • The influence of mass of beds and cycle time on the system performance is discussed. • Sizing of the beds for a given cooling capacity is recommended

  14. Mathematical modelling of nutrient balance of a goldfish (Carassius auratus Linn. recirculating aquaculture system (GRAS

    Directory of Open Access Journals (Sweden)

    Sudeep Puthravilakom Sadasivan Nair

    2010-08-01

    Full Text Available In the present study, a goldfish (Carassius auratus Linn. recirculating aquaculture system (GRAS has been developed. The GRAS consisted of a culture tank, a screen filter and a foam fractionator for removal of particulate and dissolved solids and a trickling filter for conversion of ammonium- and nitrite-nitrogen to relatively harmless nitrate-nitrogen. The culture of goldfish at a stocking density of 1.08 kg/m3 was continued for a period of two and half months. Based on mass balance analysis of ammonium- and nitrate-nitrogen and assuming the trickling filter to be a plug flow reactor, a model was formulated to determine the necessary recirculation flow rate at different times of culture for maintaining the major nutrients, viz., ammonium- and nitrate-nitrogen below their permissible limits. The model was calibrated and validated using the real time data obtained from the experimental run. The high values of coefficient of determination and low values of root mean square error show the effectiveness of the model.

  15. Reliability problems in the recirculated cooling water system at Cernavoda NPP and corrective maintenance operations adopted

    International Nuclear Information System (INIS)

    Between February 18 and March 5, 2002 the Unit 1 of Cernavoda NPP was shutdown in an un-planned outage necessary to repair a crack on the piping of the Recirculated Cooling Water System. The large pipe diameter and the requirement of maintaining the system in operation during the outage, imposed a special technology for fixing the leak (isolation of the line with ice plugs). The paper presents information about the performed repair work. After repair operations the failed duct was checked by non-destructive methods and the results were submitted and approved by regulation authorities. The repair was considered successfully completed and the Unit restarted on March 5, 2002 at 0.57 am when the electric generator was switched on in parallel to the national electric power system. (authors)

  16. Reliability analysis of the recirculation phase of the safety injection system of Angra-1

    International Nuclear Information System (INIS)

    The calculation of several reliability parameters-failure probability, unavailability and unreliability - of the recirculation phase of the safety injection system of Angra-1, was done. This system has two distinct modes of operation (short term and long term) which were fault tree analysed both separately and as a whole. To obtain quantitative results the computer codes SAMPLE and PRET-KITT were utilized. The former was used to consider the uncertainties in the failure data (drawn integrally from WASH-1400) and the latter to obtain time dependent unreliability values. Hardware failures and common-mode failures were considered. Altough the analysis methods employed here differ somewhat from those used in WASH-1400, the results which could be compared were found to have the order of magnitude. A viability study of some suggestions of system's modifications was performed, and it has shown that some significant reliability improvements can be achieved with reasonably simple changes. (Author)

  17. Recirculating aquaculture system for high density production of the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Vu, Minh Thi Thuy; Øie, Gunvor; Reinertsen, Helge

    . Both RAS and FTAS (3 replicates per system) were set up in the same room to ensure the equal condition. The initial densities of copepods were 20000 nauplii L-1 for investigation of growth and development in the early phase and 5000 ind L-1 in the copepodite and adult stages for testing reproduction...... similar survival, growth, and reproduction, yet the nauplii developed into copepodites faster in RAS (110h) compared to FTAS (158h). This can be an indication for the potential for culturing or maintaining A. tonsa nauplii and early copepodite stages at higher densities before feeding larvae of marine...... fish larvae. Yet, the biomass and egg production of A. tonsa has been limited mainly due to the challanges to culture them at high density. The development of recirculating aquaculture system (RAS) in recent decades has opened a new culturing system that is expected to provide more stable environmental...

  18. Probiotic effects on cobia Rachycentron canadum larvae reared in a recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    M. Angélica Garrido-Pereira

    2014-11-01

    Full Text Available Cobia (Rachycentron canadum is a marine finfish with good potential for mariculture. This study analyzes the effects of probiotic Bacillus spp. on the performance of cobia larvae reared in a recirculating aquaculture system (RAS. Larvae were stocked into two independent RAS for 26 days after hatching. One of the systems (Probiotic treatment received the addition of a commercial probiotic consisting of B. subtilis, B. licheniformis and B. pumilus directly into the water and by live feed. Survival, final weight and water quality were not affected by probiotics. Results showed larvae of the probiotic treatment demonstrated a greater resistance to salinity stress. Immunohistochemical analysis showed a higher expression of CD4 in probiotic treatment. These results suggest that Bacillus spp. probiotics used in RAS have a potential stimulating impact on immune system differentiation and increases salinity stress resistance of cobia larvae.

  19. Association of mycobacteria in recirculating aquaculture systems and mycobacterial disease in fish.

    Science.gov (United States)

    Yanong, Roy P E; Pouder, Deborah B; Falkinham, Joseph O

    2010-12-01

    Mycobacterium marinum isolates cultivated from tissue containing granulomatous lesions in Florida pompano Trachinotus carolinus and from biofilm samples collected from their tank and water recirculating system had identical (L1 of 11 bands) repetitive-sequence-based polymerase chain reaction (rep-PCR) DNA fingerprints. A second M. marinum clone sharing 4 of 11 rep-PCR bands with the first clone was isolated from some fish tissues but not from system samples. Water samples yielded low numbers of colonies of mycobacteria (0.08-1.3/mL), but high numbers were recovered from biofilms (260-12,000/swab) and filters (63-21,000/ filter). Mycobacterium hemophilum, M. chelonae, M. trivale, M. gastri, and M. gordonae were isolated from system samples alone. PMID:21413504

  20. Characterization of Mycobacterium salmoniphilum as causal agent of mycobacteriosis in Atlantic salmon, Salmo salar L., from a freshwater recirculation system.

    Science.gov (United States)

    Aro, L; Correa, K; Martínez, A; Ildefonso, R; Yáñez, J M

    2014-04-01

    Thirty Atlantic salmon, Salmo salar L., with low corporal condition relative to other fish present in the culture system, were sampled from a freshwater recirculation pisciculture located in Chile. The most characteristic signs and lesions were cachexia and presence of multiple greyish-white granulomas within internal organs. The external and internal lesions, along with the microscopic, histologic and biochemical findings, were consistent with mycobacteriosis. The identification of Mycobacterium salmoniphilum as the causal agent of the lesions was possible through the use of molecular analyses. This study represents the first report of Mycobacterium salmoniphilum in a freshwater recirculation system and the first case of fish mycobacteriosis described in Chile. PMID:23952471

  1. Speeding up the synchronization of pseudorandom signals by a system comprising a convolver and a recirculation-type delay line

    Science.gov (United States)

    Kuzichkin, A. V.

    1983-10-01

    An algorithm is proposed for the multistage search for pseudorandom signals (PRSs) by a system comprising an acoustoelectronic convolver (AC) and a recirculation-type delay line (RDL). The algorithm is based on the dependence of the maximum output signal of the RDL on the time mismatch between the received PRS and the recirculation period. The noise immunity of the proposed algorithm is evaluated, and it is shown that the proposed AC-RDL system can speed up considerably the synchronization of long-duration PRSs.

  2. Development of adsorber system utilizing ocean current for uranium recovery from seawater

    International Nuclear Information System (INIS)

    Based on the concept of adsorber previously proposed by some of the present authors, a submarine adsorber system utilizing the energy of ocean current was proposed. In order to make the concept of adsorber practical, the system design was made by taking into account the support of equipment in the sea, the equipment structure, the packed bed of adsorbents, the mooring method and the replacement of adsorbents. An estimation equation of adsorber cost was derived for the present type of adsorber. The optimum dimensions of adsorber were determined under the restrictions such as the size of dock in a shipbuilding factory and the stability in towing and mooring the equipment. The calculated results suggested that the adsorber cost decreased by around 30 % under the optimum condition. And the transportation system of the adsorbent was investigated. In the case where a mother ship system was adopted, the transportation cost was 5,000 yen/ton-adsorbent. It was made clear that the total recovery cost of uranium from the seawater could be reduced to 140,000 yen/kg-U from 190,000 yen/kg-U based on the above consideration. It was also considered necessary to further improve the adsorption capacity of adsorbent in order to realize a sharp reduction in the recovery cost of uranium. (author)

  3. Degradation and effect of hydrogen peroxide in small-scale recirculation aquaculture system biofilters

    DEFF Research Database (Denmark)

    Møller, Martin Sune; Arvin, Erik; Pedersen, Lars-Flemming

    2010-01-01

    applied in different systems. In this study, we investigated the degradation kinetics of HP in biofilters from water recirculating aquaculture systems (RAS). The potential effect of HP on the nitrification process in the biofilters was also examined. Biofilter elements from two different pilot-scale RAS......−1 maintained over 3 h had a moderate inhibitory effect on the biofilter elements from one of the RAS with relatively high organic loading, while the nitrification was severely inhibited in the pilot-scale biofilters from the other RAS with a relatively low organic loading. A pilot-scale RAS......, equipped with two biofilter units, both a moving-bed (Biomedia) and a fixed-bed (BIO-BLOK®) biofilter, was subjected to an average HP concentration of ∼12 mg L−1 for 3 h. The ammonium- and nitrite-degrading efficiencies of both the Biomedia and the BIO-BLOK® filters were drastically reduced. The filters...

  4. Integrated fish-seaweed cultivation in recirculating aquaculture systems: objectives and preliminary results of "IntegRAS" project

    OpenAIRE

    Oca Baradad, Joan; Pintado Valverde, José; Cremades Ugarte, Javier; Masaló Llorà, Ingrid; Ruiz, Patricia; Alamrousi, A; Jiménez de Ridder, Patrícia; Machado, Samuel; Reig Puig, Lourdes

    2015-01-01

    Recirculating aquaculture systems (RAS) allow minimizing the water renewal flow rate needed in fish production by increased Nitrogen (NO3 ) and Phosphorous concentrations. Integrating seaweed production to RAS can improve its performances and reduce soluble wastes, contributing to a more sustainable production system.

  5. Purification Performance and Production of a Re-circulating Pond Aquaculture System Based on Paddy Field

    Directory of Open Access Journals (Sweden)

    Gu Li

    2012-10-01

    Full Text Available Developing improved aquaculture systems with a more efficient use of water and less environmental impact is becoming a crying need. A re-circulating aquaculture system consisting of paddy field and fish pond is a new culture mode due to aquaculture combing with agriculture. The present study focused on the purification capacity of the paddy field on nitrogen, phosphorus and organic matter, the fluctuation trend of water quality conditions during the whole rearing process and the culture efficacy of the main culture species of grass carp (Ctenopharyngodon idella. The results were as follows: under a flow rate of 1.4-5.5 m3/h for the recirculation treatment, the average removal rate of ammonia nitrogen, nitrate nitrogen, total nitrogen, total phosphorus and biochemical oxygen demand for the aquaculture effluent amounted to 40.5, 43.5, 31.9, 23.9, 20.7 and 52.4%, respectively, But the dissolved oxygen content in the rice fields increased obviously. During the whole process of fish rearing, the main physicochemical parameters of water quality for the experimental ponds were all maintained at a suitable level for the growth of the grass carp. In addition, there were significant differences (p<0.05 in DO, TSS, NH4+ -N, NO--N, BOD5 and Chl-&alpha between the experimental and control ponds. As far as the yield per unit and survival rate was concerned, the level of the experimental ponds was obviously higher than that of the control, while the feed conversion ratio displayed the opposite trend. Overall, the new aquaculture system realized the double aims of water reuse and the reduction of waste water discharge.

  6. Recent advances within intensive Recirculated Aquaculture System cultivation of the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Jepsen, Per Meyer; Højgaard, Jacob Kring; Drillet, Guillaume;

    2014-01-01

    interesting trait with the species is that the eggs can be provoked into a resting stage, where the egg can be stored for one year, similar to Artemia cysts. This is the most promising storage technique for distribution of copepod eggs to aquaculture facilities worldwide. The eggs can be hatched and the...... nauplii can be feed to marine fish larvae. A restriction is that copepod cultures for producing eggs are after 30 years of research still not stable and in large enough scale for bulk production of eggs. Recently a unique copepod Recirculated Aquaculture System (RAS) at Roskilde University (Denmark) was...... constructed as a part of the IMPAQ project “IMProvement of AQuaculture high quality fish fry production”. We present recent advance within RAS culture for copepods, and lesson learned from rearing the specie. Further we present physical and biological culture restrictions in terms of water quality (NH3...

  7. Broodstock management of the fine flounder Paralichthys adspersus (Steindachner, 1867) using recirculating aquaculture systems

    OpenAIRE

    Lili Carrera; Noemí Cota; Melissa Montes; Enrique Mateo; Verónica Sierralta; Teresa Castro; Angel Perea; Cristian Santos; Christian Catcoparco; Carlos Espinoza

    2013-01-01

    The present study describes the methodology used at IMARPE for the capture, acclimation and management of P. adspersus broodstock using recirculating aquaculture systems (RAS). RAS improved the water quality and maintained the environmental parameters during the acclimation period, temperature (17.2±1°C), oxygen (8.1±0.7 mg L-1), pH (7.3±0.2), ammonia (0.004±0.003 mg L-1), nitrite (0.52±0.2 mg L-1) and nitrate (3.45±2.6 mg L-1). Fish began to be fed normally from day 15 post-capture, once or ...

  8. Fate of water borne therapeutic agents and associated effects on nitrifying biofilters in recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming

    of these agents on biofilter nitrification performance. All experiments were conducted through addition of chemical additives to closed pilot scale recirculating aquaculture systems (RAS) with fixed media submerged biofilters under controlled operating conditions with rainbow trout (Oncorhynchus mykiss......) in a factorial design with true replicates. Biofilter nitrification performances were evaluated by changes in chemical processes, and nitrifying populations were identified by fluorescence in situ hybridisation (FISH) analysis. FA was degraded at a constant rate immediately after addition, and found......Recent discharge restrictions on antibiotics and chemotherapeutant residuals used in aquaculture have several implications to the aquaculture industry. Better management practices have to be adopted, and documentation and further knowledge of the chemical fate is required for proper administration...

  9. REARING EFFICIENCY AND NUTRITIONAL QUALITY ASSESSMENT FOR CARP SAPLING (CYPRINUS CARPIO LINNE, 1758 FROM RECIRCULATING SYSTEMS

    Directory of Open Access Journals (Sweden)

    ELPIDA PALTENEA

    2013-12-01

    Full Text Available Common carp, Cyprinus carpio L. of 8 months older, rearing in recirculation system during 107 days period - he has been analysed from the point of view of feeding efficiency and nutritional quality of carp carcass. The stocking of breeding ponds has been made at 12.17 kg/m3 density, the initial average weight of fishes has been 82.2 g/ex., biochemical composition of carp carcass has been following: protein 14.35%, fat 1.10%, ash 1.67% and moisture 82.22%. Weekly, there has been analysed biochemical composition of meat and protein efficiency coefficient (PER, protein using efficiency (PUE, retained protein (RP. The nutritional quality of fish meat and appreciation coefficients of fish rearing they indicate a good capitalization of delivered food.

  10. Preliminary results on growth of the Polyodon spathula juveniles in recirculating system conditions

    Directory of Open Access Journals (Sweden)

    Marian T. Coadă

    2011-04-01

    Full Text Available t. The main purpose of the present experiment consists in evaluating the growth performances of North-American sturgeon larvae (Polyodon spathula (Walbaum, 1792, raised in the recirculating system. Growth performance is influenced by many factors including food quality, quantity of food, culture species, fish size and water quality. The research was conducted between May 12thto June 8th,2010, in the pilot laboratory of Department of Aquaculture, Environmental Science and Cadastre of the Faculty of Food Science and Engineering, Galaţi. Ewos type growing unit (1.40 x 1.40 x 0.40 m was populated with 1500 larvae with an age of 72-120 hours and with an average weight of 8±0.2 mg/larva. During the experiment the physico-chemical water parameters were within the admissible limit of sturgeons growth (temperature 4-26oC, dissolved oxygen 5-14 mg L-1, pH 6.5-8.5, N-N03-1-20 mg L-1,N-NO2-0-0.01 mg L-1, N-NH4+0.05-2 mg L-1. The experiment results indicated a 78% survival and anindividual body biomass of 1.15 ± 0.21 g. The research goal is to achieve the following objectives:a.optimization of feeding parameters (ratio, fodders type and frequency and the efficiency of different fodders types usage (conversion signs of fodders; b. providing the conditions for the biological material adaptation to the growth condition of the recirculating system.

  11. Effects of exhaust gas recirculation on the thermal efficiency and combustion characteristics for premixed combustion system

    International Nuclear Information System (INIS)

    In this research, a boiler in a premixed combustion system used to achieve exhaust gas recirculation was investigated as a way to achieve high thermal efficiencies and low pollutant emissions. The effects of various exhaust gas recirculation (EGR) ratios, equivalence ratios and boiler capacities on thermal efficiency, NOx and CO emissions and the flame behavior on the burner surface were examined both experimentally and numerically. The results of the experiments showed that when EGR was used, the NOx and CO concentrations decreased and the thermal efficiency increased. In the case of a 15% EGR ratio at an equivalence ratio of 0.90, NOx concentrations were found to be smaller than for the current operating condition of the boiler, and the thermal efficiency was approximately 4.7% higher. However, unlike NOx concentrations, although the EGR ratio was increased to 20% at an equivalence ratio of 0.90, the CO concentration was higher than in the current operating condition of the boiler. From the viewpoint of burner safety, the red glow on the burner surface was noticeably reduced when EGR was used. These results confirmed that the EGR method is advantageous from the standpoint of reducing emission concentrations and ensuring burner safety. -- Highlights: ► The premixed boiler system applied EGR was investigated to achieve high thermal efficiencies and low pollutant emissions. ► Thermal efficiency and emission characteristics were examined with EGR ratios, equivalence ratios and boiler capacities. ► EGR method is advantageous from the standpoint of reducing emission concentrations and ensuring burner safety.

  12. The impact of water exchange rate on the health and performance of rainbow trout Oncorhynchus mykiss in recirculation aquaculture systems

    Science.gov (United States)

    Fish mortality in recirculating aquaculture systems (RAS) has been observed by the authors to increase when RAS are managed at low makeup water exchange rates with relatively high feed loading. The precise etiology of this elevated mortality was unknown, all typical water quality parameters were wit...

  13. Effect of inoculum addition modes and leachate recirculation on anaerobic digestion of solid cattle manure in an accumulation system

    NARCIS (Netherlands)

    El-Mashad, H.M.; Loon, van W.K.P.; Zeeman, G.; Bot, G.P.A.; Lettinga, G.

    2006-01-01

    The effect of both leachate recirculation (at 40 and 50 °C) and the mode of inoculum addition (at 50 °C) on the performance of a non-mixed accumulation (i.e. fed batch) system treating solid cattle wastes was investigated, using laboratory scale reactors at a filling time of 60 days. A relatively hi

  14. Abnormal swimming behavior and increased deformities in rainbow trout Oncorhynchus mykiss cultured in low exchange water recirculation aquaculture systems

    Science.gov (United States)

    Two studies were conducted to determine if accumulating water quality parameters would negatively impact rainbow trout Oncorhynchus mykiss health and welfare within water recirculation aquaculture systems (WRAS) that were operated at low and near-zero water exchange, with and without ozonation, and ...

  15. Production characteristics and body composition of juvenile cobia fed three different commercial diets in recirculating aquaculture systems

    Science.gov (United States)

    The effect of feeding three commercial diets on production characteristics and body composition of juvenile cobia Rachycentron canadum reared using recirculating aquaculture systems (RAS) was evaluated in a 56 d growth trial. Juvenile cobia (29.2 +/= 0.7 g, mean weight +/= SE) were stocked into thr...

  16. Preliminary studies on the depuration of common off-flavors from fish raised in recirculating aquaculture systems

    Science.gov (United States)

    “Off-flavor” problems can adversely impact the growth of the aquaculture industry. Fish raised in recirculating systems have the potential to develop the common off-flavors “earthy” and “musty” due to accumulation of the microbial metabolites geosmin and 2-methylisoborneol (MIB) in the fish flesh. ...

  17. Full-scale demonstration of in situ cometabolic biodegradation of trichloroethylene in groundwater 1. Dynamics of a recirculating well system

    Science.gov (United States)

    Gandhi, Rahul K.; Hopkins, Gary D.; Goltz, Mark N.; Gorelick, Steven M.; McCarty, Perry L.

    2002-04-01

    Recirculating well systems provide an engine for the in situ treatment of subsurface contaminants. Although numerous recirculating wells have been installed in the field, for such systems, there is a paucity of comprehensive monitoring data and models constrained to data appearing in the research literature. Here we present an extensive data set combined with detailed inverse and simulation analyses for a two-well groundwater recirculation system used for in situ bioremediation at Edwards Air Force Base in southern California. The ``conveyor belt'' flow system, which was established for in situ treatment of trichloroethylene (TCE) in two bioactive zones, was created by pumping water upward in one well and downward in another well, each well being screened in both the upper and lower aquifers. A bromide tracer test was conducted and extensively monitored for 60 days. Combined inverse analysis was conducted on hydraulic heads from 38 monitoring wells, 32 bromide concentration histories, and a constraint on the degree of recirculation that was based on TCE concentration data. Four different formulations involving alternative weighting schemes used in a nonlinear weighted least squares simulation-regression analysis were explored. The best formulation provided parameter estimates with tight bounds on estimated covariances, suggesting that the model provides a reasonable description of the hydrogeologic system. Our investigation indicates the geometry of the recirculation zone and the degree of recirculation under two different sets of operating conditions. Surprisingly, our analysis suggests that the effects of aquifer heterogeneity are not significant at this site under the conditions of forced recirculation. Furthermore, anomalous flow through an open monitoring well created significant vertical short-circuiting between the generally insulated aquifers. Flow through this small open conduit was equivalent to as much as 33% of the flow through the pumping wells. Using

  18. Recovery system for uranium from seawater with fibrous adsorbent and its preliminary cost estimation

    International Nuclear Information System (INIS)

    The cost of uranium recovered from seawater was estimated to extract the technical problems in the practical application of the fibrous amidoxime adsorbent synthesized by radiation graftpolymerization. Each cost of the adsorbent production, the dipping in seawater for uranium absorption, and the uranium elution from the adsorbent was estimated in three different mooring systems of a buoy, floating body, and chain binding system. The recovery cost was estimated to be 5-10 times of that from mining uranium. More than 80% of the total cost was occupied by the cost for marine equipment for mooring the adsorbents in seawater, which is owing to a weight of metal cage for adsorbents. Thus, the cost can be reduced to half by the reduction of the equipment weight to 1/4. The improvement of adsorbent ability is research subjects in the future also, since the cost directly depends on the adsorbent performance. (author)

  19. High ratio recirculating gas compressor

    Science.gov (United States)

    Weinbrecht, John F.

    1989-01-01

    A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor.

  20. Low concentration volatile organic pollutants removal in combined adsorber-desorber-catalytic reactor system

    Directory of Open Access Journals (Sweden)

    Arsenijević Zorana

    2008-01-01

    Full Text Available The removal of volatile organic compounds (VOCs from numerous emission sources is of crucial importance due to more rigorous demands on air quality. Different technologies can be used to treat the VOCs from effluent gases: absorption, physical adsorption, open flame combustion, thermal and catalytic incineration. Their appropriateness for the specific process depends on several factors such as efficiency, energy consumption, secondary pollution, capital investments etc. The distinctive features of the catalytic combustion are high efficiency and selectivity toward be­nign products, low energy consumption and absence of secondary polluti­on. The supported noble catalysts are widely used for catalytic incineration due to their low ignition temperatures and high thermal and chemical stability. In our combined system adsorption and desorption are applied in the spouted bed with draft tube (SBDT unit. The annular zone, loaded with sorbent, was divided in adsorption and desorption section. Draft tube enabled sorbent recirculation between sections. Combustion of desorbed gases to CO2 and water vapor are realized in additive catalytic reactor. This integrated device provided low concentrations VOCs removal with reduced energy consumption. Experiments were conducted on a pilot unit of 220 m3/h nominal capacity. The sorbent was activated carbon, type K81/B - Trayal Corporation, Krusevac. A sphere shaped commercial Pt/Al2O3 catalyst with "egg-shell" macro-distribution was used for the investigation of xylene deep oxidation. Within this paper the investigations of removal of xylene vapors, a typical pollutant in production of liquid pesticides, in combined adsorber/desorber/catalytic reactor system is presented.

  1. Characterising organic matter in recirculating aquaculture systems with fluorescence EEM spectroscopy.

    Science.gov (United States)

    Hambly, A C; Arvin, E; Pedersen, L-F; Pedersen, P B; Seredyńska-Sobecka, B; Stedmon, C A

    2015-10-15

    The potential of recirculating aquaculture systems (RAS) in the aquaculture industry is increasingly being acknowledged. Along with intensified application, the need to better characterise and understand the accumulated dissolved organic matter (DOM) within these systems increases. Mature RASs, stocked with rainbow trout and operated at steady state at four feed loadings, were analysed by dissolved organic carbon (DOC) analysis and fluorescence excitation-emission matrix (EEM) spectroscopy. The fluorescence dataset was then decomposed by PARAFAC analysis using the drEEM toolbox. This revealed that the fluorescence character of the RAS water could be represented by five components, of which four have previously been identified in fresh water, coastal marine water, wetlands and drinking water. The fluorescence components as well as the DOC showed positive correlations with feed loading, however there was considerable variation between the five fluorescence components with respect to the degree of accumulation with feed loading. The five components were found to originate from three sources: the feed; the influent tap water (groundwater); and processes related to the fish and the water treatment system. This paper details the first application of fluorescence EEM spectroscopy to assess DOM in RAS, and highlights the potential applications of this technique within future RAS management strategies. PMID:26141427

  2. Quantitative role of shrimp fecal bacteria in organic matter fluxes in a recirculating shrimp aquaculture system.

    Science.gov (United States)

    Beardsley, Christine; Moss, Shaun; Malfatti, Francesca; Azam, Farooq

    2011-07-01

    Microorganisms play integral roles in the cycling of carbon (C) and nitrogen (N) in recirculating aquaculture systems (RAS) for fish and shellfish production. We quantified the pathways of shrimp fecal bacterial activities and their role in C- and N-flux partitioning relevant to culturing Pacific white shrimp, Penaeus (Litopenaeus) vannamei, in RAS. Freshly produced feces from P. vannamei contained 0.6-7 × 10(10) bacteria g(-1) dry wt belonging to Bacteroidetes (7%), Alphaproteobacteria (4%), and, within the Gammaproteobacteria, almost exclusively to the genus Vibrio (61%). Because of partial disintegration of the feces (up to 27% within 12 h), the experimental seawater became inoculated with fecal bacteria. Bacteria grew rapidly in the feces and in the seawater, and exhibited high levels of aminopeptidase, chitinase, chitobiase, alkaline phosphatase, α- and β-glucosidase, and lipase activities. Moreover, fecal bacteria enriched the protein content of the feces within 12 h, potentially enriching the feces for the coprophagous shrimp. The bacterial turnover time was much faster in feces (1-10 h) than in mature RAS water (350 h). Thus, shrimp fecal bacteria not only inoculate RAS water but also contribute to bacterial abundance and productivity, and regulate system processes important for shrimp health. PMID:21426366

  3. Integrated Multi-Trophic Recirculating Aquaculture System for Nile Tilapia (Oreochlomis niloticus

    Directory of Open Access Journals (Sweden)

    Puchong Sri-uam

    2016-06-01

    Full Text Available Three densities of the sex-reversed male Nile tilapia, Oreochromis niloticus (20, 25, 50 fish/m3 were cultivated in an integrated multi-trophic recirculating aquaculture system (IMRAS that involves the ecological relationship between several living organisms, i.e., phytoplankton, zooplankton, and aquatic plants. The results indicated that, by providing proper interdependency between various species of living organisms, the concentrations of ammonia, nitrite, nitrate, and phosphate in the system were maintained below dangerous levels for Nile tilapia throughout the cultivation period. The highest wet weight productivity of Nile tilapia of 11 ± 1 kg was achieved at a fish density of 50 fish/m3. The aquatic plants in the treatment tank could effectively uptake the unwanted nitrogen (N and phosphorus (P compounds with the highest removal efficiencies of 9.52% and 11.4%, respectively. The uptake rates of nitrogen and phosphorus by aquatic plants could be ranked from high to low as: Egeria densa > Ceratophyllum demersum > Vallisneria spiralis and Vallisneria americana > Hygrophila difformis. The remaining N was further degraded through nitrification process, whereas the remaining P could well precipitate in the soil sediment in the treatment tank.

  4. Nitrogen and Phosphorus Removal in the Recirculating Aquaculture System with Water Treatment Tank containing Baked Clay Beads and Chinese Cabbage

    OpenAIRE

    Aeknarin Thanakitpairin; Wiboonluk Pungrasmi; Sorawit Powtongsook

    2014-01-01

    This research aims to describe the nitrogen and phosphorus removal in Recirculating Aquaculture System (RAS) by crop plants biomass production. The 3 experiment systems consisted of 1 treatment (fish tank + baked clay beads + Chinese cabbage) and 2 controls as control-1 (fish tank only) and control-2 (fish tank + baked clay beads), were performed. With all experimental RAS, Nile tilapia (Oreochromis niloticus) was cultured at 2 kg/m3 density. The baked clay beads (8-16 mm in diameter) were fi...

  5. RESEARCHES REGARDING THE TECHNOLOGICAL PERFORMANCES OF CARP REARING DURING WINTER PERIOD IN THE CONDITIONS OF A RECIRCULATING AQUACULTURE SYSTEM

    OpenAIRE

    G. STEFAN; Cristea, V.; A. MIHALACHE; Grecu, I.; I. VASILEAN; L. SFETCU; Gheorghe, D.; A. DOCAN

    2013-01-01

    The techniques of carp culture are highly diversified, ranging from the extensive production in pond or open water with no fertilization or supplemental feeding to highly intensive systems in concrete tanks or cages. Among the different carp species, common carp is the best species reared in intensive monoculture, the others (Chinese and Indian carps) being usually cultivated in polyculture (P. Kestemont, 1995). An experiment was conducted in inside recirculation system conditions to identify...

  6. Pilot-scale study of powdered activated carbon recirculation for micropollutant removal.

    Science.gov (United States)

    Meinel, F; Sperlich, A; Jekel, M

    2016-01-01

    Adsorption onto powdered activated carbon (PAC) is a promising technique for the removal of organic micropollutants (OMPs) from treated wastewater. To enhance the adsorption efficiency, PAC is recycled back into the adsorption stage. This technique was examined in pilot scale in comparison to a reference without recirculation. Coagulation with Fe(3+) was carried out simultaneously to adsorption. Extensive OMP measurements showed that recirculation significantly increased OMP eliminations. Thus, significant PAC savings were feasible. The PAC concentration in the contact reactor proved to be an important operating parameter that can be surrogated by the easily measurable total suspended solids (TSS) concentration. OMP eliminations increased with increasing TSS concentrations. At 20 mg PAC L(-1) and 2.8 g TSS L(-1) in the contact reactor, well-adsorbable carbamazepine was eliminated by 97%, moderately adsorbable diclofenac was eliminated by 92% and poorly-adsorbable acesulfame was eliminated by 54% in comparison to 49%, 35% and 18%, respectively, without recirculation. The recirculation system represents an efficient technique, as the PAC's adsorption capacity is practically completely used. Small PAC dosages yield high OMP eliminations. Poorly-adsorbable gabapentin was eliminated to an unexpectedly high degree. A laboratory-scale biomass inhibition study showed that aerobic biodegradation removed gabapentin in addition to adsorption. PMID:27533867

  7. Cryogenic adsorber design in a helium refrigeration system

    Science.gov (United States)

    Hu, Zhongjun; Zhang, Ning; Li, Zhengyu; Li, Q.

    2012-06-01

    The cryogenic adsorber is specially designed to eliminate impurities in gaseous helium such as O2, and N2 which is normally difficult to remove, based on the reversible cryotrapping of impurities on an activated carbon bed. The coconut shell activated carbon is adopted because of its developed micropore structure and specific surface area. This activated carbon adsorption is mostly determined by the micropore structure, and the adsorption rate of impurities is inversely proportional to the square of the particle sizes. The active carbon absorber's maximum permissible flow velocity is 0.25 m/s. When the gas flow velocity increases, the adsorption diffusion rate of the adsorbent is reduced, because an increase in the magnitude of the velocity resulted in a reduced amount of heat transfer to a unit volume of impure gas. According to the numerical simulation of N2 adsorption dynamics, the appropriate void tower link speed and the saturated adsorption capacity are determined. Then the diameter and height of the adsorber are designed. The mass transfer length should be taken into account in the adsorber height design. The pressure decrease is also calculated. The important factors that influence the adsorber pressure decrease are the void tower speed, the adsorbed layer height, and the active carbon particle shape and size.

  8. Biomethanation and microbial community changes in a digester treating sludge from a brackish aquaculture recirculation system.

    Science.gov (United States)

    Zhang, Xuedong; Tao, Yu; Hu, Jianmei; Liu, Gang; Spanjers, Henri; van Lier, Jules B

    2016-08-01

    Using a high-salinity-adapted inoculum and a moderate stepwise-increased organic loading rate (OLR), a stable digester performance was achieved in treating sludge from a brackish aquaculture recirculation system. The specific methane yield was distinctly enhanced, reaching 0.203LCH4/gCODadded, compared to literature values (0.140-0.154LCH4/gCODadded) from the salty sludges. OLR adjustment and the fecal substrate substantially influenced population changes in the digester. Within the bacterial subpopulations, the relative abundance of Bacillus and Bacteroides declined, accompanied by the increase of Clostridium and Trigonala over time. The results show Trigonala was derived from the substrate and accumulated inside the digester. The most abundant methanogen was Methanosarcina in the inoculum and the digestates. The Methanosarcina proliferation can be ascribed to its metabolic versatility, probably a feature of crucial importance for high-salinity environments. Other frequently observed methanogens were outcompeted. The population similarity at the genus level between inoculum and digestates declined during the initial stage and afterwards increased. PMID:27155261

  9. Increasing the electric efficiency of a fuel cell system by recirculating the anodic offgas

    Science.gov (United States)

    Heinzel, A.; Roes, J.; Brandt, H.

    The University of Duisburg-Essen and the Center for Fuel Cell Technology (ZBT Duisburg GmbH) have developed a compact multi-fuel steam reformer suitable for natural gas, propane and butane. Fuel processor prototypes based on this concept were built up in the power range from 2.5 to 12.5 kW thermal hydrogen power for different applications and different industrial partners. The fuel processor concept contains all the necessary elements, a prereformer step, a primary reformer, water gas shift reactors, a steam generator, internal heat exchangers, in order to achieve an optimised heat integration and an external burner for heat supply as well as a preferential oxidation step (PrOx) as CO purification. One of the built fuel processors is designed to deliver a thermal hydrogen power output of 2.5 kW according to a PEM fuel cell stack providing about 1 kW electrical power and achieves a thermal efficiency of about 75% (LHV basis after PrOx), while the CO content of the product gas is below 20 ppm. This steam reformer has been combined with a 1 kW PEM fuel cell. Recirculating the anodic offgas results in a significant efficiency increase for the fuel processor. The gross efficiency of the combined system was already clearly above 30% during the first tests. Further improvements are currently investigated and developed at the ZBT.

  10. Advanced Horizontal Well Recirculation Systems for Geothermal Energy Recovery in Sedimentary Formations

    Energy Technology Data Exchange (ETDEWEB)

    Mike Bruno; Russell L. Detwiler; Kang Lao; Vahid Serajian; Jean Elkhoury; Julia Diessl; Nicky White

    2012-09-30

    There is increased recognition that geothermal energy resources are more widespread than previously thought, with potential for providing a significant amount of sustainable clean energy worldwide. Recent advances in drilling, completion, and production technology from the oil and gas industry can now be applied to unlock vast new geothermal resources, with some estimates for potential electricity generation from geothermal energy now on the order of 2 million megawatts. Terralog USA, in collaboration with the University of California, Irvine (UCI), are currently investigating advanced design concepts for paired horizontal well recirculation systems, optimally configured for geothermal energy recovery in permeable sedimentary and crystalline formations of varying structure and material properties. This two-year research project, funded by the US Department of Energy, includes combined efforts for: 1) Resource characterization; 2) Small and large scale laboratory investigations; 3) Numerical simulation at both the laboratory and field scale; and 4) Engineering feasibility studies and economic evaluations. The research project is currently in its early stages. This paper summarizes our technical approach and preliminary findings related to potential resources, small-scale laboratory simulation, and supporting numerical simulation efforts.

  11. Argon Purification Studies and a Novel Liquid Argon Re-circulation System

    CERN Document Server

    Mavrokoridis, K; Coleman, J; Lightfoot, P K; McCauley, N; McCormick, K J; Touramanis, C

    2011-01-01

    Future giant liquid argon (LAr) time projection chambers (TPCs) require a purity of better than 0.1 parts per billion (ppb) to allow the ionised electrons to drift without significant capture by any electronegative impurities. We present a comprehensive study of the effects of electronegative impurity on gaseous and liquid argon scintillation light, an analysis of the efficacy of various purification chemicals, as well as the Liverpool LAr setup, which utilises a novel re-circulation purification system. Of the impurities tested - Air, O_2, H_2O, N_2 and CO_2 in the range of between 0.01 ppm to 1000 ppm - H_2O was found to have the most profound effect on gaseous argon scintillation light, and N_2 was found to have the least. Additionally, a correlation between the slow component decay time and the total energy deposited with 0.01 ppm - 100 ppm O_2 contamination levels in liquid argon has been established. The superiority of molecular sieves over anhydrous complexes at absorbing Ar gas, N_2 gas and H_2O vapou...

  12. Observations on side-swimming rainbow trout in water recirculation aquaculture systems.

    Science.gov (United States)

    Good, Christopher; Davidson, John; Kinman, Christin; Kenney, P Brett; Bæverfjord, Grete; Summerfelt, Steven

    2014-12-01

    During a controlled 6-month study using six replicated water recirculation aquaculture systems (WRASs), it was observed that Rainbow Trout Oncorhynchus mykiss in all WRASs exhibited a higher-than-normal prevalence of side swimming (i.e., controlled, forward swimming but with misaligned orientation such that the fish's sagittal axis is approximately parallel to the horizontal plane). To further our understanding of this abnormality, a substudy was conducted wherein side swimmers and normally swimming fish were selectively sampled from each WRAS and growth performance (length, weight), processing attributes (fillet yield, visceral index, ventrum [i.e., thickness of the ventral "belly flap"] index), blood gas and chemistry parameters, and swim bladder morphology and positioning were compared. Side swimmers were found to be significantly smaller in length and weight and had less fillet yield but higher ventrum indices. Whole-blood analyses demonstrated that, among other things, side swimmers had significantly lower whole-blood pH and higher Pco2. Side swimmers typically exhibited swim bladder malformations, although the positive predictive value of this subjective assessment was only 73%. Overall, this study found several anatomical and physiological differences between side-swimming and normally swimming Rainbow Trout. Given the reduced weight and fillet yield of market-age side swimmers, producers would benefit from additional research to reduce side-swimming prevalence in their fish stocks. PMID:25250476

  13. Broodstock management of the fine flounder Paralichthys adspersus (Steindachner, 1867 using recirculating aquaculture systems

    Directory of Open Access Journals (Sweden)

    Lili Carrera

    2013-03-01

    Full Text Available The present study describes the methodology used at IMARPE for the capture, acclimation and management of P. adspersus broodstock using recirculating aquaculture systems (RAS. RAS improved the water quality and maintained the environmental parameters during the acclimation period, temperature (17.2±1°C, oxygen (8.1±0.7 mg L-1, pH (7.3±0.2, ammonia (0.004±0.003 mg L-1, nitrite (0.52±0.2 mg L-1 and nitrate (3.45±2.6 mg L-1. Fish began to be fed normally from day 15 post-capture, once or twice a day using live fish (Odonthestes regia regia, Mugil cephalus, crustacean (Emerita analoga, fresh food (Engraulis ringens and Dosidicus gigas and artificial feed. A significant loss in the weight of the fish was registered during the first days of captivity, followed by a continuous increase in both sexes. The specific growth rate was positive from the third month of captivity, being the relative growth rate 24.5% and 16.2% in August 2010 in males and females, respectively. Different internal and external parasites were detected in the fish, being Entobdella sp. and Philometra sp. the prevailing parasites observed during samplings.

  14. Membrane filtration coupled with chemical precipitation to treat recirculating aquaculture system effluents.

    Science.gov (United States)

    Yang, Ling; Zhou, Hongde; Moccia, Richard

    2006-01-01

    Effluents from recirculating aquaculture systems (RAS) contain high concentrations of nitrogen and phosphorous wastes and thus often require proper treatment to prevent potential detrimental impacts on receiving water bodies. The purpose of this study was to evaluate the feasibility of membrane filtration coupled with chemical precipitation as a pretreatment step with emphasis on phosphorus removal from RAS effluents. Chemical precipitation tests were conducted by adding magnesium chloride and alum at different chemical concentrations and pH values, respectively. Crossflow, flat-sheet membrane filtration modules were used to examine the effects of transmembrane pressure and crossflow velocity in terms of solid/liquid separation efficiency and permeate flux decline. The results showed that membrane filtration can effectively separate the phosphorus precipitates after chemical precipitation. The total phosphorus in the treated effluent was reduced to less than 0.05 mg L(-1) with a removal efficiency of more than 90%. However, much lower removal efficiencies were obtained for total organic carbon (TOC), total nitrogen, and turbidity. It was concluded that membrane filtration coupled with chemical precipitation can become an effective, compact treatment technology to meet the stringent regulatory requirements for RAS effluent discharge. PMID:17071913

  15. Conditioning of broodstock of tiger grouper, Epinephelus fuscoguttatus, in a recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    Saleem Mustafa

    2015-11-01

    Full Text Available Closing the cycle of commercial species of fish in a recirculating aquaculture system is gaining importance for a number of practical advantages. Founder broodstock originating from the wild population is conditioned to live in hatchery tanks under suitable environmental and feeding conditions and is induced to breed. The juveniles are grown to maturity and facilitated to spawn in captivity to close the life cycle in the hatchery. This experiment was carried out on tiger grouper (Epinephelus fuscoguttatus. After preliminary observations, it was possible to identify appropriate environmental conditions in terms of water quality parameters, volume of broodstock tanks and ration. Growth was nearly isometric (growth exponent = 2.9185 and the condition factor = 1.86. This reflected good management conditions. Cues that trigger sex reversal in this protogynous fish in the hatchery were different from those that operate in nature. It appears that the differentiation of some individuals of a cohort into male sex is linked to socio-demographic cues as well as internal condition of the fish because it related to age and physiological condition. This view was reinforced by a lack of response in young fish to similar cues. The information generated through this study defines what is required for optimum conditioning of tiger grouper broodstock and explains the cues involved in sex differentiation.

  16. [Nitrate removal from recirculating aquaculture system using polyhydroxybutyrate-co-hydroxyvalerate as carbon source ].

    Science.gov (United States)

    Zhang, Lanhe; Liu, Lili; Qiu, Tianlei; Gao, Min; Han, Meilin; Yuan, Ding; Wang, Xuming

    2014-09-01

    [ OBJECTIVE] Polyhydroxybutyrate-co-hydroxyvalerate (PHBV) was used as solid carbon source and biofilm carrier to remove nitrate from recirculating aquaculture system (RAS). Dynamics of microbial community structure in biofilm coating on carbon source packed into denitrification reactor were investigated. [METHODS] Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) was used to analyze the microbial community in biofilm from denitrifiation reactor. Bacteria degrading PHBV were isolated from the reactor using pure culture method. [RESULTS] Nitrate decreased remarkably in the RAS connected with dentrification reactor. In contrast, Nitrate increased continuously in the conventional RAS without dentrification reactor. According to the phylogenetic analysis, the microbes in the biofilm samples from denitrification reactor were divided into Proteobacteria ( p-proteobacteria, γ-proteobacteria and δ- proteobacteria) , Firmicutes and Bacteroidetes. The major advantageous populations were Acidovorax and Bacillus in the 40-day reactor. The advantageous populations in the 150-day reactor were in order of Clostridium, Desulfitobacterium, Dechloromonas, Pseudoxanthomonas and Flavobacterium. Pure cultures of bacteria degrading PHBV isolated from denitrification reactor were classified into Acidovorax, Methylibium, Pseudoxanthomonas and Dechloromonas. [CONCLUSION] Nitrate could be removed effectively from RAS using PHBV as carbon source. Advantageous bacteria and their dynamic changes were ascertained in biofilm from denitrification reactor packed with PHBV. PMID:25522594

  17. Preliminary research on the anammox process and control of nitrogen compounds in a recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    Savin Cristian

    2013-01-01

    Full Text Available Using anammox process in biological filtration of technological water within recirculatingaquaculture system is an alternative to nitrification / denitrification process which can reduce productioncosts, especially energy by replacing aerobic biological processes that require high oxygen consumption,provided through the addition for optimal function of biofilter (conversion of N-NH4 and N-NO2. Aim ofthis paper is to highlight the first steps in the control of nitrogen compounds in recirculating aquaculturesystems using anammox process. Data shown are obtained after 78 researching days (research stillongoing, the results being encouraging, registering an ammonium removal efficiency of 77% in SC1 andof 32% in SC2. Nitrites registered an increase in SC1 and a decrease in SC2 and there are allprerequisites showing that in SC2 anammox activity is more advanced than in SC1. The average ofoxygen consumption rate was 0.73 mgL-1 in SC1 smaller than 0.99 mgL-1 from SC2, which reinforces theidea that there are anammox process in SC2.

  18. A study on the optimal hydraulic loading rate and plant ratios in recirculation aquaponic system.

    Science.gov (United States)

    Endut, Azizah; Jusoh, A; Ali, N; Wan Nik, W B; Hassan, A

    2010-03-01

    The growths of the African catfish (Clarias gariepinus) and water spinach (Ipomoea aquatica) were evaluated in recirculation aquaponic system (RAS). Fish production performance, plant growth and nutrient removal were measured and their dependence on hydraulic loading rate (HLR) was assessed. Fish production did not differ significantly between hydraulic loading rates. In contrast to the fish production, the water spinach yield was significantly higher in the lower hydraulic loading rate. Fish production, plant growth and percentage nutrient removal were highest at hydraulic loading rate of 1.28 m/day. The ratio of fish to plant production has been calculated to balance nutrient generation from fish with nutrient removal by plants and the optimum ratio was 15-42 gram of fish feed/m(2) of plant growing area. Each unit in RAS was evaluated in terms of oxygen demand. Using specified feeding regime, mass balance equations were applied to quantify the waste discharges from rearing tanks and treatment units. The waste discharged was found to be strongly dependent on hydraulic loading rate. PMID:19819130

  19. Influence of mechanical abrasion of carbon adsorbents on aerodynamic resistance of filters of system of ventilation of NPS

    International Nuclear Information System (INIS)

    Influence of mechanical abrasion of granules on aerodynamic resistance of different carbon adsorbents at conditions similar to work of filters AU-1500 is studied. The change of fractional composition of the probed adsorbents by abrasion is determined. The obtained experimental data allow making conclusion about practicability using mixture of adsorbent Norit with different fractional composition for renewal of adsorbers of ventilation system of NPS.

  20. Performance of a constructed wetland in treating brackish wastewater from commercial recirculating and super-intensive shrimp growout systems.

    Science.gov (United States)

    Shi, Yonghai; Zhang, Genyu; Liu, Jianzhong; Zhu, Yazhu; Xu, Jiabo

    2011-10-01

    A recirculating aquaculture system was developed for treating Pacific white shrimp (Litopenaeus vannamei) production wastewater using an integrated vertical-flow (IVF) and five connected integrated horizontal flow (IHF) constructed wetlands as water treatment filters for mesohaline conditions (8.25‰-8.26‰ salinity). The constructed wetlands demonstrated the ability to reduce total nitrogen, total ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, total phosphorous, chemical oxygen demand, and total suspended solids to levels significantly lower than those in effluents from culture tanks. Various water quality parameters in the culture tanks were deemed suitable for shrimp culture. The actual ratio of wetland area (A(w)) to culture tank area (A(t)) was 1.1439, and the estimated optimal ratio A(w)/A(t) was approximately 1. The IVF-IHF wetlands showed flexibility and reliability in consistently removing the main pollutants from commercial recirculating and super-intensive shrimp growout systems throughout the culture period. PMID:21852127

  1. Identification of Bacteria Potentially Responsible for Oxic and Anoxic Sulfide Oxidation in Biofilters of a Recirculating Mariculture System

    OpenAIRE

    Cytryn, Eddie; van Rijn, Jaap; Schramm, Andreas; Gieseke, Armin; Beer, Dirk de; Minz, Dror

    2005-01-01

    Bacteria presumably involved in oxygen- or nitrate-dependent sulfide oxidation in the biofilters of a recirculating marine aquaculture system were identified using a new application of reverse transcription-PCR denaturing gradient gel electrophoresis (DGGE) analysis termed differential-transcription (DT)-DGGE. Biofilter samples were incubated in various concentrations of sulfide or thiosulfate (0 to 5 mM) with either oxygen or nitrate as the sole electron acceptor. Before and after short-term...

  2. Potential and limitations of ozone in marine recirculating aquaculture systems - Guidelines and thresholds for a safe application

    OpenAIRE

    Schröder, Jan

    2011-01-01

    The aim of the present thesis was to assess the potential and limitations of ozonation in marine recirculating aquaculture systems (RAS) while particularly focussing on the toxicity, formation and removal of ozone-produced oxidants (OPO) in order to develop guidelines and thresholds for a reasonable and safe ozone application. In the first two chapters the toxicity of OPO was investigated for Pacific white shrimp (Litopenaeus vannamei) and turbot (Psetta maxima) and maximum safe exposure leve...

  3. The Effects of Some Phytobiotics on Biochemical Composition of Oreochromis Niloticus Meat Reared in a Recirculating Aquaculture System

    OpenAIRE

    Alina Antache; Cristea Victor; Grecu Iulia; Dediu Lorena; Mocanu (Cretu) Mirela; Ion (Placinta) Sandita; Petrea Stefan Mihai

    2013-01-01

    The purpose of this experiment is the evaluation of biochemical composition of Nile tilapia meat by administrating  several phytobiotics in feed. Oreochromis niloticus, with an initial average weight of 125.41±34.33 g/exemplar, were reared, during six weeks in a recirculating aquaculture system. The phytobiotics from this experiment were administered in feed in a concentration of 1%/kg feed and consist in: thyme (Thymus vulgaris), fenugreek (Trigonela foenum graecum), neem (Azadirachta indica...

  4. Effect of stocking density on growth and survival of spotted sand bass Paralabrax maculatofasciatus larvae in a closed recirculating system

    OpenAIRE

    Álvarez González, Carlos; Ortiz Galindo, José Luis; Dumas, Silvie; Martínez Díaz, Sergio Francisco; Hernández Ceballos, Dora Esther; Grayeb del Alamo, Tanos; Moreno Lagorreta, Manuel; Peña Martínez, Renato; Civera Cerecedo, Roberto

    2001-01-01

    The effect on growth and survival of the initial stocking density (50, 100, 150, and 200 larvae/ L) in larval rearing of spotted sand bass was evaluated over 30 d in a closed recirculating system. Larvae were fed with rotifers, copepods, nauplii and adult Artemia, and spotted sand bass yolk-sac larvae. Water quality was monitored daily. The notochordal or standard length of sampled larvae was measured by image analysis. Specific growth rates at each density were compared by covariance analysi...

  5. Preliminary results on growth of the Polyodon spathula juveniles in recirculating system conditions

    OpenAIRE

    Marian T. Coadă; Neculai Patriche; Victor Cristea; Mioara Costache; Elena Bocioc; Săndiţa Ion (Placintă)

    2011-01-01

    t. The main purpose of the present experiment consists in evaluating the growth performances of North-American sturgeon larvae (Polyodon spathula (Walbaum, 1792)), raised in the recirculating system. Growth performance is influenced by many factors including food quality, quantity of food, culture species, fish size and water quality. The research was conducted between May 12thto June 8th,2010, in the pilot laboratory of Department of Aquaculture, Environmental Science and Cadastre of the Fa...

  6. Failure to Correct a Temporary (Test) Configuration that Precludes Safety Injection System Switch to Recirculation Mode

    International Nuclear Information System (INIS)

    During refuelling outage of PWR unit, a plant operator performed a safety injection (SI) test with the vessel open and the core unloaded. In order to perform this task, it was necessary for the operator to install a temporary shunt and disconnect two wires to simulate closure of the automatic reactor trip breakers (RTBs). One year later, during the next outage, the operator detected a malfunction while testing reactor protection system relays. The two wires that were disconnected to simulate RTB closure during the safety injection test with vessel open/core unloaded had been found to be still disconnected. The original work request contained ambiguities that resulted in a second operator who was returning the system to its initial configuration, failing to identify that the RTB wires, simulating closure, were still disconnected. This temporary configuration performed during the earlier SI test, prevented the 'RTB open' confirmation signal from being initiated as would normally occur in the safety injection sequence. Without receipt of this signal the safety injection signal will not be reset and will prevent the SI system switching to recirculation mode. During this period of disconnection, no accident requiring safety injection had occurred. The temporary configuration which was still in place had no direct impact on safety. However, a large or intermediate-break Loss of Coolant Accident (LOCA) or a Steam Generator Tube Rupture (SGTR) occurring during this period would have had significant impact on safety. It was identified that the probability of core damage should such a incident occur would be severe. This incident was classified level 1 on the INES scale. (author)

  7. Study on the combustion characteristics of a premixed combustion system with exhaust gas recirculation

    International Nuclear Information System (INIS)

    The boiler of a premixed combustion system with EGR (exhaust gas recirculation) is investigated to explore the potential for increasing thermal efficiency and lowering pollutant emissions. To achieve this purpose, a thermodynamic analysis is performed to predict the effect of EGR on the thermodynamic efficiency for various equivalence ratios. Experiments of a preheated air condensing boiler with EGR were conducted to measure the changes in the thermal efficiency and the characteristics of the pollutant emission. Finally, a 1-D premixed code was calculated to understand the effect of the EGR method on the NO reduction mechanism. The results of the thermodynamic analysis show that the thermodynamic efficiency is not changed because the temperature and the amount of the exhaust gas are unchanged, even though the EGR method is implemented in the system. However, when the EGR method is used with an equivalence ratio near 1.00, it is experimentally verified that the thermal efficiency increases and the NOx concentration decreases. Based on the results from numerical calculations, it is shown that the NO production rates of N + O2 ↔ NO + O and N + OH ↔ NO + H are remarkably changed due to the decrease in the flame temperature and the NO mole fraction is decreased. - Highlights: • Premixed combustion system with EGR is studied for a high efficiency and low NOx. • All research is performed with various EGR and equivalence ratios. • It verified that efficiency increases and the NOx emission decreases with EGR method. • NO production rates are remarkably changed by N + O2 ↔ NO + O and N + OH ↔ NO + H with EGR

  8. Impact of water boundary layer diffusion on the nitrification rate of submerged biofilter elements from a recirculating aquaculture system

    DEFF Research Database (Denmark)

    Prehn, Jonas; Waul, Christopher Kevin; Pedersen, Lars-Flemming;

    2012-01-01

    Total ammonia nitrogen (TAN) removal by microbial nitrification is an essential process in recirculating aquaculture systems (RAS). In order to protect the aquatic environment and fish health, it is important to be able to predict the nitrification rates in RAS’s. The aim of this study was to...... determine the impact of hydraulic film diffusion on the nitrification rate in a submerged biofilter. Using an experimental batch reactor setup with recirculation, active nitrifying biofilter units from a RAS were exposed to a range of hydraulic flow velocities. Corresponding nitrification rates were...... measured following ammonium chloride, NH4Cl, spikes and the impact of hydraulic film diffusion was quantified. The nitrification performance of the tested biofilter could be significantly increased by increasing the hydraulic flow velocity in the filter. Area based first order nitrification rate constants...

  9. Performance of different biofilters in a recirculating system for rainbow trout farming

    Directory of Open Access Journals (Sweden)

    Iván Sánchez O

    2016-05-01

    Full Text Available Objective. To evaluate the performance of different biofilters in a recirculating aquaculture system (RAS for trout farming. Materials and methods. It was used a 1m3 plastic tank for fries farming; fabric bags to solids retention; a submersible pump; a constant water level and flow distribution box; six up flow biofilters in 3” PVC tube; sand of D10=0.45mm as carrier. The reactors were operated at local temperature and with hydraulic retention time (HRT of 11 min, the biofilters were inoculated in the next way: R1-Control: RAS water; R2-Fish culture farm sludges; R3- Water from aerated lagoon of Antanas landfill (AL; R4-Aquarium sediments; R5- Aerated lagoon of AL sludges; R6-Sludges from sulfidogenic reactor of AL. The weight gain (WG and the food conversion (FC were evaluated, some physic-chemical parameters were monitored and the nitrogen and suspended solids removal efficiency were evaluated. Results. The WG of the cultured animals was 1.58 g/d and the FC was 1.41. There were no differences for ammonium and nitrite removal between the reactors; the average removal efficiencies were: ammonium 4.78%, nitrite 27.2%, nitrate 32.3%, suspended solids 37.5%; R4 and R5 reactors presented the best performance on nitrate removal, with average efficiencies of 47.4% and 42.8%. R3 presented the best SS removal with an average of 58.2%. Conclusions. The RAS water treatment system guaranteed appropriated liquid quality conditions for trout farming; the most efficient reactor for removal of the different forms of nitrogen was the inoculated with the aerated lagoon of AL sludges.

  10. Removal efficiency and balance of nitrogen in a recirculating aquaculture system integrated with constructed wetlands.

    Science.gov (United States)

    Zhong, Fei; Liang, Wei; Yu, Tao; Cheng, Shui P; He, Feng; Wu, Zhen B

    2011-01-01

    The nitrogen (N) balance for aquaculture is an important aspect, especially in China, and it is attributed to the eutrophication in many freshwater bodies. In recent years, constructed wetlands (CWs) have been widely used in wastewater treatment and ecosystem restoration. A recirculating aquaculture system (RAS) consisting of CWs and 4 fish ponds was set up in Wuhan, China. Channel catfish (Ictalurus punctatus) fingerlings were fed for satiation daily for 168 days with 2 diets containing 5.49 % and 6.53 % nitrogen, respectively. The objectives of this study were to investigate the N budget in the RAS, and try to find out the feasibility of controlling N accumulation in the fish pond. It is expected that the study can provide a mass balance for the fate of N in the eco-friendly treatment system to avoid eutrophication. The results showed that the removal rates of ammonia (NH(+)(4)-N), sum of nitrate & nitrite (NO(-)(X)-N), and total nitrogen (TN) by the CWs were 20-55%, 38-84 % and 39-57 %, respectively. Denitrification in the CWs was the main pathway of nitrogen loss (41.67 %). Nitrogen accumulation in pond water and sediment accounted for 3.39 % and 12.65 % of total nitrogen loss, respectively. The nitrogen removal efficiency and budget showed that the CW could be used to control excessive nitrogen accumulation in fish ponds. From the viewpoint of the nitrogen pollution control, the RAS combined with the constructed wetland can be applied to ensure the sustainable development for aquaculture. PMID:21644158

  11. Association between trichodiniasis in eel ( Anguilla anguilla ) and water quality in recirculation systems

    DEFF Research Database (Denmark)

    Madsen, H.C.K.; Buchmann, K.; Mellergaard, Stig

    2000-01-01

    Association between various water quality parameters and the infection level of Trichodina jadranica in cultured eels were examined in nine recirculation farms in Denmark. Production units suffering from trichodiniasis (n = 4) had relatively high contents of organic dry matter (13-65 mg l(-1)), low...

  12. Removal of nitrogen by Algal Turf Scrubber Technology in recirculating aquaculture system

    NARCIS (Netherlands)

    Valeta, J.; Verdegem, M.C.J.

    2015-01-01

    Ongoing research in recirculation aquaculture focuses on evaluating and improving the purification potential of different types of filters. Algal Turf Scrubber (ATS) are special as they combine sedimentation and biofiltration. An ATS was subjected to high nutrient loads of catfish effluent to examin

  13. The influence of pellets quality on the growth of sterlet, in recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    Corina Sion

    2011-04-01

    Full Text Available The paper presents some aspects regarding the influence of food quality on the breeding of sterlet, Acipenser ruthenus Linnaeus, 1758, in a recirculating aquaculture system (RAS. The experiment took place over 30 days, in four pilot breeding units type aquaria of 300 liters in volume. Two kind of variants were compared, with repetition, V1 with 46% crude protein and V2 with 30% crude protein, respectively. The stocking density was of 14 fish/unit. The same feeding level of 8 g/kg metabolic weight (1.5% from total biomass was used in every unit. The technological indicators that showed up at the end of the experiment revealed the following: the mean biomass gain in V1 was of 0.74 kg/m3 compared to 0.39 kg/m3in V2; this was nearly perfectly correlated with the food quality. The growth rate (GR variated from 6.70 to 8.13 g/day in V1 and 3.63-4.17 g/day in V2; the specific growth rate (SGR, calculated as a mean value of the two repetitions of each variant, was of 1.11 g%/day in V1 and 0.63 g%/day in V2; the feed conversion ratio (FCR, calculated as the mean value of the two repetitions from the two variants, was of 1.49 in V1 and of 2.81 in V2. The parameters of fish breeding showed that changing the quality of fodder, the fish growing was positively influenced. This experiment showed also that sterlet is a sturgeon with a moderate growth rate and it is possible to obtain an increase of fish biomass using pellets with 30-46 % crude protein.

  14. Numerical simulation of the hydrodynamics within octagonal tanks in recirculating aquaculture systems

    Science.gov (United States)

    Liu, Yao; Liu, Baoliang; Lei, Jilin; Guan, Changtao; Huang, Bin

    2016-07-01

    A three-dimensional numerical model was established to simulate the hydrodynamics within an octagonal tank of a recirculating aquaculture system. The realizable k-ɛ turbulence model was applied to describe the flow, the discrete phase model (DPM) was applied to generate particle trajectories, and the governing equations are solved using the finite volume method. To validate this model, the numerical results were compared with data obtained from a full-scale physical model. The results show that: (1) the realizable k-ɛ model applied for turbulence modeling describes well the flow pattern in octagonal tanks, giving an average relative error of velocities between simulated and measured values of 18% from contour maps of velocity magnitudes; (2) the DPM was applied to obtain particle trajectories and to simulate the rate of particle removal from the tank. The average relative error of the removal rates between simulated and measured values was 11%. The DPM can be used to assess the self-cleaning capability of an octagonal tank; (3) a comprehensive account of the hydrodynamics within an octagonal tank can be assessed from simulations. The velocity distribution was uniform with an average velocity of 15 cm/s; the velocity reached 0.8 m/s near the inlet pipe, which can result in energy losses and cause wall abrasion; the velocity in tank corners was more than 15 cm/s, which suggests good water mixing, and there was no particle sedimentation. The percentage of particle removal for octagonal tanks was 90% with the exception of a little accumulation of ≤ 5 mm particle in the area between the inlet pipe and the wall. This study demonstrated a consistent numerical model of the hydrodynamics within octagonal tanks that can be further used in their design and optimization as well as promote the wide use of computational fluid dynamics in aquaculture engineering.

  15. Effect of Recirculating Aquaculture System (RAS) on Growth Performance, Body Composition and Hematological Indicators of Allogynogenetic crucian Carp (Carassius auratus gibelio)

    OpenAIRE

    Xiao-li Li; Gu Li; Shi-yang Zhang; Ling Tao

    2013-01-01

    A Ditch Constructed Wetland unit (DCW) was integrated into an outdoor RAS with four fishponds. This study evaluated the performance of the wetland unit in treating the recirculating wastewater and examined the effect of Recirculating Aquaculture System (RAS) on growth performance, body composition and hematological indicators of the rearing fish. During a 165-days culture period, the DCW effectively reduced the influent concentrations of nutrients and can keep a good water quality at acceptab...

  16. Florfenicol residues in rainbow trout after oral dosing in recirculating and flow-through culture systems.

    Science.gov (United States)

    Meinertz, J R; Hess, K R; Bernardy, J A; Gaikowski, M P; Whitsel, M; Endris, R G

    2014-12-01

    Aquaflor is a feed premix for fish containing the broad spectrum antibacterial agent florfenicol (FFC) incorporated at a ratio of 50% (w/w). To enhance the effectiveness of FFC for salmonids infected with certain isolates of Flavobacterium psychrophilum causing cold water disease, the FFC dose must be increased from the standard 10 mg·kg⁻¹ body weight (BW)·d⁻¹ for 10 consecutive days. A residue depletion study was conducted to determine whether FFC residues remaining in the fillet tissue after treating fish at an increased dose would be safe for human consumption. Groups of Rainbow Trout Oncorhynchus mykiss (total n = 144; weight range, 126-617 g) were treated with FFC at 20 mg·kg⁻¹ BW·d⁻¹ for 10 d in a flow-through system (FTS) and a recirculating aquaculture system (RAS) each with a water temperature of ∼13°C. The two-tank RAS included a nontreated tank containing 77 fish. Fish were taken from each tank (treated tank, n = 16; nontreated tank, n = 8) at 6, 12, 24, 48, 72, 120, 240, 360, and 480 h posttreatment. Florfenicol amine (FFA) concentrations (the FFC marker residue) in skin-on fillets from treated fish were greatest at 12 h posttreatment (11.58 μg/g) in the RAS and were greatest at 6 h posttreatment (11.09 μg/g) in the FTS. The half-lives for FFA in skin-on fillets from the RAS and FTS were 20.3 and 19.7 h, respectively. Assimilation of FFC residues in the fillets of nontreated fish sharing the RAS with FFC-treated fish was minimal. Florfenicol water concentrations peaked in the RAS-treated tank and nontreated tanks at 10 h (453 μg/L) and 11 h (442 μg/L) posttreatment, respectively. Monitoring of nitrite concentrations throughout the study indicated the nitrogen oxidation efficiency of the RAS biofilter was minimally impacted by the FFC treatment. PMID:25321636

  17. The use of high rate algal ponds for the treatment of marine effluent from a recirculating fish rearing system

    OpenAIRE

    Pagand, Pascal; Blancheton, Jean-Paul; Lemoalle, J; Casellas, C.

    2000-01-01

    A high rate algal pond (HRAP) system was used to treat effluent from a recirculating sea water aquaculture system in southern France. Dicentrarchus labrax L. were farmed at a high density, with effluents containing an average of 10 mg L-1 dissolved inorganic nitrogen (DIN) and 1.3 mg L-1 reactive phosphorus (RP). On a yearly basis, the algal pond removed 59% of the dissolved nitrogen and 56% of the phosphorus input, which was converted into 3.3 kg DW m(-2) algae. Green macroalgae were dominan...

  18. Trichodina sp. ( Ciliophora: Peritrichida ) in eel Anguilla anguilla in recirculation systems in Denmark : host-parasite relations

    DEFF Research Database (Denmark)

    Madsen, H.C.K.; Buchmann, Kurt; Mellergaard, Stig

    2000-01-01

    Farmed eel cultured in recirculation systems in Denmark were found infected by Trichodina jadranica Raabe, 1958. Associations between parasite abundance and fish size was examined in 2 different production systems. In one system, stocked with relatively well-nourished eels (3 to 31 g), most of th...... more parasites (0.06 ± 0.02 [SD]) were present on fish with a low condition factor than on fish with a higher condition factor (0.13 ± 0.01 [SD]). In this eel stock the vast majority of the trichodines were found on the gills.......Farmed eel cultured in recirculation systems in Denmark were found infected by Trichodina jadranica Raabe, 1958. Associations between parasite abundance and fish size was examined in 2 different production systems. In one system, stocked with relatively well-nourished eels (3 to 31 g), most of the...... parasites (66%) were found on the dorsal part on the skin and relatively few were found on the gills (approx. 8%). The infection level was significantly positively correlated both with fish weight and length. In the other system, stocked with relatively malnourished small eels (0.5 to 4 g), significantly...

  19. Colwellia aquaemaris sp. nov., isolated from the Cynoglossus semilaevis culture tank in a recirculating mariculture system.

    Science.gov (United States)

    Liu, Ying; Liu, Liang-Zi; Zhong, Zhi-Ping; Zhou, Yu-Guang; Liu, Ying; Liu, Zhi-Pei

    2014-12-01

    A Gram-staining-negative, heterotrophic, facultatively anaerobic bacterium, designated S1(T), was isolated from the Cynoglossus semilaevis culture pond in a recirculating mariculture system in Tianjin, China. The taxonomy of strain S1(T) was studied by using a polyphasic approach. Cells of strain S1(T) were non-spore-forming, curved rods, 0.4-0.6 µm wide and 1.2-2.0 µm long, and motile by means of a single polar flagellum. The strain was positive for oxidase and catalase activities. Strain S1(T) was able to grow at 4-30 °C (optimum, 25 °C), at pH 5.5-10.0 (optimum, pH 6.5-7.5) and in the presence of 1-5 % (w/v) NaCl (optimum, 2 %). Strain S1(T) contained Q-8 as the sole respiratory quinone and C16 : 1ω7c/C16 : 1ω6c and C16 : 0 as the predominant cellular fatty acids. The genomic DNA G+C content was 40.1 mol% (Tm). Phylogenetic analysis based on 16S rRNA gene sequences placed strain S1(T) in the genus Colwellia, and it formed a distinct lineage in the phylogenetic tree together with Colwellia meonggei MA1-3(T), Colwellia aestuarii SMK-10(T), Colwellia polaris 537(T) and Colwellia chukchiensis BCw111(T), with 97.7, 96.1, 95.9 and 95.0 % 16S rRNA gene sequence similarity to these strains, respectively. DNA-DNA relatedness of strain S1(T) to Colwellia meonggei MA1-3(T) was 23.5±3.6 %. On the basis of the phylogenetic and phenotypic evidence, strain S1(T) is considered to represent a novel species of the genus Colwellia, for which the name Colwellia aquaemaris sp. nov. is proposed. The type strain is S1(T) ( = CGMCC 1.12165(T) = JCM 18479(T)). PMID:25201915

  20. Effect of stocking density on performances of juvenile turbot (Scophthalmus maximus) in recirculating aquaculture systems

    Institute of Scientific and Technical Information of China (English)

    LI Xian; LIU Ying; Jean-Paul BLANCHETON

    2013-01-01

    Limited information has been available about the influence of loading density on the performances of Scophthalmus maximus,especially in recirculating aquaculture systems (RAS).In this study,turbot (13.84±2.74 g; average weight±SD) were reared at four different initial densities (low 0.66,medium 1.26,sub-high 2.56,high 4.00 kg/m2) for 10 weeks in RAS at 23±1℃.Final densities were 4.67,7.25,14.16,and 17.47 kg/m2,respectively,which translate to 82,108,214,and 282 percent coverage of the tank bottom.Density had both negative and independent impacts on growth.The final mean weight,specific growth rate (SGR),and voluntary feed intake significantly decreased and the coefficient of variation (CV) of final body weight increased with increase in stocking density.The medium and sub-high density groups did not differ significantly in SGR,mean weight,CV,food conversion rate (FCR),feed intake,blood parameters,and digestive enzymes.The protease activities of the digestive tract at pH 7,8.5,9,and 10 were significantly higher for the highest density group,but tended to be lower (not significantly) at pH 4 and 8.5for the lowest density group.The intensity of protease activity was inversely related to feed intake at the different densities.Catalase activity was higher (but not significantly) at the highest density,perhaps because high density started to induce an oxidative effect in turbot.In conclusion,turbot can be cultured in RAS at a density of less than 17.47 kg/m2.With good water quality and no feed limitation,initial density between 1.26 and 2.56 kg/m2 (final:7.25 and 14.16 kg/m2) would not negatively affect the turbot cultured in RAS.For culture at higher density,multi-level feeding devices are suggested to ease feeding competition.

  1. Effect of stocking density on performances of juvenile turbot ( Scophthalmus maximus) in recirculating aquaculture systems

    Science.gov (United States)

    Li, Xian; Liu, Ying; Blancheton, Jean-Paul

    2013-05-01

    Limited information has been available about the influence of loading density on the performances of Scophthalmus maximus, especially in recirculating aquaculture systems (RAS). In this study, turbot (13.84±2.74 g; average weight±SD) were reared at four different initial densities (low 0.66, medium 1.26, sub-high 2.56, high 4.00 kg/m2) for 10 weeks in RAS at 23±1°C. Final densities were 4.67, 7.25, 14.16, and 17.47 kg/m2, respectively, which translate to 82, 108, 214, and 282 percent coverage of the tank bottom. Density had both negative and independent impacts on growth. The final mean weight, specific growth rate (SGR), and voluntary feed intake significantly decreased and the coefficient of variation (CV) of final body weight increased with increase in stocking density. The medium and sub-high density groups did not differ significantly in SGR, mean weight, CV, food conversion rate (FCR), feed intake, blood parameters, and digestive enzymes. The protease activities of the digestive tract at pH 7, 8.5, 9, and 10 were significantly higher for the highest density group, but tended to be lower (not significantly) at pH 4 and 8.5 for the lowest density group. The intensity of protease activity was inversely related to feed intake at the different densities. Catalase activity was higher (but not significantly) at the highest density, perhaps because high density started to induce an oxidative effect in turbot. In conclusion, turbot can be cultured in RAS at a density of less than 17.47 kg/m2. With good water quality and no feed limitation, initial density between 1.26 and 2.56 kg/m2 (final: 7.25 and 14.16 kg/m2) would not negatively affect the turbot cultured in RAS. For culture at higher density, multi-level feeding devices are suggested to ease feeding competition.

  2. Controllable Catalysis with Nanoparticles: Bimetallic Alloy Systems and Surface Adsorbates

    KAUST Repository

    Chen, Tianyou

    2016-05-16

    Transition metal nanoparticles are privileged materials in catalysis due to their high specific surface areas and abundance of active catalytic sites. While many of these catalysts are quite useful, we are only beginning to understand the underlying catalytic mechanisms. Opening the “black box” of nanoparticle catalysis is essential to achieve the ultimate goal of catalysis by design. In this Perspective we highlight recent work addressing the topic of controlled catalysis with bimetallic alloy and “designer” adsorbate-stabilized metal nanoparticles.

  3. The effect of density on sea bass (Dicentrarchus labrax) performance in a tank-based recirculating system

    OpenAIRE

    Sammouth, Sophie; Roque d'Orbcastel, Emmanuelle; Gasset, Eric; Lemarie, Gilles; Breuil, Gilles; Marino, Giovanna; Coeurdacier, Jean-luc; Fivelstad, Sveinung; Blancheton, Jean-Paul

    2009-01-01

    Sea bass (Dicentrarchus tabrax) (135 +/- 4 g) were reared under tank-based recirculating aquaculture system for a 63-day period at four densities: 10, 40, 70, 100 kg m(-3). Fish performance, stress indicators (plasma cortisol, proteonemia plus other blood parameters-Na+, K+, glucose, pH, total CO2- and water quality were monitored. At the end of the 63-day period, resistance to infection was also studied by a nodavirus challenge. A 25-day test was performed on fish from two extreme densities ...

  4. Effectiveness of Floating Micro-Bead Bio-Filter for Ornamental Fish in a Re-Circulating Aquaculture System

    OpenAIRE

    R Fadhil

    2011-01-01

    Bio-filtration has been widely used in re-circulating aquaculture system to remove waste and to convert toxic ammonia andnitrite into safe end products ornamental fish and other aquatic organisms. However, the study of micro-bead usage as the filter medium has not yet been broadened and thoroughly developed. Therefore, the aim of this study is to construct a biological filter made from polyethylene micro-bead as the filter medium and to analyze its effectiveness in removingwaste as well as in...

  5. The influence of different stocking densities on biochemical composition of rainbow trout meat reared in a recirculating aquaculture system

    OpenAIRE

    Mirela Cretu; Cristea Victor; Dediu Lorena; Petrea Stefan Mihai

    2014-01-01

    The aim of this study is to evaluate the biochemical composition of rainbow trout meat, reared in a recirculating aquaculture system, at different stocking densities (DS1-2,64 kg/m3, DS2-5,16 kg/m3, DS3-7,12 kg/m3, DS4-9,42 kg/m3). The analyses were performed in the research laboratory of Aquaculture, Environmental Science and Cadastre Department – Faculty of Food Science and Engineering, from ,,Dunarea de Jos’’University of Galati. The content of meat proteins, fats, dry substance and ash wa...

  6. Char-recirculation biomass gasification system--a site-specific feasibility study

    International Nuclear Information System (INIS)

    A site-specific feasibility study was conducted for a char-recirculation biomass gasification plant which would dispose of the chippable solid residues of the area sawmills. The plant would receive green hardwood chips and convert them into active charcoal while producing process steam and electrical power. An economic analysis was performed on the basis of not-for-profit operation, marketing crushed active charcoal to a broker at a discounted price, and displacing purchased electric power. Given a market for the active charcoal, the plant was judged to be economically viable

  7. RESEARCHES REGARDING THE TECHNOLOGICAL PERFORMANCES OF CARP REARING DURING WINTER PERIOD IN THE CONDITIONS OF A RECIRCULATING AQUACULTURE SYSTEM

    Directory of Open Access Journals (Sweden)

    G. STEFAN

    2013-12-01

    Full Text Available The techniques of carp culture are highly diversified, ranging from the extensive production in pond or open water with no fertilization or supplemental feeding to highly intensive systems in concrete tanks or cages. Among the different carp species, common carp is the best species reared in intensive monoculture, the others (Chinese and Indian carps being usually cultivated in polyculture (P. Kestemont, 1995. An experiment was conducted in inside recirculation system conditions to identify the technological performances on carp growth and survival at the Fishing and Aquaculture Department, Galati, during winter period (February, 2007 – March, 2007. The 1-year-old carp (Cyprinus carpio 4792g; 4594 g; 4561 g and 4525 g (total weight grew to 7384g; 7017g; 6924g and 7125 g in 44 days in aquarium 1, 2, 3 and 4, respectively. In all aquariums, the fish appeared healthy and no mortality was observed. Feed conversion efficiencies (FCE had similar values among all aquariums, the highest FCE being found in B4 aquarium with 1, 57 value. Water quality parameters were acceptable range for fish culture. Results show that the carp rearing during winter period in the inside recirculation system is a very good economic solution.

  8. Anaerobic ammonium-oxidizing (anammox) bacteria and associated activity in fixed-film biofilters of a marine recirculating aquaculture system.

    Science.gov (United States)

    Tal, Yossi; Watts, Joy E M; Schreier, Harold J

    2006-04-01

    Microbial communities in the biological filter and waste sludge compartments of a marine recirculating aquaculture system were examined to determine the presence and activity of anaerobic ammonium-oxidizing (anammox) bacteria. Community DNA was extracted from aerobic and anaerobic fixed-film biofilters and the anaerobic sludge waste collection tank and was analyzed by amplifying 16S rRNA genes by PCR using anammox-selective and universal GC-clamped primers. Separation of amplified PCR products by denaturing gradient gel electrophoresis and sequencing of the different phylotypes revealed a diverse biofilter microbial community. While Planctomycetales were found in all three communities, the anaerobic denitrifying biofilters contained one clone that exhibited high levels of sequence similarity to known anammox bacteria. Fluorescence in situ hybridization studies using an anammox-specific probe confirmed the presence of anammox Planctomycetales in the microbial biofilm from the denitrifying biofilters, and anammox activity was observed in these biofilters, as detected by the ability to simultaneously consume ammonia and nitrite. To our knowledge, this is the first identification of anammox-related sequences in a marine recirculating aquaculture filtration system, and our findings provide a foundation for incorporating this important pathway for complete nitrogen removal in such systems. PMID:16597996

  9. Growth of juvenile Atlantic cod Gadus morhua in land-based recirculation systems: Effects of feeding regime, photoperiod and diet

    DEFF Research Database (Denmark)

    Fülberth, Michael; Moran, Damian; Jarlbæk, Henrik;

    2009-01-01

    feeding duration. In each RAS unit three diets (A, B and C) were tested, which were broadly similar in composition but from different manufacturers. Water exchange rate averaged 10–19% in the three recirculation systems, and key water quality parameters such as NH4+ and CO2 remained at low effect......The combined effect of feeding regime and photoperiod on the growth of juvenile Atlantic cod Gadus morhua in land-based recirculating aquaculture systems (RAS) was examined using three different commercial diets. Fish of 8–10 g were reared in 1 m3 tanks at an initial density of 10 kg m− 3 for 78 d...... concentrations (<0.4 and <3 mg L− 1, respectively). Final stocking densities were 45–60 kg m− 3. There was a significant influence of both feed/photoperiod regime and diet on specific growth rate (SGR). Fish receiving the LD12:11 and LD6:6 regimes and Diet A grew best (SGR 2.59 and 2.54% d− 1 respectively). Fish...

  10. Biogas recirculation for simultaneous calcium removal and biogas purification within an expanded granular sludge bed system treating leachate.

    Science.gov (United States)

    Luo, Jinghuan; Lu, Xueqin; Liu, Jianyong; Qian, Guangren; Lu, Yongsheng

    2014-12-01

    Biogas, generated from an expanded granular sludge bed (EGSB) reactor treating municipal solid waste (MSW) leachate, was recirculated for calcium removal from the leachate via a carbonation process with simultaneous biogas purification. Batch trials were performed to optimize the solution pH and imported biogas (CO2) for CaCO3 precipitation. With applicable pH of 10-11 obtained, continuous trials achieved final calcium concentrations of 181-375 mg/L (removal efficiencies≈92.8-96.5%) in the leachate and methane contents of 87.1-91.4% (purification efficiencies≈65.4-82.2%) in the biogas. Calcium-balance study indicates that 23-986 mg Ca/d was released from the bio-system under the carbonized condition where CaCO3 precipitating was moved outside the bioreactor, whereas 7918-9517 mg Ca/d was trapped into the system for the controlled one. These findings demonstrate that carbonation removal of calcium by biogas recirculation could be a promising alternative to pretreat calcium-rich MSW leachate and synergistically to improve methane content. PMID:25310868

  11. Impact of water boundary layer diffusion on the nitrification rate of submerged biofilter elements from a recirculating aquaculture system.

    Science.gov (United States)

    Prehn, Jonas; Waul, Christopher K; Pedersen, Lars-Flemming; Arvin, Erik

    2012-07-01

    Total ammonia nitrogen (TAN) removal by microbial nitrification is an essential process in recirculating aquaculture systems (RAS). In order to protect the aquatic environment and fish health, it is important to be able to predict the nitrification rates in RAS's. The aim of this study was to determine the impact of hydraulic film diffusion on the nitrification rate in a submerged biofilter. Using an experimental batch reactor setup with recirculation, active nitrifying biofilter units from a RAS were exposed to a range of hydraulic flow velocities. Corresponding nitrification rates were measured following ammonium chloride, NH₄Cl, spikes and the impact of hydraulic film diffusion was quantified. The nitrification performance of the tested biofilter could be significantly increased by increasing the hydraulic flow velocity in the filter. Area based first order nitrification rate constants ranged from 0.065 m d⁻¹ to 0.192 m d⁻¹ for flow velocities between 2.5 m h⁻¹ and 40 m h⁻¹ (18 °C). This study documents that hydraulic film diffusion may have a significant impact on the nitrification rate in fixed film biofilters with geometry and hydraulic flows corresponding to our experimental RAS biofilters. The results may thus have practical implications in relation to the design, operational strategy of RAS biofilters and how to optimize TAN removal in fixed film biofilter systems. PMID:22507250

  12. Characterizing the structural diversity of a bacterial community associated with filter materials in recirculating aquaculture systems of Scortum barcoo.

    Science.gov (United States)

    Zhu, Peng; Ye, Yangfang; Pei, Fangfang; Lu, Kaihong

    2012-03-01

    The bacterial community structure associated with filter materials in the recirculating aquaculture system of Scortum barcoo was investigated using the 16S rRNA gene clone library method. Preliminary results showed that the clone library constructed from the initial operation condition was characterized by 31 taxa of bacteria belonging to eight phyla including Proteobacteria, Acidobacteria, Firmicutes, Fusobacteria, Sphingobacteria, Bacteroidetes, Verrucomicrobiae, and Actinobacteria. There were 14 taxa of bacteria belonging to four phyla including Proteobacteria, Acidobacteria, Planctomycetacia, and Nitrospirae from the stable operation condition where the water quality was well maintained. Nitrospirae was only found under the stable operation condition in this study. Our results further indicated that Nitrospira was dominated by members of the Nitrospira sp. lineages, with a minor fraction related to Nitrospira moscoviensis and an unknown Nitrospira cluster. These great differences of both diversity and composition between two operation conditions suggested that the composition of the microbial community varied with the degree of water quality in the recirculating aquaculture system of S. barcoo. PMID:22339297

  13. The Molecular Adsorbent Recirculating System (MARS®) in the intensive care unit: a rescue therapy for patients with hepatic failure

    OpenAIRE

    Saliba, Faouzi

    2006-01-01

    Treatment in the intensive care unit of patients with end-stage liver disease has been limited. Liver transplantation has been a major improvement in this and has become standard in the management of these patients. However, many patients die awaiting liver transplantation, mainly due to the scarcity of organ donors. Conventional hemodialysis techniques have little or no effect on liver detoxification and do not improve the prognosis of these patients. In patients with acute hepatic failure, ...

  14. Implementation of an experimental pilot reproducing the fouling of the exhaust gas recirculation system in diesel engines

    Science.gov (United States)

    Gaborieau, Cécile; Sommier, Alain; Toutain, Jean; Anguy, Yannick; Crepeau, Gérald; Gobin, Benoît

    2012-04-01

    The European emission standards EURO 5 and EURO 6 define more stringent acceptable limits for exhaust emissions of new vehicles. The Exhaust Gas Recirculation (EGR) system is a partial but essential solution for lowering the emission of nitrogen oxides and soot particulates. Yet, due to a more intensive use than in the past, the fouling of the EGR system is increased. Ensuring the reliability of the EGR system becomes a main challenge. In partnership with PSA Peugeot Citroën, we designed an experimental setup that mimics an operating EGR system. Its distinctive features are (1) its ability to reproduce precisely the operating conditions and (2) its ability to measure the temperature field on the heat exchanger surface with an Infra Red camera for detecting in real time the evolution of the fooling deposit based on its thermal resistance. Numerical codes are used in conjunction with this experimental setup to determine the evolution of the fouling thickness from its thermal resistance.

  15. Control of biological growth in recirculating cooling systems using treated secondary effluent as makeup water with monochloramine.

    Science.gov (United States)

    Chien, Shih-Hsiang; Chowdhury, Indranil; Hsieh, Ming-Kai; Li, Heng; Dzombak, David A; Vidic, Radisav D

    2012-12-01

    Secondary-treated municipal wastewater, an abundant and widely distributed impaired water source, is a promising alternative water source for thermoelectric power plant cooling. However, excessive biological growth is a major challenge associated with wastewater reuse in cooling systems as it can interfere with normal system operation as well as enhance corrosion and scaling problems. Furthermore, possible emission of biological aerosols (e.g., Legionella pneumophila) with the cooling tower drift can lead to public health concerns within the zone of aerosol deposition. In this study, the effectiveness of pre-formed and in-situ-formed monochloramine was evaluated for its ability to control biological growth in recirculating cooling systems using secondary-treated municipal wastewater as the only makeup water source. Bench-scale studies were compared with pilot-scale studies for their ability to predict system behavior under realistic process conditions. Effectiveness of the continuous addition of pre-formed monochloramine and monochloramine formed in-situ through the reaction of free chlorine with ammonia in the incoming water was evaluated in terms of biocide residual and its ability to control both planktonic and sessile microbial populations. Results revealed that monochloramine can effectively control biofouling in cooling systems employing secondary-treated municipal wastewater and has advantages relative to use of free chlorine, but that bench-scale studies seriously underestimate biocide dose and residual requirements for proper control of biological growth in full-scale systems. Pre-formed monochloramine offered longer residence time and more reliable performance than in-situ-formed monochloramine due to highly variable ammonia concentration in the recirculating water caused by ammonia stripping in the cooling tower. Pilot-scale tests revealed that much lower dosing rate was required to maintain similar total chlorine residual when pre-formed monochloramine

  16. A low energy, bio-secure, 'hybrid' recirculation system incorporating air lift pumps for water circulation, aeration, and CO2 degassing

    Science.gov (United States)

    A ‘Hybrid’ recirculating aquaculture system design utilizes elements of both a ‘Centralized’ design concept with a single water treatment system for a number of fish tanks and the ‘Modular’ design concept which employs a individual treatment system for each fish culture tank. The ‘Hybrid’ recirculat...

  17. Impact of depuration of earth-musty off-flavors on fillet quality of atlantic salmon, Salmo salar, cultured in a recirculating aquaculture system

    Science.gov (United States)

    Over the past decade in the United States, there has been increased interest in the establishment and use of land-based, closed-containment systems [e.g., recirculating aquaculture system (RAS)] for salmonid culture. These culture systems have unique challenges compared to net pen culture of salmon...

  18. Field evaluation of a horizontal well recirculation system for groundwater treatment: Pilot test at the Clean Test Site Portsmouth Gaseous Diffusion Plant, Piketon, Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Muck, M.T.; Kearl, P.M.; Siegrist, R.L. [and others

    1998-08-01

    This report presents the results of field testing a horizontal well recirculation system at the Portsmouth Gaseous Diffusion Plant (PORTS). The recirculation system uses a pair of horizontal wells, one for groundwater extraction and treatment and the other for reinjection of treated groundwater, to set up a recirculation flow field. The induced flow field from the injection well to the extraction well establishes a sweeping action for the removal and treatment of groundwater contaminants. The overall purpose of this project is to study treatment of mixed groundwater contaminants that occur in a thin water-bearing zone not easily targeted by traditional vertical wells. The project involves several research elements, including treatment-process evaluation, hydrodynamic flow and transport modeling, pilot testing at an uncontaminated site, and pilot testing at a contaminated site. The results of the pilot test at an uncontaminated site, the Clean Test Site (CTS), are presented in this report.

  19. Field evaluation of a horizontal well recirculation system for groundwater treatment: Pilot test at the Clean Test Site Portsmouth Gaseous Diffusion Plant, Piketon, Ohio

    International Nuclear Information System (INIS)

    This report presents the results of field testing a horizontal well recirculation system at the Portsmouth Gaseous Diffusion Plant (PORTS). The recirculation system uses a pair of horizontal wells, one for groundwater extraction and treatment and the other for reinjection of treated groundwater, to set up a recirculation flow field. The induced flow field from the injection well to the extraction well establishes a sweeping action for the removal and treatment of groundwater contaminants. The overall purpose of this project is to study treatment of mixed groundwater contaminants that occur in a thin water-bearing zone not easily targeted by traditional vertical wells. The project involves several research elements, including treatment-process evaluation, hydrodynamic flow and transport modeling, pilot testing at an uncontaminated site, and pilot testing at a contaminated site. The results of the pilot test at an uncontaminated site, the Clean Test Site (CTS), are presented in this report

  20. The influence of stocking density on the growth of common carp, Cyprinus carpio, in a recirculating aquaculture system

    OpenAIRE

    Ionica Enache; Victor Cristea; Tudor Ionescu; Săndita Ion

    2011-01-01

    The paper presents some aspects regarding the influence of stocking density on the breeding of the common carp in a recirculating aquaculture system (RAS). The experiment covered a 30 dayperiod. It was conducted in four aquaculture tanks, 500 L/tank, in the recirculating aquaculture pilot system of “Dunarea de Jos” University of Galați. Two kind of stocking density variants were compared: 64 kg/m3 in V1 (B1, B3) and 32 kg/m3 in V2 (B2, B4). The stocking density was: 491 fish in B1, avera...

  1. Performance enhancement of leaf vegetable waste in two-stage anaerobic systems under high organic loading rate: Role of recirculation and hydraulic retention time

    International Nuclear Information System (INIS)

    Highlights: • Limited hydrolysis under high loading rate resulted in process failure. • Recirculation improves methane production under high loading rate. • Short HRT under high recirculation rate caused instability of methanogenic reactor. • Increased recirculation and retention time further improved overall performance. - Abstract: Continuous laboratory-scale experiments were conducted on two-stage anaerobic systems treating vegetable waste (VW) to improve CH4 production. The acidogenic reactors were employed with a serial methanogenic reactor configuration with volume distribution ratios of 3 L/4 L and 3 L/7 L (acidogenic reactor/methanogenic reactor), as well as recirculation rates (RRs) of 0.8 and 1.6. Results showed that recirculation improved the performance of VW anaerobic digestion under an organic loading rate (OLR) of 2.6 g VS/L/d. The OLR increased from 2.6 g VS/L/d to 3.0 g VS/L/d to compare the stability of the processes and to study the behavior response of serial systems. System control without recirculation was susceptible to overloading and volatile fatty acids (VFAs) utilization was inhibited in the methanogenic reactor, which was implemented as a fixed-bed biofilm reactor with active carbon fiber textiles. These findings indicated overall process failure. The ratio of total volatile fatty acid (TVFA) and alkalinity gives a good indication of the process stability of anaerobic digestion. The TVFA/alkalinity ratio of the methanogenic reactor in the 3 L/4 L configuration, with RR of 1.6, increased to approximately 0.5, which indicates potential imminent failure of the methanogenic process. However, the methanogenic reactorin the 3 L/7 L configuration helped in utilizing the VFA produced by the overloading in the acidogenic reactor, which improved the CH4 production and conversion efficiency of the system

  2. New steam generation system for lead-cooled fast reactors, based on steam re-circulation through ejector

    International Nuclear Information System (INIS)

    Highlights: • Innovative steam generation system for lead-cooled fast reactors secondary loop. • Water evaporation outside of vessel heated by recirculation steam in a surface exchanger. • Steam recirculation occurs through steam jet ejector feeding bayonet heat exchangers. • Improvement of safety, availability and efficiency with respect to Loeffler system (EBBSG). - Abstract: The EBBSG (External Boiling Bayonet Steam Generator) system, proposed in previous publications, offers an alternative to the classical once-through high pressure steam generators. This system exploits the combination between the Loeffler external boiling scheme and the bayonet-tube steam generator and is expected to provide advantages in terms of safety while keeping good values of cycle performance and vessel size. The main disadvantages result in the increased size of the heat exchangers with respect to once-through steam boilers and in the need of steam blowers, as envisaged under the Loeffler scheme. In the present paper, a new and more efficient system is proposed, in which the steam circulation is assured by steam-jet ejectors instead of blowers. The innovative solution, named SJ-EBBSG (Steam-Jet External Boiling Bayonet Steam Generator), is expected to provide several advantages with respect to the original scheme. In particular, the advantages envisage an increased global efficiency (+0.49% with respect to EBBSG) due to the lower power consumption of the auxiliaries and smaller size of the bayonet heat exchangers (−6.1% diameter, −7.3% length), other than increased safety and plant availability. Throughout the article, the two steam generation solutions are compared and the advantages demonstrated by calculations

  3. Particle size distribution and removal efficiency for three types of clarifiers in a warm-water, low-salinity, recirculating aquaculture system for juvenile red drum culture

    Science.gov (United States)

    Recirculating aquaculture systems offer a solution to declining natural finfish stocks while limiting nutrient outputs and eutrophication of effluent waters. Because water is reused in these systems, the solids must be efficiently removed by mechanical treatment devices otherwise the solids buildup...

  4. Foam fractionation efficiency for particulate matter removal from a low salinity, lowhead recirculating aquaculture system utilized for the culture of red drum, Sciaenops ocellatus

    Science.gov (United States)

    In recirculating aquaculture systems (RAS), the water which is treated and reused must be of such quality to maintain the culture organism in a healthy and fast growing condition, especially as such systems are intensified. Managing particulate matter and different chemical compounds is a key factor...

  5. Ion Transport across a Polyelectrolyte-Adsorbed Cellulose Triacetate Membrane in the Multicomponent Ionic Systems.

    Science.gov (United States)

    Murata; Tanioka

    1999-01-15

    The effects of polyelectrolyte adsorption by cellulose triacetate (CTA) membrane on ionic transport are investigated in two systems: the three-ionic-component system and the multicomponent-ionic system. In the three-ionic-component system, the permeabilities of two anions are affected by the competitive ion. Especially in the case of the albumin-adsorbed CTA membrane, there exists much greater specificity for the permeability of SO2-4 than in the case of the lysozyme-adsorbed membrane. On the other hand, in the case of the PAS-H(10L)(polydiallyldimethylammonium chloride)-adsorbed membrane, the permeability coefficient of HPO2-4 increases, though there exists the effect of a competitive ion. In a multicomponent-ionic system, the logarithmic permeability coefficient ratios (rP) of each ion in an adsorbed membrane to that in a nonadsorbed membrane decreased by PAS-H(10L) adsorption for all cations. The rP of bivalent cations decreased more than those of univalent cations because of the rejection from the positively charged adsorbed layer. On the other hand, the permeabilities slightly increase because of the attraction from the PAS-H(10L)-adsorbed layer when competitive anions exist among them. Furthermore, the increase in the HPO2-4 permeability is confirmed by PAS-H(10L)-adsorption on a CTA membrane for a case very similar to the actual anion multicomponent system. These are the most important results in the application for an approach to phosphate extraction from blood across an artificial kidney membrane. Copyright 1999 Academic Press. PMID:9885263

  6. The influence of stocking density on the growth of common carp, Cyprinus carpio, in a recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    Ionica Enache

    2011-04-01

    Full Text Available The paper presents some aspects regarding the influence of stocking density on the breeding of the common carp in a recirculating aquaculture system (RAS. The experiment covered a 30 dayperiod. It was conducted in four aquaculture tanks, 500 L/tank, in the recirculating aquaculture pilot system of “Dunarea de Jos” University of Galați. Two kind of stocking density variants were compared: 64 kg/m3 in V1 (B1, B3 and 32 kg/m3 in V2 (B2, B4. The stocking density was: 491 fish in B1, average weight - 65 g/ fish; 245 fish in B2, average weight - 66 g/ fish; 211 fish in B3, average weight - 152 g/fish; 107 fish in B4, average weight - 150 g/fish. The technological indicators obtained revealed the following: the specific growth rate (SGR, calculated as a mean value on the two repetitions, was 1.28%/day in V1 and 1.49 %/day in V2, indicating better growth in V2; the food conversion ratio (FCR, calculated as the mean value of the two repetitions, was 1.28 in V1 and 1.06 in V2, expressing a higher efficiency in capitalization of food in V2. The mean biomass gain in V1 was 30.46 kg/m3 as compared to 18.55 kg/m3 in V2, almost perfectly correlated with the stocking density. The daily growth rate (DGR varied in a similar way, from 494.57 to 520.90 g/day in V1 and 302.4 to 315.9 g/day in V2. The experiment demonstrated a remarkable technological plasticity in both experimental variants, whereas, in terms of technological performance indicators, it was found that the application of lower stocking densities lead to higher crop biomass. The high stocking density means, therefore, large amounts of metabolic waste, removed from the breeding units through their effluent, the recirculating flow of which is 4m3/h, enough to ensure the whole volume of water in a growth tank to be changed every half hour.

  7. Performance of Nile tilapia Oreochromis niloticus fingerlings in a hyper-intensive recirculating aquaculture system with low water exchange

    Directory of Open Access Journals (Sweden)

    M Gullian-Klanian

    2013-03-01

    Full Text Available The aim of this paper was evaluate the performance of Nile tilapia fingerlings (Oreochromis niloticus raised at hyper intensive stocking density in a recirculating aquaculture system (RAS with minimum water replacing. The experimental system was performed in a single-batch nursery system to obtain 50 g fish size in 60 days. Fish (2.07 ± 0.04 g were stocked in triplicate at 400 (T1, 500 (T2 and 600 (T3 fish m-3 (0.84, 1.05, 1.22 kg m-3. RAS functioned with 12,000 L of recirculating water and 252 L day-1of water replacing (2.1% daily. The efficiency of the biofilter for removing the total ammonia nitrogen (TAN was 48 ± 12.5 mg L-1. Stocking density did not affect significantly the survival (89.5 to 93.6%. The growth rate of T1 (0.96 g day-1; 5.01% day-1 and T2 (0.92 g day-1; 4.95 % day-1 was significantly higher than T3 (0.83 g day-1; 4.80% day-1. The specific growth rate (SGR of T1 was 41% influenced by temperature. For T2 and T3 the SGR were influenced by the variation of dissolved oxygen (DO that explained 47 and 44% of the fish weight variation, respectively. The SGR from T3 was also affected by the concentration of ammonia nitrogen (31%. The high stocking density affected the overall size of fish and the size homogeneity, but had no negative effect on the length-weight relationship (L-W. Data support the conclusion that fingerling stocked at 400 and 500 fish m-3 shows high performance during 9-weeks when the biomass not exceed 37 kg m-3. At this time fish have reached the desired final nursery weight (50 g for transfer to grow-out facilities.

  8. Investigation of the Makeup, Source, and Removal Strategies for Total Organic Carbon in the Oxygen Generation System Recirculation Loop

    Science.gov (United States)

    Bowman, Elizabeth M.; Carpenter, Joyce; Roy, Robert J.; Van Keuren, Steve; Wilson, Mark E.

    2015-01-01

    Since 2007, the Oxygen Generation System (OGS) on board the International Space Station (ISS) has been producing oxygen for crew respiration via water electrolysis. As water is consumed in the OGS recirculating water loop, make-up water is furnished by the ISS potable water bus. A rise in Total Organic Carbon (TOC) was observed beginning in February, 2011, which continues through the present date. Increasing TOC is of concern because the organic constituents responsible for the TOC were unknown and had not been identified; hence their impacts on the operation of the electrolytic cell stack components and on microorganism growth rates and types are unknown. Identification of the compounds responsible for the TOC increase, their sources, and estimates of their loadings in the OGA as well as possible mitigation strategies are presented.

  9. Optimization and evaluation of a bottom substrate denitrification tank for nitrate removal from a recirculating aquaculture system.

    Science.gov (United States)

    Pungrasmi, Wiboonluk; Playchoom, Cholticha; Powtongsook, Sorawit

    2013-08-01

    A bottom substrate denitrification tank for a recirculating aquaculture system was developed. The laboratory scale denitrification tank was an 8 L tank (0.04 m2 tank surface area), packed to a depth of 5 cm with a bottom substrate for natural denitrifying bacteria. An aquarium pump was used for gentle water mixing in the tank; the dissolved oxygen in the water was maintained in aerobic conditions (e.g. > 2 mg/L) while anoxic conditions predominated only at the bottom substrate layer. The results showed that, among the four substrates tested (soil, sand, pumice stone and vermiculite), pumice was the most preferable material. Comparing carbon supplementation using methanol and molasses, methanol was chosen as the carbon source because it provided a higher denitrification rate than molasses. When methanol was applied at the optimal COD:N ratio of 5:1, a nitrate removal rate of 4591 +/- 133 mg-N/m2 tank bottom area/day was achieved. Finally, nitrate removal using an 80 L denitrification tank was evaluated with a 610 L recirculating tilapia culture system. Nitrate treatment was performed by batch transferring high nitrate water from the nitrification tank into the denitrification tank and mixing with methanol at a COD:N ratio of 5:1. The results from five batches of nitrate treatment revealed that nitrate was successfully removed from water without the accumulation of nitrite and ammonia. The average nitrate removal efficiency was 85.17% and the average denitrification rate of the denitrification tank was 6311 +/- 945 mg-N/m2 tank bottom area/day or 126 +/- 18 mg-N/L of pumice packing volume/day. PMID:24520693

  10. Optimization and evaluation of a bottom substrate denitrification tank for nitrate removal from a recirculating aquaculture system

    Institute of Scientific and Technical Information of China (English)

    Wiboonluk Pungrasmi; Cholticha Playchoom; Sorawit Powtongsook

    2013-01-01

    A bottom substrate denitrification tank for a recirculating aquaculture system was developed.The laboratory scale denitrification tank was an 8 L tank (0.04 m2 tank surface area),packed to a depth of 5 cm with a bottom substrate for natural denitrifying bacteria.An aquarium pump was used for gentle water mixing in the tank; the dissolved oxygen in the water was maintained in aerobic conditions (e.g.> 2 mg/L) while anoxic conditions predominated only at the bottom substrate layer.The results showed that,among the four substrates tested (soil,sand,pumice stone and vermiculite),pumice was the most preferable material.Comparing carbon supplementation using methanol and molasses,methanol was chosen as the carbon source because it provided a higher denitrification rate than molasses.When methanol was applied at the optimal COD∶N ratio of 5∶1,a nitrate removal rate of 4591 ± 133 mg-N/m2 tank bottom area/day was achieved.Finally,nitrate removal using an 80 L denitrification tank was evaluated with a 610 L recirculating tilapia culture system.Nitrate treatment was performed by batch transferring high nitrate water from the nitrification tank into the denitrification tank and mixing with methanol at a COD∶N ratio of 5∶1.The results from five batches of nitrate treatment revealed that nitrate was successfully removed from water without the accumulation of nitrite and ammonia.The average nitrate removal efficiency was 85.17% and the average denitrification rate of the denitrification tank was 6311 ± 945 mg-N/m2 tank bottom area/day or 126 ± 18 mg-N/L of pumice packing volume/day.

  11. Potential jamming of recirculation system valves in the safety injection system (SI) and containment spray (CS) systems for 1300 MW/P'4 PWRs

    International Nuclear Information System (INIS)

    By the end of the year 2000, an anomaly has been found in the recirculation system valves of the Safety Injection (SI) and Containment Spray (CS) systems on twelve French 1300 MWe/P'4 pressurized water reactors. This anomaly might block the valve and prevent its opening, especially in case of loss of coolant primary accident (LOCA), due to an operating stress exceeding the value considered for motorization sizing. The reason is a high overpressure in the valve body caused by a temperature rise of the water contained in the body ('thermal binding'). This fault constitutes a potential common-mode failure risk, which could cause the inoperability of the recirculation flow both redundant tracks of the SI and CS systems. The Institute for Protection and Nuclear Safety estimated the core damage risk in this situation at 3 x 10-4 per unit per year. The emergency of processing the generic anomaly led the utility Electricite de France (EdF) to develop a modification in two steps (temporary solution and final solution). (author)

  12. The impact of water exchange rate and treatment processes on water-borne hormones in recirculation aquaculture systems containing sexually maturing Atlantic salmon Salmo salar

    Science.gov (United States)

    A controlled seven-month study was conducted in six replicated water recirculation aquaculture systems (WRAS) to assess post-smolt Atlantic salmon (Salmo salar) performance in relation to WRAS water exchange rate. Unexpectedly high numbers of precocious sexually mature fish were observed in all WRAS...

  13. Stressing fish in Recirculating Aquaculture Systems (RAS): Does stress induced in one group of fish affect the feeding motivation of other fish sharing the same RAS?

    NARCIS (Netherlands)

    Martins, C.I.; Eding, E.H.; Verreth, J.A.J.

    2011-01-01

    As a consequence of water re-use and high stocking densities, Recirculating Aquaculture Systems (RAS) may lead to an accumulation of substances released by the fish into the water, e.g. cortisol and alarm pheromones. This study investigated the effect of stressing fish on the feeding motivation of o

  14. The effects of ozone and water exchange rates on water quality and rainbow trout Oncorhynchus mykiss performance in replicated water recirculating systems

    Science.gov (United States)

    Rainbow trout Oncorhynchus mykiss performance and water quality were evaluated and compared within six replicated 9.5 cubic meter water recirculating aquaculture systems (WRAS) operated with and without ozone at various water exchange rates. Three separate studies were conducted: 1) low water exchan...

  15. Evaluation of ozonation on levels of the off-flavor compounds geosmin and 2-methylisoborneol in water and rainbow trout Oncorhynchus mykiss from water recirculation aquaculture systems

    Science.gov (United States)

    Common “off-flavors” in fish cultured in water recirculation aquaculture systems (WRAS) are “earthy” and “musty” due to the presence of the off-flavor metabolites geosmin and 2-methylisoborneol (MIB), respectively. Previously, ozone addition has been applied to WRAS at relatively low doses to break...

  16. Evaluation of depuration procedures to mitigate off-flavor from harvest size Atlantic Salmon Salmo Salar cultured in a land-based recirculating aquaculture system

    Science.gov (United States)

    Fish cultured within water recirculating aquaculture systems (RAS) can develop “earthy” or “musty” off-flavors in their flesh due to the bioaccumulation of the compounds geosmin and 2-methylisoborenol (MIB), respectively, that are produced by certain bacteria (e.g., actinomycetes). These bacteria an...

  17. Comparing the effects of high vs. low nitrate on the health, performance, and welfare of juvenile rainbow trout Oncorhynchus mykiss within water recirculating aquaculture systems

    Science.gov (United States)

    Previous research indicates that rainbow trout (Oncorhynchus mykiss) begin to exhibit health and welfare problems when cultured within water recirculating aquaculture systems (WRAS) operated at low exchange (6.7 days hydraulic retention time) and a mean feed loading rate of 4.1 kg feed/m3 daily make...

  18. Production characteristics of body composition of Florida pompano reared to market size at two different densities in low salinity recirculating aquaculture systems

    Science.gov (United States)

    The effect of culture density on production characteristics and body composition of Florida pompano Trachinotus carolinus reared to market size using recirculating aquaculture systems (RAS) at a salinity of 5 g/L was evaluated in a 110 day growth trial (water temperature, 27.0-28.5 C). Juvenile pom...

  19. An in-situ RBS system for measuring nuclides adsorbed at the liquid-solid interface

    Energy Technology Data Exchange (ETDEWEB)

    Morita, K.; Yuhara, J.; Ishigami, R. [Nagoya Univ. (Japan). School of Engineering] [and others

    1997-03-01

    An in-situ RBS system has been developed in which heavier nuclides adsorbed at the inner surface of a thin lighter window specimen of liquid container in order to determine the rate constants for their sorption and release at the interface. The testing of a thin silicon window of the sample assembly, in which Xe gas of one atmosphere was enclosed, against the bombardment of the probing ion beam has been performed. A desorption behavior of a lead layer adsorbed at the SiO{sub 2} layer of silicon window surface into deionized water has been measured as a preliminary experiment. (author)

  20. Effect of copper on the growth of shrimps Litopenaeus vannamei: water parameters and copper budget in a recirculating system

    Science.gov (United States)

    Cheng, Bo; Liu, Ying; Yang, Hongsheng; Song, Yi; Li, Xian

    2014-09-01

    Shrimps ( Litopenaeus vannamei) were intensively cultured in a recirculating aquaculture system for 98 days to investigate effects of 0.3 mg/L Cu on its performance, Cu budget, and Cu distribution. Shrimps in Cu-treated systems had greater mean final weight (11.10 vs 10.50 g), body length (107.23 vs 106.42 mm), survival rate (67.80% vs 66.40%), and yield (6.42 vs 5.99 kg/m3), and lower feed conversion ratio (1.20 vs 1.29) than those in control systems but the differences were not significant. Vibrio numbers remained stable (104-106 colony forming units/mL) in the rearing tanks of both control and treated systems. Total ammonium-N, nitrite-N, nitrate-N, pH, chemical oxygen demand, 5-day carbonaceous biochemical oxygen demand, and total suspended solids were similar in controls and treatments. Dissolved Cu concentration in the treated systems decreased from 0.284 to 0.089 mg/L while in the control systems it increased from 0.006 2 to 0.018 mg/L. The main sources of Cu in the treated systems were the artificially added component (75.7% of total input), shrimp feed (21.0%), water (2.06%), and shrimp biomass (1.22%). The major outputs of Cu occurred via the mechanical filter (41.7%), water renewal (15.6%), and draining of the sediment trap (15.1%). The foam fractionator removed only 0.69% of total Cu input. Harvested shrimp biomass accounted for 11.68% of Cu input. The Cu concentration of shrimps in the Cu-treated systems (30.70 mg/kg wet weight) was significantly higher than that in control systems (22.02 mg/kg). Both were below the maximum permissible concentration (50 mg/kg) for Cu in seafood for human consumption in China. Therefore, recirculating systems can be used for commercial on-growing of Litopenaeus vannamei without loss of shrimp quality, even in water polluted by 0.30 mg/L Cu. The mechanical filter is the main route for Cu removal.

  1. Study complex of properties of the adsorbent for renewal filters of ventilation systems NPP

    International Nuclear Information System (INIS)

    Using standard and developed at NSC KIPT techniques it was carried out a comprehensive research of working characteristics (aerodynamic resistance in conditions modeling work adsorber AU-1500; mechanical strength abrasion; adsorption capacity for iodine and methyl iodide) of activated coals from different manufacturers, intended for use in rehabilitation and reconstruction of the adsorption filter ventilation system at NPP

  2. Analyzing and Evaluating of Recirculating Aquaculture Systems (RAS) of Rainbow Trout in Order to Designing a Conceptual Model of Efficient RAS in Iran (Tehran)

    OpenAIRE

    M. Mahmoodzadeh; M Almassi; A.M. Borghei; B. Beheshti

    2013-01-01

    In this study, Recirculation Aquaculture Systems (RAS) of rainbow trout were analyzed and evaluated in Iran (Tehran). After analyzing these systems it was found which of them were better than others and then their parameters were used for designing a conceptual model of efficient RAS. This study was conducted in Iran (Tehran) in 2012 and statistical population and samples were 8 systems. Systems were analyzed and evaluated by five criteria which were as follows: economy, energy, consumption a...

  3. Effects of elevated atmospheric carbon dioxide concentrations on water and acid requirements of soybeans grown in a recirculating hydroponic system

    Science.gov (United States)

    Mackowiak, C. L.; Wheeler, R. M.; Lowery, W.; Sager, J. C.

    1990-01-01

    Establishing mass budgets of various crop needs, i.e. water and nutrients, in different environments is essential for the Controlled Ecological Life Support System (CELSS). The effects of CO2 (500 and 1000 umol mol (exp -1)) on water and acid use (for pH control) by soybeans in a recirculating hydroponic system were examined. Plants of cvs. McCall and Pixie were grown for 90 days using the nutrient film technique (NFT) and a nitrate based nutrient solution. System acid use for both CO2 levels peaked near 4 weeks during a phase of rapid vegetative growth, but acid use decreased more rapidly under 500 compared to 1000 umol mol (exp GR) CO2. Total system water use by 500 and 1000 umol mol (exp -1) plants was similar, leaving off at 5 weeks and declining as plants senesced (ca. 9 weeks). However, single leaf transpiration rates were consistently lower at 1000 umol mol (exp -1). The data suggest that high CO2 concentrations increase system acid (and nutrient) use because of increased vegetative growth, which in turn negates the benefit of reduced water use (lower transpiration rates) per unit leaf area.

  4. Implementation of an experimental pilot reproducing the fouling of the exhaust gas recirculation system in diesel engines

    Directory of Open Access Journals (Sweden)

    Crepeau Gérald

    2012-04-01

    Full Text Available The European emission standards EURO 5 and EURO 6 define more stringent acceptable limits for exhaust emissions of new vehicles. The Exhaust Gas Recirculation (EGR system is a partial but essential solution for lowering the emission of nitrogen oxides and soot particulates. Yet, due to a more intensive use than in the past, the fouling of the EGR system is increased. Ensuring the reliability of the EGR system becomes a main challenge. In partnership with PSA Peugeot Citroën, we designed an experimental setup that mimics an operating EGR system. Its distinctive features are (1 its ability to reproduce precisely the operating conditions and (2 its ability to measure the temperature field on the heat exchanger surface with an Infra Red camera for detecting in real time the evolution of the fooling deposit based on its thermal resistance. Numerical codes are used in conjunction with this experimental setup to determine the evolution of the fouling thickness from its thermal resistance.

  5. Non-equilibrium Transport in Carbon based Adsorbate Systems

    Science.gov (United States)

    Fürst, Joachim; Brandbyge, Mads; Stokbro, Kurt; Jauho, Antti-Pekka

    2007-03-01

    We have used the Atomistix Tool Kit(ATK) and TranSIESTA[1] packages to investigate adsorption of iron atoms on a graphene sheet. The technique of both codes is based on density functional theory using local basis sets[2], and non-equilibrium Green's functions (NEGF) to calculate the charge distribution under external bias. Spin dependent electronic structure calculations are performed for different iron coverages. These reveal adsorption site dependent charge transfer from iron to graphene leading to screening effects. Transport calculations show spin dependent scattering of the transmission which is analysed obtaining the transmission eigenchannels for each spin type. The phenomena of electromigration of iron in these systems at finite bias will be discussed, estimating the so-called wind force from the reflection[3]. [1] M. Brandbyge, J.-L. Mozos, P. Ordejon, J. Taylor, and K. Stokbro. Physical Review B (Condensed Matter and Materials Physics), 65(16):165401/11-7, 2002. [2] Jose M. Soler, Emilio Artacho, Julian D. Gale, Alberto Garcia, Javier Junquera, Pablo Ordejon, and Daniel Sanchez-Portal. Journal of Physics Condensed Matter, 14(11):2745-2779, 2002. [3] Sorbello. Theory of electromigration. Solid State Physics, 1997.

  6. Bacterially mediated removal of phosphorus and cycling of nitrate and sulfate in the waste stream of a "zero-discharge" recirculating mariculture system

    OpenAIRE

    M. D. Krom; A. Ben David; E. D. Ingall; Liane G. Benning; S. Clerici; S. Bottrell; C. Davies; N. J. Potts; R. J. G. Mortimer; J. van Rijn

    2014-01-01

    Simultaneous removal of nitrogen and phosphorus by microbial biofilters has been used in a variety of water treatment systems including treatment systems in aquaculture. In this study, phosphorus, nitrate and sulfate cycling in the anaerobic loop of a zero-discharge, recirculating mariculture system was investigated using detailed geochemical measurements in the sludge layer of the digestion basin. High concentrations of nitrate and sulfate, circulating in the overlying water (∼15 mM), were r...

  7. Effectiveness of Floating Micro-Bead Bio-Filter for Ornamental Fish in a Re-Circulating Aquaculture System

    Directory of Open Access Journals (Sweden)

    R Fadhil

    2011-01-01

    Full Text Available Bio-filtration has been widely used in re-circulating aquaculture system to remove waste and to convert toxic ammonia andnitrite into safe end products ornamental fish and other aquatic organisms. However, the study of micro-bead usage as the filter medium has not yet been broadened and thoroughly developed. Therefore, the aim of this study is to construct a biological filter made from polyethylene micro-bead as the filter medium and to analyze its effectiveness in removingwaste as well as in converting the toxic organic matter into stable substances. The bio-filter was constructed under a rotational molding process. The tubes, hoses, and piping were made from polyvinyl chloride (PVC while the fasteners were made from stainless steel and other non-corrosive materials. The effectiveness of this bio-filter was measured by using biochemical oxygen demand (BOD and total suspended solids (TSS analysis. Results indicated that this bio-filter is efficient enough to remove suspended solids and BOD. Therefore, this floating micro-bead bio-filter can be used in aquaculture systems.

  8. Ammonia-oxidizing archaea and nitrite-oxidizing nitrospiras in the biofilter of a shrimp recirculating aquaculture system.

    Science.gov (United States)

    Brown, Monisha N; Briones, Aurelio; Diana, James; Raskin, Lutgarde

    2013-01-01

    This study analysed the nitrifier community in the biofilter of a zero discharge, recirculating aquaculture system (RAS) for the production of marine shrimp in a low density (low ammonium production) system. The ammonia-oxidizing populations were examined by targeting 16S rRNA and amoA genes of ammonia-oxidizing bacteria (AOB) and archaea (AOA). The nitrite-oxidizing bacteria (NOB) were investigated by targeting the 16S rRNA gene. Archaeal amoA genes were more abundant in all compartments of the RAS than bacterial amoA genes. Analysis of bacterial and archaeal amoA gene sequences revealed that most ammonia oxidizers were related to Nitrosomonas marina and Nitrosopumilus maritimus. The NOB detected were related to Nitrospira marina and Nitrospira moscoviensis, and Nitrospira marina-type NOB were more abundant than N. moscoviensis-type NOB. Water quality and biofilm attachment media played a role in the competitiveness of AOA over AOB and Nitrospira marina-over N. moscoviensis-type NOB. PMID:22775980

  9. Molecular Analysis of Bacterial Communities and Detection of Potential Pathogens in a Recirculating Aquaculture System for Scophthalmus maximus and Solea senegalensis

    OpenAIRE

    Patrícia Martins; Cleary, Daniel F. R.; Pires, Ana C. C.; Ana Maria Rodrigues; Victor Quintino; Ricardo Calado; Gomes, Newton C M

    2013-01-01

    The present study combined a DGGE and barcoded 16S rRNA pyrosequencing approach to assess bacterial composition in the water of a recirculating aquaculture system (RAS) with a shallow raceway system (SRS) for turbot (Scophthalmus maximus) and sole (Solea senegalensis). Barcoded pyrosequencing results were also used to determine the potential pathogen load in the RAS studied. Samples were collected from the water supply pipeline (Sup), fish production tanks (Pro), sedimentation filter (Sed), b...

  10. A model for predicting the quantities of dissolved inorganic nitrogen released in effluents from a sea bass (Dicentrarchus labrax) recirculating water system

    OpenAIRE

    Pagand, Pascal; Blancheton, Jean-Paul; Casellas, Claude

    2000-01-01

    Fish excretions and the transformation of nitrogen by bacteria in the nitrifying biofilter are two of the main sources of dissolved inorganic nitrogen (DIN) in fish farms that use recirculating water systems. In this study, the DIN concentration in an experimental Dicentrarchus labrax aquaculture system was calculated using empirical sub-models for fish growth, ingested food and water replacement. The specific growth rate (SGR) (% day(-1)) and the daily feeding rate (DFR) (% day(-1)) both dep...

  11. New catalysts and adsorbents on the basis of the InSb-CdTe semiconducting system

    International Nuclear Information System (INIS)

    The acid-base, adsorption, and catalytic properties of solid solutions and binary components of the InSb-CdTe system were studied. The nature, strength, and concentration of acid centers were determined. Changes in the concentration of acid centers under the action of gases (NO2 and NH3), gamma radiation, and composition variations were estimated. The experimental dependences, thermodynamic and kinetic adsorption characteristics, the electrophysical, acid-base, and other physicochemical characteristics of the adsorbents, and adsorption characteristic-composition phase diagrams were analyzed taking into account the electronic nature of adsorbate molecules to determine the mechanism and characteristics of adsorption processes depending on the conditions of adsorption and the composition of the system

  12. Measurement of in-core and recirculation system response to hydrogen water chemistry at Nine Mile Point 1

    International Nuclear Information System (INIS)

    The value of hydrogen water chemistry (HWC) as a mitigation technique for out-of-core piping systems susceptible to intergranular stress corrosion cracking (IGSCC) is well established. However, certain reactor internal components exposed to high levels of radiation are susceptible to a cracking mechanism referred to as irradiation assisted stress corrosion cracking (IASCC). Some of the components potentially affected by IASCC include the top guide, SRM/IRM housings, the core shroud, and control blades. Fortunately, laboratory data indicate that IASCC can be controlled by altering the coolant environment. Hot cell tests performed at GE's Vallecitos Nuclear Center (VNC) on highly irradiated material produced a fracture surface with 99% IGSCC under normal BWR water chemistry. However, under HWC conditions, only ductile failure occurred. With this background, a program was established to determine the chemistry and oxidizing potential of the core bypass coolant at Nine Mile Point-1 (NMP-1) under normal and HWC conditions. The objective of the program was to assess whether HWC could sufficiently modify the core bypass environment to mitigate IASCC. Results showed that with the addition of hydrogen to the feedwater, core bypass dissolved oxygen decreased very rapidly, compared to the recirculation water, indicating very efficient recombination of hydrogen and oxygen in the non-boiling core bypass region. Since low concentrations of dissolved oxygen have been shown to eliminate IASCC, these results are encouraging. 8 figs., 1 tab

  13. Comparison of aerobically-treated and untreated crop residue as a source of recycled nutrients in a recirculating hydroponic system

    Science.gov (United States)

    Mackowiak, C. L.; Garland, J. L.; Strayer, R. F.; Finger, B. W.; Wheeler, R. M.

    1996-01-01

    This study compared the growth of potato plants on nutrients recycled from inedible potato biomass. Plants were grown for 105 days in recirculating, thin-film hydroponic systems containing four separate nutrient solution treatments: (1) modified half-strength Hoagland's (control), 2) liquid effluent from a bioreactor containing inedible potato biomass, 3) filtered (0.2 micrometer) effluent, and 4) the water soluble fraction of inedible potato biomass (leachate). Approximately 50% of the total nutrient requirement in treatments 2-4 were provided (recycled) from the potato biomass. Leachate had an inhibitory effect on leaf conductance, photosynthetic rate, and growth (50% reduction in plant height and 60% reduction in tuber yield). Plants grown on bioreactor effluent (filtered or unfiltered) were similar to the control plants. These results indicated that rapidly degraded, water soluble organic material contained in the inedible biomass, i.e., material in leachate, brought about phytotoxicity in the hydroponic culture of potato. Recalcitrant, water soluble organic material accumulated in all nutrient recycling treatments (650% increase after 105 days), but no increase in rhizosphere microbial numbers was observed.

  14. Hydroxyl carboxylate based non-phosphorus corrosion inhibition process for reclaimed water pipeline and downstream recirculating cooling water system.

    Science.gov (United States)

    Wang, Jun; Wang, Dong; Hou, Deyin

    2016-01-01

    A combined process was developed to inhibit the corrosion both in the pipeline of reclaimed water supplies (PRWS) and in downstream recirculating cooling water systems (RCWS) using the reclaimed water as makeup. Hydroxyl carboxylate-based corrosion inhibitors (e.g., gluconate, citrate, tartrate) and zinc sulfate heptahydrate, which provided Zn(2+) as a synergistic corrosion inhibition additive, were added prior to the PRWS when the phosphate (which could be utilized as a corrosion inhibitor) content in the reclaimed water was below 1.7mg/L, and no additional corrosion inhibitors were required for the downstream RCWS. Satisfactory corrosion inhibition was achieved even if the RCWS was operated under the condition of high numbers of concentration cycles. The corrosion inhibition requirement was also met by the appropriate combination of PO4(3-) and Zn(2+) when the phosphate content in the reclaimed water was more than 1.7mg/L. The process integrated not only water reclamation and reuse, and the operation of a highly concentrated RCWS, but also the comprehensive utilization of phosphate in reclaimed water and the application of non-phosphorus corrosion inhibitors. The proposed process reduced the operating cost of the PRWS and the RCWS, and lowered the environmental hazard caused by the excessive discharge of phosphate. Furthermore, larger amounts of water resources could be conserved as a result. PMID:26899639

  15. Biological denitrification using poly(butylene succinate) as carbon source and biofilm carrier for recirculating aquaculture system effluent treatment.

    Science.gov (United States)

    Zhu, Song-Ming; Deng, Ya-Le; Ruan, Yun-Jie; Guo, Xi-Shan; Shi, Ming-Ming; Shen, Jia-Zheng

    2015-09-01

    Nitrate removal is essential for the sustainable operation of recirculating aquaculture system (RAS). This study evaluated the heterotrophic denitrification using poly(butylene succinate) as carbon source and biofilm carrier for RAS wastewater treatment. The effect of varied operational conditions (influent type, salinity and nitrate loading) on reactor performance and microbial community was investigated. The high denitrification rates of 0.53 ± 0.19 kg NO3(-)-N m(-3) d(-1) (salinity, 0‰) and 0.66 ± 0.12 kg NO3(-)-Nm(-3) d(-1) (salinity, 25‰) were achieved, and nitrite concentration was maintained below 1mg/L. In addition, the existence of salinity exhibited more stable nitrate removal efficiency, but caused adverse effects such as excessive effluent dissolved organic carbon (DOC) and dissimilation nitrate reduce to ammonia (DNRA) activity. The degradation of PBS was further confirmed by SEM and FTIR analysis. Illumina sequencing revealed the abundance and species changes of functional denitrification and degradation microflora which might be the primary cause of varied reactor performance. PMID:26093254

  16. The influence of different stocking densities on biochemical composition of rainbow trout meat reared in a recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    Mirela Cretu

    2014-05-01

    Full Text Available The aim of this study is to evaluate the biochemical composition of rainbow trout meat, reared in a recirculating aquaculture system, at different stocking densities (DS1-2,64 kg/m3, DS2-5,16 kg/m3, DS3-7,12 kg/m3, DS4-9,42 kg/m3. The analyses were performed in the research laboratory of Aquaculture, Environmental Science and Cadastre Department – Faculty of Food Science and Engineering, from ,,Dunarea de Jos’’University of Galati. The content of meat proteins, fats, dry substance and ash was determined. After a 33 days experimental trial, the biochemical analysis of meat from all four experimental variants shows that protein content was higher in DS1 and DS4 variants, while the smallest amount of fats was quantified at DS1 and DS2 variants, without significant differences (p >0.05 for none of the biochemical compounds analyzed, at the mean comparison on experimental variants. Thus, it can be concluded that biochemical composition of rainbow trout meat was not influenced by the tested stocking densities.

  17. The effects of different seeding ratios on nitrification performance and biofilm formation in marine recirculating aquaculture system biofilter.

    Science.gov (United States)

    Zhu, Songming; Shen, Jiazheng; Ruan, Yunjie; Guo, Xishan; Ye, Zhangying; Deng, Yale; Shi, Mingming

    2016-07-01

    Rapid start-up of biofilter is essential for intensive marine recirculating aquaculture system (RAS) production. This study evaluated the nitrifying biofilm formation using mature biofilm as an inoculum to accelerate the process in RAS practice. The effects of inoculation ratios (0-15 %) on the reactor performance and biofilm structure were investigated. Complete nitrification was achieved rapidly in reactors with inoculated mature biofilm (even in 32 days when 15 % seeding ratio was applied). However, the growth of target biofilm on blank carrier was affected by the mature biofilm inoculated through substrate competition. The analysis of extracellular polymeric substance (EPS) and nitrification rates confirmed the divergence of biofilm cultivation among reactors. Besides, three N-acyl-homoserine lactones (AHLs) were found in the process, which might regulate the activities of biofilm. Multivariate analysis based on non-metric multidimensional scaling (nMDS) also indicated the great roles of AHLs and substrate supply which might fundamentally determine varied cultivation performance on target biofilm. PMID:27068911

  18. The Effects of Some Phytobiotics on Biochemical Composition of Oreochromis Niloticus Meat Reared in a Recirculating Aquaculture System

    Directory of Open Access Journals (Sweden)

    Alina Antache

    2013-05-01

    Full Text Available The purpose of this experiment is the evaluation of biochemical composition of Nile tilapia meat by administrating  several phytobiotics in feed. Oreochromis niloticus, with an initial average weight of 125.41±34.33 g/exemplar, were reared, during six weeks in a recirculating aquaculture system. The phytobiotics from this experiment were administered in feed in a concentration of 1%/kg feed and consist in: thyme (Thymus vulgaris, fenugreek (Trigonela foenum graecum, neem (Azadirachta indica. Thus, the experimental variants were: V1-control, V2-thyme, V3-fenugreek and V4-neem. Fish were fed with SOPROFISH pelleted feed with 38% crude protein and 7% crude fat. During the experiment, the physico-chemical parameters of technological water were situated in normal range for optimal growth. At the end of the experiment, significant differences (p<0.05 were recorded between the experimental variants, regarding to moisture, protein content, fat content and dry matter; unsignificant differences were recorded regarding the percentage of ash (p>0.05; p=0.68. The highest value of moisture (87.25% was registered in V2; the lowest value of fat content (0.05% was recorded in V4 and the lowest protein content (10.79% in V2. In conclusion, thyme, fenugreek and neem administration, in concentration of 1%/kg feed, influenced significantly the biochemical composition of Oreochromis niloticus.

  19. Application of CFD Modeling to Hydrodynamics of CycloBio Fluidized Sand Bed in Recirculating Aquaculture Systems

    Institute of Scientific and Technical Information of China (English)

    LIU Yao; SONG Xiefa; LIANG Zhenlin; PENG Lei

    2014-01-01

    To improve the efficiency of a CycloBio fluidized sand bed (CB FSB) in removal of dissolved wastes in recirculating aquaculture systems, the hydrodynamics of solid-liquid flow was investigated using computational fluid dynamics (CFD) modeling tools. The dynamic characteristics of silica sand within the CB FSB were determined using three-dimensional, unsteady-state simula-tions with the granular Eulerian multiphase approach and the RNG k-ε turbulence model, and the simulation results were validated using available lab-scale measurements. The bed expansion of CB FSB increased with the increase in water inflow rate in numerical simulations. Upon validation, the simulation involving 0.55 mm particles, the Gidaspow correlation for drag coefficient model and the Syamlal-O’Brien correlation for kinetic granular viscosity showed the closest match to the experimental results. The volume frac-tion of numerical simulations peaked as the wall was approached. The hydrodynamics of a pilot-scale CB FSB was simulated in or-der to predict the range of water flow to avoid the silica sand overflowing. The numerical simulations were in agreement with the experimental results qualitatively and quantitatively, and thus can be used to study the hydrodynamics of solid-liquid multiphase flow in CB FSB, which is of importance to the design, optimization, and amplification of CB FSBs.

  20. Effects of solid-phase denitrification on the nitrate removal and bacterial community structure in recirculating aquaculture system.

    Science.gov (United States)

    Qiu, Tianlei; Liu, Lili; Gao, Min; Zhang, Lanhe; Tursun, Haireti; Wang, Xuming

    2016-06-01

    A solid-phase denitrification (SPD) reactor packed with poly (3-hydroxybutyrate-co-3-hydroxyvalerate) as a carbon source was incorporated into a recirculating aquaculture system (RAS) to remove accumulated nitrate. Bacterial community structures in different parts of the RAS, including biofilter unit, SPD reactor, and culture water, were analyzed using Illumina MiSeq sequencing technology. The data showed that nitrate levels decreased remarkably in the RAS connected with SPD reactor (RAS-DR). In contrast, nitrate levels increased continuously in the conventional RAS without SPD reactor (RAS-CK). Biofilter unit and culture water in RAS-DR developed lower species richness and higher bacterial community diversity than that in RAS-CK. The bacterial community structure of RAS was significantly affected by the SPD process and the changes included an increase in the proportion of Proteobacteria and Firmicutes and a decrease in Nitrospira abundance in RAS-DR. Firmicutes was the most abundant phylum (56.9 %) and mainly consisted of Clostridium sensu stricto (48.3 %) in SPD reactor. PMID:27125529

  1. Regression equations for predicting discharge performance of adsorbed natural gas storage systems

    International Nuclear Information System (INIS)

    Simple regression equations are proposed to predict the discharge performance of adsorbed natural gas storage systems consisting of tubular reactors filled with MAXSORB III. The regression equations are obtained for discharge time and heat transferred in terms of few relevant and statistically significant non-dimensional numbers. The data required for regression analysis is generated by numerically solving the transient heat and mass transfer equations of adsorbed natural gas (ANG) storage system undergoing discharge under constant flow condition. The regression equations are compared with the values obtained from numerical simulations and it is observed that the difference between the two is well within 25% for all the parameters. Using the correlations it is possible to quickly estimate important performance parameters such as delivery capacity and energy to be supplied for a variety of tubular ANG reactors filled with MAXSORB III. - Highlights: • Theoretical analysis of adsorbed natural gas storage reactors is carried out. • The governing equations in non-dimensional form are solved numerically. • Based on the results, regression equations for discharge are proposed. • The regression equations cover a wide range of design and operating conditions. • Proposed equations are useful in quick estimation of system performance

  2. Ethanol adsorption onto carbonaceous and composite adsorbents for adsorptive cooling system

    International Nuclear Information System (INIS)

    The aim of the present paper is the experimental characterization of adsorbent materials suitable for practical applications in adsorption refrigeration systems, employing ethanol as refrigerant. Different commercial activated carbons as well as a properly synthesized porous composite, composed of LiBr inside a silica gel host matrix, have been tested. A complete thermo-physical characterization, comprising nitrogen physi-sorption, specific heat and thermo-gravimetric equilibrium curves of ethanol adsorption over the sorbents, has been carried out. The equilibrium data have been fitted by means of the Dubinin – Astakhov equation. On the basis of the experimental data, a thermodynamic evaluation of the achievable performance of each adsorbent pair has been estimated by calculating the maximum COP (Coefficient of Performance) under typical working boundary conditions for refrigeration and air conditioning applications. The innovative composite material shows the highest thermodynamic performances of 0.64–0.72 for both tested working conditions. Nevertheless, the best carbonaceous material reaches COP value comparable with the synthesized composite. The results have demonstrated the potential of the chosen adsorbents for utilization in adsorption cooling systems. - Highlights: • We studied ethanol adsorption for adsorption cooling systems. • Commercial activated carbons and composite sorbent, LiBr/SiO2, are tested by complete thermo-physical characterization. • A thermodynamic evaluation has been carried out on each working pairs to estimate the performance of a refrigeration cycle

  3. Potential jamming of recirculation system valves in the safety injection (SI) and containment spray (CS) systems for 1300 MWEP'4 PWR's

    International Nuclear Information System (INIS)

    By the end of the year 2000, an anomaly has been found in the recirculation system valves of the Safety Injection (SI) and Containment Spray (CS) systems on twelve French 1300 MWe/P'4 pressurized water reactors. This anomaly might block the valve and prevent its opening, especially in case of loss of coolant primary accident (LOCA), due to an operating stress exceeding the value considered for motorization sizing. The reason is a high overpressure in the valve body caused by a temperature rise of the water contained in the body ('thermal binding'). This fault constitutes a potential common-mode failure risk, which could cause the inoperability of the recirculation flow both redundant tracks of the SI and CS systems. The Institute for Protection and Nuclear Safety estimated the core damage risk in this situation at 3 x 10-4 per unit per year. The emergency of processing the generic anomaly led the utility Electricite de France (EdF) to develop a modification in two steps (temporary solution and final solution). (author)

  4. Nitrogen and Phosphorus Removal in the Recirculating Aquaculture System with Water Treatment Tank containing Baked Clay Beads and Chinese Cabbage

    Directory of Open Access Journals (Sweden)

    Aeknarin Thanakitpairin

    2014-01-01

    Full Text Available This research aims to describe the nitrogen and phosphorus removal in Recirculating Aquaculture System (RAS by crop plants biomass production. The 3 experiment systems consisted of 1 treatment (fish tank + baked clay beads + Chinese cabbage and 2 controls as control-1 (fish tank only and control-2 (fish tank + baked clay beads, were performed. With all experimental RAS, Nile tilapia (Oreochromis niloticus was cultured at 2 kg/m3 density. The baked clay beads (8-16 mm in diameter were filled as a layer of 10 cm in the water treatment tank of control-2. While in the treatment tank, Chinese cabbage (Brassica pekinensis was planted at 334 plants/m2 in baked clay beads layer. During 35 days of experiment, the average fish wet-weight in control-1, control-2 and treatment systems increased from 16.31±1.49, 15.18±1.28 and 11.31±1.49 g to 29.43±7.06, 28.65±3.12 and 27.20±6.56 g, respectively. It was found that the growth rate of 0.45±0.15 g-wet weight/day in a treatment tank was higher than in those 2 controls, which were rather similar at 0.37±0.16 and 0.38±0.05 g-wet weight/day, respectively. The fish survival rate of all experimental units was 100%. The average Chinese cabbage wet-weight in treatment system increased from 0.15±0.02 g to 1.00±0.38 g. For water quality, all parameters were within the acceptable range for aquaculture. The assimilation inorganic nitrogen in a treatment tank showed a slower rate and lower nitrite accumulation relative to those in control tanks. The nitrogen and phosphorus balance analysis illustrated that most of the nitrogen and phosphorus input in all systems was from feed (82-87% and 21-87% while at the final day of experiments, nitrogen and phosphorus in tilapia culture revealed at 15-19% and 4-13%. The accumulation of nitrogen and phosphorus in the water, up to 56% and 70%, was found in control-1 while water in the tank with baked clay beads had substantial lower nitrogen and phosphorus concentration. The

  5. Study of Water Quality of Recirculated Water in Aquaponic Systems: Study of speciation of selected metals and characterization of the properties of natural organic matter

    OpenAIRE

    Gjesteland, Ingrid

    2013-01-01

    This thesis describes an extensive study on how water quality changes over time in a small scale recirculating system where waste water from smolt production was used to grow lettuce for commercial use. The treatment effect of lettuce on different solutions was tested and corresponding lettuce yield was evaluated. In order to enhance the treatment effect a rock wool filter was used on certain solutions. Important water quality parameters were measured every day, and the element concentration ...

  6. Improved water quality in recirculating aquaculture systems (RAS) by applying a membrane bioreactor (MBR) concept for removal of colloidal and fine suspended solids

    OpenAIRE

    Holan, Astrid Buran

    2013-01-01

    The world’s human population is growing, and there is an increased demand for food. Aquaculture production is increasing rapidly to meet these demands and there is a growing interest for recirculating aquaculture systems (RAS) to maximize production. A typical RAS facility consists of production tanks and a water treatment compartment for removal or conversion of accumulated nutrients, organic matter and particulates where the treated water is recycled to the production tanks. Reuse of water ...

  7. The impact of level of the stocking density on the haematological parameters of rainbow trout (Oncorhynchus mykiss) reared in recirculating aquaculture systems

    OpenAIRE

    Angelica Docan; Victor Cristea; Lorena Dediu; Mirela Mocanu; Iulia Grecu

    2011-01-01

    Hematological indices are important parameters for the evaluation of fish physiological status.The purpose of this experiment was to evaluate how level of the stocking density influence the bloodphysiology of of juvenile rainbow trout (Oncorhynchus mykiss) reared in a recirculating system. Theexperiment was conducted over a period of 33 days. A number of 254 rainbow trout with an averageweight of 29.51 ± 1.32 g were divided into four rearing units in order to create different stockingdensitie...

  8. Simulation and tests to individual and coupled models of the reactor vessel simulator and the recirculation system for the SUN-RAH

    International Nuclear Information System (INIS)

    The present project, is continuation of the project presented in the congress SNM-2003. In this new phase of the project, they were carried out adaptive changes to the modeling and implementation of the module of the full superior of the core of the reactor, they were carried out those modeling of the generation of heat as well as of the energy transfer in the one fuel. These models present the main characteristics of the vessel of the one reactor and of the recirculation system, defined by the main phenomena that they intervene in the physical processes, in the previous version the simulation in real time it required of an extremely quick computer and without executing collateral processes. The tests are presented carried out to the different models belonging to the Simulator of the Reactor Vessel and the Recirculation system for the SUN-RAH (University Simulator of Nucleo electric with Boiling Water Reactor), as well as the results hurtled by this tests. In each section the executions of the tests and the corresponding analyses of results are shown for each pattern. Besides the above mentioned, the advantages presented by the Simulator of the reactor vessel and the recirculation system are pointed. (Author)

  9. End-of-pipe single-sludge denitrification in pilot-scale recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Suhr, Karin Isabel; Pedersen, Lars-Flemming; Nielsen, J.L.

    2014-01-01

    A step toward environmental sustainability of recirculat aquaculture systems (RAS) is implementation ofsingle-sludge denitrification, a process eliminating nitrate from the aqueous environment while reduc-ing the organic matter discharge simultaneously. Two 1700 L pilot-scale RAS systems each wit...

  10. Effect of Recirculating Aquaculture System (RAS on Growth Performance, Body Composition and Hematological Indicators of Allogynogenetic crucian Carp (Carassius auratus gibelio

    Directory of Open Access Journals (Sweden)

    Xiao-li Li

    2013-03-01

    Full Text Available A Ditch Constructed Wetland unit (DCW was integrated into an outdoor RAS with four fishponds. This study evaluated the performance of the wetland unit in treating the recirculating wastewater and examined the effect of Recirculating Aquaculture System (RAS on growth performance, body composition and hematological indicators of the rearing fish. During a 165-days culture period, the DCW effectively reduced the influent concentrations of nutrients and can keep a good water quality at acceptable concentrations for growth of the fish. Growth performance, body composition and hematological indicators of Allogynogenetic crucian carp were closely related to water quality of their living environment. The RAS had improved the growth performance and quality of Allogynogenetic crucian carp.

  11. Aging assessment of nuclear air-treatment system HEPA filters and adsorbers

    International Nuclear Information System (INIS)

    A Phase I aging assessment of high-efficiency particulate air (HEPA) filters and activated carbon gas adsorption units (adsorbers) was performed by the Pacific Northwest Laboratory (PNL) as part of the US Nuclear Regulatory Commission's (NRC) Nuclear Plant Aging Research (NPAR) Program. Information concerning design features; failure experience; aging mechanisms, effects, and stressors; and surveillance and monitoring methods for these key air-treatment system components was compiled. Over 1100 failures, or 12 percent of the filter installations, were reported as part of a Department of Energy (DOE) survey. Investigators from other national laboratories have suggested that aging effects could have contributed to over 80 percent of these failures. Tensile strength tests on aged filter media specimens indicated a decrease in strength. Filter aging mechanisms range from those associated with particle loading to reactions that alter properties of sealants and gaskets. Low radioiodine decontamination factors associated with the Three Mile Island (TMI) accident were attributed to the premature aging of the carbon in the adsorbers. Mechanisms that can lead to impaired adsorber performance include oxidation as well as the loss of potentially available active sites as a result of the adsorption of pollutants. Stressors include heat, moisture, radiation, and airborne particles and contaminants

  12. The structure and function of microbial communities in recirculating hydroponic systems

    Science.gov (United States)

    Garland, J. L.

    1994-11-01

    Strategies to control the microbial community associated with plant growth systems need to be based on a fundamental understanding of the factors which structure and regulate the community. Spatial and temporal patterns in the abundance and production rate of microorganisms in hydroponic systems containing wheat were examined to evaluate how root-derived carbon is processed. The relevance of results to monitoring and control strategies is discussed.

  13. Development of a water recirculating system for bullfrog production: technological innovation for small farmers

    Directory of Open Access Journals (Sweden)

    Sílvia Conceição Reis Pereira Mello

    2016-02-01

    Full Text Available ABSTRACT Despite the technological progress in frog farming, issues related to the environment, biosafety, and the use of technologies that minimise environmental impacts are frequently neglected by farmers. With the goal of developing a low-cost technology for reuse and preservation of water quality, an anaerobic filtering system combined with an aerobic filtering system was implemented in the grow-out sector in the Frog Culture Research Unit at Fundação Instituto de Pesca do Estado do Rio de Janeiro (FIPERJ. The filtering system received the effluent from six pens of frogs that were populated with 362 frogs in different development phases. The efficiency of the filtering system was evaluated by an analysis of the water before and after passing through the filters. In addition to the standards of water quality, the animals' performance was also observed through monitoring rates of survival, weight gain and feed conversion ratio. The results showed the effectiveness of the filtering system by removing organic matter, on average 87%. The values of total ammonia and non-ionisable reached 1.04 and 0.004 mg/L, respectively. Also, frogs subjected to the system presented satisfactory rates of weight gain and a high survival rate (97%.

  14. Uncultured bacterial diversity in a seawater recirculating aquaculture system revealed by 16S rRNA gene amplicon sequencing.

    Science.gov (United States)

    Lee, Da-Eun; Lee, Jinhwan; Kim, Young-Mog; Myeong, Jeong-In; Kim, Kyoung-Ho

    2016-04-01

    Bacterial diversity in a seawater recirculating aquaculture system (RAS) was investigated using 16S rRNA amplicon sequencing to understand the roles of bacterial communities in the system. The RAS was operated at nine different combinations of temperature (15°C, 20°C, and 25°C) and salinity (20‰, 25‰, and 32.5‰). Samples were collected from five or six RAS tanks (biofilters) for each condition. Fifty samples were analyzed. Proteobacteria and Bacteroidetes were most common (sum of both phyla: 67.2% to 99.4%) and were inversely proportional to each other. Bacteria that were present at an average of ≥ 1% included Actinobacteria (2.9%) Planctomycetes (2.0%), Nitrospirae (1.5%), and Acidobacteria (1.0%); they were preferentially present in packed bed biofilters, mesh biofilters, and maturation biofilters. The three biofilters showed higher diversity than other RAS tanks (aerated biofilters, floating bed biofilters, and fish tanks) from phylum to operational taxonomic unit (OTU) level. Samples were clustered into several groups based on the bacterial communities. Major taxonomic groups related to family Rhodobacteraceae and Flavobacteriaceae were distributed widely in the samples. Several taxonomic groups like [Saprospiraceae], Cytophagaceae, Octadecabacter, and Marivita showed a cluster-oriented distribution. Phaeobacter and Sediminicola-related reads were detected frequently and abundantly at low temperature. Nitrifying bacteria were detected frequently and abundantly in the three biofilters. Phylogenetic analysis of the nitrifying bacteria showed several similar OTUs were observed widely through the biofilters. The diverse bacterial communities and the minor taxonomic groups, except for Proteobacteria and Bacteroidetes, seemed to play important roles and seemed necessary for nitrifying activity in the RAS, especially in packed bed biofilters, mesh biofilters, and maturation biofilters. PMID:27033205

  15. ATLAS monitored drift tube long-term stability and aging study performed for the first time with the gas-recirculation system planned for LHC

    CERN Document Server

    Zimmermann, S

    2004-01-01

    The monitored drift tubes (MDTs) of the ATLAS muon spectrometer have to sustain count rates up to 1500 Hz/cm and must be able to survive an accumulated charge of up to 0.6 C/cm during 10 years of operation. This paper presents results of aging studies carried out at the CERN Gamma Irradiation Facility GIF for the first time with a final ATLAS muon chamber and a prototype of the gas recirculation system planned at LHC. A loss in pulse height was observed for MDTs under gas recirculation after an accumulated charge equivalent to only 1 year of LHC operation; the effect was traced to a silicone contamination from bad components in the gas recirculation system. Tubes operated with the classical one-pass, flushing mode did not show any evidence of aging, thus (re)validating the materials and components used in the MDT construction. Questions of long-term stability when recycling the major part of the operating gas could also be addressed by the measurements performed; results on this will also be discussed. (6 ref...

  16. A simple regression equation for predicting charge characteristics of adsorbed natural gas storage systems

    International Nuclear Information System (INIS)

    In this paper simple regression equations are proposed to predict the charge characteristics of tubular, adsorbed natural gas storage systems. The regression equations are obtained in terms of relevant, statistically significant non-dimensional numbers. The data required for regression analysis is generated by solving the transient heat and mass transfer equations of adsorbed natural gas (ANG) storage system undergoing charging under constant pressure condition. The governing equations are non-dimensionalized and relevant non-dimensional numbers are identified. Then by fixing suitable ranges for various material related, design and operating parameters, the range of different non-dimensional parameters are found. Then based on a large amount of data obtained in non-dimensional form by numerically solving the heat and mass transfer equations, correlations are developed for 1) the time required for 90% adsorption, 2) total heat transferred during 90% adsorption, and 3) the maximum temperature experienced by the bed during 90% adsorption. The regression equations are compared with the simulated values and it is observed that the difference is within 25% for all the three parameters. It is expected that the proposed regression equations will be useful in fast evaluation of charging performance of the ANG systems. - Highlights: • A transient heat and mass transfer model for adsorbed natural gas (ANG) storage reactor is formulated. • The system of equations are non-dimensionalized • A large amount of data on charging characteristics of the reactor is generated by solving the system of equations. • Regression equations are obtained for estimating the performance in terms of non-dimensional numbers. • Regression equations can be used for quick evaluation of ANG systems under charging

  17. Modeling of adsorber/desorber/catalytic reactor system for ethylene oxide removal

    OpenAIRE

    ZELJKO B. GRBAVCIC; BOSKO V. GRBIC; ZORANA LJ. ARSENIJEVIC

    2004-01-01

    The removal of ethylene oxide (EtO) in a combined system adsorber/desorber/catalytic reactor has been investigated. The combined system was a modified draft tube spouted bed reactor loaded with Pt/Al2O3 catalyst. The annular region was divided into two sectons, the hot section contained about 7 % of catalyst and it behaved as a desorber and catalytic incinerator, while the cold section, with the rest of the catalyst, behaved as a sorber. The catalyst particles were circulated between the two ...

  18. Optimizing hydraulic retention times in denitrifying woodchip bioreactors treating recirculating aquaculture system wastewater

    Science.gov (United States)

    The performance of wood-based denitrifying bioreactors to treat high-nitrate wastewaters from aquaculture systems has not previously been demonstrated. Four pilot-scale woodchip bioreactors (approximately 1:10 scale) were constructed and operated for 268 d to determine the optimal range of design hy...

  19. Processes to improve energy efficiency during pumping and aeration of recirculating water in circular tank systems

    Science.gov (United States)

    Conventional gas transfer technologies for aquaculture systems occupy a large amount of space, require considerable capital investment, and can contribute to high electricity demand. In addition, diffused aeration in a circular tank can interfere with the hydrodynamics of water rotation and the spee...

  20. Particle sieve analysis for solids removal efficiency for recirculating aquaculture system components

    Science.gov (United States)

    As the aquaculture industry develops, opportunites for small-scale farms to become an integral part of the industry will become more prevalent. For small-scale operations it is important to have a system design that is efficient in water and energy use. If such operations decide to utilize recircula...

  1. Stocking density effects on production characteristics and body composition of market size cobia, Rachycentron canadum, reared in recirculating aquaculture systems

    Science.gov (United States)

    Production density in excess of a critical threshold can result in a negative relationship between stocking density and fish production. This study was conducted to evaluate production characteristics of juvenile cobia Rachycentron canadum, reared to market size in production-scale recirculating aq...

  2. Effects of welding fumes on nuclear air cleaning system carbon adsorber banks

    International Nuclear Information System (INIS)

    Standard Technical Specifications for nuclear air cleaning systems include requirements for surveillance tests following fire, painting, or chemical release in areas communicating with the affected system. To conservatively implement this requirement, many plants categorize welding as a chemical release process, and institute controls to ensure that welding fumes do not interact with carbon adsorbers in a filter system. After reviewing research data that indicated welding had a minimal impact on adsorber iodine removal efficiency, further testing was performed with the goal of establishing a welding threshold. It was anticipated that some quantity of weld electrodes could be determined that had a corresponding detrimental impact on iodine removal efficiency for the exposed adsorber. This value could be used to determine a conservative sampling schedule that would allow the station to perform laboratory testing to ensure system degradation did not occur without a full battery of surveillance tests. A series of tests was designed to demonstrate carbon efficiency versus cumulative welding fume exposure. Three series of tests were performed, one for each of three different types of commonly used weld electrodes. Carbon sampling was performed at baseline conditions, and every five pounds of electrode thereafter. Two different laboratory tests were performed for each sample; one in accordance with ASTM 3803/1989 at 95% relative humidity and 30 degrees C, and another using the less rigorous conditions of 70% relative humidity and 80 degrees C. Review of the test data for all three types of electrodes failed to show a significant correlation between carbon efficiency degradation and welding fume exposure. Accordingly, welding is no longer categorized as a 'chemical release process' at McGuire Nuclear Station, and limits on welding fume interaction with ventilation systems have been eliminated. 4 refs., 3 figs., 1 tab

  3. Effects of welding fumes on nuclear air cleaning system carbon adsorber banks

    Energy Technology Data Exchange (ETDEWEB)

    Roberson, P.W. [Duke Power Company, Huntersville, NC (United States)

    1997-08-01

    Standard Technical Specifications for nuclear air cleaning systems include requirements for surveillance tests following fire, painting, or chemical release in areas communicating with the affected system. To conservatively implement this requirement, many plants categorize welding as a chemical release process, and institute controls to ensure that welding fumes do not interact with carbon adsorbers in a filter system. After reviewing research data that indicated welding had a minimal impact on adsorber iodine removal efficiency, further testing was performed with the goal of establishing a welding threshold. It was anticipated that some quantity of weld electrodes could be determined that had a corresponding detrimental impact on iodine removal efficiency for the exposed adsorber. This value could be used to determine a conservative sampling schedule that would allow the station to perform laboratory testing to ensure system degradation did not occur without a full battery of surveillance tests. A series of tests was designed to demonstrate carbon efficiency versus cumulative welding fume exposure. Three series of tests were performed, one for each of three different types of commonly used weld electrodes. Carbon sampling was performed at baseline conditions, and every five pounds of electrode thereafter. Two different laboratory tests were performed for each sample; one in accordance with ASTM 3803/1989 at 95% relative humidity and 30 degrees C, and another using the less rigorous conditions of 70% relative humidity and 80 degrees C. Review of the test data for all three types of electrodes failed to show a significant correlation between carbon efficiency degradation and welding fume exposure. Accordingly, welding is no longer categorized as a `chemical release process` at McGuire Nuclear Station, and limits on welding fume interaction with ventilation systems have been eliminated. 4 refs., 3 figs., 1 tab.

  4. Recirculating rotary gas compressor

    Science.gov (United States)

    Weinbrecht, John F.

    1992-01-01

    A positive displacement, recirculating Roots-type rotary gas compressor which operates on the basis of flow work compression. The compressor includes a pair of large diameter recirculation conduits (24 and 26) which return compressed discharge gas to the compressor housing (14), where it is mixed with low pressure inlet gas, thereby minimizing adiabatic heating of the gas. The compressor includes a pair of involutely lobed impellers (10 and 12) and an associated port configuration which together result in uninterrupted flow of recirculation gas. The large diameter recirculation conduits equalize gas flow velocities within the compressor and minimize gas flow losses. The compressor is particularly suited to applications requiring sustained operation at higher gas compression ratios than have previously been feasible with rotary pumps, and is particularly applicable to refrigeration or other applications requiring condensation of a vapor.

  5. On-line 60Co monitor for reactor recirculation system piping in primary containment vessel during reactor operation

    International Nuclear Information System (INIS)

    Highlights: • We developed an on-line 60Co monitor for reactor recirculation system piping during reactor operation. • Energy resolution at 1.4 × 106 cps is 33 keV at 1332 keV using a pulse integral method. • A coincidence method is applied to reduce an effect of background gamma rays. • The coincidence counting of 60Co cascade gamma rays could be detected for a background dose rate of 4.8 mSv/h. - Abstract: Water chemistry control during reactor operation and installation of temporary radiation shielding prior to scheduled outages are carried out in order to reduce workers’ dose exposure caused by 60Co which is the main radiation source during scheduled outages of boiling water reactor (BWR) power plants. It is necessary to monitor the deposited 60Co on inner surfaces of reactor recirculation system (RRS) piping to evaluate effects of water chemistry control. We have developed an on-line 60Co monitor (OLCM) for this purpose. The OLCM applies a pulse integral method as a new method to measure gamma-ray counts of more than 1.0 × 106 counts per second (cps) and a coincidence counting method to reduce an effect of background gamma rays caused by 16N in the measurement of 60Co cascade gamma rays. Energy resolution at 1.4 × 106 cps is 33 keV using the pulse integral method and single LaBr3:Ce scintillation detector. The energy resolutions of this detector using the fast response photo multiplier tube (PMT) are 50 keV at 1.5 × 106 cps and 59 keV at 2.1 × 106 cps. Furthermore, we measured the energy spectra using the pulse integral method, the coincidence counting method and two LaBr3:Ce scintillation detectors and examined the transition of coincidence counting for 60Co detection under high dose rate during reactor operation at the Kyoto University Research Reactor (KUR). The coincidence counting of 60Co cascade gamma rays could be detected, and the result was average values of 47.9 counts per 40 min and standard deviations of 34%, 58.3 counts per 60 min

  6. Charge-stripping system for 238U ion beam with recirculating He gas

    International Nuclear Information System (INIS)

    Recent developments in a charge-stripping system employing high-flow rate He gas circulation (∼200 L/min) for 238U35+ beams injected at 10.8 MeV/u are reported. He gas is confined in a target section and is separated from a vacuum duct using five-stage differentially-pumped sections. To minimize the gas leakage rate via beam apertures, a high-performance differential pumping was required. To avoid huge gas consumption, a clean gas recycling with high-flow rate was simultaneously required. To realize these, we developed multi-stage mechanical booster pump array. The recycling rate of He gas was achieved as more than 99 %. The system performance has been checked with the present maximum beam current up to 13 eμA (∼1 kW beam power). (author)

  7. Preliminary research on the anammox process and control of nitrogen compounds in a recirculating aquaculture system

    OpenAIRE

    Savin Cristian; Păsărin Benone; Patriche Neculai; Talpeş Marilena; Cristea Victor; Tenciu Magdalena

    2013-01-01

    Using anammox process in biological filtration of technological water within recirculatingaquaculture system is an alternative to nitrification / denitrification process which can reduce productioncosts, especially energy by replacing aerobic biological processes that require high oxygen consumption,provided through the addition for optimal function of biofilter (conversion of N-NH4 and N-NO2). Aim ofthis paper is to highlight the first steps in the control of nitrogen compounds in recirculat...

  8. Applying rotary jet heads for mixing and mass transfer in a forced recirculation tank reactor system

    DEFF Research Database (Denmark)

    Nordkvist, Mikkel; Grotkjær, Thomas; Hummer, J.S.;

    2003-01-01

    or an external loop.In this study, we determine mixing times in water and CMC solutions and oxygen mass transfer coefficients in water for a tank reactor system where a small fraction of the total liquid volume is rapidly circulated through an external loop and injected through the nozzles of rotary jet heads....... The system has a very simple design with no internal baffles or heat exchange area, and between batches the rotary jet heads are used for cleaning in place.Mixing time decreases and mass transfer increases with increasing circulation flow rate. For nozzle diameters between 5.5 and 10 mm and with one or two...... rotary jet heads, it is shown that a remarkable saving in power input for a fixed mixing time or mass transfer coefficient can be obtained by using a large nozzle diameter and two rather than one rotary jet heads.At the experimental conditions of the study the system is scaleable by simple formulas...

  9. Identification of bacteria potentially responsible for oxic and anoxic sulfide oxidation in biofilters of a recirculating mariculture system.

    Science.gov (United States)

    Cytryn, Eddie; van Rijn, Jaap; Schramm, Andreas; Gieseke, Armin; de Beer, Dirk; Minz, Dror

    2005-10-01

    Bacteria presumably involved in oxygen- or nitrate-dependent sulfide oxidation in the biofilters of a recirculating marine aquaculture system were identified using a new application of reverse transcription-PCR denaturing gradient gel electrophoresis (DGGE) analysis termed differential-transcription (DT)-DGGE. Biofilter samples were incubated in various concentrations of sulfide or thiosulfate (0 to 5 mM) with either oxygen or nitrate as the sole electron acceptor. Before and after short-term incubations (10 to 20 h), total DNA and RNA were extracted, and a 550-bp fragment of the 16S rRNA genes was PCR amplified either directly or after reverse transcription. DGGE analysis of DNA showed no significant change of the original microbial consortia upon incubation. In contrast, DGGE of cDNA revealed several phylotypes whose relative band intensities markedly increased or decreased in response to certain incubation conditions, indicating enhanced or suppressed rRNA transcription and thus implying metabolic activity under these conditions. Specifically, species of the gammaproteobacterial genus Thiomicrospira and phylotypes related to symbiotic sulfide oxidizers could be linked to oxygen-dependent sulfide oxidation, while members of the Rhodobacteraceae (genera Roseobacter, Rhodobacter, and Rhodobium) were putatively active in anoxic, nitrate-dependent sulfide oxidation. For all these organisms, the physiology of their closest cultured relatives matches their DT-DGGE-inferred function. In addition, higher band intensities following exposure to 5 mM sulfide and nitrate were observed for Thauera-, Hydrogenophaga-, and Dethiosulfovibrio-like phylotypes. For these genera, nitrate-dependent sulfide oxidation has not been documented previously and therefore DT-DGGE might indicate a higher relative tolerance to high sulfide concentrations than that of other community members. We anticipate that DT-DGGE will be of general use in tracing functionally equivalent yet

  10. Systems and methods for reactive distillation with recirculation of light components

    Science.gov (United States)

    Stickney, Michael J.; Jones, Jr., Edward M.

    2011-07-26

    Systems and methods for producing gas-to-liquids products using reactive distillation are provided. The method for producing gas-to-liquids products can include reacting a feedstock in a column having a distillation zone and a reaction zone to provide a bottoms stream and an overhead stream. A first portion of the overhead stream can be recycled to the column at the top of the reaction zone and second portion of the overhead stream can be recycled to the column at the bottom of the reaction zone.

  11. Use of Produced Water in Recirculated Cooling Systems at Power Generating Facilities

    Energy Technology Data Exchange (ETDEWEB)

    C. McGowin; M. DiFilippo; L. Weintraub

    2006-06-30

    Tree ring studies indicate that, for the greater part of the last three decades, New Mexico has been relatively 'wet' compared to the long-term historical norm. However, during the last several years, New Mexico has experienced a severe drought. Some researchers are predicting a return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters to supplement current fresh water supplies for power plant operation and cooling and other uses. The U.S. Department of Energy's National Energy Technology Laboratory sponsored three related assessments of water supplies in the San Juan Basin area of the four-corner intersection of Utah, Colorado, Arizona, and New Mexico. These were (1) an assessment of using water produced with oil and gas as a supplemental supply for the San Juan Generating Station (SJGS); (2) a field evaluation of the wet-surface air cooling (WSAC) system at SJGS; and (3) the development of a ZeroNet systems analysis module and an application of the Watershed Risk Management Framework (WARMF) to evaluate a range of water shortage management plans. The study of the possible use of produced water at SJGS showed that produce water must be treated to justify its use in any reasonable quantity at SJGS. The study identified produced water volume and quality, the infrastructure needed to deliver it to SJGS, treatment requirements, and delivery and treatment economics. A number of produced water treatment alternatives that use off-the-shelf technology were evaluated along with the equipment needed for water treatment at SJGS. Wet surface air-cooling (WSAC) technology was tested at the San Juan Generating Station (SJGS) to determine its capacity to cool power plant circulating water using degraded water. WSAC is a commercial cooling technology and has been used for many years to cool and/or condense process fluids. The purpose of the pilot test was to

  12. Comparative performance of CO2 measuring methods: marine aquaculture recirculation system application

    Science.gov (United States)

    Pfeiffer, T.J.; Summerfelt, S.T.; Watten, B.J.

    2011-01-01

    Many methods are available for the measurement of dissolved carbon dioxide in an aqueous environment. Standard titration is the typical field method for measuring dissolved CO2 in aquaculture systems. However, titrimetric determination of dissolved CO2 in marine water aquaculture systems is unsuitable because of the high dissolved solids, silicates, and other dissolved minerals that interfere with the determination. Other methods used to measure dissolved carbon dioxide in an aquaculture water included use of a wetted CO2 probe analyzer, standard nomographic methods, and calculation by direct measurements of the water's pH, temperature, and alkalinity. The determination of dissolved CO2 in saltwater based on partial pressure measurements and non-dispersive infra-red (NDIR) techniques with a CO2 gas analyzer are widely employed for oceanic surveys of surface ocean CO2 flux and are similar to the techniques employed with the head space unit (HSU) in this study. Dissolved carbon dioxide (DC) determination with the HSU using a infra-red gas analyzer (IRGA) was compared with titrimetric, nomographic, calculated, and probe measurements of CO2 in freshwater and in saltwater with a salinity ranging from 5.0 to 30 ppt, and a CO2 range from 8 to 50 mg/L. Differences in CO2 measurements between duplicate HSUs (0.1–0.2 mg/L) were not statistically significant different. The coefficient of variation for the HSU readings averaged 1.85% which was better than the CO2 probe (4.09%) and that for the titrimetric method (5.84%). In all low, medium and high salinity level trials HSU precision was good, averaging 3.39%. Differences existed between comparison testing of the CO2 probe and HSU measurements with the CO2 probe readings, on average, providing DC estimates that were higher than HSU estimates. Differences between HSU and titration based estimates of DC increased with salinity and reached a maximum at 32.2 ppt. These differences were statistically significant (P < 0.05) at all

  13. Recirculation System for Geothermal Energy Recovery in Sedimentary Formations: Laboratory Experiments and Numerical Simulations

    Science.gov (United States)

    Elkhoury, J. E.; Detwiler, R. L.; Serajian, V.; Bruno, M. S.

    2012-12-01

    Geothermal energy resources are more widespread than previously thought and have the potential for providing a significant amount of sustainable clean energy worldwide. In particular, hot permeable sedimentary formations provide many advantages over traditional geothermal recovery and enhanced geothermal systems in low permeability crystalline formations. These include: (1) eliminating the need for hydraulic fracturing, (2) significant reduction in risk for induced seismicity, (3) reducing the need for surface wastewater disposal, (4) contributing to decreases in greenhouse gases, and (5) potential use for CO2 sequestration. Advances in horizontal drilling, completion, and production technology from the oil and gas industry can now be applied to unlock these geothermal resources. Here, we present experimental results from a laboratory scale circulation system and numerical simulations aimed at quantifying the heat transfer capacity of sedimentary rocks. Our experiments consist of fluid flow through a saturated and pressurized sedimentary disc of 23-cm diameter and 3.8-cm thickness heated along its circumference at a constant temperature. Injection and production ports are 7.6-cm apart in the center of the disc. We used DI de-aired water and mineral oil as working fluids and explored temperatures from 20 to 150 oC and flow rates from 2 to 30 ml/min. We performed experiments on sandstone samples (Castlegate and Kirby) with different porosity, permeability and thermal conductivity to evaluate the effect of hydraulic and thermal properties on the heat transfer capacity of sediments. The producing fluid temperature followed an exponential form with time scale transients between 15 and 45 min. Steady state outflow temperatures varied between 60% and 95% of the set boundary temperature, higher percentages were observed for lower temperatures and flow rates. We used the flow and heat transport simulator TOUGH2 to develop a numerical model of our laboratory setting. Given

  14. Optimizing Hydraulic Retention Times in Denitrifying Woodchip Bioreactors Treating Recirculating Aquaculture System Wastewater.

    Science.gov (United States)

    Lepine, Christine; Christianson, Laura; Sharrer, Kata; Summerfelt, Steven

    2016-05-01

    The performance of wood-based denitrifying bioreactors to treat high-nitrate wastewaters from aquaculture systems has not previously been demonstrated. Four pilot-scale woodchip bioreactors (approximately 1:10 scale) were constructed and operated for 268 d to determine the optimal range of design hydraulic retention times (HRTs) for nitrate removal. The bioreactors were operated under HRTs ranging from 6.6 to 55 h with influent nitrate concentrations generally between 20 and 80 mg NO-N L. These combinations resulted in N removal rates >39 g N m d, which is greater than previously reported. These high removal rates were due in large part to the relatively high chemical oxygen demand and warm temperature (∼19°C) of the wastewater. An optimized design HRT may not be the same based on metrics of N removal rate versus N removal efficiency; longer HRTs demonstrated higher removal efficiencies, and shorter HRTs had higher removal rates. When nitrate influent concentrations were approximately 75 mg NO-N L ( = 6 sample events), the shortest HRT (12 h) had the lowest removal efficiency (45%) but a significantly greater removal rate than the two longest HRTs (42 and 55 h), which were N limited. Sulfate reduction was also observed under highly reduced conditions and was exacerbated under prolonged N-limited environments. Balancing the removal rate and removal efficiency for this water chemistry with a design HRT of approximately 24 h would result in a 65% removal efficiency and removal rates of at least 18 g N m d. PMID:27136146

  15. Adsorbate-induced quantum Hall system probed by scanning tunneling spectroscopy combined with transport measurements

    International Nuclear Information System (INIS)

    An adsorbate-induced quantum Hall system at the cleaved InSb surfaces is investigated in magnetic fields up to 14 T using low-temperature scanning tunneling microscopy and spectroscopy combined with transport measurements. We show that an enhanced Zeeman splitting in the Shubnikov-de Haas oscillations is explained by an exchange enhancement of spin splitting and potential disorder, both of which are obtained from the spatially averaged density of states (DOS). Moreover, the Altshuler–Aronov correlation gap is observed in the spatially averaged DOS at 0 T

  16. Modeling and Analysis of the Electrokinetic Mass Transport and Adsorption Mechanisms of a Charged Adsorbate in Capillary Electrochromatography Systems Employing Charged Nonporous Adsorbent Particles.

    Science.gov (United States)

    Grimes, B. A.; Liapis, A. I.

    2001-02-01

    Mass-transfer systems based on electrokinetic phenomena (i.e., capillary electrochromatography (CEC)) have shown practical potential for becoming powerful separation methods for the biotechnology and pharmaceutical industries. A dynamic mathematical model, consisting of the momentum balance and the Poisson equations, as well as the unsteady-state continuity expressions for the cation and anion of the background electrolyte and of a positively charged analyte (adsorbate), is constructed and solved to determine quantitatively the electroosmotic velocity, the electrostatic potential, the concentration profiles of the charged species in the double layer and in the electroneutral core region of the fluid in the interstitial channels for bulk flow in the packed chromatographic column, and the axial current density profiles as the adsorbate adsorbs onto the negatively charged fixed sites on the surface of the nonporous particles packed in the chromatographic column. The frontal analysis mode of operation is simulated in this work. The results obtained from model simulations provide significant physical insight into and understanding of the development and propagation of the dynamic profile of the concentration of the adsorbate (analyte) and indicate that sharp, highly resolved adsorption fronts and large amounts of adsorbate in the adsorbed phase for a given column length can be obtained under the following conditions: (i) The ratio, gamma(2, 0), of the electroosmotic velocity of the mobile liquid phase at the column entrance after the adsorption front has passed the column entrance to the electrophoretic velocity of the anion is very close to -1. The structure of the equations of the model and model simulations indicate that a stable adsorption front cannot develop when gamma(2, 0) is less than -1 unless the value of the mobility of the cation is less than the value of the mobility of the analyte, which may be a rare occurrence in practical CEC systems. (ii) The ratio of

  17. Statistical properties of abnormal nano-sized adsorbate islands growth in a model of adsorptive multilayer system

    Science.gov (United States)

    Kharchenko, Vasyl O.; Kharchenko, Dmitrii O.

    2015-07-01

    A generalized model for nano-sized islands growth in substratum-mediated adsorption multilayer system is proposed. It is shown that the system manifests cascade of first order transitions related to the number of growing atomic layers. We have found that pattern formation on low layers is governed by a rate of adatom transference between neighboring layers. Critical coverage and critical island size governing adsorbate islands formation are defined. Anomalous dynamics of adsorbate island size growth and a crossover of dynamical regimes are discussed. Distributions of adsorbate/vacancy islands over their sizes are studied in details. It is shown that the linear size of vacancy/adsorbate islands varies from 20 to 100 nm.

  18. Elimination of root-infecting pathogens in recirculation water from closed cultivation systems by ultra-violet radiation

    International Nuclear Information System (INIS)

    The development from growing in border soil to soilless cultures has not resulted in the disappearance of soil-borne diseases. Most root-infecting pathogens also occur in these new cultivation systems. Some pathogens such as Pythium, Phytophthora, cucumber green mottle mosaic virus and tomato mosaic virus are easily transmitted in recirculation water as is Olpidium, the vector of several viruses. To exclude any risk of dispersal of plant pathogens the water has to be sterilised before re-use. Rainwater collected from the glasshouse roof can also be contaminated with pathogens. When this rainwater is used for irrigation water it should be disinfected first. Currently water disinfection by heating or ozonisation is applied on some 450 nurseries. Initially ultra-violet(UV) radiation was not effective against plant pathogens. Only at a low capacity of 18 l h-1 and a high UV-dose of 430 mJ cm-2 could fungal spores be eliminated in nutrient solution. A low capacity however implies a poor turbulence in the water, resulting in varying UV-doses in the different water layers. Two new UV-installations with high capacities were tested for their efficacy against fungal and viral plant pathogens. One installation was equipped with a high-pressure and the other with a low-pressure mercury vapour lamp. In both installations a sandfilter first removed organic particles from the water. A UV-dose from the high-pressure lamp of 28 mJ cm-2 reduced the infectivity of conidia of Fusarium oxysporum f.sp lycopersici by 90 % resulting in a 99.9 % reduction at 84 mJ cm-2. The low-pressure lamp completely eliminated conidia of Fusarium at a UV-dose of 70 mJ cm-2. Tomato mosaic virus was reduced by 99 % using a UV-dose of 100 mJ cm-2 in both installations. Ultra-violet radiation can be effective against plant pathogens providing the dose under controlled conditions is sufficient. Numerous growers use UV-radiation for the disinfection of water in closed cultivation systems. (author)

  19. Performance of Water Recirculation Loop Maintenance Components for the Advanced Spacesuit Water Membrane Evaporator

    Science.gov (United States)

    Rector, Tony; Peyton, Barbara M.; Steele, John W.; Makinen, Janice; Bue, Grant C.; Campbell, Colin

    2014-01-01

    Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a second SWME water recirculation loop with no water quality maintenance. Results show the benefits of periodic water maintenance. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the evaluation of water recirculation maintenance components was to further enhance this advantage through the leveraging of fluid loop management lessons learned from the International Space Station (ISS). A bed design that was developed for a UTAS military application, and considered for a potential ISS application with the Urine Processor Assembly, provided a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for ISS to introduce a biocide in a microgravity compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  20. Cribrihabitans marinus gen. nov., sp. nov., isolated from a biological filter in a marine recirculating aquaculture system.

    Science.gov (United States)

    Chen, Zhu; Liu, Ying; Liu, Liang-Zi; Zhong, Zhi-Ping; Liu, Zhi-Pei; Liu, Ying

    2014-04-01

    A Gram-negative bacterium, strain CZ-AM5(T), was isolated from an aerated biological filter in a marine recirculating aquaculture system in Tianjin, China. Its taxonomic position was investigated by using a polyphasic approach. Cells of strain CZ-AM5(T) were non-spore-forming rods, 0.5-0.8 µm wide and 1.2-2.0 µm long, and motile by means of one or two polar or lateral flagella. Strain CZ-AM5(T) was strictly aerobic, heterotrophic, oxidase-negative and catalase-positive. Growth occurred at 15-40 °C (optimum, 30-35 °C), at pH 6.5-10.5 (optimum, pH 7.0-7.5) and in the presence of 0-12.0 % (w/v) NaCl (optimum, 4.0 %). The predominant fatty acid was C18 : 1ω7c (80.3 %). Ubiquinone 10 (Q-10) was the sole respiratory quinone. The polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, an unknown aminolipid, an unknown phospholipid and three unknown lipids. The DNA G+C content was 60.4 mol%. Strain CZ-AM5(T) showed the highest 16S rRNA gene sequence similarity (96.5 %) to Phaeobacter caeruleus LMG 24369(T); it exhibited 16S rRNA gene sequence similarity of 95.0-96.5, 95.2-96.3, 96.2, 94.6-95.7 and 94.8-95.8 % to members of the genera Phaeobacter, Ruegeria, Citreimonas, Leisingera and Donghicola, respectively. However, phylogenetic trees based on 16S rRNA gene sequences showed that strain CZ-AM5(T) did not join any of the above genera, but formed a distinct lineage in the trees. On the basis of phenotypic, chemotaxonomic and phylogenetic analyses, strain CZ-AM5(T) is considered to represent a novel genus and species of the family Rhodobacteraceae, for which the name Cribrihabitans marinus gen. nov., sp. nov. is proposed. The type strain of Cribrihabitans marinus is CZ-AM5(T) ( = CGMCC 1.13219(T) = JCM 19401(T)). PMID:24425741

  1. 欧洲循环水养殖系统研究进展%Developments of recirculating aquaculture systems in Europe

    Institute of Scientific and Technical Information of China (English)

    丁建乐; 鲍旭腾; 梁澄

    2011-01-01

    The innovation and development of recirculating aquaculture system ( RAS) technology in Europe keeps continuing, with the strengthening of environmental regulations in EU and European countries. This paper introduced and analyzed the development status of European recirculating aquaculture system, such as the application of Life Cycle Assessment (LCA) method for evaluating the environmental impact of RAS, and the increasing species diversity of RAS production, etc. The paper also highlighted the application of denitrifying reaction technology, sludge concentration technology, and ozone treatment technology in RAS. On this basis, the paper pointed out the new challenges with which the recirculating aquaculture system may be faced.%欧洲循环水养殖系统技术随着欧盟和欧洲各国环保法规的加强而不断创新和发展.本文对欧洲正在使用生命周期法对循环水养殖进行环境影响评估的状况,以及欧洲应用独特的循环水养殖系统技术增加了养殖的品种进行了介绍和分析.并着重介绍了欧洲循环水养殖系统新技术的应用及其发展状况,特别阐述了脱硝反应技术、淤泥浓缩技术和臭氧技术等新技术在循环水养殖系统的应用情况.在此基础上,指出了循环水养殖可能面临的新挑战.

  2. Results regarding growth performance of Nile tilapia (Oreochromis niloticus, Linnaeus, 1758) fed with an additive feed, vitamin C, in a recirculating aquaculture system.

    OpenAIRE

    Catalina Ciortan Mirea

    2013-01-01

    The aim of this study was to determine the vitamin C status on growth performance, survival rate and biochimical parameters from tissue of Nile tilapia (Oreochromis niloticus, Linnaeus, 1758) with average weight of 93±1,0 g were fed with different dietary vitamin C rations and reared in a recirculating aquaculture system (RAS). Growth performance , survival rate and biochimical parameters from tissue of Nile tilapia were measured in groups fed diets supplemented with 100, 750, 2000 mg.kg-1L-a...

  3. A practical application for the chemical treatment of Southern California`s reclaimed, Title 22 water for use as makeup water for recirculating cooling water systems

    Energy Technology Data Exchange (ETDEWEB)

    Zakrzewski, J. [Calgon Corp., Pittsburgh, PA (United States); Cosulich, J.; Bartling, E. [County Sanitation Districts of Los Angeles County, Whittier, CA (United States)

    1998-12-31

    Pilot cooling water studies conducted at a Southern California landfill/cogeneration station demonstrated a successful chemical treatment program for recirculating cooling water that used unnitrified, reclaimed, Title 22 water as the primary makeup water source. The constituents in the reclaimed water are supplied by variety of residential and waste water sources resulting in a water quality that may vary to a greater degree than domestic water supplies. This water contains high concentrations of orthophosphate, ammonia, chlorides and suspended solids. The impact of which, under cycled conditions is calcium orthophosphate scaling, high corrosion of yellow metal and mild steel, stress cracking of copper alloys and stainless steel and rapidly growing biological activity. A mobile cooling water testing laboratory with two pilot recirculating water systems modeled the cogeneration station`s cooling tower operating conditions and parameters. The tube and shell, tube side cooling heat exchangers were fitted with 443 admiralty, 90/10 copper nickel, 316 stainless steel and 1202 mild steel heat exchanger tubes. Coupons and Corrater electrodes were also installed. A chemical treatment program consisting of 60/40 AA/AMPS copolymer for scale, deposits and dispersion, sodium tolyltriazole for yellow metal corrosion, and a bromination program to control the biological activity was utilized in the pilot systems. Recirculating water orthophosphate concentrations reached levels of 70 mg/L as PO, and ammonia concentrations reached levels of 35 mg/L, as total NH3. The study successfully demonstrated a chemical treatment program to control scale and deposition, minimize admiralty, 90/10 copper nickel and carbon steel corrosion rates, prevent non-heat transfer yellow metal and stainless steel stress cracking, and control the biological activity in this high nutrient water.

  4. Mediatorless electron transfer in glucose dehydrogenase/laccase system adsorbed on carbon nanotubes

    International Nuclear Information System (INIS)

    Highlights: • Glucose dehydrogenase from Ewingella americana (GDH) demonstrated an effective mediatorless oxidation of glucose on single-walled carbon nanotubes (SWCNT). • Laccase from Trichaptum abietinum (LAC) exhibited mediatorless oxygen reduction when the enzyme was adsorbed on SWCNT. • Simultaneous adsorption of GDH and LAC on SWCNT formed an electron transfer chain in which glucose and lactose were oxidized by oxygen in mediatorless manner. - Abstract: A mediatorless electron transfer in the chain of glucose dehydrogenase (GDH) and laccase (LAC) catalysing the oxidation of glucose by molecular oxygen was studied. To demonstrate mediatorless processes, the GDH from Ewingella americana was adsorbed on single-walled carbon nanotubes (SWCNT). The effective mediatorless oxidation of glucose proceeded at 0.2–0.4 V vs. SCE. The electrode was most active at pH 6.1, and generated 0.8 mA cm−2 biocatalytic current in the presence of 50 mM glucose. The electrode showed a bell-shaped pH dependence with pKa values of 4.1 and 7.5. LAC from Trichaptum abietinum adsorbed on SWCNT exhibited mediatorless oxygen reduction at electrode potential less than 0.65 V. The electrode was most active at pH 3.0–4.0 and generated 1.1 mA cm−2 biocatalytic current in the presence of 0.254 mM oxygen, with an apparent pKa of 1.0 and 5.4. The electrodes prepared by simultaneous adsorption of GDH and LAC on SWCNT exhibited glucose oxidation at a potential higher than 0.25 V. The oxygen consumption in the chain was demonstrated using a Clark-type oxygen electrode. The dependence of oxygen consumption on glucose and lactose concentrations as well as activity of the system on pH were measured. A model of the pH dependence as well as mediatorless consecutive glucose oxidation with oxygen catalysed by LAC/GDH system is presented. This work provides a novel approach towards the synthesis of artificial multi enzyme systems by wiring oxidoreductases with SWCNT, and offers a better

  5. Automatic technology in a recirculating aquaculture system%工厂化水产养殖中的自动控制技术

    Institute of Scientific and Technical Information of China (English)

    曹广斌; 蒋树义; 韩世成; 陈忠祥

    2011-01-01

    本文从工厂化水产养殖自动控制系统的组成、自动控制方法、自动控制技术在水质参数检测与调控中的应用等方面,论述了有关研究的技术成果和未来发展趋势.根据水产养殖工业化和自动化发展,以及自动控制技术在水产养殖中的广阔应用前景,指出了发展水产养殖自动化检测和调控精准技术的必要性,提出发展规范化、标准化的水产养殖自动化技术,以推动水产养殖工业化的发展.%The research and development of an automatic control system are summarized in the recirculating aquaculture, including the components of the system, the method of control, and the application of automatic technology in aquaculture.According to the need of aquaculture and the wide perspective application, it is necessary to research advanced automatic technology and to establish some standards for application of the technology in the recirculating aquaculture system.

  6. Performance of a Water Recirculation Loop Maintenance Device and Process for the Advanced Spacesuit Water Membrane Evaporator

    Science.gov (United States)

    Steele, John W.; Rector, Tony; Bue, Grant C.; Campbell, Colin; Makinen, Janice

    2013-01-01

    A dual-bed device to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop has been designed and is undergoing testing. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the development of a water recirculation maintenance device is to further enhance this advantage through the leveraging of fluid loop management lessons-learned from the International Space Station (ISS). A bed design that was developed for a Hamilton Sundstrand military application, and considered for a potential ISS application with the Urine Processor Assembly, provides a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The bed design further leverages a sorbent developed for ISS that introduces a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  7. Performance analyses of oxy-fuel power generation systems including CO2 capture: comparison of two cycles using different recirculation fluids

    International Nuclear Information System (INIS)

    With increasing concerns on global warming, reduction of CO2 emission has become a hot issue and studies of CO2 capture and storage (CCS) technology in power plant applications are in progress. Oxy-fuel combustion is one of the several available technologies that intend to capture CO2. Since the combustion gas consists mainly of CO2 and H2O in oxy-fuel combustion systems, it is easy to separate CO2 from the flue gas using a simple mechanical method instead of complex chemical processes. There have been suggested a couple of power cycles using different recirculation fluids for combustion dilution purpose. This study aimed to investigate the influence of CO2 capture on the performance of two promising oxy-fuel combustion power cycles adopting H2O and CO2 as the recirculation fluid. Optimal integration between the carbon capture process and the power cycle was examined and the influences of carbon capture on the entire system performance were compared for the two cycles

  8. 封闭循环水养殖中曝气系统设计及曝气器的选择%Aeration system design and aeration devices selection in Recirculating Aquaculture System

    Institute of Scientific and Technical Information of China (English)

    宋奔奔; 吴凡; 倪琦; 张宇雷; 庄保陆

    2011-01-01

    随着水产养殖业逐渐向高密度、集约化方向的发展,对养殖水体溶解氧浓度的要求越来越高.目前对循环水高密度养殖水体中溶解氧收支平衡的基础研究较少.如何提高氧气的溶解效率、减少氧气的逸出、合理控制溶解氧水平等技术难关的突破,对循环水养殖技术的提高具有重大的意义.本文旨在通过阐述曝气技术的设计理论基础以及曝气设备的最近发展状况,比较各式曝气器的性能参数,从而为封闭循环水养殖曝气系统的设计和曝气器的选择提供理论支持,推动封闭式循环水养殖向精准化的环保节能方向发展.%Dissolved oxygen in water body plays an important role in recirculating aquaculture while developing to higher density and intensification. At present, it' s studied not so much about dissolved oxygen budget and mass balance in intensive recirculating aquaculture system. These problems such as how to improve oxygen dissolving efficiency, decrease oxygen loss and control dissolved oxygen in appropriate level are growing more prominent in recirculating aquaculture system technology. Aeration theory and designing principles, aeration devices characteristics are illustrated and elaborated in this paper to improve the design of recirculating aquaculture aeration system and the selecting of aeration devices, promoting recirculating aquaculture system technology to more environment-friendly and energy conservation.

  9. Depurative capacity of molecular adsorbent recycling system (MARS): A focus on bilirubin removal.

    Science.gov (United States)

    Gong, D; Cruz, D; Ronco, C

    2008-10-01

    The molecular adsorbent recycling system (MARS) is now widely used in the treatment of patients with hepatic failure (HF). A great deal of interest has been directed toward its effect on clinical outcome, whereas its depurative capacity also needs attention. Bilirubin, a tightly albumin-bound toxin accumulating in patients with HF, is regarded as a surrogate to evaluate the depurative capacity of albumin-bound toxins by blood purification modalities. The removal of bilirubin by MARS is difficult to predict, because both the clearance of bilirubin and the reduction ratio of bilirubin after a single session differ between patients and sessions. A reduction of depurative capacity over the course of a treatment is observed. Furthermore, the later sessions are likely less efficient than previous ones. It cannot be taken for granted that the reduction of depurative capacity is due to the saturation and reduced efficiency of the adsorbent columns used in MARS. The answer lies in the property of bilirubin/albumin binding. The removal of bilirubin by MARS is a diffusion process, dependent on the free bilirubin concentration. Bilirubin binds to albumin in 3 ways with different affinity. High-affinity binding bilirubin is difficult to dissociate from albumin and is accompanied by a smaller free fraction, which means it is also difficult for MARS to remove. The factors affecting the free fraction of bilirubin will impact on bilirubin removal by MARS. Among them, the molar ratio of bilirubin to albumin is the most important one. Other factors include the interaction of other agents with bilirubin/albumin binding, the albumin concentration, plasma ion strength, and pH. PMID:19009505

  10. Modeling of adsorber/desorber/catalytic reactor system for ethylene oxide removal

    Directory of Open Access Journals (Sweden)

    ZELJKO B. GRBAVCIC

    2004-12-01

    Full Text Available The removal of ethylene oxide (EtO in a combined system adsorber/desorber/catalytic reactor has been investigated. The combined system was a modified draft tube spouted bed reactor loaded with Pt/Al2O3 catalyst. The annular region was divided into two sectons, the “hot” section contained about 7 % of catalyst and it behaved as a desorber and catalytic incinerator, while the “cold” section, with the rest of the catalyst, behaved as a sorber. The catalyst particles were circulated between the two sections by use of a draft tube riser. The Computational Fluid Dynamics (CFD program package FLUENT was used for simulations of the operation of the combined system. In addition, a one-dimensional numerical model for the operation of the packed bed reactor was compared with the corresponding FLUENT calculations. The results of the FLUENT simulations are in very good agreement with the experimental observations, as well as with the results of the one-dimensional numerical simulations.

  11. Effect of Hydraulic Loading Rate on the Efficiency of Effluent Treatment in a Recirculating Puffer Aquaculture System Coupled with Constructed Wetlands

    Institute of Scientific and Technical Information of China (English)

    XU Jiabo; SHI Yonghai; ZHANG Genyu; LIU Jianzhong; ZHU Yazhu

    2014-01-01

    Constructed wetlands (CWs) were integrated into an indoor recirculating aquaculture system of obscure puffer (Takifugu obscurus) for effluent treatment. The effect of hydraulic loading rate (HLR) on the efficiency of effluent treatment by CWs was ex-amined for over a month. The CWs were operated under brackish conditions (salinity 7.4-7.6) at 3 different HLRs (0.762, 0.633, and 0.458 m d-1) 3 times, 10 days each. Overall, the CWs exhibited high efficiency in removal of total ammonium nitrogen (by 81.03-92.81%) and nitrite nitrogen (by 99.40%-99.68%). The efficiency of CWs in removal of total ammonium nitrogen, nitrate nitrogen, total Kjeldahl nitrogen, total phosphorous, and total suspended solids (TSS) increased with the decrease of HLR. The CWs operated at the 3 HLRs in a decreasing trend proves to be effective, providing a useful method for effluent treatment in commercial puffer aquaculture systems.

  12. Grid type culture of Portunus trituberculatus in a recirculating aquaculture system%梭子蟹格栅式循环水养殖技术

    Institute of Scientific and Technical Information of China (English)

    许程林; 赵永超; 陈玉生; 吉红九; 贲成恺; 钟非

    2015-01-01

    Traditional Portunus trituberculatusculture in pond , isolated net, cage and basket are subject to the natural environment and are characterized by poor controllability, great labor intensity, low yield.In this study, a grid type culture of P.trituberculatus in a recirculating aquaculture system was explored, which have advantages of avoiding cannibolism, sunshade and heat preservation, aeration and decontamination.Crabs at stage of C8-C9 were moved into the grid type recirculating culture system and cultured for 113 days to commercial crab at stage of C11-C12 , the carapace breadth and body weight reached to 168 mm and 253 g respectively.And the average yield reached to 3.054 kg/m2 with survival rate of 75.4%.Compared to the traditional culture model, the average yield of grid type recirculating culture system has significantly increased.%传统的梭子蟹池塘养殖、围网养殖以及后来发展的笼养、筐养等对自然环境依赖性强、可控性差、劳动强度大、养殖产量低。本研究针对传统养殖方式的不足,采用格栅式单体养殖方法,有机组合生物净化水处理单元,构建了温室大棚梭子蟹格栅式循环水养殖系统,研发了具有“防止互残、遮阳保温、增氧去污”等性能的梭子蟹养殖新模式。结果表明,格栅式养殖池放养梭子蟹C8~C9期大规格苗种,经113 d养成至C11~C12期商品蟹,平均甲宽168 mm、平均体重253 g,存活率75.4%,养殖平均产量3.054 kg/m2。与传统养殖方式相比,采用温室大棚格栅式循环水养殖技术能有效延长梭子蟹的生长期,单位面积养殖产量和存活率均有显著提高。

  13. Continuous reduction of cyclic adsorbed and desorbed NOx in diesel emission using nonthermal plasma.

    Science.gov (United States)

    Kuwahara, Takuya; Nakaguchi, Harunobu; Kuroki, Tomoyuki; Okubo, Masaaki

    2016-05-01

    Considering the recent stringent regulations governing diesel NOx emission, an aftertreatment system for the reduction of NOx in the exhaust gas has been proposed and studied. The proposed system is a hybrid method combining nonthermal plasma and NOx adsorbent. The system does not require precious metal catalysts or harmful chemicals such as urea and ammonia. In the present system, NOx in diesel emission is treated by adsorption and desorption by adsorbent as well as nonthermal plasma reduction. In addition, the remaining NOx in the adsorbent is desorbed again in the supplied air by residual heat. The desorbed NOx in air recirculates into the intake of the engine, and this process, i.e., exhaust gas components' recirculation (EGCR) achieves NOx reduction. Alternate utilization of two adsorption chambers in the system can achieve high-efficiency NOx removal continuously. An experiment with a stationary diesel engine for electric power generation demonstrates an energy efficiency of 154g(NO2)/kWh for NOx removal and continuous NOx reduction of 70.3%. Considering the regulation against diesel emission in Japan, i.e., the new regulation to be imposed on vehicles of 3.5-7.5 ton since 2016, the present aftertreatment system fulfills the requirement with only 1.0% of engine power. PMID:26844402

  14. Application of a fluidized bed reactor charged with aragonite for control of alkalinity, pH and carbon dioxide in marine recirculating aquaculture systems

    Science.gov (United States)

    Paul S Wills, PhD; Pfeiffer, Timothy; Baptiste, Richard; Watten, Barnaby J.

    2016-01-01

    Control of alkalinity, dissolved carbon dioxide (dCO2), and pH are critical in marine recirculating aquaculture systems (RAS) in order to maintain health and maximize growth. A small-scale prototype aragonite sand filled fluidized bed reactor was tested under varying conditions of alkalinity and dCO2 to develop and model the response of dCO2 across the reactor. A large-scale reactor was then incorporated into an operating marine recirculating aquaculture system to observe the reactor as the system moved toward equilibrium. The relationship between alkalinity dCO2, and pH across the reactor are described by multiple regression equations. The change in dCO2 across the small-scale reactor indicated a strong likelihood that an equilibrium alkalinity would be maintained by using a fluidized bed aragonite reactor. The large-scale reactor verified this observation and established equilibrium at an alkalinity of approximately 135 mg/L as CaCO3, dCO2 of 9 mg/L, and a pH of 7.0 within 4 days that was stable during a 14 day test period. The fluidized bed aragonite reactor has the potential to simplify alkalinity and pH control, and aid in dCO2 control in RAS design and operation. Aragonite sand, purchased in bulk, is less expensive than sodium bicarbonate and could reduce overall operating production costs.

  15. Engineering development for a small-scale recirculator experiment

    International Nuclear Information System (INIS)

    Lawrence Livermore National Laboratory (LLNL) is evaluating the physics and technology of recirculating induction accelerators for heavy-ion inertial-fusion drivers. As part of this evaluation, the authors are building a small-scale recirculator to demonstrate the concept and to use as a test bed for the development of recirculator technologies. System designs have been completed and components are presently being designed and developed for the small-scale recirculator. This paper discusses results of the design and development activities that are presently being conducted to implement the small-scale recirculator experiments. An, overview of the system design is presented along with a discussion of the implications of this design on the mechanical and electrical hardware. The paper focuses primarily on discussions of the development and design of the half-lattice period hardware and the advanced solid-state modulator

  16. A fiber optics system for monitoring utilization of ZnO adsorbent beds during desulfurization for logistic fuel cell applications

    Science.gov (United States)

    Sujan, Achintya; Yang, Hongyun; Dimick, Paul; Tatarchuk, Bruce J.

    2016-05-01

    An in-situ fiber optic based technique for direct measurement of capacity utilization of ZnO adsorbent beds by monitoring bed color changes during desulfurization for fuel cell systems is presented. Adsorbents composed of bulk metal oxides (ZnO) and supported metal oxides (ZnO/SiO2 and Cusbnd ZnO/SiO2) for H2S removal at 22 °C are examined. Adsorbent bed utilization at breakthrough is determined by the optical sensor as the maximum derivative of area under UV-vis spectrum from 250 to 800 nm observed as a function of service time. Since the response time of the sensor due to bed color change is close to bed breakthrough time, a series of probes along the bed predicts utilization of the portion of bed prior to H2S breakthrough. The efficacy of the optical sensor is evaluated as a function of inlet H2S concentration, H2S flow rate and desulfurization in presence of CO, CO2 and moisture in feed. A 6 mm optical probe is employed to measure utilization of a 3/16 inch ZnO extrudate bed for H2S removal. It is envisioned that with the application of the optical sensor, desulfurization can be carried out at high adsorbent utilization and low operational costs during on-board miniaturized fuel processing for logistic fuel cell power systems.

  17. Literature review of the potential effects of hydrogen peroxide on nitrogen oxidation efficiency of the biofilters of recirculating aquaculture systems (RAS) for freshwater finfish

    Science.gov (United States)

    Fredricks, Kim T.

    2015-01-01

    A comprehensive literature review was done for the effects of hydrogen peroxide (HP) on biofilter function in recirculating aquaculture systems (RAS) using these databases: ISI/Web of Knowledge, Scopus, and Pubmed. Inclusion and exclusion criteria were developed as the literature review was conducted. The initial search produced 5,748 potential citations. Once the literature search was complete, these 5,748 titles were screened for applicable papers using the inclusion and exclusion criteria. If the title contained any of the inclusion terms, it was retained. Titles of the remaining papers were then screened for exclusion terms. If the title contained one or more of the exclusion terms, it was eliminated from further consideration. This refined search produced 1,405 papers.

  18. Water and Energy Savings using Demand Hot Water Recirculating Systems in Residential Homes: A Case Study of Five Homes in Palo Alto, California

    Energy Technology Data Exchange (ETDEWEB)

    Ally, M.R.

    2002-11-14

    This report summarizes a preliminary study aimed at estimating the potential of saving potable water, (and the electrical energy used to heat it), that is presently lost directly to the drain while occupants wait for hot water to arrive at the faucet (point of use). Data were collected from five single-family homes in Palo Alto, California. Despite the small sample size in this study, the results make a compelling case for retrofitting homes with hot water recirculation systems to eliminate unnecessary wastage of water at the point of use. Technical as well as behavioral and attitudinal changes towards water conservation are necessary for a fulfilling and successful conservation effort. This report focuses on the technical issues, but behavioral issues are also noted, which may be factored into future studies involving local and state governments and utility companies.

  19. Analyzing and Evaluating of Recirculating Aquaculture Systems (RAS of Rainbow Trout in Order to Designing a Conceptual Model of Efficient RAS in Iran (Tehran

    Directory of Open Access Journals (Sweden)

    M. Mahmoodzadeh

    2013-09-01

    Full Text Available In this study, Recirculation Aquaculture Systems (RAS of rainbow trout were analyzed and evaluated in Iran (Tehran. After analyzing these systems it was found which of them were better than others and then their parameters were used for designing a conceptual model of efficient RAS. This study was conducted in Iran (Tehran in 2012 and statistical population and samples were 8 systems. Systems were analyzed and evaluated by five criteria which were as follows: economy, energy, consumption and recycling of water, technical and engineering and management. Analyzing and evaluating were conducted by Data Envelopment Analysis (DEA method and also GAMS software was used for solving DEA model. It was found that in economy, energy, water consumption and recycling, technical and engineering and management criteria systems were efficient systems respectively. Based on the results, system 3th with regard to all the criteria was efficient system. Quality and quantity factors and equipments of system 3th were used in order to design a conceptual model of RAS in rainbow trout.

  20. Changes in sex steroids, growth hormone, and insulin-like growth factor-I during ovarian development in Rainbow Trout cultured within a recirculating system with 24-hour Light

    Science.gov (United States)

    Female rainbow trout (Onchorynchus mykiss) were cultured within a freshwater recirculating aquaculture system under 24-h constant lighting in 13oC water, and they were fed every six hours to near satiation. An opaque roof allowed surface light intensity to vary between <200 to ~1500 lx. Growth per...

  1. Comparing the effects of feeding a grain- or a fish meal-based diet on water quality, waste production, and rainbow trout Oncorhynchus mykiss performance within low exchange water recirculating aquaculture systems

    Science.gov (United States)

    Feeding a fish meal-free grain-based diet (GB) was compared to feeding a fish meal-based diet (FM) relative to water quality criteria, waste production, water treatment process performance, and rainbow trout Oncorhynchus mykiss performance within six replicated water recirculating aquaculture system...

  2. Evaluation of the impact of nitrate-nitrogen levels in recirculating aquaculture systems on concentrations of the off-flavor compounds geosmin and 2-methylisoborneol in water and rainbow trout (Oncorhynchus mykiss)

    Science.gov (United States)

    Aquatic animals raised in recirculating aquaculture systems (RAS) can develop preharvest “off-flavors” such as “earthy” or “musty” which are caused by the bioaccumulation of the odorous compounds geosmin or 2-methylisoborneol (MIB), respectively, in their flesh. Tainted aquatic products cause large...

  3. 臭氧处理技术在工厂化水产养殖中的应用研究%Application of Ozone in Recirculating Aquaculture System

    Institute of Scientific and Technical Information of China (English)

    周煊亦; 房燕; 曹广斌; 蒋树义; 韩世成; 陈忠祥; 郭常有

    2012-01-01

    臭氧消毒是工厂化水产养殖中水处理的关键技术之一。本文详细介绍了臭氧的物理、化学性质,论述了臭氧制造、水中溶解及水中溶解浓度的检测方法。结合国内外有关水产养殖水处理技术的研究成果与发展趋势,分析了臭氧在工厂化水产养殖水处理中的一些作用和应用特性。介绍了臭氧在工厂化水产养殖中消毒杀菌、氧化有机物、凝聚悬浮物、除臭与除色方面的作用,阐明了臭氧在工厂化水产养殖中的应用前景。%Ozone disinfection of water is one kind of key technology in water treatment of recirculating aquaculture system.This paper describes the physical and chemical nature of ozone and several ways of manufacturing,dissolving and detection of ozone.Based on aquaculture water treatment technology research and development trends,some of the role and the application feature that ozone used in aquaculture water treatment factory are analyzed.In recirculating aquaculture,ozone can be used in disinfection and sterilization,oxidation of organic compounds,suspended solids cohesion,deodorization and decolourization.Meanwhile,the application prospect of ozone was discussed.

  4. Discussion on the precision of energy conserving industrialized recirculation aquaculture system%论节能型工厂化循环水养殖的精准化

    Institute of Scientific and Technical Information of China (English)

    黄滨; 高淳仁; 关长涛; 梁友; 崔勇; 李娇

    2011-01-01

    渔业实施精准化战略,是我国现代渔业向工业化发展的必由之路.工厂化循环水养殖作为一种环境友好型和资源节约型先进养殖模式的典范,实施精准化是推动水产养殖产业向工业化迈进的加速器和重要标志,有积极的示范作用.本文论节能型工厂化循环水养殖的精准化,从养殖技术与设施装备,以及集成的各个环节和不同角度进行了可精准化的分析,对其实现途径作了较全面的阐述.%Precision fisheries strategy is a necessary pathway for the industrialization of modern fisheries in China. The land - based industrialized recirculation aquaculture system is an example of advanced environment - friendly and resource - conserving cultivation mode. Implementation of precision approach is an accelerator and indicator for aquaculture industrialization, which may act as a positive paradigm. Precision of energy conserving industrialized recirculation aquaculture is discussed in this paper, with analysis of various aspects including the cultivation technologies and facilities, as well as each integrated step and different elements in cultivation that could be improved in precision management, and with detailed illustration on the way to its realization.

  5. AP1000 Features Prevent Potential Containment Recirculation Screen Plugging

    International Nuclear Information System (INIS)

    This paper presents the results of plant design development and evaluations that demonstrate that the AP1000 plant is not subject to potential containment recirculation screen plugging following a loss-of-coolant-accident (LOCA). Following a LOCA in a pressurized water reactor, it is necessary to recirculate water from the containment back into the reactor to maintain long term core cooling. The AP1000 utilizes passive safety systems to provide containment recirculation for long term core cooling following a LOCA. The AP1000 also has non-safety pumps which provide a backup means of providing recirculation. Screens are provided around the recirculation pipes to prevent debris from blocking recirculation flow and core cooling passages. Debris may be generated by the LOCA blowdown from insulation and coatings used inside containment. Even with effective cleanliness programs, there may be some resident debris such as dust and dirt. The potential for plugging the recirculation screens is a current PWR licensing issue. The AP1000 design provides inherent advantages with respect to the potential plugging of containment recirculation screens. These characteristics include prevention of fibrous debris generation, improved debris settling and improved recirculation screen design. Debris settling analysis demonstrates that failure of coatings does not result in debris being transported to the screens before it settles to the floor. Additional analysis also shows that the plant can tolerate conservative amounts of resident debris being transported to the screens. The AP1000 significantly reduces the probability of plugging the containment recirculation screens and significantly reduces inspection and maintenance of coatings used inside containment. (authors)

  6. Simultaneous study by scanning tunneling spectroscopy and transport measurements in adsorbate-induced two-dimensional systems

    International Nuclear Information System (INIS)

    An adsorbate-induced two-dimensional electron system at cleaved surfaces of InSb is investigated by low-temperature scanning tunneling microscope and spectroscopy combined with transport measurements in magnetic fields up to 10 T. The magnitude of the potential disorder obtained from the spatially averaged density of states agrees with that deduced from the analysis of the Shubnikov-de Haas oscillations

  7. Molecular Adsorber Coating

    Science.gov (United States)

    Straka, Sharon; Peters, Wanda; Hasegawa, Mark; Hedgeland, Randy; Petro, John; Novo-Gradac, Kevin; Wong, Alfred; Triolo, Jack; Miller, Cory

    2011-01-01

    A document discusses a zeolite-based sprayable molecular adsorber coating that has been developed to alleviate the size and weight issues of current ceramic puck-based technology, while providing a configuration that more projects can use to protect against degradation from outgassed materials within a spacecraft, particularly contamination-sensitive instruments. This coating system demonstrates five times the adsorption capacity of previously developed adsorber coating slurries. The molecular adsorber formulation was developed and refined, and a procedure for spray application was developed. Samples were spray-coated and tested for capacity, thermal optical/radiative properties, coating adhesion, and thermal cycling. Work performed during this study indicates that the molecular adsorber formulation can be applied to aluminum, stainless steel, or other metal substrates that can accept silicate-based coatings. The coating can also function as a thermal- control coating. This adsorber will dramatically reduce the mass and volume restrictions, and is less expensive than the currently used molecular adsorber puck design.

  8. Airlift recirculation well test results - Southern sector

    International Nuclear Information System (INIS)

    Chlorinated solvents used in the A and M-Areas at the Savannah River Site (SRS) from 1952--1982 have contaminated the groundwater under the site. A plume of groundwater contaminated with trichloroethylene (TCE) and perchloroethylene (PCE) in the Lost Lake aquifer is moving generally southward with the natural flow of groundwater. To comply with the requirements of the current SCDHEC Part B Permit, a series of wells is being installed to contain and treat the plume. Airlift Recirculation Wells (ARW) are a new and innovative technology with potential for more cost effective implementation than conventional pump and treat systems. Two Airlift Recirculation Wells have been installed and tested to quantify performance parameters needed to locate a line of these wells along the leading edge of the contaminant plume. The wells proved to be very sensitive to proper development, but after this requirement was met, performance was very good. The Zone of Capture has been estimated to be within a radius of 130--160 ft. around the wells. Thus a line of wells spaced at 250 ft. intervals could intercept the contaminant plume. At SSR-012, TCE was stripped from the groundwater at approximately 1.2 lb./day. The longer term effect of the recirculation wells upon the plume and the degree of recirculation within the aquifer itself will require additional data over a longer time period for an accurate review. Data collection is ongoing

  9. Hydraulic study of parallel channels coupled to recirculation loops

    International Nuclear Information System (INIS)

    In this work is integrated a model of recirculation loops that allows to characterize each loop for separate and with which is possible to analyze events as shot of recirculation bombs or its transfer of high to low speed. The recirculation pattern is integrated to a model of 36 channels in parallel that represents the core of a BWR. Because the core reactor is conformed by fuel assemblies physically prepared in a parallel arrangement, it is natural to obtain a parallel application of complete pattern, where are have 36 channels tasks more other two tasks that calculates recirculation and punctual kinetics, respectively. As initial test of system, which even it is found in development, was analyzed a discharge of both recirculation pumps. In this test transitory it is only verified the hydraulic behavior, the power is imposed artificially as frontier condition that is function of flow in the calculated core by the recirculation pattern. The pattern of thermal hydraulics channel and the recirculation loops are programmed in language C, the neutronic pattern is programmed in Fortran 77. For the simulations was used a work station Alpha Station DS20E with operative system Unix and the communication system Parallel Virtual Machine, that allows to a heterogeneous collection of computers in net to work like a virtual computer in parallel. (Author)

  10. Systemic antibody response to nano-size calcium phospate biocompatible adjuvant adsorbed HEV-71 killed vaccine

    Science.gov (United States)

    2015-01-01

    Purpose Since 1980s, human enterovirus-71 virus (HEV-71) is one of the common infectious disease in Asian Pacific region since late 1970s without effective commercial antiviral or protective vaccine is unavailable yet. The work examines the role of vaccine adjuvant particle size and the route of administration on postvaccination antibody response towards HEV-71 vaccine adsorbed to calcium phosphate (CaP) adjuvant. Materials and Methods First, CaP nano-particles were compared to a commercial micro-size and vaccine alone. Secondly, intradermal reduced dosage was compared to the conventional intramuscular immunization. Killed HEV-71 vaccines adsorbed to CaP nano-size (73 nm) and commercial one of micro-size (1.7 µm) were administered through intradermal, intramuscular, rabbits received vaccine alone and unvaccinated animals. Results CaP nano-particles adsorbed HEV-71 vaccine displayed higher antibody than the micro-size or unadsorbed vaccine alone, through both parenteral immunization routes. Moreover, the intradermal route (0.5 µg/mL) of 0.1-mL volume per vaccine dose induced equal IgG antibody level to 1.0-mL intramuscular route (0.5 µg/mL). Conclusion The intradermal vaccine adsorbed CaP nano-adjuvant showed safer and significant antibody response after one-tenth reduced dose quantity (0.5 µg/mL) of only 0.1-mL volume as the most suitable protective, cost effective and affordable formulation not only for HEV-71; but also for developing further effective vaccines toward other human pathogens. PMID:25649429

  11. Proposal to recirculate glove box and fabrication area air in a plutonium fuel fabrication plant

    International Nuclear Information System (INIS)

    Recirculating glove box and fabrication area ventilation systems are proposed for a 40 Te/yr mixed plutonium--uranium oxide fuel fabrication plant. The ventilation design criteria are outlined, features of the fabricating plant relating to the ventilation system are shown and the recirculating systems are described. A method of operating and recirculating systems during unusual situations, energy conservation and system advantages are discussed. (U.S.)

  12. Coke-free dry reforming of model diesel fuel by a pulsed spark plasma at low temperatures using an exhaust gas recirculation (EGR) system

    Energy Technology Data Exchange (ETDEWEB)

    Sekine, Yasushi; Furukawa, Naotsugu; Matsukata, Masahiko; Kikuchi, Eiichi, E-mail: ysekine@waseda.jp [Department of Applied Chemistry, Waseda University, 65-301, Okubo, Shinjuku, Tokyo 169-8555 (Japan)

    2011-07-13

    Dry reforming of diesel fuel, an endothermic reaction, is an attractive process for on-board hydrogen/syngas production to increase energy efficiency. For operating this dry reforming process in a vehicle, we can use the exhaust gas from an exhaust gas recirculation (EGR) system as a source of carbon dioxide. Catalytic dry reforming of heavy hydrocarbon is a very difficult reaction due to the high accumulation of carbon on the catalyst. Therefore, we attempted to use a non-equilibrium pulsed plasma for the dry reforming of model diesel fuel without a catalyst. We investigated dry reforming of model diesel fuel (n-dodecane) with a low-energy pulsed spark plasma, which is a kind of non-equilibrium plasma at a low temperature of 523 K. Through the reaction, we were able to obtain syngas (hydrogen and carbon monoxide) and a small amount of C{sub 2} hydrocarbon without coke formation at a ratio of CO{sub 2}/C{sub fuel} = 1.5 or higher. The reaction can be conducted at very low temperatures such as 523 K. Therefore, it is anticipated as a novel and effective process for on-board syngas production from diesel fuel using an EGR system.

  13. Coke-free dry reforming of model diesel fuel by a pulsed spark plasma at low temperatures using an exhaust gas recirculation (EGR) system

    Science.gov (United States)

    Sekine, Yasushi; Furukawa, Naotsugu; Matsukata, Masahiko; Kikuchi, Eiichi

    2011-07-01

    Dry reforming of diesel fuel, an endothermic reaction, is an attractive process for on-board hydrogen/syngas production to increase energy efficiency. For operating this dry reforming process in a vehicle, we can use the exhaust gas from an exhaust gas recirculation (EGR) system as a source of carbon dioxide. Catalytic dry reforming of heavy hydrocarbon is a very difficult reaction due to the high accumulation of carbon on the catalyst. Therefore, we attempted to use a non-equilibrium pulsed plasma for the dry reforming of model diesel fuel without a catalyst. We investigated dry reforming of model diesel fuel (n-dodecane) with a low-energy pulsed spark plasma, which is a kind of non-equilibrium plasma at a low temperature of 523 K. Through the reaction, we were able to obtain syngas (hydrogen and carbon monoxide) and a small amount of C2 hydrocarbon without coke formation at a ratio of CO2/Cfuel = 1.5 or higher. The reaction can be conducted at very low temperatures such as 523 K. Therefore, it is anticipated as a novel and effective process for on-board syngas production from diesel fuel using an EGR system.

  14. Photoassisted electrochemical recirculation system with boron-doped diamond anode and carbon nanotubes containing cathode for degradation of a model azo dye

    International Nuclear Information System (INIS)

    In this research work, a photoassisted electrochemical system under recirculation mode and with UV irradiation was designed for treatment of C.I. Acid Blue 92 (AB92) as a model anionic azo dye in aqueous solution. Degradation experiments were carried out with boron-doped diamond (BDD) anode and carbon nanotubes-polytetrafluoroethylene (CNTs-PTFE) cathode in the presence of sulfate as an electrolyte. A comparative study of AB92 degradation by photolysis, electrochemical oxidation and photoassisted electrochemical processes after 45 min of treatment demonstrated that degradation efficiency was 27.89, 37.65 and 95.86%, respectively. Experimental data revealed that the degradation rate of AB92 in all of the processes obeyed pseudo-first-order kinetics and application of photoassisted electrochemical system reduced electrical energy per order (EEO), considerably. Degradation efficiency of photoassisted electrochemical process enhanced by increasing applied current and flow rate values, but vice versa trend was observed for initial dye concentration and an optimum amount of 6 was obtained for initial pH. The TOC measurement results demonstrated that 93.24% of organic substrates were mineralized after 120 min of photoassisted electrochemical process and GC–Mass analysis was performed for identification of degradation intermediates

  15. Coke-free dry reforming of model diesel fuel by a pulsed spark plasma at low temperatures using an exhaust gas recirculation (EGR) system

    International Nuclear Information System (INIS)

    Dry reforming of diesel fuel, an endothermic reaction, is an attractive process for on-board hydrogen/syngas production to increase energy efficiency. For operating this dry reforming process in a vehicle, we can use the exhaust gas from an exhaust gas recirculation (EGR) system as a source of carbon dioxide. Catalytic dry reforming of heavy hydrocarbon is a very difficult reaction due to the high accumulation of carbon on the catalyst. Therefore, we attempted to use a non-equilibrium pulsed plasma for the dry reforming of model diesel fuel without a catalyst. We investigated dry reforming of model diesel fuel (n-dodecane) with a low-energy pulsed spark plasma, which is a kind of non-equilibrium plasma at a low temperature of 523 K. Through the reaction, we were able to obtain syngas (hydrogen and carbon monoxide) and a small amount of C2 hydrocarbon without coke formation at a ratio of CO2/Cfuel = 1.5 or higher. The reaction can be conducted at very low temperatures such as 523 K. Therefore, it is anticipated as a novel and effective process for on-board syngas production from diesel fuel using an EGR system.

  16. Molecular adsorbent recycling system (MARS): clinical results of a new membrane-based blood purification system for bioartificial liver support.

    Science.gov (United States)

    Stange, J; Mitzner, S R; Risler, T; Erley, C M; Lauchart, W; Goehl, H; Klammt, S; Peszynski, P; Freytag, J; Hickstein, H; Löhr, M; Liebe, S; Schareck, W; Hopt, U T; Schmidt, R

    1999-04-01

    The use of xenogenic or genetically engineered cell types in bioartificial liver support systems requires separation methods between the patients' blood and the liver support bioreactors that guarantee the sufficient transfer of pathophysiologically relevant substances but prevent complications. The present paper describes a new membrane separation system that is nearly impermeable to proteins but enables the exchange of water soluble and protein bound toxins by a special membrane and a recycled protein containing dialysate. Because the full range of toxins in hepatic failure has still not been identified, the value of this membrane separation method was evaluated clinically. Thirteen patients suffering from life threatening hepatic failure who had not responded to state of the art therapy were treated with this device, the molecular adsorbent recycling system (MARS). The overall survival rate was 69%. All patients showed positive response to the therapy, indicating that the presented membrane separator combines therapeutic effectivity with the highest safety criteria for the patient by cutting the exchange of substances below the level of proteins. PMID:10226696

  17. Depletion of florfenicol amine in tilapia (Oreochromis sp.) maintained in a recirculating aquaculture system following Aquaflor®-medicated feed therapy

    Science.gov (United States)

    Gaikowski, Mark P.; Whitsel, Melissa K.; Charles, Shawn; Schleis, Susan M.; Crouch, Louis S.; Endris, Richard G.

    2015-01-01

    Aquaflor® [50% w w−1 florfenicol (FFC)], is approved for use in freshwater-reared warmwater finfish which include tilapia Oreochromis spp. in the United States to control mortality from Streptococcus iniae. The depletion of florfenicol amine (FFA), the marker residue of FFC, was evaluated after feeding FFC-medicated feed to deliver a nominal 20 mg FFC kg−1 BW d−1 dose (1.33× the label use of 15 mg FFC kg−1 BW d−1) to Nile tilapia O. niloticus and hybrid tilapia O. niloticus × O. aureus held in a recirculating aquaculture system (RAS) at production-scale holding densities. Florfenicol amine concentrations were determined in fillets taken from 10 fish before dosing and from 20 fish at nine time points after dosing (from 1 to 240 h post-dosing). Water samples were assayed for FFC before, during and after the dosing period. Parameters monitored included daily feed consumption and biofilter function (levels of ammonia, nitrite and nitrate). Mean fillet FFA concentration decreased from 13.77 μg g−1 at 1-h post dosing to 0.39 μg g−1 at 240-h post dosing. Water FFC concentration decreased from a maximum of 1400 ng mL−1 at 1 day post-dosing to 847 ng mL−1 at 240 h post-dosing. There were no adverse effects noted on fish, feed consumption or biofilter function associated with FFC-medicated feed administration to tilapia.

  18. Results regarding growth performance of Nile tilapia (Oreochromis niloticus, Linnaeus, 1758 fed with an additive feed, vitamin C, in a recirculating aquaculture system.

    Directory of Open Access Journals (Sweden)

    Catalina Ciortan Mirea

    2013-10-01

    Full Text Available The aim of this study was to determine the vitamin C status on growth performance, survival rate and biochimical parameters from tissue of Nile tilapia (Oreochromis niloticus, Linnaeus, 1758 with average weight of 93±1,0 g were fed with different dietary vitamin C rations and reared in a recirculating aquaculture system (RAS. Growth performance , survival rate and biochimical parameters from tissue of Nile tilapia were measured in groups fed diets supplemented with 100, 750, 2000 mg.kg-1L-ascorbic acid (AA and almost ascorbate free diet (Total AA> 5 mg.kg-1 as a control. They were stocked in 12 rearing units at 28 oC water temperature for 30 days. Diet of 33 % protein was offered as feed, 3 times daily. Growth measurements of tilapia were recorded on beginning and at the end of the experiment. Results showed that growth performance for Nile tilapia had not significantly (p>0.05 differences between the control and the tretments . Survival rate was the same for al the treatments. The feed conversio ratio (FCR was not significant (p>0.05 between the control and the treatments. Resuls showed that the feed impoved with AA had no significant differences between treatments and control regarding the  optimum growth performance and survival rate at Nile tilapia.  

  19. Evaluation of feed and feeding regime on growth performance, flesh quality and fecal viscosity of Atlantic salmon ( Salmo salar L.) in recirculating aquaculture systems

    Science.gov (United States)

    Sun, Guoxiang; Liu, Ying; Li, Yong; Li, Xian; Wang, Shunkui

    2015-10-01

    The effects of different feeds and feeding regimes on growth performance, flesh quality and fecal viscosity of Atlantic salmon ( Salmo salar L.) in recirculating aquaculture systems (RAS) were investigated. Fish (initial body weight of 1677 g ± 157 g) were fed with four commercial feeds (Nosan salmon-NS, Aller gold-AG, Skretting salmon-SS and Han ye-HY) in two feeding regimes (80% and 100% satiation) for 78 d. The results showed that salmon specific growth ratio (SGR) and weight gain ratio (WGR) were significantly affected by feed type and feeding regime ( P < 0.05). Feed conversion ratio (FCR) varied between 0.93 and 3.40, which was significantly affected by feed type ( P < 0.05), and slightly improved with increased satiation degree. The activities of digestive enzymes including protease, lipase and amylase were also significantly affected by feed type and feeding regime ( P < 0.05), increasing with satiation degree. Flesh qualities for vitamin E, hydroxyproline (HYP), liquid loss and muscle pH among all groups showed significant differences ( P < 0.05), ranging from 26.67 to 29.67, while no obvious difference was found in flesh color. Fecal viscosity for different treatments showed no significant difference, though improvement was found in 100% satiation group. From present experiment, it was concluded that both feed type and feeding regime can affect the important quality attributes of Atlantic salmon.

  20. Application of chemical coagulation aids for the removal of suspended solids (TSS) and phosphorus from the microscreen effluent discharge of an intensive recirculating aquaculture system

    Science.gov (United States)

    Ebeling, J.M.; Ogden, S.R.; Sibrell, P.L.; Rishel, K.L.

    2004-01-01

    An evaluation of two commonly used coagulation-flocculation aids (alum and ferric chloride) was conducted to determine optimum conditions for treating the backwash effluent from microscreen filters in an intensive recirculating aquaculture system. Tests were carried out to evaluate the dosages and conditions (mixing and flocculation stirring speeds, durations, and settling times) required to achieve optimum waste capture. The orthophosphate removal efficiency for alum and ferric chloride were greater than 90% at a dosage of 60 mg/L. Optimum turbidity removal was achieved with a 60-mg/L dosage for both alum and ferric chloride. Both alum and ferric chloride demonstrated excellent removal of suspended solids from initial total suspended solid values of approximately 320 mg/L to approximately 10 mg/L at a dosage of 60 mg/L. Flocculation and mixing speed and duration played only a minor role in the removal efficiencies for both orthophosphates and suspended solids. Both coagulation-flocculation aids also exhibited excellent settling characteristics, with the majority of the floc quickly settling out in the first 5 min.

  1. 循环流水产养殖系统净化研究%Research on Purification of Recirculating Aquaculture System

    Institute of Scientific and Technical Information of China (English)

    汪辉; 马伟芳; 郭浩; 曾凡刚; 韩冬梅; 丁志伟

    2012-01-01

    文章研究了不同水力停留时间和壳聚糖的投加对循环流水产养殖系统的影响,结果表明,当水力停留时间为8h,系统内除磷,除氨氮、COD效果明显,通过生物滤池和植物滤池的去除,NO2^-浓度下降,植物滤池平均出水浓度总磷1.60mg/L、氨氮0.016mg/L、COD为21.788mg/L;养鱼池投加壳聚糖,出水的色度和浊度都明显降低。%This paper studied the influence of different hydraulic retention time and chitosan additive on recirculating aquaculture system. The results show that, when the hydraulic retention time was 8 h, the removal efficiency of phosphorus, ammonia nitrogen and COD was high. Through the bio - filter and plants filter, the NO2^- concentration dropped. In the effluent of plant filter, the average concentration of phosphorus, ammonia nitrogen and COD was 1.60 mg/L, 0. 016 mg/L and 21. 788 rag/L, respectively. The turbidity and chromaticity were obviously reduced by dosing ehitosan in the fish pond.

  2. Effects of spectral composition, photoperiod and light intensity on the gonadal development of Atlantic salmon Salmo salar in recirculating aquaculture systems (RAS)

    Science.gov (United States)

    Qiu, Denggao; Xu, Shihong; Song, Changbin; Chi, Liang; Li, Xian; Sun, Guoxiang; Liu, Baoliang; Liu, Ying

    2015-01-01

    Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement. However, when these operations are applied in commercial recirculating aquaculture systems (RAS) using standard lighting technology, sexual maturation is not suppressed. In this study, an L9 (33) orthogonal design was used to determine the effects of three factors (spectral composition, photoperiod, and light intensity) on the gonadal development of Atlantic salmon in RAS. We demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light intensity. The photoperiod had a significant effect on the secretion of sex steroids and melatonin ( P0.05). The optimum lighting levels in female and male Atlantic salmon were LD 8:16, 455 nm (or 625 nm), 8.60 W/m2; and LD 8:16, 8.60 W/m2, 455 nm respectively. These conditions not only delayed gonadal development, but also had no negative effects on Atlantic salmon growth in RAS. These results demonstrate that a combination of spectral composition, photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.

  3. Removal of Pb(II), Cu(II) and Cd(II) from aqueous solution by some fungi and natural adsorbents in single and multiple metal systems

    International Nuclear Information System (INIS)

    Six fungal and 10 natural biosorbents were analyzed for their Cu(II), Cd(II) and Pb(II) uptake capacity from single, binary and ternary metal ion system. Preliminary screening biosorption of assays revealed 2 fungi (Aspergillus niger and Cunninghamella echinulata) and three natural [Cicer arietinum husk, Moringa oleifera flower and soil (clay)] adsorbents hold considerable high adsorption efficiency and capacity for 3 meta l ions amongst the adsorbents. Further biosorption trials with five elected adsorbents showed a considerable reduction in metal uptake capability of adsorbents in binary- and ternary systems as compared to singly metal system. Cd(II) manifested the highest inhibitory effect on the biosorption of other metal ions, followed by Pb(II) and Cu(II). On account of metal preference, the selectivity order for metal ion towards the studied biomass matrices was Pb(II) (40-90%) > Cd(II) (2-53%) > Cu(II) (2-30%). (author)

  4. Assessment of the adsorber surface density influence on the performance and operation of the intermittent SAR system

    International Nuclear Information System (INIS)

    Highlights: • Adsorber surface density effect on the SAR system performance is studied. • The cycle COP increases with decreasing the surface density. • The studied chiller has an optimum solar-to-cold conversion factor of 0.2. - Abstract: The adsorber surface density is a chief factor which is strongly coupled with other design parameters and climate conditions. This parameter has a considerable impact on the behaviour and operation of the intermittent solar adsorption refrigeration (SAR) system. This paper presents a theoretical investigation of the impact of the adsorption reactor surface density on the behaviour and overall performance indices of the intermittent SAR system. A water chiller which uses silica gel and water adsorption pair is studied under the climate conditions of Riyadh. The mathematical model is developed and a computer program is constructed to run the dynamic simulation of the chiller. Results obtained from the study show that the studied water chiller will fail to complete the cycle and to produce a cooling effect when the surface density is greater than 44 kg/m2. Moreover, the coefficient of performance (COP) increases with decreasing the surface density. Additionally, the optimum solar-to-cold conversion factor attains a value of 0.2 corresponding to surface density of 12.6 kg/m2 and COP of 0.43. This shows that the COP is not the accurate gauge for the SAR system performance and the solar-to-cold conversion factor is suggested when evaluating SAR system performance

  5. Recirculation pump shaft cracking experience at Chin-Shan station

    International Nuclear Information System (INIS)

    This paper reviews the experience of the Chin-Shan Nuclear Power Station with recirculation pump shaft cracking experience. The topics of the paper include a description of the Chin-Shan boiling water reactor plant, a summary of the disassembly and inspection of the recirculation pump, a description of the provisions for pump inspection, the pump vibration monitoring system, and the location of accelerometers, proximity probes, keyphasor and velocity transducers

  6. Dry-Scrubbing of Acid Gases in Recirculating Cyclones

    OpenAIRE

    Chibante, Vania; Fonseca, Ana; Salcedo, Romualdo

    2007-01-01

    This paper describes a laboratory-scale study on the use of recirculating cyclones as reaction chambers for dry scrubbing of gaseous HCl with solid slaked lime particles. This gas cleaning system combines a numerically optimized reverse flow gas cyclone (RS_VHE geometry) with a straight-through cyclone concentrator, which simultaneously increases the capture of the solid particles and promotes their partial recirculation. A laboratory-scale study was undertaken to test this technology and to ...

  7. The use of nile tilapia (Oreochromis niloticus) cultivation wastewater for the production of romaine lettuce (Lactuca sativa L. var. longifolia) in water recirculation system

    Science.gov (United States)

    Effendi, Hefni; Wahyuningsih, Sri; Wardiatno, Yusli

    2016-05-01

    In the recirculation aquaponic system (RAS), fish farming waste was utilized as a nutrient for plant, minimizing the water need, reducing the waste disposal into the environment, and producing the fish and plant as well. The study aimed to examine the growth of romaine lettuce (Lactuca sativa L. var. Longifolia) in aquaponic system without the addition of artificial nutrient. The nutrient relies solely on wastewater of nile tilapia (Oreochromis niloticus) cultivation circulated continuously on the aquaponic system. The results showed that tilapia weight reached 48.49 ± 3.92 g of T3 (tilapia, romaine lettuce, and inoculated bacteria), followed by T2 (tilapia and romaine lettuce) and T1 (tilapia) of 47.80 ± 1.97 and 45.89 ± 1.10 g after 35 days of experiment. Tilapia best performance in terms of growth and production occurred at T3 of 3.96 ± 0.44 g/day, 12.10 ± 0.63 %/day, 96.11 ± 1.44 % and 1.60 ± 0.07 for GR, SGR, SR, and FCR, respectively. It is also indicated by better water quality characteristic in this treatment. Romaine lettuce harvests of T2 and T3 showed no significant difference, with the final weight of 61.87 ± 5.59 and 57.74 ± 4.35 g. Overall, the integration of tilapia fish farming and romaine lettuce is potentially a promising aquaponic system for sustainable fish and horticulture plant production.

  8. Molecular analysis of bacterial communities and detection of potential pathogens in a recirculating aquaculture system for Scophthalmus maximus and Solea senegalensis.

    Science.gov (United States)

    Martins, Patrícia; Cleary, Daniel F R; Pires, Ana C C; Rodrigues, Ana Maria; Quintino, Victor; Calado, Ricardo; Gomes, Newton C M

    2013-01-01

    The present study combined a DGGE and barcoded 16S rRNA pyrosequencing approach to assess bacterial composition in the water of a recirculating aquaculture system (RAS) with a shallow raceway system (SRS) for turbot (Scophthalmus maximus) and sole (Solea senegalensis). Barcoded pyrosequencing results were also used to determine the potential pathogen load in the RAS studied. Samples were collected from the water supply pipeline (Sup), fish production tanks (Pro), sedimentation filter (Sed), biofilter tank (Bio), and protein skimmer (Ozo; also used as an ozone reaction chamber) of twin RAS operating in parallel (one for each fish species). Our results revealed pronounced differences in bacterial community composition between turbot and sole RAS, suggesting that in the systems studied there is a strong species-specific effect on water bacterial communities. Proteobacteria was the most abundant phylum in the water supply and all RAS compartments. Other important taxonomic groups included the phylum Bacteriodetes. The saltwater supplied displayed a markedly lower richness and appeared to have very little influence on bacterial composition. The following potentially pathogenic species were detected: Photobacterium damselae in turbot (all compartments), Tenacibaculum discolor in turbot and sole (all compartments), Tenacibaculum soleae in turbot (all compartments) and sole (Pro, Sed and Bio), and Serratia marcescens in turbot (Sup, Sed, Bio and Ozo) and sole (only Sed) RAS. Despite the presence of these pathogens, no symptomatic fish were observed. Although we were able to identify potential pathogens, this approach should be employed with caution when monitoring aquaculture systems, as the required phylogenetic resolution for reliable identification of pathogens may not always be possible to achieve when employing 16S rRNA gene fragments. PMID:24278329

  9. Molecular analysis of bacterial communities and detection of potential pathogens in a recirculating aquaculture system for Scophthalmus maximus and Solea senegalensis.

    Directory of Open Access Journals (Sweden)

    Patrícia Martins

    Full Text Available The present study combined a DGGE and barcoded 16S rRNA pyrosequencing approach to assess bacterial composition in the water of a recirculating aquaculture system (RAS with a shallow raceway system (SRS for turbot (Scophthalmus maximus and sole (Solea senegalensis. Barcoded pyrosequencing results were also used to determine the potential pathogen load in the RAS studied. Samples were collected from the water supply pipeline (Sup, fish production tanks (Pro, sedimentation filter (Sed, biofilter tank (Bio, and protein skimmer (Ozo; also used as an ozone reaction chamber of twin RAS operating in parallel (one for each fish species. Our results revealed pronounced differences in bacterial community composition between turbot and sole RAS, suggesting that in the systems studied there is a strong species-specific effect on water bacterial communities. Proteobacteria was the most abundant phylum in the water supply and all RAS compartments. Other important taxonomic groups included the phylum Bacteriodetes. The saltwater supplied displayed a markedly lower richness and appeared to have very little influence on bacterial composition. The following potentially pathogenic species were detected: Photobacterium damselae in turbot (all compartments, Tenacibaculum discolor in turbot and sole (all compartments, Tenacibaculum soleae in turbot (all compartments and sole (Pro, Sed and Bio, and Serratia marcescens in turbot (Sup, Sed, Bio and Ozo and sole (only Sed RAS. Despite the presence of these pathogens, no symptomatic fish were observed. Although we were able to identify potential pathogens, this approach should be employed with caution when monitoring aquaculture systems, as the required phylogenetic resolution for reliable identification of pathogens may not always be possible to achieve when employing 16S rRNA gene fragments.

  10. Sorption of lead, mercury and cadmium ions in multi-component system using carbon aerogel as adsorbent

    International Nuclear Information System (INIS)

    In the present study, adsorption of three metal ions Pb(II), Hg(II) and Cd(II) on carbon aerogel a new form of activated carbon has been investigated in mono- and multi-component (binary and tertiary) system. Batch experiments were also carried out for mono- and multi-component systems with varying metal ion concentration (mg/l) to investigate the competitive adsorption characteristics. Many adsorbents have been studied for their adsorption properties pertaining to mono-component solutions of metal ions. However, to treat wastewater with new materials, their performance needs to be ascertained in multi-component system. The scanning electron micrographs (SEM) and EDAX spectrum of carbon aerogel surfaces before and after the adsorbent was equilibrated with the metal ion solution clearly establishes the presence of the metal ions and some surface modifications can be observed on the carbon aerogel particles adsorption with (i) surface chemistry of the pellets on the surface of carbon aerogel and (ii) inside layers of the carbon aerogel. Applicability of the isotherm models namely Freundlich and Langmuir to predict the equilibrium uptake of Pb(II), Hg(II) and Cd(II) in mono-component, binary and tertiary system has also been tested. Langmuir and Freundlich models are found to generally represent the experimental though but not consistently

  11. Bacterially mediated removal of phosphorus and cycling of nitrate and sulfate in the waste stream of a "zero-discharge" recirculating mariculture system.

    Science.gov (United States)

    Krom, M D; Ben David, A; Ingall, E D; Benning, L G; Clerici, S; Bottrell, S; Davies, C; Potts, N J; Mortimer, R J G; van Rijn, J

    2014-06-01

    Simultaneous removal of nitrogen and phosphorus by microbial biofilters has been used in a variety of water treatment systems including treatment systems in aquaculture. In this study, phosphorus, nitrate and sulfate cycling in the anaerobic loop of a zero-discharge, recirculating mariculture system was investigated using detailed geochemical measurements in the sludge layer of the digestion basin. High concentrations of nitrate and sulfate, circulating in the overlying water (∼15 mM), were removed by microbial respiration in the sludge resulting in a sulfide accumulation of up to 3 mM. Modelling of the observed S and O isotopic ratios in the surface sludge suggested that, with time, major respiration processes shifted from heterotrophic nitrate and sulfate reduction to autotrophic nitrate reduction. The much higher inorganic P content of the sludge relative to the fish feces is attributed to conversion of organic P to authigenic apatite. This conclusion is supported by: (a) X-ray diffraction analyses, which pointed to an accumulation of a calcium phosphate mineral phase that was different from P phases found in the feces, (b) the calculation that the pore waters of the sludge were highly oversaturated with respect to hydroxyapatite (saturation index = 4.87) and (c) there was a decrease in phosphate (and in the Ca/Na molar ratio) in the pore waters simultaneous with an increase in ammonia showing there had to be an additional P removal process at the same time as the heterotrophic breakdown of organic matter. PMID:24657541

  12. Kinetics of electro-oxidation of ammonia-N, nitrites and COD from a recirculating aquaculture saline water system using BDD anodes.

    Science.gov (United States)

    Díaz, V; Ibáñez, R; Gómez, P; Urtiaga, A M; Ortiz, I

    2011-01-01

    The viability of the electro-oxidation technology provided with boron doped diamond (BDD) electrodes for the treatment and reuse of the seawater used in a Recirculating Aquaculture System (RAS) was evaluated in this work. The influence of the applied current density (5-50 A m(-2)) in the removal of Total Ammonia Nitrogen (TAN), nitrite and chemical oxygen demand (COD) was analyzed observing that complete TAN removal together with important reductions of the other considered contaminants could be achieved, thus meeting the requirements for reuse of seawater in RAS systems. TAN removal, mainly due to an indirect oxidation mechanism was described by a second order kinetics while COD and nitrite removal followed zero-th order kinetics. The values of the kinetic constants for the anodic oxidation of each compound were obtained as a function of the applied current density (k(TAN) = 7.86 × 10(-5) · exp(6.30 × 10(-2) J); kNO2 = 3.43 × 10(-2) J; k(COD) = 1.35 × 10(-2) J). The formation of free chlorine and oxidation by-products, i.e., trihalomethanes (THMs) was followed along the electro-oxidation process. Although a maximum concentration of 1.7 mg l(-1) of total trihalomethanes was detected an integrated process combining electrochemical oxidation in order to eliminate TAN, nitrite and COD and adsorption onto activated carbon to remove the residual chlorine and THMs is proposed, as an efficient alternative to treat and reuse the seawater in fish culture systems. Finally, the energy consumption of the treatment has been evaluated. PMID:20832837

  13. 鳗鲡循环水养殖系统构建与养殖效果%Constrution and cultured effect of a recirculating aquaculture system for Anguilla

    Institute of Scientific and Technical Information of China (English)

    陈熙春

    2013-01-01

    构建了鳗鲡( Anguilla)循环水养殖系统,该系统由玻璃钢养殖池、生物滤池等关键设施与设备组成。试验分设个体规格为19.60,8.20,2.99 g/尾等3个组,各组放养密度分别为14.92,11.33,9.25 kg/m3。养殖品种为太平洋双色鳗(Anguilla bicolor pacifica),养殖周期为113 d。试验结果显示:各组个体规格达74.99,25.95,7.74 g/尾,各组养殖密度分别达56.89,35.63,23.68 kg/m3,特定生长率分别为1.18,1.02,0.84%/d,饵料系数分别为1.28,1.25,1.42,存活率在98.9%以上。实现水循环利用率84.5%,生产1 kg鳗耗水量约为0.65 m3,单位净产量的电耗与能耗分别为4.69 kW· h/kg和2.01元/kg。结果表明,系统具有节能减排、养殖效果好等优点。%The recirculating aquaculture system for Anguilla constructed of the breeding pool of fiber reinforced plastics and biological aerated filters .The grouper Anguilla bicolor pacifica with an initial boby weight of 19 .6 (A),8.2(B),2.99(C)g were reared in this system at stocking density of 14.92(A),11.33(B),9.25(C) kg/m3 for 113 days.The results showed that the final body weight of 74.99(A),25.95(B) and 7.74(C)g, which the stocking density of 23.68 kg/m3,35.63 kg/m3,56.89 kg/m3, which the specific growth rate(SGR) of 1.18%/d,1.02%/d,0.84%/d, and food conversion rate ( FCR) of 1.28,1.25,1.42 were reached for grouper , and the survival rates were above 98 .9%.The water recycling rate was 84.5% in re-circulating aquaculture system .The water consumption was about 0.65 m3/kg fish in this system .The power consumption and energy consumption of unit net yield was 4.69 kW· h/kg, 2.01 yuan/kg.The results showed that the system has a good property with energy-saving and emission-reductions and better effect of culture .

  14. 冬季罗非鱼循环水暂养系统研究%Study on the temporary rearing of tilapia in recirculating aquaculture system in winter

    Institute of Scientific and Technical Information of China (English)

    周游; 陈石; 张成林

    2015-01-01

    为探索解决罗非鱼越冬问题,开展了利用循环水养殖系统进行暂养的试验研究。以具有代表性的吉富罗非鱼( Orcochromis niloticus)为研究对象,设计并构建了一套室内罗非鱼循环水养殖系统,并对罗非鱼进行了为期30 d的养殖试验。整个养殖周期内,罗非鱼养殖系统环境稳定、水质稳定良好。结果显示,系统养殖负荷总量从1024.2 kg增长到2309.1kg,鱼体平均体重由(170.7±10.8) g增重至(385.5±7.5) g,养殖密度由(22.9±3.5) kg/m3增加到(51.5±4.2) kg/m3,存活率达99.8%,饵料系数1.35。水质检测结果显示,水体进水口总氨氮0.21~0.33 mg/L,去除率20.64%;亚硝酸盐氮0.067~0.13 mg/L,去除率13.82%;溶氧6.5~7.4 mg/L,pH8.15~8.65,水温23.9~24.7℃。研究表明,罗非鱼生长状况良好,系统中各水质参数符合养殖要求。循环水养殖系统用于罗非鱼冬季暂养具有一定的可行性。%In order to enrich the data of temporary rearing system in the real production of tilapia in winter, an experimental study on the use of the recirculating aquaculture system for the breeding of tilapia ( Orcochromis niloticus) was conducted.The recirculating aquaculture system was evaluated as culture environments for tilapia were reared in the system for 30 days.Throughout the experiment, water quality parameters were stable and remained within ranges suitable for tilapias.The experiment results showed that:the carrying capacity of the farming system increased from 1 024.2 kg to 2 309.1 kg.The average body weight increased from (170.7 ±10.8) g to (385.5 ±7.5) g, and the stocking density of the fish increased from (22.9 ±14.5) kg/m3 to (51.5 ±10.2) kg/m3 .The survival rate was 99.8%.The feed coefficient ratio was 1.35.Water quality test results showed:the contents of ammonia nitrogen from fish pond water inlet was 0

  15. Development of a Vertical Recirculation Well System for the A/M Area of the Savannah River Site

    International Nuclear Information System (INIS)

    The objective of this work is to examine and develop a remediation scenario to provide long term hydraulic control and remediation of the dissolved chlorinated solvent plume within the Western and Southern Sectors of the A/M Area. This scope includes the development and siting of a remediation system that will contain the 500 part per billion trichloroethylene isoconcentration contour within each sector

  16. Use of recirculating aquaculture systems to increase production and quality of hatchery reared juvenile red drum for marine stock enhancement

    Science.gov (United States)

    The abundance of economically important marine sportfish has declined in Florida’s waters due to factors such as over-fishing and critical habitat disturbance. Hatchery production and enhancement stocking has traditionally been used in freshwater systems as a means of mitigating for effects such as ...

  17. The impact of level of the stocking density on the haematological parameters of rainbow trout (Oncorhynchus mykiss reared in recirculating aquaculture systems

    Directory of Open Access Journals (Sweden)

    Angelica Docan

    2011-10-01

    Full Text Available Hematological indices are important parameters for the evaluation of fish physiological status.The purpose of this experiment was to evaluate how level of the stocking density influence the bloodphysiology of of juvenile rainbow trout (Oncorhynchus mykiss reared in a recirculating system. Theexperiment was conducted over a period of 33 days. A number of 254 rainbow trout with an averageweight of 29.51 ± 1.32 g were divided into four rearing units in order to create different stockingdensities: in B1-2.64 kg/m3, with an average weight of 31.68 g/ex, B2 – 5.16 kg/m3 with an averageweight of 30.39 g/ex, B3 – 7.12 kg/m3 with an average weight of 28.52 g/ex and B4- 9.42 kg/m3 with anaverage weight of 27.46 g. The sampling of O. mykiss blood from the four variants before and after theexperimental trial allowed determination of hematological indices. Red blood cell counts (RBCc,haematocrit values (Ht, haemoglobin concentration (Hb, mean corpuscular volume (MCV, meancorpuscular haemoglobin (MCH and mean corpuscular haemoglobin concentration (MCHC weremeasured and analyzed, with routine methods used in fish hematology (Blaxhall & Daisley 1973;Svobodova 2001. Some hematological indicators (Hb, MCV, MCH had been influenced by the stockingdensity. The results of our research provide a contribution to the knowledge of the hematologicalparameters of the rainbow trout reared in different level of stocking densities, under the recirculatingsystems condition.

  18. Thalassotalea marina sp. nov., isolated from a marine recirculating aquaculture system, reclassification of Thalassomonas eurytherma as Thalassotalea eurytherma comb. nov. and emended description of the genus Thalassotalea.

    Science.gov (United States)

    Hou, Ting-Ting; Liu, Ying; Zhong, Zhi-Ping; Liu, Hong-Can; Liu, Zhi-Pei

    2015-12-01

    A Gram-stain-negative, facultatively anaerobic bacterium, strain QBLM2T, was isolated from rearing water of a marine recirculating aquaculture system in Tianjin, China. Its taxonomic position was investigated through a polyphasic approach. Cells of strain QBLM2T were non-spore-forming rods, motile by means of a single polar flagellum. Positive for oxidase and catalase. Growth occurred at 15-40 °C (optimum 30 °C), at pH 6.5-10.5 (optimum pH 7.5-8.5) and in the presence of 0-5.0 % (w/v) NaCl (optimum 3 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain QBLM2T formed a distinct lineage within the genus Thalassotalea and exhibited sequence similarities of 94.5-96.3 % to members of the genus Thalassotalea. The predominant fatty acids (>10 %) were C17 : 1ω8c and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The major polar lipids were phosphatidylglycerol and phosphatidylethanolamine. Ubiquinone 8 (Q-8) was the major ubiquinone. The DNA G+C content was 37.1 mol%. Based on the data above, strain QBLM2T is considered to represent a novel species of the genus Thalassotalea, for which the name Thalassotalea marina sp. nov. is proposed. The type strain is QBLM2T ( = CGMCC 1.12814T = KCTC 42731T). Phylogenetic analyses indicated that Thalassomonas eurytherma Za6a-12T fell within the genus Thalassotalea, so it is reclassified as Thalassotalea eurytherma comb. nov. and the description of the genus Thalassotalea is emended. PMID:26400666

  19. 循环水养殖系统中的固体悬浮物去除技术%Suspended solids removal technology in recirculating aquaculture systems

    Institute of Scientific and Technical Information of China (English)

    倪琦; 张宇雷

    2007-01-01

    循环水养殖系统(Recirculating aquaculture systems,RAS)中固体悬浮物(Suspended solids,SS)的去除效果直接影响到鱼类生长、生物净化效果、系统配置和运行成本等诸多重要因子.根据固体悬浮物产生、物理特性和分布规律,结合颗粒悬浮物去除工艺特点,对去除技术进行系统研究分析.固体悬浮物源自饲料,密度一般为1.05~1.19 g/cm3,运用重力分离、过滤和泡沫分离等工艺通过预处理、粗过滤和精处理三道工艺步骤,可分别去除不同直径的颗粒物质,在达到合理含量的前提下,获得低能耗、低成本和系统稳定运行的综合效果.固体悬浮物的去除符合目标明确、排出及时和区别对待三原则,去除工艺注重相关技术的优化集成.

  20. RESEARCH REGARDING THE EVOLUTION OF CORPORAL WEIGHTES AND FOOD CONVERSSION ON JUVENILE OF SIBERIAN STURGEON (Acipenser baeri RAISED IN RECIRCULATING SYSTEM

    Directory of Open Access Journals (Sweden)

    M. BURA

    2013-07-01

    Full Text Available The research was performed within the recirculating aquaculture system for sturgeon growth, in Banat's Universsity of Agricultural Sciences and Veterinary Medicine from Timisoara, on 2851 juveniles of Siberian sturgeons (Acipenser baeri, aged between 132-175 days. Juveniles were maintained in 4 tanks with volume of 5.63 m3, fed with granulated feed of 2 mm (44 & 22% PB and GB. Every 2 weeks the weight and body length was determinate on an effective of 30 individuals from each tank. Based on the obtained body weight, it has been established the food quantity used and bioproductive indicators. Having the weight differences between the individuals of a Siberian sturgeon population, it is needed at certain time intervals to practice assortment by body development. At the age of 175 days, Siberian sturgeons reached an average body weight between 90.13 ± 4.56 g and 197.63 ± 7.22 g and average body length between 28.73 ± 0.43 cm and 37.55 ± 0.38 cm. Individual values of minimum and maximum body weight varied between 32 g and 307 g and body length between 24.5 cm and 42 cm. For the entire population of Siberian sturgeons, there is a middle and high variability for the average body weight and a small variability for the average body length. During the 43 experimental days, the 2851 Siberian sturgeons have acquired a real weight gain of 184.66 kg, with a conversion factor of 0.84 kilograms of feed / kg growth and an index of feed conversion of 1.19 kilograms spore / kg feed consumed.

  1. Dietary supplementation of short-chain fructooligosaccharides influences gastrointestinal microbiota composition and immunity characteristics of Pacific white shrimp, Litopenaeus vannamei, cultured in a recirculating system.

    Science.gov (United States)

    Li, Peng; Burr, Gary S; Gatlin, Delbert M; Hume, Michael E; Patnaik, Susmita; Castille, Frank L; Lawrence, Addison L

    2007-12-01

    Supplementation of prebiotic compounds, including short-chain fructooligosaccharides (scFOS) has been shown to confer benefits on nutrient utilization, growth, and disease resistance of various animal species through improved gastrointestinal (GI) microbiota. However, potential uses of prebiotics for shrimp have not been defined. A 6-wk feeding trial was conducted in a recirculating system to determine the effects of scFOS supplementation on growth performance, immune functions, and GI microbiota composition of Pacific white shrimp (Litopenaeus vannamei). scFOS was supplemented in a nutritionally complete diet (35% crude protein) at 0.025, 0.0500, 0.075, 0.100, 0.200, 0.400, and 0.800% by weight. After 6 wk of feeding, shrimp fed 0, 0.1, and 0.8% scFOS were sampled for assays of immune function and GI microbiota. Dietary supplementation of scFOS did not improve weight gain, feed conversion ratio, or survival of shrimp. Denaturing gradient gel electrophoresis analysis suggested the intestinal tract microbial community from shrimp fed the basal diet was different from that of shrimp fed the scFOS diets [similarity coefficient (SC) = 74.9%)], although the intestinal tract microbial community from shrimp fed the scFOS-supplemented diets was very similar (SC = 92.3%). All the bacterial species contributing to the GI microbial differences were identified, although most of them are uncultured species. Both total hemocyte count and hemocyte respiratory burst increased (P < 0.05) by incremental dietary supplementation of scFOS (0-0.8%). This study is the first to our knowledge to show that dietary scFOS can selectively support growth of certain bacterial species in the GI tract of shrimp and enhance immunity, which may facilitate development of alternative strategies, including novel probiotics and synbiotics, for shrimp growth and health management. PMID:18029496

  2. 对虾高位池循环水养殖水体浮游动物生态特征研究%Ecological Characteristics of Zooplankton in the Higher Place Pond of Shrimp Recirculating Aquaculture System

    Institute of Scientific and Technical Information of China (English)

    魏小岚; 李纯厚; 颉晓勇; 戴明; 廖秀丽; 胡维安; 肖雅元; 李朋

    2013-01-01

    为了掌握对虾高位池循环水养殖过程中浮游动物的变动规律,有效管理水体环境质量,提高养殖效益,于2010年8月-11月,以凡纳滨对虾(Litopenaeus vannarnei)为试验对象,研究了循环水处理高位池养殖水体中浮游动物的群落结构及其动态变化,试验设计3种不同循环处理量组,即20 m3·h-1(P1组)、40 m3·h-1(P2组)和60 m3·h-1(P3组),探讨不同的循环水处理量和养殖模式对水体中浮游动物的生态特征影响.结果表明,从各试验塘鉴定出浮游动物主要隶属于四大类,循环塘21属35种,对照塘43属61种,种类最多的为轮虫,占总数的34.4%,其次为原生动物,占总数的31.1%,再次为枝角类,占总数的19.7%,最后为桡足类,占总数的14.8%.循环塘的优势种以原生动物和轮虫为主,而对照塘试验中后期的浮游动物以大型甲壳动物为主,循环塘和对照塘中浮游动物的密度分别为:131.52~497.17 ind· L-1和122.09~373.15 ind·L-1,其生物量分别为1.19~3.87 mg·L-1和0.64~3.01 mg· L-1,循环塘中浮游动物的密度和生物量明显高于对照塘,且存在显著性差异(P<0.05).循环塘浮游动物Shannon-Wiener多样性指数(H’)在1.01~2.08之间波动,而对照塘浮游动物多样性指数(H’)在0.76~1.56之间波动.%shrimp recirculating aquaculture system, to effective manage environmental quality of cultured waters, and to rise cultured benefit. From August to November in 2010, by Litopenaeus vannarnei as experimental object was research in the higher place pond of shrimp recirculating aquaculture system. Experiments were designed three different recirculating treatment groups, they were 20 m3-h-1 (Group of pond one), 40 m3>h-1'( Group of pond two) and 60 m3-h-1( Group of pond three), respectively. Community structure and its dynamic changes of zooplankton were studied in the higher-place pond of shrimp recirculating aquaculture system. The experimental results showed that

  3. Single-sludge denitrification in recirculating aquaculture systems: Effects of pre-fermentation and pH

    DEFF Research Database (Denmark)

    Suhr, Karin Isabel; Letelier Gordo, Carlos Octavio; Prat Busquets, Pau

    2014-01-01

    Single-sludge denitrification (DN) reactors in aquaculture utilize the solid fish waste produced in the system to reduce the nitrate load discharged. The solid waste is available for denitrifiers when present in soluble readily biodegradable form. A transformation accomplished by bacterial...... hydrolysis (and fermentation). The objective of this study was to quantify the effect of pre-fermentation of the solid fish waste on single-sludge DN-reactor efficiency. Pre-fermentation times tested were; 0 (no pre-fermentation), 1 d, 5 d, and 10 d. The efficiency was quantified as the potential DN-rates in...... laboratory assessments. Results showed that the highest DN-rate obtained was achieved by 1 d pre-fermentation. The volumetric DN-rate measured in decreasing order was; 23.4 ± 0.00 (1 d); 20.5 ± 0.35 (5 d); 17.0 ± 0.47 (10 d); 14.2 ± 0.24 (0 d) mg NO3-N (L∗h)-1 It was suspected that the poor utilization of s...

  4. Single-sludge denitrification in recirculating aquaculture systems: effects of pre-fermentation and pH

    DEFF Research Database (Denmark)

    Suhr, Karin Isabel; Letelier-Gordo, Carlos Octavio; Prat Busquets, Pau

    2015-01-01

    Single-sludge denitrification (DN) reactors in aquaculture use the carbonous solid fish waste produced in the system to reduce the discharged nitrate load. The solid waste is available for denitrifiers when present in soluble, readily biodegradable form, and the transformation is accomplished by...... bacterial hydrolysis and fermentation. The objective of this study was to quantify the effect of pre-fermentation of solid fish waste on single-sludge DN reactor efficiency. Pre-fermentation times tested were 0 d (no pre-fermentation), 1 d, 5 d, and 10 d, and the efficiency was quantified as the potential...... 14.2 +/- 0.24 mg NO3-N L-1 h(-1) (0 d). It was suspected that the poor utilization of soluble COD (sCOD) in the 5 d and 10 d pre-fermentation treatments was due to the low starting pH (pH <7). Subsequently, the experiments were repeated in 0.1 M HEPES buffer (pH = 7.1) and showed a clear correlation...

  5. Phase I aging assessment of nuclear air-treatment system HEPA filters and adsorbers

    International Nuclear Information System (INIS)

    A Phase I aging assessment of high-efficiency particulate air filters and activated carbon gas adsorption units was performed by the Pacific Northwest Laboratory as part of the U.S. Nuclear Regulatory Commission's Nuclear Plant Aging Research Program. Information was compiled concerning design features; failure experience; aging mechanisms, effects, and stressors; and monitoring methods. Over 1100 failures, or 12 percent of the filter installations, were reported as part of a U.S. Department of Energy survey. Investigators from other laboratories have suggested that aging could have contributed to over 80 percent of these failures. Several instances of impaired performance as the result of the premature aging of carbon were reported. Filter aging mechanisms range from those associated with particle loading to reactions that alter properties of gaskets. Mechanisms that can lead to impaired adsorber performance include the loss of potentially available active sites as a result of the adsorption of moisture or pollutants. Stressors include heat, moisture, radiation and airborne particles and contaminants

  6. Radiation-Induced Grafting for the Synthesis of Adsorbents for Phosphate and Chromate Removal from Aqueous Systems

    International Nuclear Information System (INIS)

    Nonwoven fabrics made of PE coated PP fibres were irradiated by accelerated electrons in inert atmospheres for grafting of two different monomers, glycidyl methacrylate and dimethylaminoethyl methacrylate. Grafting conditions were optimized by a systematic investigation of the effects of absorbed dose, monomer concentration, grafting reaction temperature and duration. 150% grafted copolymers were later modified by protonation and quaternization of poly(dimethylaminoethyl methacrylate) chains and by Cu(II) loading of dipyridyl amine modified poly(glycidyl methacrylate) graft chains. The PE/PP based adsorbents thus prepared were used for their suitability of removing phosphate and chromate ions from aqueous systems. Adsorption/removal studies were carried out in both batch and continuous flow type systems. The selectivity of adsorption of phosphate ions in the presence of other competing anions were also checked showing the enhanced selectivity for phosphate ions. (author)

  7. The effect of density in larval rearing of the pullet carpet shell Venerupis corrugata (Gmelin, 1791) in a recirculating aquaculture system

    OpenAIRE

    Joaquim, S.; Matias, D.; A Matias; Leitão, A; Soares, F.; Cabral, M.; Chícharo, L.; Gaspar, M.B.

    2014-01-01

    The pullet carpet shell Venerupis corrugata is an economically valuable species in several European countries, however, nowadays stocks are under high fishing pressure. Hatchery production of juveniles for release is a major contributor to strengthen the stock and consequently improve the sustainability of the natural stocks. This study aimed to determine the feasibility of rearing V. corrugata larvae with different larval densities (10, 40 and 200 larvae per mL) in a recirculating aquacultur...

  8. 基于STELLA的循环水养殖系统池塘总氨氮动态模拟%Dynamic Simulation of Total Ammonia in Culture Ponds of Recirculating Aquaculture System Based on STELLA Model

    Institute of Scientific and Technical Information of China (English)

    于涛; 钟非; 贺锋; 梁威; 吴振斌

    2013-01-01

    A theoretical model to evaluate total ammonia concentration in recirculating aquaculture system was established by investigating the relationship between impact factors of total ammonia.Subsequently,a system dynamics model for total ammonia in the recirculating aquaculture system was developed based on the theoretical model.The dynamics of total ammonia concentration in a culture pond during the breeding process was simulated by using STELLA simulation software.The simulation results were consistent with the measured values approximately,indicating that this model could simulate the experimental system to a certain extent and could provide suggestions on design and operation of the recirculating aquaculture system.%通过对影响循环水养殖系统养殖池塘中总氨氮动态的各种因素及其因果关系的分析,得出了养殖池塘中总氨氮的理论模型.在理论模型基础上,使用STELLA系统动力学模拟软件建立了循环水养殖实验系统中池塘水体总氨氮的系统动力学模型.通过将系统设计和运行的相关参数代人到该模型中,对养殖过程中池塘中总氨氮的动态变化进行了模拟运算,模拟结果与实测值基本吻合,说明该模型对实验系统的模拟具有一定的可信度,可为循环水养殖系统的设计和运行优化提供依据.

  9. Efficiency enhancement in gasoline reforming through the recirculation of reformate

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, J. [DaimlerChrysler AG, RBP/AS, 89081 Ulm (Germany); Sommer, M. [DaimlerChrysler AG, RTC/A, 70567 Stuttgart (Germany); Diezinger, S.; Trimis, D.; Durst, F. [FAU Erlangen-Nurnberg, LSTM, 91031 Erlangen (Germany)

    2006-03-21

    Fuel processors for on-board hydrogen production have to meet numerous technical demands. They should be efficient, compact and lightweight, capable of different loads and able to perform cold start ups. In this paper, the recirculation of reformate is proposed as a means of efficiency enhancement. Different system configurations based on this idea are introduced and simulated. The resulting effect on the system's efficiency, the water balance as well as the impact of recirculation on the system's volume and weight are discussed. (author)

  10. Low Load Model of a Once-through Boiler with Recirculation

    DEFF Research Database (Denmark)

    Trangbæk, Klaus

    2006-01-01

    A dynamic simulation model of a once-through boiler in low to medium load is developed. When the system is in low load, water from the evaporator is recirculated through a bottle. This recirculation system is included in the model, which is then shown to fit closed-loop data from a real plant...

  11. Economic values of growth and feed efficiency for fish farming in recirculating aquaculture system with density and nitrogen output limitations: a case study with African catfish (Clarias gariepinus).

    Science.gov (United States)

    Besson, M; Komen, H; Aubin, J; de Boer, I J M; Poelman, M; Quillet, E; Vancoillie, C; Vandeputte, M; van Arendonk, J A M

    2014-12-01

    In fish farming, economic values (EV) of breeding goal traits are lacking, even though they are key parameters when defining selection objectives. The aim of this study was to develop a bioeconomic model to estimate EV of 2 traits representing production performances in fish farming: the thermal growth coefficient (TGC) and the feed conversion ratio (FCR). This approach was applied to a farm producing African catfish (Clarias gariepinus) in a recirculating aquaculture system (RAS). In the RAS, 2 factors could limit production level: the nitrogen treatment capacity of the biofilter or the fish density in rearing tanks at harvest. Profit calculation includes revenue from fish sales, cost of juveniles, cost of feed, cost of waste water treatment, and fixed costs. In the reference scenario, profit was modeled to zero. EV were calculated as the difference in profit per kilogram of fish between the current population mean for both traits (µt) and the next generation of selective breeding (µt+Δt) for either TGC or FCR. EV of TGC and FCR were calculated for three generations of hypothetical selection on either TGC or FCR (respectively 6.8% and 7.6% improvement per generation). The results show that changes in TGC and FCR can affect both the number of fish that can be stocked (number of batches per year and number of fish per batch) and the factor limiting production. The EV of TGC and FCR vary and depend on the limiting factors. When dissolved NH3-N is the limiting factor for both µt and µt+Δt, increasing TGC decreases the number of fish that can be stocked but increases the number of batches that can be grown. As a result, profit remains constant and EVTGC is zero. Increasing FCR, however, increases the number of fish stocked and the ratio of fish produced per kilogram of feed consumed ("economic efficiency"). The EVFCR is 0.14 €/kg of fish, and profit per kilogram of fish increases by about 10%. When density is the limiting factor for both µt and µt+Δt, the

  12. Water treatment processes in marine recirculating aquaculture systems: A review%海水循环养殖系统水处理工艺综述

    Institute of Scientific and Technical Information of China (English)

    姜妍君; 强志民; 董慧峪; 贲伟伟; 王磊

    2013-01-01

    This paper reviews the key water quality parameters and the related unit treatment processes in marine recirculating aquaculture systems ( RAS). Besides routinely monitoring and controlling salinity, pH, temperature, and dissolved oxygen, RAS usually adopts physical, chemical and biological combinational treatment processes to reduce the concentrations of solid particles, ammonia nitrogen, nitrite, nitrate, organic matter and pathogens. Solid particles can be removed by sedimentation, filtration, foam fractionation or biofiltration according to different particle sizes and settlabilities. Ammonia nitrogen, nitrite and nitrate are mainly removed by biological nitrification and denitrification. Organic matter can be decomposed by microorganisms. Chemical oxidants and ultraviolet radiation are commonly-used disinfection methods in RAS. Disinfectant residue and disinfection byproducts, two critical factors impacting water quality and animal health, should be primarily concerned when selecting appropriate disinfection method. Finally, several commonly-adopted combinational treatment processes for RAS are exemplified with suggestions for future improvement provided.%论述了海水循环养殖系统(RAS)需要控制的水质参数及相关单元水处理工艺.RAS需要对盐度、pH、温度、溶解氧等水质参数进行监测控制,并常采用物理、生物、化学处理的组合工艺,使固体物质、氨氮、亚硝酸盐、硝酸盐、有机物以及致病微生物等的浓度维持在安全范围内.固体物质根据粒径和可沉降性的不同,可采用沉降、过滤、泡沫分离或生物过滤法去除;氨氮、亚硝酸盐以及硝酸盐主要通过生物的硝化和反硝化作用去除;有机物主要通过生物降解去除;化学药剂消毒以及紫外辐照是RAS常用的消毒方法,消毒剂残余及消毒副产物对水质和动物健康的影响是选择合适消毒方法需要考虑的两个关键因素.最后,列举了几种海

  13. Oxygen absorption efficiency of gas/liquid mixing device in closed recirculating aquaculture systems%闭合循环水产养殖系统中气/液混合装置的增氧效果

    Institute of Scientific and Technical Information of China (English)

    谭洪新; 刘文畅; 孙大川; 罗国芝; 马念念

    2014-01-01

    为了研究纯氧气/液混合装置在循环水养殖系统中的实际使用效果,对闭合循环水产养殖系统中气/液混合装置的氧气吸收效率(absorption efficiency,AE)及运行效果进行了研究。结果表明,气/液混合比(gas to liquid ratio,G/L)变化在0.333%~3.333%(O2流量0.57~5.70 g/min)之间时,气/液混合装置的平均氧气吸收效率变化在94.001%~36.049%之间。当G/L=0.667%(O2流量1.141 g/min),在30.5℃、26.3℃、22.9℃和19.2℃水温条件下,气/液混合装置的氧气吸收效率别为87.833%、90.451%、93.606%和94.001%;其中,试验水温为19.2℃时, AE达到最大(94.001%),混合器出水溶解氧浓度达13.36 mg/L。当G/L大于或小于0.667%时,AE均随G/L的变化而降低;各温度组AE值的方差分析表明,温度对AE值有显著影响。%Control of dissolved gases, especially oxygen and carbon dioxide, is an essential component of closed recirculating aquaculture systems. The use of oxygenation in closed recirculating aquaculture systems increases the mass of fish that can be supported in a given water flow by removing oxygen as a limiting factor to a system’s carrying capacity. In general, oxygenation technique in aquaculture is relatively mature with well established operational principles, techniques, and equipment. Since the 1970s, pure oxygen gas has been used as an economical means of providing supersaturated dissolved oxygen and thereby intensifying fish production in recirculating systems. Use of pure oxygen can lower fish production costs by supporting high fish and feed loading rates and reducing water flow requirements, which in turn reduces the size and cost of pumping, culture tanks, and water reuse equipment. Transferring pure oxygen rather than air into water can increase the mol fraction of gaseous oxygen and solubility of dissolved oxygen in water. The maximal dissolved oxygen concentration can be influenced by the

  14. Prevention on adverse reaction and nursing care of patients applied molecular absorbent recirculating system treatment%应用分子吸附再循环系统治疗中不良反应的预防及护理

    Institute of Scientific and Technical Information of China (English)

    李丹; 吴静; 王青霞; 蒋英

    2005-01-01

    分子吸附再循环系统(molecular adsorbent recirculating systern,MARS)是近年来发展起来的一种新型非生物型人工肝支持系统,是以白蛋白透析原理清除病人体内的蛋白结合毒素和小分子水溶性物质。由于重型肝炎病人肝脏和心脏贮备功能差,每次治疗时间长,在治疗过程中常存在一些不良反应,因此,采用MARS治疗中不良反应的预防是确保治疗顺利进行的重要环节。我科于2004年1月开始应用MARS治疗慢性重型肝炎,现就25例58次MARS治疗过程中出现的不良反应及其护理进行总结,结果如下。

  15. Scanning tunneling microscopy theory for an adsorbate: Application to adenine adsorbed on a graphite surface

    OpenAIRE

    Ou-Yang, Hui; Marcus, R. A.; Källebring, Bruno

    1994-01-01

    An expression is obtained for the current in scanning tunneling microscopy (STM) for a single adsorbate molecule. For this purpose the ``Newns–Anderson'' treatment (a ``discrete state in a continuum'' treatment) is used to obtain wave functions and other properties of the adsorbate/substrate system. The current is expressed in terms of the adsorbate–tip matrix elements, and an effective local density of states of the adsorbate/substrate system, at the adsorbate. As an example, the treatment i...

  16. Dispersant application: (1) during steam generator wet layup for removal of existing deposits, and (2) during the long-path recirculation cleanup process of the condensate/feedwater system to reduce startup corrosion product transport to the steam generators

    International Nuclear Information System (INIS)

    management operations (e.g., sludge lancing, chemical cleaning, etc.). In 2009 EPRI worked with Exelon Corporation to develop and implement a plan for a trial dispersant application during the SG wet layup at Three Mile Island Unit 1 (TMI-1). Because the SGs were scheduled for replacement during the Fall 2009 outage, this trial represented a unique opportunity to evaluate the efficacy of a dispersant wet layup application with minimal risk to the SGs. This paper discusses the technical bases supporting the addition of dispersant during wet layup at TMI-1 and the results of the Fall 2009 trial application. Additional applications, under EPRI sponsorship, have either just taken place (Doel 3 in Summer 2010) or are planned (Braidwood 1 in Fall 2010). It is anticipated that addition of a dispersant during the long-path recirculation cleanup process will more readily clean up transportable corrosion products from the system and increase their retention time in solution, thereby increasing the amount of iron removed from the condensate and feedwater systems prior to initiation of flow to the SGs. Evaluations preparing for applications of this type include: Reviews of the procedure and general characteristics of the long-path recirculation cleanup process at three plants: Byron Unit 1, Millstone Unit 2 and Three Mile Island (TMI) Unit 1; A laboratory test program to assess dispersant efficacy under the conditions present during the long-path recirculation cleanup process. A number of different dispersant chemicals, including the polyacrylic acid (PAA) used in online applications, were investigated; Generic and plant-specific evaluations (for the above three units) of the compatibility of PAA with the secondary system components anticipated to be wetted during the long-path recirculation cleanup process. Based on the results of this study, inputs concerning the recommended dispersant chemical, concentration, application schedule, and cleanup criteria were generated to aid interested

  17. Use of Treated Municipal Wastewater as Power Plant Cooling System Makeup Water: Tertiary Treatment versus Expanded Chemical Regimen for Recirculating Water Quality Management

    Energy Technology Data Exchange (ETDEWEB)

    David Dzombak; Radisav Vidic; Amy Landis

    2012-06-30

    Treated municipal wastewater is a common, widely available alternative source of cooling water for thermoelectric power plants across the U.S. However, the biodegradable organic matter, ammonia-nitrogen, carbonate and phosphates in the treated wastewater pose challenges with respect to enhanced biofouling, corrosion, and scaling, respectively. The overall objective of this study was to evaluate the benefits and life cycle costs of implementing tertiary treatment of secondary treated municipal wastewater prior to use in recirculating cooling systems. The study comprised bench- and pilot-scale experimental studies with three different tertiary treated municipal wastewaters, and life cycle costing and environmental analyses of various tertiary treatment schemes. Sustainability factors and metrics for reuse of treated wastewater in power plant cooling systems were also evaluated. The three tertiary treated wastewaters studied were: secondary treated municipal wastewater subjected to acid addition for pH control (MWW_pH); secondary treated municipal wastewater subjected to nitrification and sand filtration (MWW_NF); and secondary treated municipal wastewater subjected nitrification, sand filtration, and GAC adsorption (MWW_NFG). Tertiary treatment was determined to be essential to achieve appropriate corrosion, scaling, and biofouling control for use of secondary treated municipal wastewater in power plant cooling systems. The ability to control scaling, in particular, was found to be significantly enhanced with tertiary treated wastewater compared to secondary treated wastewater. MWW_pH treated water (adjustment to pH 7.8) was effective in reducing scale formation, but increased corrosion and the amount of biocide required to achieve appropriate biofouling control. Corrosion could be adequately controlled with tolytriazole addition (4-5 ppm TTA), however, which was the case for all of the tertiary treated waters. For MWW_NF treated water, the removal of ammonia by

  18. PREPARATION AND CHARACTERIZATION OF SOLID SELF MICROEMULSIFYING DRUG DELIVERY SYSTEM BY ADSORBENT TECHNIQUE TO IMPROVE DISSOLUTION PROFILE OF POORLY AQUEOUS SOLUBLE DRUG RAMIPRIL

    OpenAIRE

    Shelke Nagsen; Pancholi Shyam Sundar; Bandivadekar Mithun Mohanrao

    2011-01-01

    The main purpose of this work is to prepare solid self-microemulsifying drug delivery system (S-SMEDDS) to improve drug dissolution profile of poorly aqueous soluble drug. Optimized formulation of SMEDDS consists of Ramipril (RAM) (10 mg), Tween 80 (160mg), Cremophor EL (640mg) and Capmul MCM (CAP) as oil (200mg). SMEDDS was adsorbed at various SMEDDS: adsorbent ratio i.e. 3:1, 1:1, 1:3 on the solid carrier Aerosil 200. Powder flow properties and drug content were evaluated of the resulting f...

  19. Sulphur recirculation for reduced boiler corrosion; Minskad pannkorrosion med svavelrecirkulation

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Sven; Karlsson, Martin (Goetaverken Miljoe AB, Goeteborg (Sweden)); Blomqvist, Evalena; Baefver, Linda; Claesson, Frida; Davidsson, Kent (SP Sveriges Tekniska Forskningsinstitut, Boraas (Sweden)); Froitzheim, Jan; Pettersson, Jesper; Steenari, Britt-Marie (Chalmers Tekniska Hoegskola, Oorganisk miljoekemi, Goeteborg (Sweden))

    2010-03-15

    Sulphur recirculation is a new technology for reducing boiler corrosion and dioxin formation, which was demonstrated in full-scale tests performed at the Renova Waste to Energy plant at Saevenaes in Goeteborg (Sweden). Sulphur is recirculated from the flue gas cleaning back to the boiler, which reduces the chloride content of the deposits, which in turn reduces boiler corrosion and dioxin formation. Sulphur dioxide was separated from the flue gas in a wet scrubber by adding hydrogen peroxide, producing sulphuric acid. The sulphuric acid was injected into the furnace using nozzles with atomization air, surrounded by recirculated flue gas for improved mixing. By recirculating the sulphur, the sulphur dioxide concentration was increased in the boiler. Each sulphur atom passed the boiler several times and no external sulphur had to be added. Dioxin, ash, deposits and particle samplings together with 1000 h corrosion probe measurements were performed for normal operation (reference) and with sulphur recirculation respectively. During spring 2009, reference measurements were made and the recirculation system was installed and tested. During autumn 2009, a long term test with sulphur recirculation was made. An SO{sub 2} concentration of approximately 800 mg/m3 (n, d.g.) was maintained in the boiler by the system except during a period of extremely low sulphur content in the waste. The sulphur dioxide stack concentrations have been far below the emission limit. Sulphuric acid dew point measurements have shown that the sulphuric acid dosage did not lead to elevated SO{sub 3} concentrations, which may otherwise lead to low temperature corrosion. The chlorine content of both fly ash and boiler ash decreased and the sulphur content increased during the sulphur recirculation tests. The molar chlorine/sulphur ratio (Cl/S) decreased by two thirds in the fly ash as well as in the boiler ash, except for one sample. With sulphur recirculation in operation, the deposit growth was

  20. Fukushima Daini Nuclear Power Station Unit No. 3 nuclear reactor recirculation pump incident

    International Nuclear Information System (INIS)

    This paper describes the incident and investigation of excessive mechanical vibration of the unit 3 recirculation pump of the Fukushima Daini Nuclear Power Station. The topics include equipment damage, failure analysis, operational issues, actions to prevent reoccurrence, metallic particle contamination and cleanup and recovery of the cooling system, and future monitoring of recirculation pumps

  1. Field evaluation of a horizontal well recirculation system for groundwater treatment: Field demonstration at X-701B Portsmouth Gaseous Diffusion Plant, Piketon, Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Korte, N.; Muck, M.; Kearl, P.; Siegrist, R.; Schlosser, R.; Zutman, J. [Oak Ridge National Lab., TN (United States); Houk, T. [Lockheed Martin Energy Systems, Piketon, OH (United States). Portsmouth Gaseous Diffusion Plant

    1998-08-01

    This report describes the field-scale demonstration performed as part of the project, In Situ Treatment of Mixed Contaminants in Groundwater. This project was a 3{1/2} year effort comprised of laboratory work performed at Oak Ridge National Laboratory and fieldwork performed at the US Department of Energy (DOE) Portsmouth Gaseous Diffusion Plant (PORTS). The overall goal of the project was to evaluate in situ treatment of groundwater using horizontal recirculation coupled with treatment modules. Specifically, horizontal recirculation was tested because of its application to thin, interbedded aquifer zones. Mixed contaminants were targeted because of their prominence at DOE sites and because they cannot be treated with conventional methods. The project involved several research elements, including treatment process evaluation, hydrodynamic flow and transport modeling, pilot testing at an uncontaminated site, and full-scale testing at a contaminated site. This report presents the results of the work at the contaminated site, X-701B at PORTS. Groundwater contamination at X-701B consists of trichloroethene (TCE) (concentrations up to 1800 mg/L) and technetium-998 (Tc{sup 99}) (activities up to 926 pCi/L).

  2. Field evaluation of a horizontal well recirculation system for groundwater treatment: Field demonstration at X-701B Portsmouth Gaseous Diffusion Plant, Piketon, Ohio

    International Nuclear Information System (INIS)

    This report describes the field-scale demonstration performed as part of the project, In Situ Treatment of Mixed Contaminants in Groundwater. This project was a 3 1/2 year effort comprised of laboratory work performed at Oak Ridge National Laboratory and fieldwork performed at the US Department of Energy (DOE) Portsmouth Gaseous Diffusion Plant (PORTS). The overall goal of the project was to evaluate in situ treatment of groundwater using horizontal recirculation coupled with treatment modules. Specifically, horizontal recirculation was tested because of its application to thin, interbedded aquifer zones. Mixed contaminants were targeted because of their prominence at DOE sites and because they cannot be treated with conventional methods. The project involved several research elements, including treatment process evaluation, hydrodynamic flow and transport modeling, pilot testing at an uncontaminated site, and full-scale testing at a contaminated site. This report presents the results of the work at the contaminated site, X-701B at PORTS. Groundwater contamination at X-701B consists of trichloroethene (TCE) (concentrations up to 1800 mg/L) and technetium-998 (Tc99) (activities up to 926 pCi/L)

  3. Performance of shrimp recirculating aquaculture system with copper polluted water%Cu污染条件下封闭循环水养虾系统的效能

    Institute of Scientific and Technical Information of China (English)

    程波; 刘鹰; 杨红生; 高喜燕

    2011-01-01

    The disease outbreaks, environmental degradation and poor management practice are the major problems to the shrimp aquaculture industry in recent years.With the developing of engineering, aeration and the high quality of artificial feeds, shrimp culture in a recirculating aquaculture system (RA.S) becomes an environmentally and economically sustainable method to solve those problems.But the copper pollution has been a big problem in the coasts of China as a result of the developing of industry, and the shrimp cultures also use copper sulfate frequently to eradicate algae during Litopenaeus vannamei culturing.An experiment was conducted for intensive culture of shrimp (L.vannamei) in RAS for a period of three months to concentrate on the performance of the biofilter and the food safety under the copper polluted water (0.3 mg/L).The results indicated that there was no significant difference in the removal rate on COD, NH4-N and NO2-N and the number of heterotrophic bacteria, ammonium-oxidizing bacteria and nitrite-oxidizing bacteria in the biofilm as the Cu2+ concentration decreased to (0.089±0.012) mg/L at the harvest.No significant difference was found between treatments concerning the feed conversion ratio (FCR), the mortality rate and the yield.The accumulated concentration of Cu2+ in the shrimp at last was (29.36±4.06) mg/kg and (42.91±6.10) mg/kg in the control and treated RAS respectively, but it was in the range of national security standards of the green food and pollution-free agriculture products.The study suggests that the RAS can work well and supply safety food shrimp under 0.3 mg/L copper pollution in three month culturing period.%为获得Cu2+污染对封闭循环水养虾系统的影响,选用0.3 mg/L Cu2+浓度,研究其对系统中水质、对虾生长、存活及生物滤器水处理效能的影响.结果表明,经过84 d的试验,养殖水体中Cu2+质量浓度在系统水处理单元作用下降为(0.089±0.012)mg/L,

  4. Time-resolved spectroscopy at surfaces and adsorbate dynamics: Insights from a model-system approach

    Science.gov (United States)

    Boström, Emil; Mikkelsen, Anders; Verdozzi, Claudio

    2016-05-01

    We introduce a model description of femtosecond laser induced desorption at surfaces. The substrate part of the system is taken into account as a (possibly semi-infinite) linear chain. Here, being especially interested in the early stages of dissociation, we consider a finite-size implementation of the model (i.e., a finite substrate), for which an exact numerical solution is possible. By time-evolving the many-body wave function, and also using results from a time-dependent density functional theory description for electron-nuclear systems, we analyze the competition between several surface-response mechanisms and electronic correlations in the transient and longer time dynamics under the influence of dipole-coupled fields. Our model allows us to explore how coherent multiple-pulse protocols can impact desorption in a variety of prototypical experiments.

  5. Unique Inflammatory Mediators and Specific IgE Levels Distinguish Local from Systemic Reactions after Anthrax Vaccine Adsorbed Vaccination.

    Science.gov (United States)

    Garman, Lori; Smith, Kenneth; Muns, Emily E; Velte, Cathy A; Spooner, Christina E; Munroe, Melissa E; Farris, A Darise; Nelson, Michael R; Engler, Renata J M; James, Judith A

    2016-08-01

    Although the U.S. National Academy of Sciences concluded that anthrax vaccine adsorbed (AVA) has an adverse event (AE) profile similar to those of other adult vaccines, 30 to 70% of queried AVA vaccinees report AEs. AEs appear to be correlated with certain demographic factors, but the underlying immunologic pathways are poorly understood. We evaluated a cohort of 2,421 AVA vaccinees and found 153 (6.3%) reported an AE. Females were more likely to experience AEs (odds ratio [OR] = 6.0 [95% confidence interval {CI} = 4.2 to 8.7]; P vaccinated 2 to 12 months prior to plasma sample collection (n = 75), individuals with LLRs (n = 33) had higher protective-antigen (PA)-specific IgE levels than matched, unaffected vaccinated individuals (n = 50; P vaccinated individuals. IP-10 was also elevated in sera of individuals who developed LLRs (P vaccine-specific IgE response and IP-10, whereas SRs demonstrate increased systemic inflammation without a skewed cytokine profile. PMID:27280620

  6. QUALITY OF THE WATER IN SHRIMP FARM Litopenaeus vannamei WITH SYSTEM OF PARTIAL RECIRCULATION SYSTEM. QUALIDADE DA ÁGUA EM FAZENDA DE CAMARÃO MARINHO Litopenaeus vannamei COM SISTEMA DE RECIRCULAÇÃO PARCIAL.

    Directory of Open Access Journals (Sweden)

    Luiz Otávio Brito

    2008-12-01

    Full Text Available The present work aim to characterize the quality of the water affluent and effluent of a shrimp Litopenaeus vannamei farm , which operates with system of partial recirculation system. The samples were accomplished during the low water and high tide periods of the day. The analyzed variables were: dissolved oxygen, temperature, pH, salinity, ammonia, nitrate, nitrite and phosphate. They samples were seven points, distributed strategically in way to characterize the water from the entrance going by the inside of the to your exit farm. ANOVA and Tukey test (P<0,05 were used in statistical analysis. Was observed the pH and dissolved oxygen stayed presenting averages of 7.72 and 6.58mg.L-1, respectively. The final averages went from 1.40 mg.L-1 to ammonia, 0.76 mg.L-1 for nitrate, 0.08 mg.L-1 for nitrite and 1.63 mg.L-1 for the phosphate.

    KEY WORDS: Quality of the water, recirculation, shrimp, vannamei.
    O presente trabalho teve como objetivo caracterizar a qualidade da água afluente e efluente de uma fazenda de camarão marinho Litopenaeus vannamei, que opera com sistema de recirculação parcial de água. As coletas foram realizadas durante os períodos de baixamar e preamar, diurnas, nos dias de lua. Analisaram-se as seguintes variáveis: oxigênio dissolvido, temperatura, pH, salinidade, amônia, nitrato, nitrito e fosfato. Escolheram-se sete pontos de coleta, distribuídos estrategicamente, de modo a caracterizar a água desde a entrada, passando pelo interior da fazenda até sua saída. Para análise estatística, utilizaram-se análise de variância (ANOVA e teste de Tukey (P<0,05. Observou-se que o pH e o oxigênio dissolvido apresentaram uma média de 7,72 e 6,58mg.L-1, respectivamente. As médias finais foram de 1,40mg.L-1 para amônia, 0,76mg.L-1 para nitrato, 0,08mg.L-1 para nitrito e 1,63mg.L-1 para o fosfato.

    PALAVRAS-CHAVES: Camarão, vannamei, qualidade da água, recirculação

  7. Construção de um sistema simples e compacto de recirculação d'água sob pressão para trompa d'água Construction of a simple and compact system to recirculate water under pressure using a water-jet aspira tor pump

    Directory of Open Access Journals (Sweden)

    Dennis de Oliveira Imbroisi

    2009-01-01

    Full Text Available Vacuum pumps are very useful in physical, chemical and biological experiments. In this communication it is described the design of a compact and low cost water recirculating system employing a water-jet aspirator pump as the vacuum source. The system requires only a water pump, water-jet aspirator pump, commercial PVC water tubes and a drain connection.

  8. 抽屉式生物滤器在漠斑牙鲆循环水养殖中的效果研究%The purification effect of drawer biofilter in recirculating aquaculture system for southern flounder

    Institute of Scientific and Technical Information of China (English)

    秦继辉; 孙建明; 班同; 徐哲; 吴垠

    2012-01-01

    A self-designed drawer biofilter used in recirculating aquaculture system for Paralichthys lethostigma,the research is about the water treatment effect of drawer biofilter,weight gain and feed utilization rate.The results show that the P.lethostigma (225.4 ± 11.9) g during follow-up of 60 days culture in recirculating system gets a weight gain rate of 49.97% (337.5 ±10.3) g,the feed coefficient of 1.06,rearing density reaches 24.1 kg/ m3 and survival rate amounts to 100%.The removal efficiencies of drawer biofdter about NH4+ -N、NO2- -N and COD are (10.61 ±1.88)%,(14.90 ±3.06)% and (16.11 ±1.704)%,respectively.Therefore,using drawer biofilter to breed P.lethostigma in recirculating aquaculture system is feasible.%采用自行设计的抽屉式生物滤器应用于漠斑牙鲆(Paralichthys lethostigma)闭合循环水养殖系统,研究其对循环养殖水的处理效果及漠斑牙鲆的增重和饲料利用率的影响.结果表明:经过60 d的循环水养殖,漠斑牙鲆从初始时的(225.41±11.9)g增加到结束时的(337.5±10.3)g,增重率49.97%;试验饲料系数1.06,养殖密度24.1kg/m3,成活率100%;抽屉式生物滤器对于NH4+-N、NO2- -N和COD去除率分别为(10.61±1.88)%、(14.90±3.06)%和(16.11±1.70)%,可满足漠斑牙鲆养殖水体的水质要求.

  9. Analysis and optimization of a coal-fired power plant under a proposed flue gas recirculation mode

    International Nuclear Information System (INIS)

    Highlights: • A new flue gas recirculation configuration in coal-fire power plant is proposed. • The influence of flue gas recirculation on thermodynamics properties is analyzed. • The key parameters are optimized and operation suggestions are provided. • The proposed system can greatly improve off-design energy efficiency. - Abstract: This study mainly investigated the influence of flue gas recirculation (FGR) on reheat steam temperature, boiler efficiency, and thermal efficiency in a proposed FGR scheme. The main parameters of the boiler are calculated under different modes on the basis of a 600 MW coal-fired boiler. Optimization is conducted, and the optimum recirculation rate and coal input are determined. Results from case study showed that under the same recirculation rate, the reheat temperature increases higher and the net coal consumption decreases more in the improved recirculation system than those in the traditional recirculation system. The key parameters, such as the FGR rate and coal feed rate are optimized. Under optimum recirculation rate and coal input conditions, the net coal consumption rate can be reduced by 2.35–2.60 g/(kW h) compared with that obtained with the use of a conventional recirculation system. This net coal consumption rate can be reduced by 3.50–5.11 g/(kW h) compared with that obtained without gas recirculation system. For a better operation, lower recirculation rate and relative higher coal input are recommended under high-load conditions, whereas higher recirculation rate and relative lower coal input are appropriate for low-load conditions

  10. A novel approach for arsenic adsorbents regeneration using MgO

    OpenAIRE

    Tresintsi, Sofia; Simeonidis, Konstantinos; Katsikini, Maria; Paloura, Eleni; Bantsis, Georgios; Mitrakas, Manassis

    2014-01-01

    An integrated procedure for the regeneration of iron oxy-hydroxide arsenic adsorbents by granulated MgO is proposed in this study. A continuous recirculation configuration, with a NaOH solution flowing sequentially through the saturated adsorbent (leaching step) and the MgO (adsorption step) column beds, was optimized by utilizing the high arsenic adsorption efficiency of MgO at strong alkaline environments. Experimental results indicated that the total amount of leached arsenic was captured ...

  11. Suppression of dioxins in waste incinerator emissions by recirculating SO2.

    Science.gov (United States)

    Lin, Xiaoqing; Zhan, Mingxiu; Yan, Mi; Dai, Ahui; Wu, Hailong; Li, Xiaodong; Chen, Tong; Lu, Shengyong; Yan, Jianhua

    2015-08-01

    Sulphur is an effective inhibitor of the formation of Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-furans (PCDD/Fs), as was proven in laboratory and pilot plant studies. In this study, a pilot-scale system with capacity 300 N m(3) h(-1) was situated at the bypass of an actual hazardous waste incinerator (HWI) and tested to reduce the emission of PCDD/Fs. Activated carbon was used as a medium to adsorb SO2 from flue gas and release it again at the higher temperature of filtered ash detoxification to achieve SO2 circulation in the system. Most PCDD/Fs in the filtered ash are decomposed by thermal treatment. Experimental results indicate that the system is capable of stable operation with SO2 accumulation at a high level of concentration and a high reduction efficiency of PCDD/Fs. A reduction of more than 80% was already achieved without addition of other sulphur compounds. When pyrite (FeS2) was added the reduction of PCDD/Fs could reach 94%, with a residual PCDD/Fs concentration in the flue gas as low as 0.13 ng TEQ N m(-3). This SO2 recirculating and suppression technology potentially provides significant progress for dioxin emission control in waste incineration and could be useful for controlling emissions of PCDD/Fs and other chlorinated organic chemicals in China. PMID:25935497

  12. 活化炉渣作为生物滤料在循环式海水工厂化养殖中的应用%The application of modified cinder as biological substrate in marine recirculating aquaculture systems

    Institute of Scientific and Technical Information of China (English)

    王际英; 乔洪金; 李宝山; 张利民; 陈玮; 宋向军

    2014-01-01

    为筛选适合于海水循环水养殖系统的高效价廉的生物滤料,研究了炉渣的活化方法,比较了活化炉渣与其它生物滤料在氨氮和亚硝酸盐氮处理效率上的差异,测定了活化炉渣生物包处理氨氮的速率,并在循环式海水工厂化养殖系统中检测了以活化炉渣填充的生物滤池去除营养盐的效果。结果显示,活化炉渣与常见生物滤料相比,在氨氮和亚硝酸盐氮处理效率上差异不显著(P<0.05);熟化的炉渣生物包处理氨氮的速率为4.21μg/( h·m2);以活化炉渣填充循环水养殖系统的生物滤池,经50 d熟化和处理后,养殖池内的氨氮浓度符合渔业水质标准。研究表明,活化炉渣是一种高效价廉的生物滤料,适合在循环式海水工厂化养殖中应用,但其发挥作用至少需要50 d的熟化。%To screen efficient and cheap biological substrate for marine recirculating aquaculture systems, in this paper, the modified method of cinder was studied, the removing efficiency of the ammonia and nitrite with modified cinder and other biological substrates were compared, and the treatment rate of ammonia with the maturated cinder package was determined as well. The removing efficiency of nutrient salts with bio-filter ponds containing modified cinder in marine recirculating aquaculture systems was also evaluated. The results showed that there was no significant difference in the removing efficiency of ammonia and nitrite( P<0.05) for modified cinder and other substrates. The treatment rate of ammonia by the maturated cinder package was 4. 21 μg/( h·m2 ) . When filling the bio-filter ponds in recirculating aquaculture systems with modified cinder, the concentrations of ammonia in culture ponds were comformed to the water quality standard for fisheries after 50 days maturation. Therefore, the modified cinder is an efficient and cheap biological substrate, and suitable for application in the

  13. A Molecular Adsorbent Recycling System in Treating Posthepatectomy Acute Hepatic Failure Patients with Hepatocellular Carcinoma: a Bridge to Liver Transplantation

    Institute of Scientific and Technical Information of China (English)

    Yu Wang; Yihe Liu; Weiping Zheng; Yu Ming; Zhongyang Shen

    2006-01-01

    OBJECTIVE To evaluate the effect and safety of a Molecular Adsorbent Recycling System (MARS) in treating posthepatoectomy hepatic failure (AHF) patients surgically treated for primary hepatocellular carcinoma (HCC).METHODS 12 AHF patients induced by resection of HCC were treated with MARS before orthotopic liver transplantation (OLT). Their vital signs, urine volume, APACHE Ⅲ and Glasgow scores were monitored. Routine laboratory blood tests, measurements of coagulatory function, liver and kidney function, serum ammonia, lactic acid and blood gas were conducted before and after treatment with MARS. All of the patients were followed up for a period of 6 months after OLT for prognosis and complication assessment.RESULTS Each patient was treated with MARS for 2~5 times (average of 3.6) with a length of 8~24 h each time. Their mean arterial blood pressure and urine volume were improved, APACHE Ⅲ and Glasgow scores were better. Liver function was improved with the following alterations before and after treatment with MARS: serum ammonia (127.1±21.4 umol/L vs. 77.4±19.7 umol/L, P<0.05), lactic acid (6.53±0.45 mmol/L vs. 3.75± 0.40 mmol/L, P<0.05) and total bilirubin (452.3±153.7 umol/L vs. 230.9± 115.2 umol/L, P<0.05). However, there was no significant change in platelet count (44.25±3.60×109/L vs. 43.19±8.26×109/L, P>0.05) on international normalized ratio (INR) (2.74±0.50 vs. 2.82±0.60, P>0.05), which showed the safety of MARS. For all patients no serious adverse effects occurred during the treatment with MARS.CONCLUSION MARS is effective and safe for treatment of AHF patients with HCC, especially as a bridge to OLT when a donor organ is not available.

  14. Treatment of Adsorbable Organic Halides from Recycled Paper Industry Wastewater using a GAC-SBBR Pilot Plant System

    OpenAIRE

    Khadum, A.A.H.; Rahman, R.A.; Mohamad, A.B.; S.R.S. Abdullah; M.H. Muhamad

    2011-01-01

    Wastewater originating from recycled paper industry is known to be potentially toxic/inhibitory. Adsorbable Organic Halides (AOX) are among the toxic constituents generated from the recycled paper industry. The problems associated with AOX in the environment are their accumulation in the food chain and their persistence in nature. Hence, it is imperative to improve the effluent quality emanating from the recycled paper industry in order to meet the future discharge limits. One the plausible t...

  15. Organo/LDH nanocomposite as an adsorbent of polycyclic aromatic hydrocarbons in water and soil-water systems

    OpenAIRE

    Bruna González, Felipe; de Celis, R; Real Ojeda, Miguel; Cornejo, J.

    2012-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are considered as priority pollutants because of their high risk to human health. In this paper, we addressed the issue of using hydrotalcite-based nanocomposites as adsorbents of six low molecular weight PAHs (acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene) to reduce their negative effects on the environment. A nanocomposite (HTDDS) was prepared by intercalating the organic anion dodecylsulfate (DDS) in a Mg¿Al hydrotalcite (...

  16. Nonlinear Adaptive Control of Exhaust Gas Recirculation for Large Diesel Engines

    OpenAIRE

    Nielsen, Kræn V.; Blanke, Mogens; Vejlgaard-Laursen, Morten

    2015-01-01

    A nonlinear adaptive controller is proposed for the exhaust gas recirculation system on large two-stroke diesel engines. The control design is based on a control oriented model of the nonlinear dynamics at hand that incorporates fuel flow and turbocharger speed changes as known disturbances to the exhaust gas recirculation. The paper provides proof of exponential stability for closed loop control of the model given. Difficulties in the system include that certain disturbance levels will make ...

  17. Theoretical and experimental studies of the recovery of volatile organic compounds from waste air streams in the thermal swing adsorption system with closed-loop regeneration of adsorbent

    International Nuclear Information System (INIS)

    Highlights: • The TSA process for VOCs recovery from the waste air was studied. • The closed-loop adsorbent regeneration method was used. • A mathematical model was developed to simulate the TSA process. • The toluene–Sorbonorit 4 activated carbon system was studied. • We proved that toluene can be recovered in moderate condensation temperature range. - Abstract: The cyclic thermal swing adsorption (TSA) process for volatile organic compounds (VOCs) recovery from the waste air is studied theoretically and experimentally. Toluene is chosen as the volatile organic compound. Activated carbon Sorbonorit 4 is used as an adsorbent. The TSA cycle is operated in three steps: an adsorption step with cold feed, a desorption step with hot purge gas and a cooling step with cold inert gas. The desorption and cooling are affected by nitrogen circulated through a heater, an adsorber and a condenser. A nonequilibrium, nonisothermal mathematical model is developed to simulate temperature and concentration breakthrough curves for both adsorption and desorption steps. The computer simulation results are compared with the experimental data. A bench scale fixed bed adsorption unit was used for the experimental study. It is shown that the theoretical model predicts the experimental results well. The computer simulation results are used to study the effect of the purge gas and condensation temperature on the process efficiency

  18. Selective NOx Recirculation for Stationary Lean-Burn Natural Gas Engines

    Energy Technology Data Exchange (ETDEWEB)

    Nigel N. Clark

    2006-12-31

    Nitric oxide (NO) and nitrogen dioxide (NO2) generated by internal combustion (IC) engines are implicated in adverse environmental and health effects. Even though lean-burn natural gas engines have traditionally emitted lower oxides of nitrogen (NOx) emissions compared to their diesel counterparts, natural gas engines are being further challenged to reduce NOx emissions to 0.1 g/bhp-hr. The Selective NOx Recirculation (SNR) approach for NOx reduction involves cooling the engine exhaust gas and then adsorbing the NOx from the exhaust stream, followed by the periodic desorption of NOx. By sending the desorbed NOx back into the intake and through the engine, a percentage of the NOx can be decomposed during the combustion process. SNR technology has the support of the Department of Energy (DOE), under the Advanced Reciprocating Engine Systems (ARES) program to reduce NOx emissions to under 0.1 g/bhp-hr from stationary natural gas engines by 2010. The NO decomposition phenomenon was studied using two Cummins L10G natural gas fueled spark-ignited (SI) engines in three experimental campaigns. It was observed that the air/fuel ratio ({lambda}), injected NO quantity, added exhaust gas recirculation (EGR) percentage, and engine operating points affected NOx decomposition rates within the engine. Chemical kinetic model predictions using the software package CHEMKIN were performed to relate the experimental data with established rate and equilibrium models. The model was used to predict NO decomposition during lean-burn, stoichiometric burn, and slightly rich-burn cases with added EGR. NOx decomposition rates were estimated from the model to be from 35 to 42% for the lean-burn cases and from 50 to 70% for the rich-burn cases. The modeling results provided an insight as to how to maximize NOx decomposition rates for the experimental engine. Results from this experiment along with chemical kinetic modeling solutions prompted the investigation of rich-burn operating conditions

  19. Study on the construction of the facility type precision recirculating aquaculture system%构建设施型精准化循环水养殖系统的技术研究

    Institute of Scientific and Technical Information of China (English)

    牛化欣; 常杰; 雷霁霖; 贾玉东

    2014-01-01

    With the hot problem of the deepening of water shortage,environmental degrada-tion,efficient development of aquaculture,food safety and security,etc,which makes that the resource-based factory farming water is gradually an urgent need to efficient type recirculating aquaculture change. In this paper,industrialized farming concept as a guide,energy saving and emission reduction targets to agro-industrial technology research of flatfish system has been based on the model-based recirculating aquaculture systems(RAS)design principles to build accurate“conserving facility type”RAS,optimize their breeding process,and preliminary ex-ploration of marine fish in this integrated system. Low build the system for the majority of aqua-culture enterprises to provide a construction cost,the system is stable,practical farming model is easy to manage,but also for the further development of aquaculture in the establishment of modern precision engineering system to provide basic theory.%鉴于当前水资源短缺、环境恶化、水产养殖业高速发展,以及保障食品安全等问题的不断呈现,促使资源型工厂化流水养殖模式急需向高效型循环水养殖方向转变,这是产业发展提升的必然趋势。本文以工业化养殖理念为指导、节能减排为目标,以鲆鲽类产业技术体系构建的循环水养殖模式为样板,按循环水养殖系统(RAS)的设计原理,优化养殖工艺流程,构建一种设施型精准化的RAS,并初步分析探讨了海水鱼类在此集成系统中的应用效果。该系统将为广大水产养殖企业提供一种建设成本低廉、系统运行稳定可控、容易管理的实用新型养殖模式,也可为下一步发展现代水产精准养殖工程体系提供理论和实践依据。

  20. 工厂化循环水养殖系统中 pH 维持系统研究%Study on pH maintains system in the factory recirculating aquaculture

    Institute of Scientific and Technical Information of China (English)

    张业韡; 张海耿; 吴凡

    2013-01-01

    为精确调节循环水养殖系统中水体的pH,使鱼类生长在最适宜环境中,建立了一种新的pH维持系统。系统采用新型控制算法,通过向养殖水体持续加碱,将水体中的pH维持在一个稳定的数值。试验设定pH的目标值为74.,采用组态软件运行将PID、TCP、预判等多种计算相结合的算法来改变计量泵的输出流量,通过计量泵向调节池中持续注入碳酸氢钠( NaHCO3)溶液,以平衡水体中碱的消耗,最终将系统水体的pH长时间稳定在7.4±0.01的范围内。本pH维持系统能实现对循环水养殖系统中水体pH的精确调控,对维持水质的稳定及促进鱼类的健康生长具有重要意义。%In order to accurately regulate the pH of recirculating aquaculture systems , and build a suitable fish growth environment , we set up a new pH maintain system .The system adopts a new control algorithm , through using the method of continuous adding alkali into aquaculture ponds to maintain the pH of water at a stable value.This test set target the values of pH at 7.4, and combined PID, TCP, anticipation and various calculation algorithms to change metering pump output flow through using configuration software .Through injecting NaHCO 3 solution by metering pump continually , it could balance the consumption of alkali in water and make the pH stability for a long time in the range of 7.4 ±0.01.The pH maintain system could realize the pH of precise control in the recirculating aquaculture system , and keep the stability of water quality .It had important significance of promoting the healthy growth of fish .

  1. Integrated system for temperature-controlled fast protein liquid chromatography comprising improved copolymer modified beaded agarose adsorbents and a travelling cooling zone reactor arrangement.

    Science.gov (United States)

    Müller, Tobias K H; Cao, Ping; Ewert, Stephanie; Wohlgemuth, Jonas; Liu, Haiyang; Willett, Thomas C; Theodosiou, Eirini; Thomas, Owen R T; Franzreb, Matthias

    2013-04-12

    An integrated approach to temperature-controlled chromatography, involving copolymer modified agarose adsorbents and a novel travelling cooling zone reactor (TCZR) arrangement, is described. Sepharose CL6B was transformed into a thermoresponsive cation exchange adsorbent (thermoCEX) in four synthetic steps: (i) epichlorohydrin activation; (ii) amine capping; (iii) 4,4'-azobis(4-cyanovaleric acid) immobilization; and 'graft from' polymerization of poly(N-isopropylacrylamide-co-N-tert-butylacrylamide-co-acrylic acid-co-N,N'-methylenebisacrylamide). FT-IR, (1)H NMR, gravimetry and chemical assays allowed precise determination of the adsorbent's copolymer composition and loading, and identified the initial epoxy activation step as a critical determinant of 'on-support' copolymer loading, and in turn, protein binding performance. In batch binding studies with lactoferrin, thermoCEX's binding affinity and maximum adsorption capacity rose smoothly with temperature increase from 20 to 50 °C. In temperature shifting chromatography experiments employing thermoCEX in thermally jacketed columns, 44-51% of the lactoferrin adsorbed at 42 °C could be desorbed under binding conditions by cooling the column to 22 °C, but the elution peaks exhibited strong tailing. To more fully exploit the potential of thermoresponsive chromatography adsorbents, a new column arrangement, the TCZR, was developed. In TCZR chromatography, a narrow discrete cooling zone (special assembly of copper blocks and Peltier elements) is moved along a bespoke fixed-bed separation columnfilled with stationary phase. In tests with thermoCEX, it was possible to recover 65% of the lactoferrin bound at 35 °C using 8 successive movements of the cooling zone at a velocity of 0.1mm/s; over half of the recovered protein was eluted in the first peak in more concentrated form than in the feed. Intra-particle diffusion of desorbed protein out of the support pores, and the ratio between the velocities of the cooling

  2. Aircraft Recirculation Filter for Air-Quality and Incident Assessment

    OpenAIRE

    Eckels, Steven J.; Jones, Byron; Mann, Garrett; Mohan, Krishnan R.; Weisel, Clifford P.

    2014-01-01

    The current research examines the possibility of using recirculation filters from aircraft to document the nature of air-quality incidents on aircraft. These filters are highly effective at collecting solid and liquid particulates. Identification of engine oil contaminants arriving through the bleed air system on the filter was chosen as the initial focus. A two-step study was undertaken. First, a compressor/bleed air simulator was developed to simulate an engine oil leak, and samples were an...

  3. Effect of hydroponic plants on water quality purification in a recirculating aquaculture system%水培植物对循环水养鱼系统的水质净化研究

    Institute of Scientific and Technical Information of China (English)

    宋红桥; 管崇武; 李月; 单建军; 刘晃

    2013-01-01

    为研究循环水养殖系统水培植物对水质的改善效果,利用水蕹菜在温室大棚中进行为期15d的养殖水体水质净化试验。试验系统以罗非鱼为养殖对象,循环率20次/d,养殖密度5 kg/m 3,植物栽培区水力负荷10 m 3/(m 2· d)。试验结果表明:栽培区水蕹菜对氨氮(NH 4+-N)、亚硝酸盐氮(NO 2--N)、硝酸盐氮(NO 3--N)、总氮(TN)、化学耗氧量(COD)、总磷(TP)等的去除率分别7.3%、19.6%、14.5%、12.5%、13.5%、1.7%。试验结束后,罗非鱼总增重630 g,水蕹菜的生长速率58.3 mg/(m2· d)。总体来看,养殖水体中的营养盐可以满足水蕹菜正常生长,水蕹菜对养殖水体表现出较好的净化能力,水体中NH 4+-N、NO 2--N、COD、TP的浓度基本维持平衡不累积上升,NO 3--N和TN虽略有累积,但可通过增大栽培区面积、降低系统水力负荷,达到净化水质的目的。研究表明水培植物是循环水养殖系统净水技术的选择方向之一。%In order to study the effect of hydroponic plants on water quality purification , a recirculating aquaculture system in greenhouse was built for the experiment , which used tilapia as the raising species and Ipomoea aquatica as the cultivation hydroponic plants .The system's recirculating rate was 20 times per day, tilapia culture density was 5 kg/m3 , and the hydraulic loading rate of the plants cultivation area was 10 m3/( m2 · d) .The whole testing period was 15 days and the results showed that the ammonia nitrogen removal rate between the inlet and outlet of the cultivation area was 7.3% on average, nitrite nitrogen 19.6%, nitrate nitrogen 14.5%, TN 12.5%, COD 13.5%and TP 1.7%.After 15 experimental days, tilapia gained 630 g, Ipomoea aquatica growth rate was 58 .3 mg/( m2 · d ) .General speaking , nutrients in the system can mostly satisfy the normal growth of Ipomoea aquatic.NH4+-N, NO2--N, COD and

  4. Bench-to-bedside review: Current evidence for extracorporeal albumin dialysis systems in liver failure

    OpenAIRE

    Karvellas, Constantine J.; Gibney, Noel; Kutsogiannis, Demetrios; Wendon, Julia; Bain, Vincent G

    2007-01-01

    Acute liver failure (ALF) and acute on chronic liver failure (AoCLF) carry a high mortality. The rationale for extracorporeal systems is to provide an environment facilitating recovery or a window of opportunity for liver transplantation. Recent technologies have used albumin as a scavenging molecule. Two different albumin dialysis systems have been developed using this principle: MARS (Molecular Adsorbent Recirculation System) and SPAD (Single-Pass Albumin Dialysis). A third system, Promethe...

  5. Application of Hydrothermal and Non-Hydrothermal TiO2 Nanoporous Materials as New Adsorbents for Removal of Heavy Metal Ions from Aqueous System

    Directory of Open Access Journals (Sweden)

    Mansoor Anbia

    2016-06-01

    Full Text Available Hydrothermal and non-hydrothermal spherical TiO2 nanoporous with crystalline framework were prepared by sol-gel method. The Crystalline structures, morphologies and surface texturing of materials were determined by X-ray diffraction (XRD, scanning electron microscopy (SEM and N2 adsorption-desorption isotherms. The Hydrothermal spherical TiO2 nanoporous was found to have a narrow and strong pore size distribution peaks with average of 37.8 Å and pore volume of 0.41 cm3/g and the (Brunauer–Emmett–TellerBET specific surface area of 365 m2/g. Hydrothermal and non-hydrothermal spherical TiO2 nanoporous have been used as adsorbent to study of the adsorption behavior of Pb(II, Co(II and Ni(II ions from aqueous system in a batch system. Effect of equilibrium time on adsorption Pb(II, Co(II and Ni(II ions on these adsorbent was studied The results show that the shaking time 0.5 to 10h has no serious effect on the percentage of ions removal, and the adsorption is fast in all cases. The maximum uptake capacities of Hydrothermal and non-hydrothermal spherical TiO2 nanoporous was calculated. Both hydrothermal and non-hydrothermal TiO2 nanoporous materials were found to have very good potential as new adsorbents in removal of these ions. In batch systems the maximum uptake capacities of Pb(II, Ni(II and Co(II on the hydrothermal and non-hydrothermal TiO2 nanoporous materials was Co(II > Pb(II > Ni(II and Co(II > Ni(II > Pb(II, respectively.

  6. 基于工厂化循环水繁育系统的胭脂鱼人工繁育效果%Effects of artificial breeding in Myxocyprinus asiaticus based on recirculation breeding system

    Institute of Scientific and Technical Information of China (English)

    张成林; 吴凡; 徐皓; 宿墨; 管崇武

    2013-01-01

    通过分析胭脂鱼传统繁育方式发展中出现的瓶颈,突出构建工厂化循环水繁育系统模式的必要性及紧迫性。介绍了重庆市万州区水产研究所总设备投资约为185万元、有效养殖水面为537.5 m2工厂化循环水繁育车间的系统构成及运行模式,着重分析了主要水质指标的变化及繁育车间的运行效果。结果显示:该繁育车间各系统运行稳定,水质指标正常,催产繁育效果明显,胭脂鱼受精卵孵化率及幼苗存活率分别可达93%和92%以上;经过6个批次的繁育,年产量500余万尾;年产值近1800万元,较往年增值700余万元,车间建设费用1年即可回收,经济社会效益显著,具备广泛的推广空间。同时,根据系统运行中存在的问题,提出了注意事项,并指出优化方向。%Through the analysis of the disadvantages of traditional breeding way in Myxocyprinus asiaticus, highlighting the necessity of building industrial recirculation breeding model .This paper introduced the system structure and operation mode of industrial recirculation breeding workshop in Chongqing Wanzhou District , which has total equipment investment of about 1.85 million Yuan and effective water aquaculture is square 537 .5 m2 .The results showed that all systems in the breeding workshop ran stably , the indicators of water quality was normal and the effect of breeding was obvious , the hatching rate and seeding survival rate of Myxocyprinus asiaticus reached more than 93%and 92%, respectively;annual output reached 5 million or so after 6 batches of breeding;annual production valued of nearly 18 million Yuan , which was added more than 700 Yuan compared with the previous year .The economic and social benefits were obvious .Meanwhile , according to the problems existed in system , this paper proposed considerations and pointed out optimization direction , in order to provide comprehensive support for the industrial

  7. Desempenho de sistema de tratamento de lixiviado de aterro sanitário com recirculação do efluente Performance of a sanitary landfill leachate treatment system with effluent recirculation

    Directory of Open Access Journals (Sweden)

    Cláudia Lavina Martins

    2010-12-01

    Full Text Available O objetivo deste estudo foi avaliar o desempenho de um sistema de tratamento de lixiviado de aterro sanitário, em escala piloto, formado por três lagoas em série (L1, L2 e L3 seguidas por um filtro de pedras (FP. Foram estudadas três condições operacionais, verificando-se o efeito da recirculação do efluente da L3 para a L1: 0, 50 e 100% da vazão. O sistema absorveu bem as flutuações de cargas, apresentando remoções superiores a 80% para DBO F, 70% para DQO T e 98% para nitrogênio amoniacal. Na lagoa L2 houve nitrificação parcial, com acúmulo de nitritos. Ocorreu presença marcante do gênero Chlamydomonas nas lagoas L2 e L3 fotossintéticas. Observou-se diminuição da toxicidade do lixiviado, com reduções superiores a 95% na saída do sistema. A melhor eficiência de remoção para as três condições operacionais estudadas foi obtida com 100% de recirculação.The objective of this study was to evaluate the performance of a landfill leachate treatment system, at pilot scale, formed by three in series ponds (L1, L2, and L3 followed by a rock filter. Three operational conditions were studied, assessing the effluent recirculation effect from L3 to L1: 0, 50 and 100% of the flow rate. The system assimilated well the load fluctuations, showing removal efficiencies over 80% for BOD F, 70% for COD T and 98% for ammonia. In the L2 pond there was partial nitrification with nitrite accumulation. It was observed an outstanding presence of the Chlamydomonas gender in photosynthetic ponds L2 and L3. A reduction of the toxicity from the landfill leachate was observed, with reduction of over 95% in the system output. The better removal efficiency for the three studied operational conditions was obtained for 100% of recirculation.

  8. 循环水养殖系统培育日本鳗鲡和美洲鳗鲡苗种的研究%Studies on fingerlings breeding of Anguilla japonica and Anguilla rastrata by recirculating aquaculture system

    Institute of Scientific and Technical Information of China (English)

    徐继松; 关瑞章; 陈学豪; 赖晓健

    2012-01-01

    采用具有气泡反冲洗型珠子过滤器的循环水养殖系统对日本鳗鲡和美洲鳗鲡进行了苗种培育的研究.2种鳗苗的放养密度约为传统模式的8~10倍,试验期间换水量约为20%~45%.结果显示:日本鳗苗和美洲鳗苗成活率均≥96.74%,高于传统模式.投喂水丝蚓阶段,日本鳗苗特定生长率和饲料系数分别为(7.08±0.08)%/d和4.92±0.03,美洲鳗苗分别为(4.83±0.06)%/d和4.74+0.19.投喂配合饲料阶段,日本鳗苗分别为(2.30±0.19)%/d和1.30±0.02,美洲鳗苗分别为(1.69±0.05)%/d和1.76±0.06.研究表明,该循环水养殖系统可适用于日本鳗苗和美洲鳗苗的培育,并具有节能、减排和无药残等优点,为开发资源节约型和环境友好型的鳗鲡育苗模式提供参考.%Anguilla japonica and A.rastrata fingerlings were bred by the recirculating aquaculture system which has the bubble bead filter.The stocking density of this experiment was 8-10 times more than the model of traditional culture.The quantity of the exchanged water was 20% 45% during the experimental period.The results showed that the survival rates of A.japonica and A.rastrata fingerlings were all above 96.74%,and higher than the model of traditional culture.The specific growth rates ( SGR) and feed conversion ratioes (FCR) of A.japonica and A.rastrata fingerlings were (7.08 ±0.08)%/d and (4.83 ±0.06)%/d,4.92± 0.03 and 4.74 ±0.19,respectively,during the period of feeding Limnodrilus hoffmeisteri.The SGR and FCR oiA.japonica and A.rastrata fingerlings were (2.30 ±0.19)%/d and (1.69 ±0.05)%/d,1.30±0.02 and 1.76 ±0.06,respectively,during the period of feeding compound diet.The results indicated that the recirculating aquaculture system was suitable for the fingerlings breeding of A.japonica and A.rastrata.The fingerlings breeding of eel were energy-saving,emission reduction and non-residue by the recirculating aquaculture system.These results will provide an important

  9. Dynamic effect of leachate recirculation on batch mode solid state anaerobic digestion: Influence of recirculated volume, leachate to substrate ratio and recirculation periodicity.

    Science.gov (United States)

    Degueurce, Axelle; Trémier, Anne; Peu, Pascal

    2016-09-01

    Performances of batch mode solid state anaerobic digestion (SSAD) were investigated through several leachate recirculation strategies. Three parameters were shown to particularly influence methane production rates (MPR) and methane yields: the length of the interval between two recirculation events, the leachate to substrate (L:S) ratio and the volume of leachate recirculated. A central composite factor design was used to determine the influence of each parameter on methane production. Results showed that lengthening the interval between two recirculation events reduced methane yield. This effect can be counteracted by recirculating a large volume of leachate at a low L:S ratio. Steady methane production can be obtained by recirculating small amounts of leachate, and by lengthening the interval between two recirculations, regardless of the L:S ratio. However, several combinations of these parameters led to similar performances meaning that leachate recirculation practices can be modified as required by the specific constraints SSAD plants configurations. PMID:27281433

  10. Hydrophobic Porous Material Adsorbs Small Organic Molecules

    Science.gov (United States)

    Sharma, Pramod K.; Hickey, Gregory S.

    1994-01-01

    Composite molecular-sieve material has pore structure designed specifically for preferential adsorption of organic molecules for sizes ranging from 3 to 6 angstrom. Design based on principle that contaminant molecules become strongly bound to surface of adsorbent when size of contaminant molecules is nearly same as that of pores in adsorbent. Material used to remove small organic contaminant molecules from vacuum systems or from enclosed gaseous environments like closed-loop life-support systems.

  11. Development of an adsorbent for both cesium and strontium

    International Nuclear Information System (INIS)

    Described is the development of the adsorbent in the title at the process of developing the agent to adsorb each element. For cooling the reactors injured by the Fukushima Nuclear Power Plant Accident by the earthquake and tsunami on the day before (Mar. 11, 2011), fresh/ sea water is supplied in the reactor and flows out contaminated with radioactive elements in the turbine building and then in the treatment plant to remove oil and cesium for re-circulation to the reactor. Water from the plant still contains radioisotopes derived from fission, like 90Sr/90Y at 1.2 x 108 Bq/L and 137Cs/137mBa at 6.1 x 103 Bq/L, and from activation of reactor materials. Before the plant, the water contains 137Cs at the level as high as 4.1 x 107 Bq/L. Authors have examined various agents to adsorb 90Sr and 137Cs with a measure of partition coefficient Kd (L of the artificial sea water/kg) and have come to find out the adsorbent in the title: it is derived from the Cs-adsorbing crystalized silico-titanate (CST). The adsorbent is obtainable by surface treatment of CST with NaOH and has high Kds of >1 x 103 and >1 x 104 L/kg for Sr and Cs, respectively, while other ordinary adsorbents' Kds are: artificial zeolite 1-10 x 102/1-10 x 101 for Sr/Cs, respectively; natural one 0.1-10 x 101/1-10 x 102; ferrocyanide 0.1-10 x 101/1-10 x 104, and CST 1 x 101/>1 x 104. When 1 m3 of the present adsorbent is used, >99% of Cs and Sr can be removable in >3,000 m3 of contaminated water, suggesting its usefulness for dealing with water after the Accident. (T.T.)

  12. Recirculation of Laser Power in an Atomic Fountain

    Science.gov (United States)

    Enzer, Daphna G.; Klipstein, WIlliam M.; Moore, James D.

    2007-01-01

    A new technique for laser-cooling atoms in a cesium atomic fountain frequency standard relies on recirculation of laser light through the atom-collection region of the fountain. The recirculation, accomplished by means of reflections from multiple fixed beam-splitter cubes, is such that each of two laser beams makes three passes. As described below, this recirculation scheme offers several advantages over prior designs, including simplification of the laser system, greater optical power throughput, fewer optical and electrical connections, and simplification of beam power balancing. A typical laser-cooled cesium fountain requires the use of six laser beams arranged as three orthogonal pairs of counter-propagating beams to decelerate the atoms and hold them in a three-dimensional optical trap in vacuum. Typically, these trapping/cooling beams are linearly polarized and are positioned and oriented so that (1) counter-propagating beams in each pair have opposite linear polarizations and (2) three of the six orthogonal beams have the sum of their propagation directions pointing up, while the other three have the sum of their propagation directions pointing down. In a typical prior design, two lasers are used - one to generate the three "up" beams, the other to generate the three "down" beams. For this purpose, the output of each laser is split three ways, then the resulting six beams are delivered to the vacuum system, independently of each other, via optical fibers. The present recirculating design also requires two lasers, but the beams are not split before delivery. Instead, only one "up" beam and one oppositely polarized "down" beam are delivered to the vacuum system, and each of these beams is sent through the collection region three times. The polarization of each beam on each pass through the collection region is set up to yield the same combination of polarization and propagation directions as described above. In comparison with the prior design, the present

  13. Ammonia Processing Technology in A Recirculating System in Industrial Aquaculture:A Review%工厂化水产养殖水中氨氮处理技术的研究

    Institute of Scientific and Technical Information of China (English)

    韩世成; 郭常有; 蒋树义; 曹广斌

    2014-01-01

    氨氮处理技术是工厂化水产养殖的关键技术之一。本文综述国内外工厂化养殖中常用的氨氮处理方法,如空气吹脱、离子交换吸附、微生物处理、臭氧氧化处理、沉水植物处理等,分析各种方法的优缺点,论证LED特定光照沉水植物处理氨氮方法的优势、可行性和发展方向,为实际应用和新技术开发提供参考。%Ammonia processing technology as a key in a recirculating aquaculture system is summarized including a bubble-washed bead filter, ion exchange and adsorption, microorganism treatment, and use of ozone and submerged plants. The advantages and disad-vantages of these methods are evaluated, and a new method, specific LED light irradiation submerged plants handling ammonia, is in-troduced. The future researches on those methods are discussed to provide a base for practice application.

  14. Observation on effects of treatments using molecular adsorbent recirculating system (MARS) in 20 patients with severe hepatitis%分子再吸附循环系统治疗重型肝炎20例疗效观察

    Institute of Scientific and Technical Information of China (English)

    金洁; 俞哲; 叶卫江; 周翔

    2006-01-01

    目的探讨分子吸附再循环系统(MARS)治疗重型肝炎的疗效和安全性.方法对20例慢性乙型重型肝炎患者在内科综合治疗基础上,使用分子吸附再循环系统支持治疗,每次6h.结果20例患者经MARS人工肝治疗后,治愈好转12例,治愈好转率60%;血中总胆红素、胆汁酸等非水溶性蛋白结合毒素及血氨等水溶性毒素明显下降(P<0.05),凝血酶原活动度显著升高(P<0.05),治疗前后肾功能、血常规和电解质无显著变化(P>0.05);治疗期间血压、心率稳定.结论MARS是临床治疗重型肝炎安全有效的方法.

  15. 复合池塘循环水养殖系统微生物群落结构分析%Analysis of microbial community structure in an integrated pond recirculating aquaculture system

    Institute of Scientific and Technical Information of China (English)

    姚延丹; 李谷; 陶玲; 李晓莉; 张世羊; 赵巧玲; 林玉良

    2011-01-01

    于2008年6至10月逐月调查研究了新型复合池塘循环水养殖系统各塘水体理化和微生物分子特征.通过提取水样中细菌总DNA,扩增其16S rDNA基因V3区,再经DGGE分析获得图谱,选择其中主要的13条特征条带进行克隆测序.研究结果表现为,随水流方向(Pl→P5),各循环塘溶氧(DO)和透明度(SD)依次呈明显下降趋势,而NH4~+-N,TP和COD_Mn水平呈明显上升趋势;与对照塘相比,循环塘DO和SD升高,COD_Mn和营养盐水平降低.DGGE图谱分析显示,各养殖塘微生物种类丰富,循环塘与对照塘的群落结构存在明显差异,且差异主要表现在较弱的条带上;13条特征条带的测序结果表明,池塘优势菌群分属4个门:放线菌门(Actinobacteria)、变形菌门(Proteobacteria)、蓝细菌门(Cyanobacteria)和拟杆菌门(Bacteroidetes),其中有2条属于蓝细菌门的条带特定分布于对照塘.典型对应分析(CCA)排序结果显示,DGGE图谱条带分布与理化因子密切相关.与传统池塘养殖相比,该养殖模式有助于改善养殖池塘微生态环境.本研究旨为池塘微生物群落结构及其功能关系研究提供借鉴.%Aquaculture has been one of the fastest growing segments of global food production sector in recent decades. With the rapid development, it also leads to many environmental problems. For example, both per unit area yield of aquatic products and their quality has declined continuously.It is important that well-balanced systems be developed that are sustainable. Constructed wetlands (CWs) are ecologically beneficial, low-cost treatment alternatives, proven capable of reducing suspended solids, 5-day biochemical oxygen demand (BOD5), nitrogen, phosphorus and heavy metals from wastewater of many sources. In the present paper, the physicochemical and microbial characteristics of culture ponds in an Integrated Pond Recirculating Aquaculture System (IPRAS)based on constructed wetland were investigated during the period

  16. Effects of Artificial Biological Purification System on Water Quality of Recirculating Aquaculture System%人工生物净化体系对循环水养殖系统水质的影响

    Institute of Scientific and Technical Information of China (English)

    李建国; 赵冬艳; 孙成渤

    2012-01-01

    In the recirculating aquaculture system, setting up the artificial purification system consisting of aquatic plants, cured indigenous microbial communities and filter-feeding fish and shellfish, can reduce the nutrients in the aquaculture water, lighten the eutrophication level and increase the stability of water quality effectively. Comparing the major water quality index before the system set up and those after that, the results show that in 2008 without the system, the average annual value of PO4-P, NH3-N, NO3-N, NO2-N and the phytoplankton gross in the purifying area were higher than that in the breeding area by 5.44 times, 1.35 times, 4.03 times, 2.55 times and 12.77 times, respectively. On the contrary, the data of the purifying area were lower than that of the breeding area by 122%, 146 %, 144%, 412% and 417%, respectively in 2009 with the system. In 2009, the economic aquatic plants absorbed the nutrient elements: N 0.208 8 kg, P 0.267 3 kg, K 0.022 5 kg in water and the filter-feeding fish and shellfish took 2 229.5 kg fish (shellfish) nutrients. The variation coefficient in the system of Alk, PO4-P, NH3-N, NO3-N, NO2-N and phytoplankton gross decreased by 8.43%, 26.98%, 62.33%, 17.01%, 0.01%, 35.55%, respectively compared with 2008.%循环水养殖系统中,建立以水生植物、固化了的土著微生物群落、滤食性鱼类及贝类等组成的人工净化体系可有效地降低养殖用水中的营养物质,减轻其富营养化程度,增加水质的稳定性。对比体系建立前后各主要水质指标的结果显示:未建立的2008年,净化区域的POrP、NH3-N、NO3-N、NO2-N、浮游植物总量的年均值分别比养殖区域高出5.44倍、1.35倍、4.03倍、2.55倍、12.77倍;而已建立该体系的2009年却相反,净化区域分别比养殖区域低了122%、146%、144%、412%、417%。2009年,水生经济植物吸收了水体中N0.2088kg、P0.2673kg、K0.0225妇的营养元素;

  17. PREPARATION AND CHARACTERIZATION OF SOLID SELF MICROEMULSIFYING DRUG DELIVERY SYSTEM BY ADSORBENT TECHNIQUE TO IMPROVE DISSOLUTION PROFILE OF POORLY AQUEOUS SOLUBLE DRUG RAMIPRIL

    Directory of Open Access Journals (Sweden)

    Shelke Nagsen

    2011-06-01

    Full Text Available The main purpose of this work is to prepare solid self-microemulsifying drug delivery system (S-SMEDDS to improve drug dissolution profile of poorly aqueous soluble drug. Optimized formulation of SMEDDS consists of Ramipril (RAM (10 mg, Tween 80 (160mg, Cremophor EL (640mg and Capmul MCM (CAP as oil (200mg. SMEDDS was adsorbed at various SMEDDS: adsorbent ratio i.e. 3:1, 1:1, 1:3 on the solid carrier Aerosil 200. Powder flow properties and drug content were evaluated of the resulting formulations. The S-SMEDDS which showed maximum drug content in formulation & good flow properties were further evaluated & characterized for globule size, reconstitution properties, DSC, SEM & in-vitro dissolution profile. Converting liquid SMEDDS formulation to solid SMEDDS formulation is easy by adsorption on solid carrier technique. Formulation to Aerosil 200 ratio of 1:1 showed passable flow properties and high drug content. Also the reconstitution properties of the S-SMEDDS were not much altered. DSC study revealed that the drug was in solubilised form. SEM photographs showed that the formed particle were smooth and not much aggregation. Dissolution profile for Ramipril from S-SMEDDS was significantly higher than the conventional capsule. After three month stability study S-SMEDDS did not show any drug precipitation as well as phase separation. Our studies suggest that solid SMEDDS could be used as an effective oral solid dosage form to improve the dissolution profile of poorly aqueous soluble drug.

  18. Ultrafast time-resolved electron diffraction on adsorbate systems on silicon surfaces. Vibrational excitation in monllayers and dynamics of phase transitions

    International Nuclear Information System (INIS)

    In the present work ultra fast time resolved electron diffraction (TR-RHEED) at various adsorbate systems on silicon (Si) substrates was performed. Using the Debye-Waller-effect, the vibrational amplitude of the excited adsorbate atoms can be directly observed in the experiments as a function of time. For a coverage of 4/3 monolayers Lead (Pb) on Si(1 1 1) forms a (√(3) x √(3))-reconstruction. The transient intensity evolution of the diffraction spots is recorded in a TR-RHEED-experiment. After excitation with a fs-laser pulse the intensity decreases due to the Debye-Waller-effect. The temporal behavior of the de-excitation process can be described with two exponential functions: a short time constant of 100 ps and a long one of 2800 ps. The two time constants can be assigned to two different phonon modes of the Pb-adsorbate. The huge difference between the two time constants and thus difference in the coupling to the substrate is explained by the bonding geometry in the structural model. To confirm this possible explanation, further TR-RHEED-experiments for the (√(7) x √(3))-reconstruction of Pb on Si(1 1 1) were performed. The (√(7) x √(3))-reconstruction with a coverage of 1.2 monolayers shows comparable structural elements. The transient intensity evolution can be described with the identical two time constants. In addition, first experiments on the β (√(3) x √(3))-phase of Pb/Si(1 1 1) are presented. This β (√(3) x √(3))-reconstruction, with a coverage of 1/3 monolayers of Pb, shows a phase transition to a (3 x 3)-reconstruction, which was observed in the experiments. Further investigated adsorbate systems are: (√(3) x √(3))Ag/Si(1 1 1), (√(3) x √(3))In/Si(1 1 1), (√(31) x √(31))In/Si(1 1 1), and (√(3) x √(3))Bi/Si(1 1 1). In the second part of the present work the structural dynamics of strongly driven surface phase transitions was analysed for the first time with TR-RHEED. As a first modell system, the Si(0 0 1) c(4 x 2

  19. Peach bottom recirculation piping replacement ALARA program

    International Nuclear Information System (INIS)

    In late 1983, Philadelphia Electric Company (PECo) began detailed planning to replace the recirculation, residual heat removal, and part of the reactor water cleanup piping of the Peach Bottom Unit 2 reactor. Included in this work was an estimate of the collective exposure expected during piping replacement. That initial estimate, 1945 man-rem, is compared with the actual collective dose incurred during the piping replacement program. Also included are the exposures incurred during two additional tasks (safe end replacement and recirculation pump disassembly and decontamination) not considered in the initial estimate

  20. Band structure and charge doping effects of the potassium-adsorbed FeSe /SrTiO3 system

    Science.gov (United States)

    Zheng, Fawei; Wang, Li-Li; Xue, Qi-Kun; Zhang, Ping

    2016-02-01

    We theoretically study, through combining the density functional theory and an unfolding technique, the electronic band structure and the charge doping effects for the deposition of potassium on multilayer FeSe films grown on SrTiO3 (001) surface. These results form a theoretical baseline for further detailed studies of low-temperature electronic properties and their multiway quantum engineering of FeSe thin films. We explain the Fermi-surface topology observed in experiment and formulate the amount of doped electrons as a function of atomic K coverage. We show that the atomic K deposition efficiently dopes electrons to the top layer of FeSe. Both checkerboard- and pair-checkerboard-antiferromagnetic (AFM) FeSe layers show electron pockets at the M point and no Fermi pocket at the Γ point with moderate atomic K coverage. The electron transfer from the K adsorbate to the FeSe film introduces a strong electric field, which leads to a double-Weyl-cone structure at the M point in the Brillouin zone of checkerboard-AFM FeSe. We demonstrate that with experimentally accessible heavy-electron doping, an electronlike Fermi pocket will emerge at the Γ point, which should manifest itself in modulating the high-temperature superconductivity of FeSe thin films.

  1. Bromocriptine tablet of self-microemulsifying system adsorbed onto porous carrier to stimulate lipoproteins secretion for brain cellular uptake.

    Science.gov (United States)

    Thongrangsalit, Sirigul; Phaechamud, Thawatchai; Lipipun, Vimolmas; Ritthidej, Garnpimol C

    2015-07-01

    Both low solubility and high hepatic metabolism cause low oral bioavailability of bromocriptine mesylate (BM) leading to very low drug amount in brain. Self-microemulsion (SME) tablets were developed to improve solubility, stimulate lipoprotein synthesis to promote lymphatic transport, avoid hepatic metabolism and target drug to brain. SME liquid containing castor oil, Tween(®) 80 and Cremophor(®) EL was prepared and then adsorbed onto solid carries, Aerosil(®)200, Aeroperl(®)300 or NeusilinUS2(®), yielding SME powders. The optimal ratios of SME liquid to carriers determined from flowability and scanning electron photomicrographs before tableting were 1.5:1, 2:1 and 2.5:1 for Aerosil(®)200, Aeroperl(®)300 and NeusilinUS2(®), respectively. Only Aeroperl(®)300 SME tablet had comparable dissolution to BM commercial tablet. From in vitro study in Caco-2 cells, fluorescein loaded SME tablet showed higher uptake than fluorescein loaded in either oil or surfactant. Although significantly lower amount of drug was permeated from SME tablet than from commercial tablet, higher drug uptake was obviously observed (Pbrain endothelial cells (bEnd.3) and astrocytes (CTX TNA2) from drug loaded SME tablet when compared to commercial tablet (Pbrain via lymphatic transport by increasing the lipoprotein synthesis. PMID:25988280

  2. Simulation and tests to individual and coupled models of the reactor vessel simulator and the recirculation system for the SUN-RAH; Simulacion y pruebas a modelos individuales y acoplados del simulador de la vasija del reactor y el sistema de recirculacion para el SUN-RAH

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez S, R.A. [UNAM, Laboratorio de Analisis de Ingenieria de Reactores Nucleares, DEPFI, Campus Morelos, en IMTA Jiutepec, Morelos (Mexico)]. e-mail: rsanchez_15@yahoo.com.mx

    2004-07-01

    The present project, is continuation of the project presented in the congress SNM-2003. In this new phase of the project, they were carried out adaptive changes to the modeling and implementation of the module of the full superior of the core of the reactor, they were carried out those modeling of the generation of heat as well as of the energy transfer in the one fuel. These models present the main characteristics of the vessel of the one reactor and of the recirculation system, defined by the main phenomena that they intervene in the physical processes, in the previous version the simulation in real time it required of an extremely quick computer and without executing collateral processes. The tests are presented carried out to the different models belonging to the Simulator of the Reactor Vessel and the Recirculation system for the SUN-RAH (University Simulator of Nucleo electric with Boiling Water Reactor), as well as the results hurtled by this tests. In each section the executions of the tests and the corresponding analyses of results are shown for each pattern. Besides the above mentioned, the advantages presented by the Simulator of the reactor vessel and the recirculation system are pointed. (Author)

  3. Sodium recirculation and isotonic transport in toad small intestine

    DEFF Research Database (Denmark)

    Nedergaard, Signe Nielsen; Larsen, Erik Hviid; Ussing, Hans H.

    1999-01-01

    Small intestine; leaky epithelia; solute-coupled water transport; Na*O+ recirculation; lateral intercellular space; flux ratio analysi......Small intestine; leaky epithelia; solute-coupled water transport; Na*O+ recirculation; lateral intercellular space; flux ratio analysi...

  4. A five-year study of coastal recirculation and its effect on air pollutants over the East Mediterranean region

    Science.gov (United States)

    Levy, Ilan; Dayan, Uri; Mahrer, Yitzhak

    2008-08-01

    Many studies have shown that air pollutants concentrations in coastal cities may be gravely affected by coastal recirculation. In this study an attempt is made to examine the properties of coastal recirculation over a long period (5 yrs) at multiple sites along the East Mediterranean Sea (EMS). For this purpose, a single station quantitative measure of horizontal recirculation is used based on wind field measurements over periods of 1-96 hrs. The horizontal recirculation is examined with respect to the integration time period, synoptic flow, seasonality, coastline variations, elevation, and air pollutants concentrations. The interaction between synoptic and mesoscales is shown to be a governing factor by allowing or overruling the land sea breeze winds. Favorite conditions for coastal recirculation are shown to be light or variable winds such as under a Cole or a High-Pressure system. The monthly distribution of the recirculation potential has a bimodal behavior with two peaks during the transitional seasons and October in particular. This is as a result of the annual cycle of night-time land-sea temperature difference driving the land breeze and the more frequent passage of synoptic scale flows with an easterly wind component at the EMS. Two factors leading to variations along the coastline are the urban heat island, weakening the breeze winds and reducing recirculation potential, and the concaved shape of the southern shoreline that causes a convergence and strengthening of the land breeze, thus supporting recirculation. The primary pollutants NOx and SO2 have the highest concentrations during weak daily mean wind speeds. O3 levels depict an almost opposite image of NOx, with higher values for both high and low recirculation, possibly resulting from either long range transport or coastal recirculation.

  5. A Study on the Adverse Effect of AOVs in AFWS Recirculation Paths on Plant Safety

    International Nuclear Information System (INIS)

    Auxiliary feedwater system (AFWS) recirculation flow paths adopted air operated valves (AOVs) which could fail close on loss of instrument air (LOIA) event. So the AOVs and recirculation paths are closed on LOIA event, which could result in Auxiliary feedwater (AFW) pump(s) damage, which contributes greatly to core damage frequency (CDF).. On February 2002, the USNRC issued an inspection finding related to potential common cause failure of AOVs in AFWS recirculation flow paths on loss of instrument air system in Point Beach nuclear power plant (Pt. Beach). The AOVs have been removed from AFWS recirculation paths in the design of Korea standard nuclear power plant (KSNP). So, there is no possibility of above mentioned failure event in KSNP. It would be beneficial to evaluate the significance of adverse effect of AOVs in AFWS recirculation paths to realize the importance of maintaining AFWS recirculation paths always open. In this study, the AFWS modeling of Ulchin unit 3 and 4 was modified to model the AOVs in AFW recirculation flow paths to evaluate the change in CDF, which is caused by the adverse effect of AOV with operation mode of 'fails close' on LOIA event. It is concluded that the existence of AOV with 'fail close' design in AFWS MDP recirculation paths results in CDF increase of 131%, which is significant adverse effect on plant safety.. In this regard, the improved Westinghouse design and KSNP design had removed the AOVs from AFWS MDP recirculation paths. However, a couple of units with old Westinghouse design, Kori 1 and 2, still have AOVs in AFWS MDP recirculation paths and throttle back operation of AFWS is in effect. Although those AOVs adopt 'fail open' design to prevent above mentioned inadvertent closure, considering the big increase in CDF, there still exists considerable risk from the possibility of 'failure to open' during this throttle back operation. Therefore, it is strongly recommended that any

  6. Biofiltration of cyclo-bio fluidized sand bed in recirculating aquaculture system%循环水养殖旋转式生物流化床生物过滤功能

    Institute of Scientific and Technical Information of China (English)

    柳瑶; 宋协法; 雷霁霖; 彭磊; 黄志涛; 刘宝良

    2015-01-01

    A lab-scale cyclobio fluidized sand biofilter was designed to study biofiltration in recirculating aquaculture systems. First, the biofiltration start was studied separately in fresh water and seawater recirculating aquaculture systems. Second, the influence of different operation conditions on water treatment were studied by natural membrane-forming, including three bed expansions (50%, 75% and 100%) and four carbon nitrogen ratios (0, 0.5, 1 and 2). A synthetic substrate solution was continuously fed into the tanks after measuring of water quality every time. The results showed that the total ammonia-nitrogen concentration was decreased, fluctuating lightly in later period. The nitrite-nitrogen concentration was in a shape of clock, increasing quickly first and keeping the maximum for days then decreasing quickly, fluctuating lightly in later period. Not only ammonia-nitrogen and nitrite-nitrogen concentrations, but also the stability of water quality should be as the criteria of completion judgement of biofiltration start. In these conditions, biofiltration start of cyclobio fluidized biofilter were 47 days in fresh water system and 60 days in seawater system. Besides, we found that the cyclobio fluidized biofilter had little help in removing phosphorous, maybe because dissolved oxygen was always more than 6 mg/L in system. The nitrate-nitrogen concentration was increased on the whole. However, high nitrite-nitrogen concentration may harm fish health. To avoid that, there were two control methods: exchanging some new water to system every day, or adding denitrification equipment to recirculating aquaculture systems. Meanwhile, the results of operation conditions showed that the maximum load of system was separately 2.5, 3.0 and 3.5 mg/L with different bed expansions 50%, 75% and 100%. And the removal efficiency of total ammonia-nitrogen increased and the nitrite-nitrogen concentration decreased with the enhancement of bed expansion. The efficiency of ammonia

  7. The bio-ethanol production with the thin stillage recirculation

    OpenAIRE

    Rakin, M.; J. Pejin; O. Grujić; Lj. Mojović; D. Pejin

    2009-01-01

    In this paper, the bioethanol production with the thin stillage recirculation in mashing was investigated. The mashing was performed with recirculation of: 0, 10, 20 and 30 % of the thin stillage. The thin stillage recirculation was repeated six times. In the experiment without the thin stillage, the recirculation bioethanol yield (compared to the theoretical yield) was 97.96 %, which implicates that the experiment conditions were chosen and performed well. With the addition of the thin still...

  8. Hydraulic study of parallel channels coupled to recirculation loops; Estudio hidraulico de canales paralelos acoplados a lazos de recirculacion

    Energy Technology Data Exchange (ETDEWEB)

    Campos G, R. M.; Cecenas F, M. [Instituto de Investigaciones Electricas, Av. Reforma 113, Col. Palmira, 62490 Cuernavaca, Morelos (Mexico)], e-mail: rmcampos@iie.org.mx

    2009-10-15

    In this work is integrated a model of recirculation loops that allows to characterize each loop for separate and with which is possible to analyze events as shot of recirculation bombs or its transfer of high to low speed. The recirculation pattern is integrated to a model of 36 channels in parallel that represents the core of a BWR. Because the core reactor is conformed by fuel assemblies physically prepared in a parallel arrangement, it is natural to obtain a parallel application of complete pattern, where are have 36 channels tasks more other two tasks that calculates recirculation and punctual kinetics, respectively. As initial test of system, which even it is found in development, was analyzed a discharge of both recirculation pumps. In this test transitory it is only verified the hydraulic behavior, the power is imposed artificially as frontier condition that is function of flow in the calculated core by the recirculation pattern. The pattern of thermal hydraulics channel and the recirculation loops are programmed in language C, the neutronic pattern is programmed in Fortran 77. For the simulations was used a work station Alpha Station DS20E with operative system Unix and the communication system Parallel Virtual Machine, that allows to a heterogeneous collection of computers in net to work like a virtual computer in parallel. (Author)

  9. 多层抽屉式循环水幼鲍养殖系统及养殖效果%Recirculating aquaculture system with multi-layer drawer culture tanks for juvenile abalone and its effects

    Institute of Scientific and Technical Information of China (English)

    吴垠; 孙建明; 柴雨; 徐长雷

    2012-01-01

    为了提高皱纹盘鲍的养殖效果,该文设计了多层抽屉式循环水养殖幼鲍系统,分析了养殖期间系统的水质指标和耗能量,及不同养殖密度下幼鲍的生长率和成活率.结果表明,该系统适宜的幼鲍养殖密度为150个,屉(70cm×40cm×10cm/屉),为流水式养鲍密度的6~9倍.试验过程中水温、溶解氧、pH值、盐度、NH4+-N和NO2--N指标均达到幼鲍生长条件,NH4+-N和NO2--N体积质量基本稳定在0.023~0.065 mg/L和0.014~0.041 mg/L范围内.试验期间总耗电量为688.88 kW·h,其中海水加热占总耗电量19.62%,相当于每天1.287 kW·h耗电量,大约是流水式养殖加热耗能的1/7.该研究表明,多层抽屉式循环水养鲍系统是一种安全、高效、节能减排的养殖模式.该系统可供选择养鲍设施时参考.%In order to improve the culture efficiency of disk abalone, Haliotis discus hannai, the recirculating aquaculture system (RAS) with multi-layer drawer abalone culture tanks (70 cm×40 cm× 10 cm per drawer) were designed. The water quality parameters, energy consumption during experiment period, as well as the growth rate and survival of juvenile abalone in different culture densities were monitored. The results showed that the culture density for 150 individuals per drawer in the recirculating systems was appropriate, which was about 6-9 times of the flow-through systems. The temperature, dissolved oxygen, pH value, salinity, NH4VN and NCV-N were all maintained within acceptable ranges for the normal growth of disk abalone. The total NH/-N and NO2-N stabilized around 0.023-0.065 mg/L and 0.014-0.041 mg/L, respectively. The power consumption per day for heating was 1.287 kW-h, where the power consumption for heating sea water accounted for 19.62% of the total power consumption (688.88 kW-h). Compared with conventional flow-through system, it was only one-seventh of energy consumption for heating sea water. The study indicates that it is a kind of

  10. 基于PLC循环水养殖温控系统的设计%The Design of Recirculating Aquaculture Temperature Control System Based on PLC

    Institute of Scientific and Technical Information of China (English)

    吴燕翔; 胡咏梅; 刘雨青

    2011-01-01

    针对目前国内水产养殖监控系统较落后的研究现状,设计了采用西门子S7-200PLC的循环水养殖温控系统,采用PID控制算法,对养殖池的水位和温度进行实时监控,实现养殖池温度和水位的恒定控制.详细介绍了系统的整体控制方案,工作原理,并给出了系统的软、硬件结构设计,有效地实现了系统的逻辑控制、安全控制、故障显示及故障处理.%Since study on the domestic aquaculture monitoring system was backward at present, the SIMATIC S7-200 CPU226 is used and adopted PID control algorithm to make real-time monitoring and controlling for the water level and temperature of closed circulating aquaculture system, thus it realized constant water level and temperature control in the culture pond. The system overall control scheme and principle are introduced in detail, and the system software and hardware structure design are given, the system has efficiently implemented system logic control, safetv control, fault display and fault treatment.

  11. Clothes washing machine with water recirculation

    Energy Technology Data Exchange (ETDEWEB)

    Condit, R.E.

    1979-09-25

    A clothes washing machine is described which recirculates wash or rinse water from a surrounding tub into a clothes holding basket to reduce the quantity of water required for wash and rinse cycles. The fil level is controlled by an adjustable pressure-sensitive switch which senses the pressure level at the drain outlet located in the bottom of the tub in order to control water fill levels at the beginning of each wash and rinse cycle. The pressure-sensitive switch is reset preparatory to the initiation of each wash or rinse cycle of the tub by the low pressure existing in the tub bottom after the tub has been drained at the end of each wash and rinse cycle. In order to prevent false resetting of the pressure-sensitive switch by recirculation flow from the tub, the recirculation pump inlet intake is elevated above the drain outlet by a stand pipe which maintains a sufficient level of water in the tub above the reset pressure level to preclude resetting of the pressure-sensitive switch until the tub is drained through the drain outlet. The stand pipe is designed to provide an anti-vortex action to minimize the air intake into the recirculation pump.

  12. Transporting method for adsorbing tower and the adsorbing tower

    International Nuclear Information System (INIS)

    A cylindrical plastic bag is disposed to the upper surface of an adsorbing tower so as to surround a suspending piece. One opening of the bag is sealed, and other opening is secured in a sealed state to a bag holding portion disposed to glove box at a gate for the adsorbing tower box. The adsorbing tower is transported into the glove box, and after the completion of the operation of the adsorbing tower, the adsorbing tower is taken out in a state that the bag is restricted and sealed at a portion below the adsorbing tower. The bag may be made of a vinyl plastic, the bag holding portion may be a short-cylindrical protrusion, and may have an O-ring groove at the outer surface. Even if the adsorbing tower is heavy, the adsorbing tower can be carried out easily in a state where it is sealed gas tightly. (N.H.)

  13. Grow-Out Of Sea Bream Sparus aurata in Turkey, Particularly in a Land-Based Farm With Recirculation System in Çanakkale: Better Use of Water, Nutrients and Space

    OpenAIRE

    , Erdem Ökte

    2002-01-01

    Gilthead sea bream (Sparus aurata) is being farmed in Turkey mostly in cages in the Aegean coast from Çe?me to Fethiye. There is also a new facility that utilizes land-based re-circulation technology in Çanakkale. Stocking densities, growth, maturation and FCR, water quality, diseases and management are examined in the different types of production techniques.

  14. Cleaning and recirculation of perfluorohexane ($C_{6} F_{14}$) in the STAR-RICH detector

    CERN Document Server

    Andrés, Yu; Cozza, D; Davenport, M; De Cataldo, G; Dell'Olio, L; Di Bari, D; Di Mauro, A; Dunlop, J C; Finch, E; Fraissard, Daniel; Franco, A; Gans, J; Ghidini, B; Harris, J W; Horsley, M; Kunde, G J; Lasiuk, B; Lesenechal, Y; Majka, R D; Martinengo, P; Morsch, Andreas; Nappi, E; Paic, G; Piuz, François; Posa, F; Raynaud, J; Salur, S; Sandweiss, J; Santiard, Jean-Claude; Satinover, J; Schyns, E M; Smirnov, N; Van Beelen, J; Williams, T D; Xu, Z

    2002-01-01

    A RICH detector with a CsI photo-cathode and liquid perfluorohexane radiator has been installed in the STAR experiment at RHIC. The liquid is continuously cleaned and distributed to a quartz containment vessel within the detector by a closed recirculation system. A VUV spectrometer is connected to the system which monitors the optical transparency of the liquid. This measurement provides one of the pieces of information necessary to model the number of Cherenkov photons which reach the pad plane. A description of the liquid recirculation system and the cleaning procedure for the liquid as well as the spectrometer is presented along with results of their performance. (23 refs).

  15. Depletion of florfenicol amine in tilapia (Oreochromis sp.) maintained in a recirculating aquaculture system following Aquaflor(R)-medicated feed therapy (20 mg/kg BW/d for 10 days)

    Science.gov (United States)

    Gaikowski, Mark P.; Whitsel, Melissa K.; Charles, Shawn; Schleis, Susan M.; Crouch, Louis S.; Endris, Richard G.

    2013-01-01

    Aquaflor® [50% w w−1 florfenicol (FFC)], is approved for use in freshwater-reared warmwater finfish which include tilapia Oreochromis spp. in the United States to control mortality from Streptococcus iniae. The depletion of florfenicol amine (FFA), the marker residue of FFC, was evaluated after feeding FFC-medicated feed to deliver a nominal 20 mg FFC kg−1 BW d−1 dose (1.33× the label use of 15 mg FFC kg−1 BW d−1) to Nile tilapia O. niloticus and hybrid tilapia O. niloticus × O. aureus held in a recirculating aquaculture system (RAS) at production-scale holding densities. Florfenicol amine concentrations were determined in fillets taken from 10 fish before dosing and from 20 fish at nine time points after dosing (from 1 to 240 h post-dosing). Water samples were assayed for FFC before, during and after the dosing period. Parameters monitored included daily feed consumption and biofilter function (levels of ammonia, nitrite and nitrate). Mean fillet FFA concentration decreased from 13.77 μg g−1 at 1-h post dosing to 0.39 μg g−1 at 240-h post dosing. Water FFC concentration decreased from a maximum of 1400 ng mL−1 at 1 day post-dosing to 847 ng mL−1 at 240 h post-dosing. There were no adverse effects noted on fish, feed consumption or biofilter function associated with FFC-medicated feed administration to tilapia.

  16. Effect of adding a swirl on flow pattern and recirculation zone in ADS windowless spallation target

    International Nuclear Information System (INIS)

    Highlights: • The reduction of the recirculation zone and the stability of the free surface are key issues in the target. • A swirl is numerically added in the target to make the recirculation zone small and stable. • Numerical simulation with different boundary conditions is carried out. • Physical analysis is presented to explain the numerical results. - Abstract: Aiming the key issues in the accelerator driven system (ADS), windowless spallation target focus on the minimization of the recirculation zone and on the stability of the free surface, an innovation has been made by numerically adding swirl to the fluid at the inlet. At first, two phase flow pattern in the simulation is compared with the experiments and numerical method is employed correctly. The results reveal that the recirculation zone and the flow pattern are greatly influenced when the swirl strength is changed from 1.0 rad/s to 2.5 rad/s. The height of the recirculation zone decreases with increase in swirl strength and completely disappears when the swirl strength reaches 2.0 rad/s. In addition, larger swirl strength leads to different flow pattern and a new cavitation zone is generated under the recirculation zone. The Bernoulli's equation and angular momentum conservation are applied to make it clear that this phenomena is due to the decrease of the axial pressure caused by the radial velocity. Moreover, the new cavitation zone totally links to the vapor area above the recirculation zone when the swirl strength is 2.5 rad/s. The results are very helpful to the design and optimization of the ADS windowless spallation target

  17. A power recirculating test rig for ball screw endurance tests

    Directory of Open Access Journals (Sweden)

    Giberti Hermes

    2016-01-01

    Full Text Available A conceptual design of an innovative test rig for endurance tests of ball screws is presented in this paper. The test rig layout is based on the power recirculating principle and it also allows to overtake the main critical issues of the ball screw endurance tests. Among these there are the high power required to make the test, the lengthy duration of the same and the high loads between the screw and the frame that holds it. The article describes the test rig designed scheme, the kinematic expedients to be adopted in order to obtain the required performance and functionality and the sizing procedure to choose the actuation system.

  18. Photochemistry of Nitrate Adsorbed on Mineral Dust

    Science.gov (United States)

    Gankanda, A.; Grassian, V. H.

    2013-12-01

    Mineral dust particles in the atmosphere are often associated with adsorbed nitrate from heterogeneous reactions with nitrogen oxides including HNO3 and NO2. Although nitrate ion is a well-studied chromophore in natural waters, the photochemistry of adsorbed nitrate on mineral dust particles is yet to be fully explored. In this study, wavelength dependence of the photochemistry of adsorbed nitrate on different model components of mineral dust aerosol has been investigated using transmission FTIR spectroscopy. Al2O3, TiO2 and NaY zeolite were used as model systems to represent non-photoactive oxides, photoactive semiconductor oxides and porous materials respectively, present in mineral dust aerosol. In this study, adsorbed nitrate is irradiated with 254 nm, 310 nm and 350 nm narrow band light. In the irradiation with narrow band light, NO2 is the only detectable gas-phase product formed from nitrate adsorbed on Al2O3 and TiO2. The NO2 yield is highest at 310 nm for both Al2O3 and TiO2. Unlike Al2O3 and TiO2, in zeolite, adsorbed nitrate photolysis to nitrite is observed only at 310 nm during narrow band irradiation. Moreover gas phase products were not detected during nitrate photolysis in zeolite at all three wavelengths. The significance of these differences as related to nitrate photochemistry on different mineral dust components will be highlighted.

  19. 工厂化循环水养殖中臭氧/紫外线反应系统的水处理性能%Water treatment performance of O3/UV reaction system in recirculating aquaculture systems

    Institute of Scientific and Technical Information of China (English)

    管崇武; 杨菁; 单建军; 张海耿; 刘晃; 王欣

    2014-01-01

    为增强臭氧在水产应用的安全性,满足工厂化循环水养殖对有机物去除和水体消毒的需要,该文开发O3/UV反应系统。通过试验方法研究该系统臭氧投加溶解区适宜的臭氧投加流量和处理量的关系、紫外辐射剂量配比等工艺参数,及对水质净化效果和水体消毒灭菌效果的影响等。试验结果表明:1)在满足所需水中溶解臭氧浓度的条件下,采用较低臭氧进气流量和较高进水流量有利于提高系统的臭氧溶解率和利用率。该系统在水流量为5 m3/h,臭氧投加量为(8.78±0.60)g/h时可得到水中臭氧溶解质量浓度为1.53 mg/L的臭氧水,臭氧溶解率为82.7%,臭氧利用率为97.7%。2)增加紫外灯的功率和数量均可提高对臭氧的去除率,但增加紫外灯的数量对其性能提升效果更明显。该系统在紫外剂量为1996 MJ/cm2,对残留臭氧的去除率为83.82%。3)该系统对紫外消光度、总有机碳、水色等指标的去除率相比单独使用臭氧分别提升109.95%、89.77%和51.44%,杀菌率可达97%以上,实现工厂化循环水养殖低臭氧残留条件下的有机物有效去除和消毒杀菌。%In order to improve the water treatment performance of ozone in recirculating aquaculture systems, and enhance its application safety in the field of aquaculture, the O3/UV integration reaction system were designed. The reaction system was mainly composed of ozone addition dissolved area, ultraviolet catalytic reaction area, stay reaction area. The system was 1 250 mm of high, 750 mm in diameter, and the ultraviolet catalytic reaction was 400 mm in diameter. The working principle of system was that using static mixer way to add ozone, which could dissolve wastewater high efficiency and low energy consumption in ozone addition dissolved area. The wastewater with not completely dissolved ozone bottom up entered to ultraviolet catalytic reaction area, which could generate two

  20. Study on estimation model of fish ammonia produce in recirculating aquaculture system%循环水养鱼系统中氨氮产生量估算模型的研究

    Institute of Scientific and Technical Information of China (English)

    刘晃; 顾川川

    2012-01-01

    循环水养鱼作为一种未来水产养殖的发展方向,其系统设计越来越受到关注,其中系统设计关键问题之一是快速去除水中的氨氮,因此准确得到氨氮产生量是系统设计中一个关键步骤.该研究基于物质平衡原理,同时假设每次投喂到鱼池中的饲料能及时地被养殖鱼摄食,并且养殖鱼排泄的粪便能在未被分解就快速排出系统,得到氨氮产生量的估算模型.该模型中氨氮产生量与循环水养殖系统的投喂量、饲料中蛋白质的含量和氮污染物的转化率成正比.在实际应用中该模型能较准确地估算出循环水养殖系统中的氨氮产生量,而且在考虑安全系数时,得到的估算值相比实际值大,符合工程设计中的系统安全需要.%Recirculating aquaculture is one of the development trends of the future aquaculture. And the system designs are being paid more and more attention. The key of system design is rapid removal of total ammonia-nitrogen. Therefore, the estimation model of fish total ammonia-nitrogen produce is important extremely to system design. Based on the material balance principle, the model to estimate the amount of total ammonia-nitrogen produced was established, assuming that feed have been eaten timely and faces have been removed from system before breaking. In this model, total ammonia-nitrogen produced increased with feeding rate, protein percentage of feed and nitrogen conversion rate. In practical application, the calculated values agree basically with those of actual operation. In consider with the safety factor, the results estimated were greater than actual values, which was accord with the system safety design needs.

  1. WGS-Adsorbent Reaction Studies at Laboratory Scale

    International Nuclear Information System (INIS)

    This document reports the most significant results obtained during the experimental work performed under task WGS adsorbent experimental studies within CAPHIGAS project (National Research Plan 2008-2011, ref: ENE2009-08002). The behavior of the binary adsorbent-catalyst system which will be used in the hybrid system is described in this document. Main results reported here were used during the design and development of the hybrid system adsorbent catalyst- membrane proposed in the CAPHIGAS project. The influence of main operating parameters and the optimized volume ratio adsorbent-catalyst are also presented in this report. (Author)

  2. Landfill leachate production, quality and recirculation treatment in northeast China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Qing-liang; LIU Xue-yan; QI Xu-dong; LIU Zhi-gang

    2006-01-01

    Landfill leachate recirculation treatment process is a promising and economic way in northeast China due to the distinct season variation. In order to study the impact of recirculation on leachate production and its quality, two simulated sanitary landfill reactors, one with leachate recirculation and the other without, were placed outdoor in Harbin. The two-year experimental results indicated that leachate production was reduced by 86% with leachate recirculation and less or no facility for leachate treatment required. Recirculation could improve the leachate quality dramatically with lower COD, SS, NH4+-N and higher pH level.Recirculation also could enhance waste degradation and stabilization and improve the efficiency of landfill. This study confirmed that leachate recirculation was a very feasible way for on-site landfill leachate treatment in cold areas.

  3. Method and apparatus for control of coherent synchrotron radiation effects during recirculation with bunch compression

    Science.gov (United States)

    Douglas, David R; Tennant, Christopher

    2015-11-10

    A modulated-bending recirculating system that avoids CSR-driven breakdown in emittance compensation by redistributing the bending along the beamline. The modulated-bending recirculating system includes a) larger angles of bending in initial FODO cells, thereby enhancing the impact of CSR early on in the beam line while the bunch is long, and 2) a decreased bending angle in the final FODO cells, reducing the effect of CSR while the bunch is short. The invention describes a method for controlling the effects of CSR during recirculation and bunch compression including a) correcting chromatic aberrations, b) correcting lattice and CSR-induced curvature in the longitudinal phase space by compensating T.sub.566, and c) using lattice perturbations to compensate obvious linear correlations x-dp/p and x'-dp/p.

  4. Method and apparatus for control of coherent synchrotron radiation effects during recirculation with bunch compression

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, David R; Tennant, Christopher

    2015-11-10

    A modulated-bending recirculating system that avoids CSR-driven breakdown in emittance compensation by redistributing the bending along the beamline. The modulated-bending recirculating system includes a) larger angles of bending in initial FODO cells, thereby enhancing the impact of CSR early on in the beam line while the bunch is long, and 2) a decreased bending angle in the final FODO cells, reducing the effect of CSR while the bunch is short. The invention describes a method for controlling the effects of CSR during recirculation and bunch compression including a) correcting chromatic aberrations, b) correcting lattice and CSR-induced curvature in the longitudinal phase space by compensating T.sub.566, and c) using lattice perturbations to compensate obvious linear correlations x-dp/p and x'-dp/p.

  5. Enhancing treatment efficiency of swine wastewater by effluent recirculation in vertical-flow constructed wetland

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Livestock wastewater has been a major contributor to Chinese cultural eutrophication of surface waters. Constructed wetlands are under study as a best management practice to treat wastewater from dairy and swine operations, but the removal efficiency of pollutants is relatively low. Enhancing the treatment efficiency of livestock wastewater by effluent recirculation was investigated in a pilot-scale vertical-flow constructed wetland. The wetland system was composed of downflow and upflow stages, on which narrow-leafPhragmites communis and common reed Phragmites Typhia are planted, respectively; each stage has a dimension of4 m2 (2 m × 2 m). Wastewater from facultative pond was fed into the system intermittently at a flow rate of 0.4 m3/d. Recirculation rates of 0, 25%, 50%, 100% and 150% were adopted to evaluate the effect of the recirculation rate on pollutants removal. It shows that with effluent recirculation the average removal efficiencies of NH4-N, biological oxygen demand (BOD5) and suspended solids(SS)obviously increase to 61.7%, 81.3%, and 77.1%, respectively, in comparison with the values of 35.6%, 50.2%, and 49.3% without effluent recirculation. But the improvement of TP removal is slight, only from 42.3% to 48.9%. The variations of NH4-N, dissolved oxygen(DO) and oxidation-reduction potential(ORP) of inflow and outflow reveal that the adoption of effluent recirculation is beneficial to the formation of oxide environment in wetland. The exponential relationships with excellent correlation coefficients (R2 >0.93)are found between the removal rates of NH4-N and BOD5 and the recirculation rates. With recirculation the pH value of the outflow decreases as the alkalinity is consumed by gradually enhanced nitrification process. When recirculation rate is kept constant 100%, the ambient temperature appears to affect NH4-N removal, but does not have significant influence on BOD5 removal.

  6. Hybrid heat exchange for the compression capture of CO2 from recirculated flue gas

    Energy Technology Data Exchange (ETDEWEB)

    Oryshchyn, Danylo B.; Ochs, Thomas L.; Summers, Cathy A.

    2004-01-01

    An approach proposed for removal of CO2 from flue gas cools and compresses a portion of a recirculated flue-gas stream, condensing its volatile materials for capture. Recirculating the flue gas concentrates SOx, H2O and CO2 while dramatically reducing N2 and NOx, enabling this approach, which uses readily available industrial components. A hybrid system of indirect and direct-contact heat exchange performs heat and mass transfer for pollutant removal and energy recovery. Computer modeling and experimentation combine to investigate the thermodynamics, heat and mass transfer, chemistry and engineering design of this integrated pollutant removal (IPR) system.

  7. Assessment of the effect of temperature on the carp physiology (Cyprinus carpio, L., 1758 fed with probiotics in condition of a recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    Elena BOCIOC

    2015-10-01

    be used for enhancing the immune system and fish health, improving disease resistance of biological material.

  8. Current status of the research about the carbon source of the heterotrophic denitrification of recirculating aquaculture system%循环水养殖用水中反硝化碳源研究现状

    Institute of Scientific and Technical Information of China (English)

    罗国芝; 鲁璐; 杜军; 刘倩; 董明来

    2011-01-01

    通过硝化作用和反硝化作用可以有效控制循环水养殖系统水中的氧氮、亚硝酸盐和硝酸盐.进行水产养殖用水硝化作用的生物过滤器的研究已经系统而深入,而关于养殖用水反硝化作用的脱氮反应器的研究则并未引起相应的关注.水产养殖用水进行异养反硝化必需添加碳源.在已有的研究中,经常使用的甲醇等有机液体碳源存在添加量不易控制、出水有残留等弊端;可生物降解聚合物被证明是比较理想的水产养殖用水异养反硝化碳源的选择之一;近年来对以养殖活动中产生的残饵和粪便作为异养反硝化内供碳源的研究也引起了广泛的关注.总结了近年来循环水养殖系统异养反硝化不同种类碳源的效率、在实际生产中的可操作性的相关研究进展.%Aerobic biological filtration systems employing nitrifying bacteria to remediate excess ammonia and nitrite concentrations are common components of recirculating aquaculture systems (RAS).Nitrite is the end result of the nitrification and is removed either by a denitrification process that ideally converts nitrate-N to nitrogen gas or by water exchange.The disadvantage of denitrification treatment with liquid carbon source is the need of a close, rather sophisticated and costly process control, the risk of overdosing and a deepened knowledge about the operation of this biological system.The biodegradable polymers as substrate and biofilm carriers is better choice for the denitrification progress of the aquaculture water.The organic solid-wastes taken from the solids-filter of a RAS as carbon source which termed single-sludge denitrification is induced much interest today.This paper reviewed the organic carbon source used in the denitrification of the aquaculture water mainly about the production scale farm.

  9. High Power Picosecond Laser Pulse Recirculation

    Energy Technology Data Exchange (ETDEWEB)

    Shverdin, M Y; Jovanovic, I; Semenov, V A; Betts, S M; Brown, C; Gibson, D J; Shuttlesworth, R M; Hartemann, F V; Siders, C W; Barty, C P

    2010-04-12

    We demonstrate a nonlinear crystal-based short pulse recirculation cavity for trapping the second harmonic of an incident high power laser pulse. This scheme aims to increase the efficiency and flux of Compton-scattering based light sources. We demonstrate up to 36x average power enhancement of frequency doubled sub-millijoule picosecond pulses, and 17x average power enhancement of 177 mJ, 10 ps, 10 Hz pulses.

  10. Advanced Petroleum-Based Fuels - Diesel Emissions Project (APBF-DEC): 2,000-Hour Performance of a NOx Adsorber Catalyst and Diesel Particle Filter System for a Medium-Duty, Pick-Up Diesel Engine Platform; Final Report

    Energy Technology Data Exchange (ETDEWEB)

    2007-03-01

    Presents the results of a 2,000-hour test of an emissions control system consisting of a nitrogen oxides adsorber catalyst in combination with a diesel particle filter, advanced fuels, and advanced engine controls in an SUV/pick-up truck vehicle platform.

  11. Design and construction technology of water-purifying facilities in recirculating aquaculture system%循环水养殖系统水质净化设施设计与建造技术

    Institute of Scientific and Technical Information of China (English)

    赵景丽; 王际英; 张利民; 曹体宏; 李宝山; 乔洪金

    2013-01-01

      水质净化设施具有投资小、运行能耗低和单位处理量大等优点,适合国内现阶段循环水养殖的普及和推广。本文介绍了沉淀池、气浮池和生物滤池三种水质净化设施的设计及建造中的关键技术。在系统正常运行的条件下,养殖水体的pH值维持在7.5以下,非离子氨、亚硝氮和磷的含量分别维持在5.60~7.96μg/L、0.08~0.10 mg/L和2.12~2.52 mg/L范围内。结果表明,系统对水体pH控制合理,对氨氮处理效果较为理想。综合分析可知,该循环水养殖系统水处理工艺和水质净化设施设计合理,能够较好的满足使用需求。%  Water-purifying facilities are suitable for popularization and promotion at present stage in China with small investment, running low energy consumption and large unit processing advantages .In this paper, three kinds of water-purifying facilities were introduced:sedimentation tank, flotation tank and biofilter.The key technologies in design and construction process were summarized .Under the normal running condition , pH in aquaculture water was maintained below 7.5.Non-ionic ammonia, nitrite nitrogen and phosphorus were maintained at the range of 5.60-7.96 μg/L, 0.08-0.10 mg/L and 2.12-2.52 mg/L, respectively.The results showed that the control of pH and treatment effect of ammonia nitrogen in the system were good .It is proved that the design of the recirculating aquaculture system and water-purifying facilities are reasonable, which could better meet the use requirements .

  12. Research on the residual feeds recognition of recirculating aquaculture systems based on computer vision%基于计算机视觉的循环水养殖系统残饵识别研究

    Institute of Scientific and Technical Information of China (English)

    穆春华; 范良忠; 刘鹰

    2015-01-01

    利用计算机视觉技术和机器学习方法研究工业化循环水养殖的残饵与粪便的识别问题,为基于残饵浓度检测的智能投喂系统提供理论依据。首先对残饵视频进行图像预处理,分割出残饵和粪便图像;然后根据残饵和粪便在灰度分布和形状上的差异,提取平均灰度,周长平方面积比、凸壳面积比、骨架数、对比度、逆差距6个特征;再分别运用4种不同核函数的支持向量机( SVM)算法和改进的决策树算法进行残饵图像识别。结果显示,径向基核函数的SVM算法识别效果最好,残饵和粪便识别率分别达到99%和97%以上;改进离散方式的决策树算法识别率与SVM算法的识别率接近,并且实时性更好。%The paper mainly researches the residual feeds and feces recognition of recirculating aquaculture systems by using the computer vision technology and the machine learning methods, which provides a theory basis for intelligent feeding system based on residual feeds concentration detection. At first, the residual feeds and impurity images were obtained by preprocessing the residual feeds video record. Then, the features were extracted by analyzing the difference between residual feeds and feces in gray level distribution and shape. The features include:AverPixel, Peri2Area, Conv2Area, Skeletons, Contrast and IDM. Finally, we realized the recognition of residual feeds image by using the support vector machine algorithm based on 4 different kinds of kernel function and the modified decision tree algorithm. Experimental results showed the SVM based on the radial basis kernel obtained the best recognition rate. And the recognition rate of residual feeds and feces were up to 99% and 97% respectively. The recognition rate of decision tree with modified discrete way is close to the SVM’ s, and the real-time performance is better.

  13. Recirculator SALO. The physical foundation

    International Nuclear Information System (INIS)

    It is presented the results of research carried out for the creation of a modern accelerator complex that could solve fundamental and applied problems of nuclear physics. It is selected and optimized scheme of magneto-optical system that meets all the requirements of the experiments with beams. Designs of magnetic devices have been developed and pre-production models have been made. Examination of influence non-linear component of magnet fields on beam parameters on an accelerator exit has been spent

  14. Highly sensitive and reconfigurable fiber optic current sensor by optical recirculating in a fiber loop.

    Science.gov (United States)

    Du, Jiangbing; Tao, Yemeng; Liu, Yinping; Ma, Lin; Zhang, Wenjia; He, Zuyuan

    2016-08-01

    An advanced fiber optic current sensor (FOCS) is proposed based on recirculating fiber loop architecture for significantly enhancing the current sensitivity. The recirculating loop is constructed by a 2X2 optical switch and the standard single mode fiber (SSMF) is used as the sensing head. The proposed FOCS is coupler-free with low insertion loss which results in a significantly improved current sensitivity. We experimentally obtained a sensitivity of 11.5 degrees/A for 1-Km SSMF FOCS and a sensitivity of 21.2 degrees/A for 500-m SSMF FOCS, both of which have been enhanced by more than ten times. The flexible switch control of recirculating can support the FOCS to work for different current scenarios with the same system and thus reconfigurable operation of the FOCS has been achieved. The significantly enhanced high sensitivity with reconfigurable operation capability makes the proposed FOCS a promising method for practical applications. PMID:27505765

  15. Optimizing Conditions to Cholesterol Adsorbed with Carboxymethyl Chitosan

    OpenAIRE

    Mardiyah Kurniasih; Dwi Kartika; Riyanti Riyanti

    2016-01-01

    A research on optimizing conditions to cholesterol adsorbed have been performed. Optimization was performed by varying: contact time, adsorbent weight and temperature of the system's. A full factorial experimental design was used in this study. Characterization performed on the synthesized chitosan and carboxymethyl chitosan including FTIR, water content, ash content, solubility, porosity, and swelling effect. The results showed that carboxymethyl chitosan able to adsorb cholesterol under con...

  16. Frequency of recirculation of nutrient solution in hydroponic cultivation of coriander with brackish water

    OpenAIRE

    Mairton G. da Silva; Tales M. Soares; Hans R. Gheyi; Itamar de S. Oliveira; José A. da Silva Filho; Francicleiton F. do Carmo

    2016-01-01

    ABSTRACT The present study used a hydroponic system with leveled channels, in order to evaluate coriander cultivation under different intervals of nutrient solution recirculation and the use of freshwater and brackish water. The experiment was carried out in a randomized block design with five replicates, in a 2 x 4 factorial scheme, from February to March 2014. Two levels of electrical conductivity (EC) of water (0.32 and 4.91 dS m-1) and four frequencies of nutrient solution recirculation (...

  17. Impact of nitrate-enhanced leachate recirculation on gaseous releases from a landfill bioreactor cell.

    Science.gov (United States)

    Tallec, G; Bureau, C; Peu, P; Benoist, J C; Lemunier, M; Budka, A; Presse, D; Bouchez, T

    2009-07-01

    This study evaluates the impact of nitrate injection on a full scale landfill bioreactor through the monitoring of gaseous releases and particularly N(2)O emissions. During several weeks, we monitored gas concentrations in the landfill gas collection system as well as surface gas releases with a series of seven static chambers. These devices were directly connected to a gas chromatograph coupled to a flame ionisation detector and an electron capture detector (GC-FID/ECD) placed directly on the field. Measurements were performed before, during and after recirculation of raw leachate and nitrate-enhanced leachate. Raw leachate recirculation did not have a significant effect on the biogas concentrations (CO(2), CH(4) and N(2)O) in the gas extraction network. However, nitrate-enhanced leachate recirculation induced a marked increase of the N(2)O concentrations in the gas collected from the recirculation trench (100-fold increase from 0.2 ppm to 23 ppm). In the common gas collection system however, this N(2)O increase was no more detectable because of dilution by gas coming from other cells or ambient air intrusion. Surface releases through the temporary cover were characterized by a large spatial and temporal variability. One automated chamber gave limited standard errors over each experimental period for N(2)O releases: 8.1 +/- 0.16 mg m(-2) d(-1) (n = 384), 4.2 +/- 0.14 mg m(-2) d(-1) (n = 132) and 1.9 +/- 0.10 mg m(-2) d(-1) (n = 49), during, after raw leachate and nitrate-enhanced leachate recirculation, respectively. No clear correlation between N(2)O gaseous surface releases and recirculation events were evidenced. Estimated N(2)O fluxes remained in the lower range of what is reported in the literature for landfill covers, even after nitrate injection. PMID:19297142

  18. Impact of nitrate-enhanced leachate recirculation on gaseous releases from a landfill bioreactor cell

    International Nuclear Information System (INIS)

    This study evaluates the impact of nitrate injection on a full scale landfill bioreactor through the monitoring of gaseous releases and particularly N2O emissions. During several weeks, we monitored gas concentrations in the landfill gas collection system as well as surface gas releases with a series of seven static chambers. These devices were directly connected to a gas chromatograph coupled to a flame ionisation detector and an electron capture detector (GC-FID/ECD) placed directly on the field. Measurements were performed before, during and after recirculation of raw leachate and nitrate-enhanced leachate. Raw leachate recirculation did not have a significant effect on the biogas concentrations (CO2, CH4 and N2O) in the gas extraction network. However, nitrate-enhanced leachate recirculation induced a marked increase of the N2O concentrations in the gas collected from the recirculation trench (100-fold increase from 0.2 ppm to 23 ppm). In the common gas collection system however, this N2O increase was no more detectable because of dilution by gas coming from other cells or ambient air intrusion. Surface releases through the temporary cover were characterized by a large spatial and temporal variability. One automated chamber gave limited standard errors over each experimental period for N2O releases: 8.1 ± 0.16 mg m-2 d-1 (n = 384), 4.2 ± 0.14 mg m-2 d-1 (n = 132) and 1.9 ± 0.10 mg m-2 d-1 (n = 49), during, after raw leachate and nitrate-enhanced leachate recirculation, respectively. No clear correlation between N2O gaseous surface releases and recirculation events were evidenced. Estimated N2O fluxes remained in the lower range of what is reported in the literature for landfill covers, even after nitrate injection.

  19. Ab initio study of Ga-GaN system: Transition from adsorbed metal atoms to a metal–semiconductor junction

    Energy Technology Data Exchange (ETDEWEB)

    Witczak, Przemysław; Kempisty, Pawel; Strak, Pawel [Institute of High Pressure Physics, Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw (Poland); Krukowski, Stanisław, E-mail: stach@unipress.waw.pl [Institute of High Pressure Physics, Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland and Interdisciplinary Centre for Modelling, University of Warsaw, Pawińskiego 5a, 02-106 Warsaw (Poland)

    2015-11-15

    Ab initio studies of a GaN(0001)-Ga system with various thicknesses of a metallic Ga layer were undertaken. The studied systems extend from a GaN(0001) surface with a fractional coverage of gallium atoms to a Ga-GaN metal–semiconductor (m–s) contact. Electronic properties of the system are simulated using density functional theory calculations for different doping of the bulk semiconductor. It is shown that during transition from a bare GaN(0001) surface to a m–s heterostructure, the Fermi level stays pinned at a Ga-broken bond highly dispersive surface state to Ga–Ga states at the m–s interface. Adsorption of gallium leads to an energy gain of about 4 eV for a clean GaN(0001) surface and the energy decreases to 3.2 eV for a thickly Ga-covered surface. The transition to the m–s interface is observed. For a thick Ga overlayer such interface corresponds to a Schottky contact with a barrier equal to 0.9 and 0.6 eV for n- and p-type, respectively. Bond polarization-related dipole layer occurring due to an electron transfer to the metal leads to a potential energy jump of 1.5 eV, independent on the semiconductor doping. Additionally high electron density in the Ga–Ga bond region leads to an energy barrier about 1.2 eV high and 4 Å wide. This feature may adversely affect the conductivity of the n-type m–s system.

  20. 环境因子对循环水养殖系统中生物膜净化效率影响综述%Progress of research on environmental factors affecting biofilter efficiency in recirculating aquaculture system

    Institute of Scientific and Technical Information of China (English)

    杨志强; 朱建新; 刘慧; 程海华; 曲克明; 刘寿堂

    2014-01-01

    循环水养殖系统的关键技术是养殖废水的处理和再利用。作为循环水养殖系统水处理的核心单元,生物膜对于养殖水体中污染物的去除起着至关重要的作用。水温、盐度、pH和溶氧等环境因子都会影响生物膜的功能,环境因子的突然变化会引起生物膜脱落、影响循环水养殖系统生物膜的形成过程及运行效果。控制好水温、盐度、pH和溶氧,生物膜净化效率就能达到较为理想的状态,养殖废水的处理效果就会更好。因此,有必要研究各个环境因子变量条件下的养殖废水去除动力学特征,以期为循环水养殖系统优化设计与运行管理提供理论依据。%Treatment and reuse of aquaculture wastewater is the key technology in recirculating aquaculture systems (RAS). Biofilter, a core unit in RAS, plays a vital role in removal of pollutants in aquaculture water. Water temperature, salinity, pH, dissolved oxygen ( DO ) and other environmental factors can affect the function of biofilter. Sudden changes of environmental factors can cause biofilm degradation or dropping off, which may seriously affect biofilter growth and water treatment effects. Biofilter efficiency can achieve the ideal state and aquaculture wastewater treatment effect be improved when the water temperature, salinity, pH and DO are well under control. It is necessary to study biofilter’ s kinetics of aquaculture wastes removal under each environmental factor, so as to provide a theoretical basis for optimizing design and operation management of RAS.

  1. 循环水养殖罗非鱼氮收支及对水质影响的初步研究%Nitrogen budget and water quality of tilapia in recirculating aquaculture system

    Institute of Scientific and Technical Information of China (English)

    王振华; 刘晃

    2011-01-01

    A preliminary study was conducted about nitrogen budget of tilapia in a recirculating aquaculture system to provide theoretical date for industrial production and improve the process of water treatment. Initial stocking density was 8 kg/m3, the feeding rate was 2% of fish body weight, the circulation volume was 1 m3/ h and total water volume was 0. 8m3. During the experiment, the dissolved oxygen was above 6 mg/L, the pH was 7.0-7.2, and water temperature was 23-25 t. Ammonia nitrogen, nitrite nitrogen and nitrate nitrogen was measured twice a week and total nitrogen was measured once a week. The nitrogen content of feed, fish, faeces and suspended particles was determined by Kjeldahl analyzer. Results showed that, the diet made (50.00 ±1.50)% growth nitrogen proportion,(32.61 ±1.38)% excretion nitrogen proportion and (17.39 ± 4. 0)% fecal nitrogen proportion. Additionally, about 58% of the fecal nitrogen was in the form of suspended solids nitrogen eventually.%为提供实际生产理论依据,改良系统水处理工艺,开展循环水养殖系统中吉富罗非鱼氮收支和对水质情况的初步研究.起始养殖密度8 kg/m3,投饲率2%,系统循环量1 m3/h,总水量0.8 m3.试验期间溶解氧大于6 mg/L,pH 7.0 ~7.2,水温23~25℃.每周监测水质2~3次,监测指标包括氨氮、亚硝酸盐氮、硝酸盐氮,每2周检测1次水中总氮.用凯氏定氮法测定实验前后饲料、试验鱼体、粪便、悬浮颗粒的氮含量.结果显示,摄食氮有50.00±1.50%转化为生长氮,32.61±1.38%转化为排泄氮,17.39±4.O%转化为粪氮;58%的粪氮为悬浮颗粒物,42%为可沉淀颗粒物.

  2. Designing and Testing of Self-Cleaning Recirculating Zebrafish Tanks.

    Science.gov (United States)

    Nema, Shubham; Bhargava, Yogesh

    2016-08-01

    Maintenance of large number of zebrafish in captive conditions is a daunting task. This can be eased by the use of recirculating racks with self-cleaning zebrafish tanks. Commercially available systems are costly, and compatibility of intercompany products has never been investigated. Although various cost-effective designs and methods of construction of custom-made recirculating zebrafish racks are available in literature, the design of self-cleaning zebrafish tanks is still not available. In this study, we report the design and method of construction of the self-cleaning unit, which can be fitted in any zebrafish tank. We validated the design by investigating sediment cleaning process in rectangular and cylindrical tank geometries using time lapse imaging. Our results suggest that for both tank geometries, the tanks fitted with self-cleaning unit provided superior sediment cleaning than the tanks fitted with overflow-drain unit. Although the self-cleaning unit could clean the sediment completely from both geometries over prolonged period, the cleaning of sediments was faster in the cylindrical tank than the rectangular tank. In conclusion, cost and efforts of zebrafish maintenance could be significantly reduced through the installation of our self-cleaning unit in any custom-made zebrafish tank. PMID:27096937

  3. Effect of irradiation on nonlinear optical recirculation cavity performance

    Science.gov (United States)

    Saitta, M.; Tikhoplav, R.; Jovanovic, I.

    2012-02-01

    In applications such as the production of hydrogen ions for accelerators in spallation neutron sources, charge stripping of hydrogen ions using high-power lasers represents an attractive technical approach. The use of laser-ion interaction in conjunction with a laser recirculation cavity holds promise for improved efficiency, but the high-radiation environment raises concerns about the longevity of the key components of such a system, especially the nonlinear crystal used for frequency conversion. We present the results of an in-reactor irradiation experiment in which a sample beta-barium borate crystal has been irradiated with fast neutrons and gamma-rays, accompanied with the Monte Carlo analysis of the irradiation dose and its comparison with typical conditions at the Spallation Neutron Source at Oak Ridge National Laboratory. The results suggest that our design of the laser recirculation cavity exhibits a radiation hardness consistent with maintaining enhancement factors of the order of 10 over >10 years, but a more detailed experimental study is needed to investigate the radiation hardness of cavity designs exhibiting greater enhancement factors.

  4. A high temperature granulation process for ecological ash recirculation

    Energy Technology Data Exchange (ETDEWEB)

    Sundqvist, Thomas

    1999-07-01

    This thesis is a summary of three papers dealing with new technologies for facilitating ecological biomass ash recirculation back to forest and farm lands. The present outtake of biomass for paper and energy production may be incompatible with a sustainable forestry. The cycle of nutrients contained in the biomass extracted must be closed by ash recirculation in an environmental compatible way. This implies stabilization of the loose ashes/rest-products to a product with low heavy metal contents, controlled leaching properties and a high spreadability. In the present work, two different techniques were evaluated for the possibilities to separate heavy metals from the nutrient elements by utilizing high process temperatures to vaporize the unwanted metals from the condensed bulk materials. The results indicated that direct in-situ separation in fluidized bed combustion systems is possible, but requires too high process temperatures to be practically attractive. On the other hand, the new proposed high temperature treatment method for granulated raw materials was found to significantly separate As, Cd and Pb, with separation efficiencies exceeding 90 % at optimal operating conditions. In addition, the results indicated that the treatment method could be used to significantly delay and control the leaching characteristics, as well as the content of products of incomplete combustion of the produced granules.

  5. Expansion Hamiltonian model for a diatomic molecule adsorbed on a surface: Vibrational states of the CO/Cu(100) system including surface vibrations

    International Nuclear Information System (INIS)

    Molecular-surface studies are often done by assuming a corrugated, static (i.e., rigid) surface. To be able to investigate the effects that vibrations of surface atoms may have on spectra and cross sections, an expansion Hamiltonian model is proposed on the basis of the recently reported [R. Marquardt et al., J. Chem. Phys. 132, 074108 (2010)] SAP potential energy surface (PES), which was built for the CO/Cu(100) system with a rigid surface. In contrast to other molecule-surface coupling models, such as the modified surface oscillator model, the coupling between the adsorbed molecule and the surface atoms is already included in the present expansion SAP-PES model, in which a Taylor expansion around the equilibrium positions of the surface atoms is performed. To test the quality of the Taylor expansion, a direct model, that is avoiding the expansion, is also studied. The latter, however, requests that there is only one movable surface atom included. On the basis of the present expansion and direct models, the effects of a moving top copper atom (the one to which CO is bound) on the energy levels of a bound CO/Cu(100) system are studied. For this purpose, the multiconfiguration time-dependent Hartree calculations are carried out to obtain the vibrational fundamentals and overtones of the CO/Cu(100) system including a movable top copper atom. In order to interpret the results, a simple model consisting of two coupled harmonic oscillators is introduced. From these calculations, the vibrational levels of the CO/Cu(100) system as function of the frequency of the top copper atom are discussed

  6. Black Molecular Adsorber Coatings for Spaceflight Applications

    Science.gov (United States)

    Abraham, Nithin Susan; Hasegawa, Mark Makoto; Straka, Sharon A.

    2014-01-01

    The molecular adsorber coating is a new technology that was developed to mitigate the risk of on-orbit molecular contamination on spaceflight missions. The application of this coating would be ideal near highly sensitive, interior surfaces and instruments that are negatively impacted by outgassed molecules from materials, such as plastics, adhesives, lubricants, epoxies, and other similar compounds. This current, sprayable paint technology is comprised of inorganic white materials made from highly porous zeolite. In addition to good adhesion performance, thermal stability, and adsorptive capability, the molecular adsorber coating offers favorable thermal control characteristics. However, low reflectivity properties, which are typically offered by black thermal control coatings, are desired for some spaceflight applications. For example, black coatings are used on interior surfaces, in particular, on instrument baffles for optical stray light control. Similarly, they are also used within light paths between optical systems, such as telescopes, to absorb light. Recent efforts have been made to transform the white molecular adsorber coating into a black coating with similar adsorptive properties. This result is achieved by optimizing the current formulation with black pigments, while still maintaining its adsorption capability for outgassing control. Different binder to pigment ratios, coating thicknesses, and spray application techniques were explored to develop a black version of the molecular adsorber coating. During the development process, coating performance and adsorption characteristics were studied. The preliminary work performed on black molecular adsorber coatings thus far is very promising. Continued development and testing is necessary for its use on future contamination sensitive spaceflight missions.

  7. Planning of experimental removal of cadmium in finite bath system using the chocolate clay B as adsorbent

    International Nuclear Information System (INIS)

    The smectite clays are characterized by having a high cation exchange capacity and ability to remove metal ions. They have great industrial importance, for its abundance and low cost. The first part of this work was to characterize the clay called Chocolate B through the techniques of X-Ray Diffraction, X-Ray Spectroscopy and Energy Dispersive Physical Adsorption of Nitrogen. The second part of the work aims to evaluate the significance of the variables: pH and initial concentration on removal of cadmium in a batch system. In the experimental design used was a 22 factorial analysis with the addition at the central point, and evaluated the percentage of removal (Rem%) and removal capacity (EQF). XRD results corroborating the chemical analysis (EDX), characterized as a B Chocolate smectite clays. Statistical analysis showed a strong influence of variable pH on the removal of cadmium. (author)

  8. Separation of Rebaudiana A from Steviol glycoside using a polymeric adsorbent with multi-hydrogen bonding in a non-aqueous system.

    Science.gov (United States)

    Ba, Jing; Zhang, Na; Yao, Lijuan; Ma, Ning; Wang, Chunhong

    2014-11-15

    Rebaudioside A (RA) and stevioside (SS) are the primary effective glycoside components in Stevia Rebaudiana. The RA glycoside is sweeter, and it tastes similarly to sucrose. Because extracts with a high RA content can be used as natural sweeteners for food additives approved by the FAO and FDA, RA should generate high market demand. In this study, an efficient method for separating RA was established based on the synergistic multi-hydrogen bonding interaction between a polymeric adsorbent and the RA glycoside. To overcome the destruction of the hydrophobic affinity required for the selective adsorption of RA, an innovative non-aqueous environment was established for adsorption and separation. To this end, an initial polymeric adsorbent composed of a glycidyl methacrylate and trimethylolpropane trimethacrylate (GMA-co-TMPTMA) copolymer matrix was synthesized, and polyethylene polyamine was employed as a functional reagent designed to react with the epoxy group on GME-co-TMPTMA to form a highly selective macroporous adsorbent. The effects of the different functional reagents and the solvent polarity on the adsorption selectivity for RA and SS, respectively, were investigated. Matching the structure of the polyethylene polyamine and sugar ligand on the glycoside molecule was essential in ensuring that the maximum synergistic interaction between adsorbent and adsorbate would be achieved. Moreover, the hydrogen-bonding force was observed to increase when the polarity of the adsorption solvent decreased. Therefore, among the synthesized macroporous polymeric adsorbents, the GTN4 adsorbent-bonding tetraethylenepentamine functional group provided the best separation in an n-butyl alcohol solution. Under the optimized gradient elution conditions, RA and SS can be effectively separated, and the contents of RA and SS increased from 33.5% and 51.5% in the initial crude extract to 95.4% and 78.2% after separation, respectively. Compared to conventional methods, the adsorption

  9. Study of the characteristics of methanol synthesis in a recirculation slurry reactor - a novel three-phase synthesis reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hu, L.H.; Wang, X.J.; Yu, G.S.; Wang, F.C.; Yu, Z.H. [Institute of Clean Coal Technology, East China University of Science and Technology, Shanghai 200237 (China)

    2008-01-15

    A process feasibility analysis on the liquid phase methanol synthesis (LPMeOH trademark) process was performed in a recirculation slurry reactor (RSR). In the three-phase RSR system, a fine catalyst is slurried in the paraffin and this catalyst slurry is continuously recirculated through the nozzle from the slurry sector to the entrained sector by a pump. The syngas is fed concurrently with the downward flow of slurry to form the methanol product. A laboratory scale mini-pilot plant version of a recirculation slurry reactor system was successfully designed and built to carry out process engineering research, and in addition, an identical cold model was built to measure the mass transfer coefficient in the recirculation slurry reactor. The effects of operating conditions, including temperature, pressure, gas flow rate and catalyst slurry recirculation flow rate on the productivity of methanol were studied. This experimental data helps the scale-up and commercialization of the methanol synthesis process in recirculation slurry reactors. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  10. Efecto de diversos sustratos artificiales en el crecimiento y supervivencia de estadios tempranos de la langosta azul (Cherax quadricarinatus cultivados en un sistema de recirculación - Effect of different artificial substrates on growth and survival of early stages of the blue lobster (Cherax quadricarinatus reared in a recirculating system

    Directory of Open Access Journals (Sweden)

    García-Ulloa Gómez, Manuel

    2012-03-01

    Full Text Available ResumenSe evaluó la influencia de diferentes sustratos artificiales (tubo, malla, tubo + malla y grupo control, sin sustrato sobre el crecimiento y la supervivencia de crías tempranas de Cherax quadricarinatus, cultivadas en un sistema derecirculación durante cuatro semanas.AbstractThe effect of different artificial substrates (tube or straw, mesh, mesh and tube or straw, and control or no substrate on growth and survival of offspring early Cherax quadricarinatus raised in a recirculating system, was evaluated during four months.

  11. A concentrated solar cavity absorber with direct heat transfer through recirculating metallic particles

    Science.gov (United States)

    Sarker, M. R. I.; Saha, Manabendra; Beg, R. A.

    2016-07-01

    A recirculating flow solar particle cavity absorber (receiver) is modeled to investigate the flow behavior and heat transfer characteristics of a novel developing concept. It features a continuous recirculating flow of non-reacting metallic particles (black silicon carbide) with air which are used as a thermal enhancement medium. The aim of the present study is to numerically investigate the thermal behavior and flow characteristics of the proposed concept. The proposed solar particle receiver is modeled using two phase discrete particle model (DPM), RNG k-flow model and discrete ordinate (DO) radiation model. Numerical analysis is carried out considering a solar receiver with only air and the mixture of non-reacting particles and air as a heat transfer as well as heat carrying medium. The parametric investigation is conducted considering the incident solar flux on the receiver aperture and changing air flow rate and recirculation rate inside the receiver. A stand-alone feature of the recirculating flow solar particle receiver concept is that the particles are directly exposed to concentrated solar radiation monotonously through recirculating flow inside the receiver and results in efficient irradiation absorption and convective heat transfer to air that help to achieve high temperature air and consequently increase in thermal efficiency. This paper presents, results from the developed concept and highlights its flow behavior and potential to enhance the heat transfer from metallic particles to air by maximizing heat carrying capacity of the heat transfer medium. The imposed milestones for the present system will be helpful to understand the radiation absorption mechanism of the particles in a recirculating flow based receiver, the thermal transport between the particles, the air and the cavity, and the fluid dynamics of the air and particle in the cavity.

  12. Gas transfer rates from airlifts used for concurrent aeration, carbon dioxide stripping, and recirculation

    Science.gov (United States)

    Airlifts simplify recirculating aquaculture systems and can potentially reduce capital costs and minimize maintenance issues. Airlifts have the ability to move and aerate water as well as degass the water of any carbon dioxide. This study evaluated the oxygen transfer and carbon dioxide removal abil...

  13. High performance Mo adsorbent PZC

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1998-10-01

    We have developed Mo adsorbents for natural Mo(n, {gamma}){sup 99}Mo-{sup 99m}Tc generator. Among them, we called the highest performance adsorbent PZC that could adsorb about 250 mg-Mo/g. In this report, we will show the structure, adsorption mechanism of Mo, and the other useful properties of PZC when you carry out the examination of Mo adsorption and elution of {sup 99m}Tc. (author)

  14. Exhaust gas recirculation in a homogeneous charge compression ignition engine

    Science.gov (United States)

    Duffy, Kevin P.; Kieser, Andrew J.; Rodman, Anthony; Liechty, Michael P.; Hergart, Carl-Anders; Hardy, William L.

    2008-05-27

    A homogeneous charge compression ignition engine operates by injecting liquid fuel directly in a combustion chamber, and mixing the fuel with recirculated exhaust and fresh air through an auto ignition condition of the fuel. The engine includes at least one turbocharger for extracting energy from the engine exhaust and using that energy to boost intake pressure of recirculated exhaust gas and fresh air. Elevated proportions of exhaust gas recirculated to the engine are attained by throttling the fresh air inlet supply. These elevated exhaust gas recirculation rates allow the HCCI engine to be operated at higher speeds and loads rendering the HCCI engine a more viable alternative to a conventional diesel engine.

  15. The bio-ethanol production with the thin stillage recirculation

    Directory of Open Access Journals (Sweden)

    M. Rakin

    2009-01-01

    Full Text Available In this paper, the bioethanol production with the thin stillage recirculation in mashing was investigated. The mashing was performed with recirculation of: 0, 10, 20 and 30 % of the thin stillage. The thin stillage recirculation was repeated six times. In the experiment without the thin stillage, the recirculation bioethanol yield (compared to the theoretical yield was 97.96 %, which implicates that the experiment conditions were chosen and performed well. With the addition of the thin stillage, the bioethanol yield increased and was above 100 %. Higher bioethanol yield than 100 % can be explained by the fact that the thin stillage contains carbohydrates, amino acids and yeast cells degradation products. The bioethanol yield increased with the increased number of thin stillage recirculation cycles. Dry matter content in fermenting slurry increased with the increased thin stillage quantity and the number of the thin stillage recirculation cycles (8.04 % for the first and 9.40 % for the sixth cycle. Dry matter content in thin stillage increased with the increased thin stillage quantity and the number of thin stillage recirculation cycles. Based on the obtained results it can be concluded that thin stillage recirculation increased the bioethanol yield. The highest bioethanol yields were obtained with recirculation of 10% thin stillage.

  16. Positronium chemistry in porous adsorbents

    International Nuclear Information System (INIS)

    Kinetic studies on the annihilation of orthopositronium in porous adsorbents have been performed using lifetime spectroscopy. The positron source applied was 22Na with 0.2 MBq activity. The adsorbents investigated were silica gels of different particle size and pore structure. The appearance of the long-lived component in the lifetime spectra can be explained by the diffusion of the orthopositronium into the pores affected by the particle size and the pore size of the adsorbent, the coverage on it and the chemical nature of the adsorbate. The long-term aim of the work is to determine and to explain these effects. (author)

  17. 封闭循环水养殖系统中池塘覆膜对水质的影响%Effects of covering membrane etange on water quality in a recirculating aquaculture system

    Institute of Scientific and Technical Information of China (English)

    李建国; 赵冬艳; 孙成渤

    2012-01-01

    In 2005 -2010, the water quality in the recirculating aquaculture system of Tianxiang Aquatic Co. Ltd was determined. The results displayed that the membrane and the area size of the membrane could change TH, AT, NH3 - N and PO4 - P of the whole aquaculture system in time and space. In time, there was extremely significant differences among different years ( P < 0. 01) ; in space, all the sampling points had remarkable differences in AT and NH3 -N ( P < 0. 05 ). Covering membrane etange reduced the stability of TH and AT in the aquaculture system, CV increased by 166. 5% ~241. 7%. This circumstance was particularly prominent in the medium of the culture process, but there was no obvious influence on the stability of NH3-N and PO4-P. For the indices of TH, AT and NH3-N, a large fraction of membrane covering in the aquaculture system (43. 7% ) was more variable than the non-covered etange ( CV elevated by 75. 86% for TH, 135. 6% for AT and 21. 6% for NH3-N) ; While the covered etange with a small covered area (19. 2% ) , was more stable than the non-covered etange (CV decreased by 71.9% for TH, 41.5% for AT and 91.4% for NH3-N). The reason for the above-mentioned differences in stability was attributed to the influence of membrane covering on substance interchange between the water and soil, as well as the biological activities within it.%2005-2010年,对天津市天祥水产有限公司封闭循环水养殖系统水质进行了检测.结果显示:养殖池塘是否覆膜、覆膜面积大小,均会使整个养殖系统中的总硬度(TH)、总碱度(AT)、NH3 -N和PO4-P在时空上产生差异.时间上,它们年份间差异极显著(P<0.01);空间上,各采样点的AT和NH3-N差异显著(P<0.05).覆膜使系统的TH和AT稳定性减弱,CV上升了166.5% ~ 241.7%,这种情况在养殖中期尤为突出,但对NH3-N和PO4-P 稳定性的影响并不明显.养殖系统中较大面积的覆膜(43.65%)对养殖池塘TH、AT和NH3-N稳定性的影响比非

  18. Integrated system for temperature-controlled fast protein liquid chromatography. II. Optimized adsorbents and 'single column continuous operation'.

    Science.gov (United States)

    Cao, Ping; Müller, Tobias K H; Ketterer, Benedikt; Ewert, Stephanie; Theodosiou, Eirini; Thomas, Owen R T; Franzreb, Matthias

    2015-07-17

    Continued advance of a new temperature-controlled chromatography system, comprising a column filled with thermoresponsive stationary phase and a travelling cooling zone reactor (TCZR), is described. Nine copolymer grafted thermoresponsive cation exchangers (thermoCEX) with different balances of thermoresponsive (N-isopropylacrylamide), hydrophobic (N-tert-butylacrylamide) and negatively charged (acrylic acid) units were fashioned from three cross-linked agarose media differing in particle size and pore dimensions. Marked differences in grafted copolymer composition on finished supports were sourced to base matrix hydrophobicity. In batch binding tests with lactoferrin, maximum binding capacity (qmax) increased strongly as a function of charge introduced, but became increasingly independent of temperature, as the ability of the tethered copolymer networks to switch between extended and collapsed states was lost. ThermoCEX formed from Sepharose CL-6B (A2), Superose 6 Prep Grade (B2) and Superose 12 Prep Grade (C1) under identical conditions displayed the best combination of thermoresponsiveness (qmax,50°C/qmax,10°C ratios of 3.3, 2.2 and 2.8 for supports 'A2', 'B2' and 'C1' respectively) and lactoferrin binding capacity (qmax,50°C∼56, 29 and 45mg/g for supports 'A2', 'B2' and 'C1' respectively), and were selected for TCZR chromatography. With the cooling zone in its parked position, thermoCEX filled columns were saturated with lactoferrin at a binding temperature of 35°C, washed with equilibration buffer, before initiating the first of 8 or 12 consecutive movements of the cooling zone along the column at 0.1mm/s. A reduction in particle diameter (A2→B2) enhanced lactoferrin desorption, while one in pore diameter (B2→C1) had the opposite effect. In subsequent TCZR experiments conducted with thermoCEX 'B2' columns continuously fed with lactoferrin or 'lactoferrin+bovine serum albumin' whilst simultaneously moving the cooling zone, lactoferrin was

  19. Monitoring extent of moisture variations due to leachate recirculation in an ELR/bioreactor landfill using resistivity imaging.

    Science.gov (United States)

    Manzur, Shahed Rezwan; Hossain, Md Sahadat; Kemler, Vance; Khan, Mohammad Sadik

    2016-09-01

    Bioreactor or enhanced leachate recirculation (ELR) landfills are designed and operated for accelerated waste stabilization, accelerated decomposition, and an increased rate of gas generation. The major aspects of a bioreactor landfill are the addition of liquid and the recirculation of collected leachate back into the waste mass through the subsurface leachate recirculation system (LRS). The performance of the ELR landfill largely depends on the existing moisture content within the waste mass; therefore, it is of utmost importance to determine the moisture variations within the landfill. Traditionally, the moisture variation of the ELR landfill is determined by collecting samples through a bucket auger boring from the landfill, followed by laboratory investigation. Collecting the samples through a bucket auger boring is time consuming, labor intensive, and cost prohibitive. Moreover, it provides the information for a single point within the waste mass, but not for the moisture distribution within the landfill. Fortunately, 2D resistivity imaging (RI) can be performed to assess the moisture variations within the landfill and provide a continuous image of the subsurface, which can be utilized to evaluate the performance of the ELR landfill. During this study, the 2D resistivity imaging technique was utilized to determine the moisture distribution and moisture movement during the recirculation process of an ELR landfill in Denton, Texas, USA. A horizontal recirculation pipe was selected and monitored periodically for 2.5years, using the RI technique, to investigate the performance of the leachate recirculation. The RI profile indicated that the resistivity of the solid waste decreased as much as 80% with the addition of water/leachate through the recirculation pipe. In addition, the recirculated leachate traveled laterally between 11m and 16m. Based on the resistivity results, it was also observed that the leachate flow throughout the pipe was non-uniform. The non

  20. Research on treatment of ammonia in lower temperature for cold water fish recirculating aquaculture system%冷水鱼循环水养殖中的低温氨氮处理技术研究

    Institute of Scientific and Technical Information of China (English)

    曹广斌; 韩世成; 程启云; 蒋树义; 陈忠祥

    2014-01-01

    In the recirculation aquaculture system, ammonia, one kind of byproduct from the digestion of protein, is the principal nitrogenous waste released by fish. When the ammonia is accumulated and reached high level concentration, it can slow down fish growth and cause tissue damage, even death. Based on the performance of bio-filter and ozone oxidation, an effective ammonia disposal system was designed, which mainly used ozonation of ammonia and bio-filter assisted. Generally, ozone can oxidized ammonia by 25. 8%directly, during the efficient of oxidation, adding some catalytic agent can increased it. The efficiency of bio-filter disposing ammonia would be decreased in lower temperature. In order to measure the capacity of disposing ammonia, an experiment was carried out in a cold water fish culture system. The experimental result shown that The design can meet the requirements of water quality index that regarding the handling of ammonia nitrogen in cold water fish factory farming , ammonia≤0.18 mg/L,nitrate≤29.43 mg/L,and nitrite≤0.1 mg/L. Meanwhile, the concentration of ozone in fish culture tank and circuit water tank was measured to ensure the safety of dissolved ozone to cultured fish and bio-filter. The residue of ozone in the water was below 0.008 mg/L, which showed that the treatment process was reliable and safe.%为解决冷水鱼养殖过程中养殖水体中的氨氮累积问题,根据低温生物滤器及臭氧催化氧化处理氨氮的特点,设计了冷水鱼工厂化养殖氨氮处理系统并进行了试验。试验基于以臭氧氧化为主、低温生物处理为辅的处理工艺,试验鱼为虹鳟鱼,养殖密度为23 kg/m3,试验水体约为10 m3,试验周期为7 d。结果表明,该系统能够满足冷水鱼工厂化养殖过程中有关氨氮处理的水质指标要求,处理后的养殖池进水口的水质指标总氨氮≤0.18 mg/L,硝酸盐氮氮≤29.43 mg/L,亚硝酸盐氮氮≤0.1 mg/L;养殖水体

  1. Pilot scale study on water quality variation characteristics of recirculating aquaculture system%循环水养殖系统水质变化特征的中试研究

    Institute of Scientific and Technical Information of China (English)

    郭浩; 马伟芳; 韩东梅; 陈国伟; 王筱雯

    2012-01-01

    A recirculating aquaculture system on rainbow trout,sturgeon and chub multistep aquaculture was used in the pilot scale study.Without changing fresh water,the system continuously run for 30 days,the variation characrastics of COD,NH+4-N and TP were analyzed.The results indicated that,with the same aquaculture density,COD,NH+4-N and TP increased by 26.6%,45.7% and 37.4%,respectively in rainbow trout aquaculture part.COD,NH+4-N and TP increased by 16.0%,21.6% and 14.4%,respectively in sturgeon aquaculture part.The removal rates of COD,NH+4-N and TP were 39.8%,50.0% and 1.9%,resprectively in biofilter.The chub aquaculture part and aquatic plant sedimentation basin were also added in the system,with the purpose of increasing the contaminant removal efficiency.In 21 days later,with adding chitosan in sedimentation basin,the turbidity and chroma reduced to 46.6% and 38.0%,respectively.With 30 days continuously running,both COD and NH+4-N achieved the Ⅲ level of GB 3838-2002,excepted TP.%采用循环水养殖系统进行虹鳟、鲟鱼和鲢鱼的阶梯养殖中试研究,在不更换新鲜水的情况下,系统连续运行30天,分析其中COD、NH4+-N和TP的变化特征。结果表明,在相同养殖密度情况下,养殖虹鳟鱼使循环水COD、NH4+-N和TP浓度分别增加26.6%、45.7%和37.4%,养殖鲟鱼使COD、NH4+-N和TP浓度分别增加16.0%、21.6%和14.4%,生化池对COD、NH4+-N和TP的去除率分别为39.8%、50.0%和1.9%。系统还加入了鲢鱼养殖单元和配置水生植物的沉淀池,增加了系统对污染物的去除效果。实验自第21天起向沉淀池投加壳聚糖,使循环水浊度降低了46.6%,色度降低了38.0%。经过30 d的连续运行,除TP指标外,COD和NH4+-N浓度仍满足《地表水环境质量标准》(GB3838-2002)中地表水Ⅲ类功能区用水标准。

  2. Approaches for Controlling the Level in Water/steam Separators of a DSG Solar Field Configured in Recirculation Mode

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela, L.; Zarza, E.; Leon, J.

    2006-07-01

    The DISS plant located at the Plataforma Solar de Almeria (PSA) serves as test bed to investigate under real solar conditions the direct steam generation (DSG) in a parabolic trough collectors field working as the boiler and superheater of a Rankine steam cycle. This solar field can be configured in different operation modes (recirculation, once-TROUGH and injection modes) being the recirculation mode the most efficient from the stability and control points of view. Within the INDITEP project, financed by the EU Commission (2002-2005), one of the tasks performed has been testing new components for the solar field with the system configured in recirculation mode. One disadvantage of this configuration is the cost of the facility; it is needed a middle water-steam separator in the solar field, which separates evaporation and superheating sections, and a recirculation pump. Reduction of the liquid inventory in the process, i.e. the volume of the middle separator tank, will reduce the cost and parasitic loads of the solar field but it requires an efficient control of the liquid level inside the separator and, with the current layout of the solar field, that means an efficient control of the inlet water flow to the solar field, affecting also to the recirculation ratio (ratio between the recirculation flow and feed water flow) established for nominal conditions. The paper presents simulation and experimental results obtained using different classical and advanced control strategies. (Author)

  3. Using computer simulation to reduce costs at a recirculating aquaculture facility

    OpenAIRE

    Simon, John

    2005-01-01

    The Recirculating Aquaculture System can be considered as a dynamic system in which the system variables change instantaneously during the growing period. This effort uses a combination of discrete and continuous simulation to model this system. Changing the values of a certain set of variables (regressors) result in changes to another set of variables (responses). So the inter relationship between the regressors and responses are first defined. Then the changes to the regressors are defined...

  4. Analysis of heat recovery from a spray dryer by recirculation of exhaust air

    International Nuclear Information System (INIS)

    Highlights: • We study a spray dryer with heat recovery by partial recirculation of exhaust air. • We examine effects of process parameters on energy efficiency and energy savings. • Decreasing drying air temperature and flow rate will increase energy efficiency. • Increasing recirculation ratio and slurry feed rate will increase energy efficiency. - Abstract: Model simulations were employed to investigate the influences of process parameters on the energy recovery in spray drying process that partially recycle the exhaust drying gas. The energy efficiency and energy saving were studied for various values of recirculation ratios with respect to the temperature and flow rate of the drying air, slurry feed rate and concentration of slurry in spray drying of advanced ceramic materials. As a result, significant gains in energy efficiency and energy saving were obtained for a spray drying system with high recirculation ratio of exhaust air. The high slurry feed rate and the low slurry concentration, inlet drying air temperature and drying air flow rate enhanced the energy efficiency of spray drying system. However, the high energy saving was obtained in spray dryers operating at low slurry feed rate and high slurry concentration

  5. Influence of mass recovery on the performance of a heat pipe type ammonia sorption refrigeration system using CaCl2/activated carbon as compound adsorbent

    International Nuclear Information System (INIS)

    The performance analyses of a sorption refrigeration system with different mass recovery processes are presented, in which compound adsorbent of CaCl2 and activated carbon is used to improve the mass and heat transfer performances of sorption bed. The heating, cooling and heat recovery processes between two sorption beds were performed by multifunction heat pipes without additional power consumption. The experimental Clapeyron diagrams showed that the cycles with mass recovery (MR), with heat and mass recoveries (HMR), and with mass and heat recoveries (MHR), have better thermodynamic performances when compared with the sorption cycle without mass recovery (MR0). The implementary order of mass recovery and heat recovery has strong influence on the efficacy of mass recovery while it has little influence on the efficacy of heat recovery. In sorption cycles with HMR and with MHR, the hot beds can be pre-cooled and cold beds can be pre-heated effectively during the switching process, and heat consumption from external heat source during desorption phase is thereby reduced. Mass recovery can enlarge cycled refrigerant mass due to the transfer of refrigerant gas between two sorption beds during mass recovery process. In comparison with sorption cycle with MR0, sorption cycles with MR, with HMR, and with MHR can generally improve the coefficient of performance (COP) and specific cooling power (SCP) by more than 20% and 16%, respectively. Especially, sorption cycle with MHR has the highest performance among different mass recovery processes due to the fact that MHR has the advantages of MR and HMR, and it can improve the COP by 46.7% when compared with the cycle with MR0

  6. 40 CFR 1065.127 - Exhaust gas recirculation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Exhaust gas recirculation. 1065.127 Section 1065.127 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.127 Exhaust gas recirculation. Use...

  7. Crescimento de jundiá e carpa húngara criados em sistema de recirculação de água Jundiá growth and Common Carp reared in recirculated water system

    Directory of Open Access Journals (Sweden)

    Viviani Corrêia

    2009-08-01

    Full Text Available O presente estudo foi realizado com o objetivo de comparar o crescimento e o rendimento de carcaça e a composição corporal de juvenis de jundiá (Rhamdia quelen e carpa húngara (Cyprinus carpio criados em sistema de recirculação de água, em mono e bicultivo, durante 60 dias, na fase de recria. Cinco tratamentos com três repetições foram testados: 100C=100% carpa; 100J=100% jundiá; 50C50J=50% carpa 50% jundiá; 75C25J=75% carpa 25% jundiá e 25C75J=25% carpa 75% jundiá, sendo utilizados 20 peixes por unidade experimental. Foram avaliados o peso (P, a biomassa total (BT, o fator de condição (FC, a conversão alimentar aparente (CAA, a taxa de crescimento específico (TCE, o rendimento de carcaça (RC, o índice digestivo-somático, o índice hepato-somático, o quociente intestinal, as composições centesimais dos peixes, as taxas de deposição de proteína e a gordura corporal. Não foram observadas diferenças no peso, no FC e na TCE dos jundiás (P>0,05. Para essas variáveis, as carpas submetidas ao tratamento 25C75J apresentaram valores significativamente maiores (PA study was conducted to evaluate growth, carcass yield and body composition of jundiá and common carp raised in mono or duoculture in a recirculated water system, for 60 days, during the growing. Five treatments were tested with three replicates: 100C=100% carp; 100J=100% jundiá, 50C50J=50% carp 50% jundiá; 75C25J=75% carp 25% jundiá and 25C75J=25% carp 75% jundiá. Twenty fishes were distributed in each experimental unit. It was evaluated weight (W, total biomass (TB, condition factor (CF, feed conversion rate (FCR, specific growth rate (SGR, carcass yield (YC, digestive-somatic index, hepatossomatic index, intestinal quotient and the proximate composition and body deposition of protein and fat. Considering jundiá performance, no statistical difference was observed for W, CF and SGR (P>0.05. Common carp from treatment 25C75J showed the highest values (P<0

  8. Ammonia-oxidizing bacterial community composition in the nitrifying biofilter of Recirculating Aquaculture System%循环海水养殖系统硝化滤器中氨氧化微生物分析

    Institute of Scientific and Technical Information of China (English)

    刘长发; 姚敬元; 袁瑗; 刘卫东

    2012-01-01

    研究循环水养殖硝化滤器裁体上附着生物膜的微生物群落结构可以为提高其处理速率和数率,并为特异性工程菌构建提供依据.采用改良的AFLP方法分析了循环水养殖硝化滤器载体上附着的氨氧化细菌16S rRNA基因和氨单加氧酶amoA基因片段及其系统发育情况.结果表明:分析16S rRNA基因得到的序列片段比分析amoA基因片段得到了更多信息,准确度较高,可作为分析循环水养殖硝化滤器氨氧化茵群组成的有效方法.克隆测序所得序列与网上公布数据比对,可见存在于循环水养殖硝化滤器载体上的氨氧化细菌与Nitrosomonas cryotolerans、Nitrosomonas oligotropha、Nitrosospira tenuis、Nitrosomonasmarina相似度达100%,与Nitrosomornas aestuarii相似度为87%.大部分属于亚硝化单胞茵属(Nitrosomonns),仅少数序列属于亚硝化螺茵属(Nitrosospira).采用16S rRNA基因和amoA片段分析方法得到的附着于封闭循环海水养殖硝化滤器载体上的氨氧化细菌主要为变形茵(Proteobacteria)的β-亚类的亚硝化单胞茵属(Nitrosomonas)和少量的亚硝化螺茵属(Nitrosospira)氨氧化细菌,以及一定数量的y-亚类氨氧化细菌.%Ammonia-oxidizing bacteria (AOB) play an important role in transformation from ammonia nitrogen to nitrite nitrogen in the nitrifying biofilter.Studying community structure of nitrifying organisms adhered on the media of nitrification biofilter in the recirculating aquaculture system (RAS) could provide a basis of improving removal rate and performance of biofilter,and construction of nitrifying engineering bacteria for removal of ammonia from RAS.The PCR-based gene cloning and mapping of 16S rRNA gene and betaproteobacteria ammonia monooxygenase subunit A (amoA) gene of ammonia-oxidizing bacteria isolated from nitrification biofilter were surveyed by using the method of improved amplified fragment length polymorphism (AFLP) analysis.The results showed that

  9. Ultrasonic downcomer flow measurements for recirculating steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Janzen, Victor, E-mail: Victor.Janzen@cnl.ca [Canadian Nuclear Laboratories, Chalk River, ON, Canada K0 J 1J0 (Canada); Luloff, Brian [Canadian Nuclear Laboratories, Chalk River, ON, Canada K0 J 1J0 (Canada); Sedman, Ken [Nuclear Safety Analysis & Support Department, Bruce Power, Toronto, ON, Canada M5G 1X6 (Canada)

    2015-08-15

    Highlights: • Measuring recirculating flow in nuclear steam generators provides useful information. • Flow measurements shed light on component performance and degradation mechanisms. • Commonly used ultrasonic technology and application methods are described. • Results of measurements at several power reactors are summarized. • Potential improvements in reliability and flexibility of application are suggested. - Abstract: Measurements of downcomer flow in nuclear steam generators can provide unique fitness for service and performance indicators related to overall thermalhydraulic performance, safety related secondary-side setpoints and certain forms of degradation. This paper reviews the benefits of downcomer-flow measurements to nuclear power–plant operators, and describes methods that are commonly used. It summarizes the history and state-of-the-art of the most widely used technology, non-intrusive ultrasonic systems, including field applications at several nuclear power plants. It also describes the technical challenges that remain, and summarizes recent technical developments and future improvements.

  10. Recycling crop residues for use in recirculating hydroponic crop production

    Science.gov (United States)

    Mackowiak, C. L.; Garland, J. L.; Sager, J. C.

    1996-01-01

    As part of bioregenerative life support feasibility testing by NASA, crop residues are being used to resupply elemental nutrients to recirculating hydroponic crop production systems. Methods for recovering nutrients from crop residues have evolved from water soaking (leaching) to rapid aerobic bioreactor processing. Leaching residues recovered the majority of elements but it also recovered significant amounts of soluble organics. The high organic content of leachates was detrimental to plant growth. Aerobic bioreactor processing reduced the organic content ten-fold, which reduced or eliminated phytotoxic effects. Wheat and potato production studies were successful using effluents from reactors having with 8- to 1-day retention times. Aerobic bioreactor effluents supplied at least half of the crops elemental mass needs in these studies. Descriptions of leachate and effluent mineral content, biomass productivity, microbial activity, and nutrient budgets for potato and wheat are presented.

  11. Substrate-adsorbate coupling in CO-adsorbed copper

    CERN Document Server

    Lewis, S P; Lewis, Steven P.; Rappe, Andrew M.

    1996-01-01

    The vibrational properties of carbon monoxide adsorbed to the copper (100) surface are explored within density functional theory. Atoms of the substrate and adsorbate are treated on an equal footing in order to examine the effect of substrate--adsorbate coupling. This coupling is found to have a significant effect on the vibrational modes, particularly the in-plane frustrated translation, which mixes strongly with substrate phonons and broadens into a resonance. The predicted lifetime due to this harmonic decay mechanism is in excellent quantitative agreement with experiment.

  12. Performance of two-stage vegetable waste anaerobic digestion depending on varying recirculation rates.

    Science.gov (United States)

    Zuo, Zhuang; Wu, Shubiao; Zhang, Wanqin; Dong, Renjie

    2014-06-01

    Vegetable waste, which characterized by high moisture content, was evaluated as a substrate for biogas production. The effects of recirculation rate (RR) on the performance of two-stage anaerobic digestion were investigated. The system was operated at an organic loading rate of 1.7 g VS/L/d with varying RRs (0, 0.6, 1, and 1.4). Results demonstrated that volumetric biogas production rates in acidogenic reactor increased from approximately 0.2 7 L/L/d to 0.97 L/L/d, when pH is increased from approximately 5.1 to 6.7. These indicate that recirculation of alkaline effluent from the methanogenic reactor helps create a favorable condition for biogas production in the acidogenic reactor. The decrease in chemical oxygen demand (COD) concentrations from approximately 21,000 mg/L to 6800 mg/L was also observed in the acidogenic reactor. This condition may be attributed to dilution under recirculation. The dynamics between hydrolysis and methanogenesis under recirculation indicated that mass transfer capacity between two-stage reactors improved. PMID:24759642

  13. The benefits of powdered activated carbon recirculation for micropollutant removal in advanced wastewater treatment.

    Science.gov (United States)

    Meinel, F; Zietzschmann, F; Ruhl, A S; Sperlich, A; Jekel, M

    2016-03-15

    PAC adsorption is a widespread option for the removal of organic micropollutants (OMP) from secondary effluent. For an optimal exploitation of the adsorption capacity, PAC recirculation is nowadays a common practice, although the mechanistic interrelations of the complex recirculation process are not fully resolved. In this work, extensive multi-stage batch adsorption testing with repeated PAC and coagulant dosage was performed to evaluate the continuous-flow recirculation system. Partly loaded PAC showed a distinct amount of remaining capacity, as OMP and DOC removals considerably increased with each additional adsorption stage. At a low PAC dose of 10 mg PAC L(-1), removals of benzotriazole and carbamazepine were shown to rise from 80% in the 11th stage at 30 min adsorption time per stage. At a high PAC dose of 30 mg PAC L(-1), OMP and DOC removals were significantly higher and reached 98% (for benzotriazole and carbamazepine) after 11 stages. Coagulant dosage showed no influence on OMP removal, whereas a major part of DOC removal can be attributed to coagulation. Multi-stage adsorption is particularly beneficial for small PAC doses and significant PAC savings are feasible. A new model approach for predicting multi-stage OMP adsorption on the basis of a single-stage adsorption experiment was developed. It proved to predict OMP removals and PAC loadings accurately and thus contributes towards understanding the PAC recirculation process. PMID:26773491

  14. Treatment efficiency of wastewater in pilot test of biofloc reactor in recirculating aquaculture systems%生物絮凝反应器对中试循环水养殖系统中污水的处理效果

    Institute of Scientific and Technical Information of China (English)

    刘文畅; 罗国芝; 谭洪新; 孙大川; 刘冰; 张世阳

    2016-01-01

    试验设计了一种生物絮凝反应器,用作中试规模循环水养殖系统(recirculating aquaculture system,RAS)的唯一水处理装置,研究其在不同水力停留时间(hydraulic retention time,HRT,12、6、4.5、3 h)条件下的运行效果。试验结果表明,反应器可耐受最小HRT为4.5 h,当HRT降低至3 h,反应器发生不可逆的洗出现象而使试验不能继续进行。反应器絮体沉降性能一般,随着HRT的减小(12、6和4.5 h HRT),絮体体积指数(SVI-30)逐渐降低,但是始终大于150 mL/g,为丝状菌膨胀,主要的丝状细菌由TM7genera incertae sedis逐渐演变为Haliscomenobacter和Meganema菌属,相对丰度逐渐降低。12 h HRT反应器污染物去除率最高。反应器亚硝氮(NO2--N)、硝氮(NO3--N)在4.5 h HRT出水质量浓度最低,分别为(0.02±0.01)、(1.70±0.06) mg/L;氨氮(total ammonium nitrogen,TAN)、总氮(total nitrogen,TN)、悬浮颗粒物(suspended solids,SS)出水质量浓度在12 h HRT时最低,分别为(0.48±0.05)、(4.47±1.00)、(14.20±8.14) mg/L,同时未造成有机污染。4.5 h HRT对RAS养殖区污染物的控制效果最佳,TAN、NO2--N、NO3--N、SS质量浓度分别被控制在0.76、0.10、2.95、60.00 mg/L以下。反应器在不同HRT条件下均以异养细菌为主,主要通过同化作用去除TAN,好氧反硝化细菌和厌氧反硝化细菌同时是反应器的优势菌属。反应器可获得较长的稳定运行状态和良好的水处理效果,具有用作RAS核心水处理装置的可行性,该研究可为其在RAS的进一步研究和应用提供参考。%Taking into account the characteristics of aquaculture, researchers have proposed the biofloc technology (BFT), and created the conditions in the BFT reactor for the treatment of pollutants. BFT reactor could treat the aquaculture wastewater and the effluents of recirculating aquaculture system (RAS). Total ammonium

  15. REVIEW: USE of COMPOSITE ADSORBENTS in ADSORPTION REFRIGERATION

    Directory of Open Access Journals (Sweden)

    Satishchandra V. Joshi

    2012-01-01

    Full Text Available The urbanization across the world has resulted in increased demand for refrigeration and air conditioning. The main disadvantage with the conventional method i.e. vapor compression system is environment pollution. Another problem faced during urbanization is energy crisis. The adsorption refrigeration system is one of the solutions to this problem. The advantages of this system are environment friendly, less noise, use of waste heat or solar energy. But the disadvantage with adsorption system is low coefficient of performance (COP and bulkiness. Researchers across the world are working on this issue to make adsorption system a viable alternative to the compression systems. Since the last two decades considerable work is being done on the use of composite adsorbents to improve the heat and mass transfer performance. This kind of adsorbent is usually obtained by the combination of a chemical adsorbents and physical adsorbents.

  16. Computer simulations of adsorbed liquid crystal films

    Science.gov (United States)

    Wall, Greg D.; Cleaver, Douglas J.

    2003-01-01

    The structures adopted by adsorbed thin films of Gay-Berne particles in the presence of a coexisting vapour phase are investigated by molecular dynamics simulation. The films are adsorbed at a flat substrate which favours planar anchoring, whereas the nematic-vapour interface favours normal alignment. On cooling, a system with a high molecule-substrate interaction strength exhibits substrate-induced planar orientational ordering and considerable stratification is observed in the density profiles. In contrast, a system with weak molecule-substrate coupling adopts a director orientation orthogonal to the substrate plane, owing to the increased influence of the nematic-vapour interface. There are significant differences between the structures adopted at the two interfaces, in contrast with the predictions of density functional treatments of such systems.

  17. Cleaning and recirculation of perfluorohexane (C sub 6 F sub 1 sub 4) in the STAR-RICH detector

    CERN Document Server

    Andrés, Yu; Cozza, D; Davenport, M; De Cataldo, G; Dell-Olio, L; Di Bari, D; Di Mauro, A; Dunlop, J C; Finch, E; Fraissard, Daniel; Franco, A; Gans, J; Ghidini, B; Harris, J W; Horsley, M; Kunde, G J; Lasiuk, B; Lesenechal, Y; Majka, R D; Martinengo, P; Morsch, Andreas; Nappi, E; Paic, G; Piuz, François; Posa, F; Raynaud, J; Salur, S; Sandweiss, J; Santiard, Jean-Claude; Satinover, J; Schyns, E; Smirnov, N; Van Beelen, J; Williams, T D; Xu, Z

    2002-01-01

    A RICH detector with a CsI photo-cathode and liquid perfluorohexane radiator has been installed in the STAR experiment at RHIC. The liquid is continuously cleaned and distributed to a quartz containment vessel within the detector by a closed recirculation system. A VUV spectrometer is connected to the system which monitors the optical transparency of the liquid. This measurement provides one of the pieces of information necessary to model the number of Cherenkov photons which reach the pad plane. A description of the liquid recirculation system and the cleaning procedure for the liquid as well as the spectrometer is presented along with results of their performance.

  18. MODIFICATION OF CARBONACEOUS ADSORBENTS WITH MANGANESE COMPOUNDS

    OpenAIRE

    Irina Ginsari; Larisa Postolachi; Vasile Rusu; Oleg Petuhov; Tatiana Goreacioc; Tudor Lupascu; Raisa Nastas

    2015-01-01

    Four series of samples containing manganese supported carbonaceous adsorbents were prepared. Obtained results reveal the importance of surface chemistry of carbonaceous adsorbents on the manganese loading.

  19. 封闭循环水系统和船体网箱驯养圆口铜鱼幼鱼的效果比较%Domestication comparison of Coreius guichenoti in the closed recirculating aquaculture system and the boat -net trunk

    Institute of Scientific and Technical Information of China (English)

    朱挺兵; 吴兴兵; 朱永久; 郭威; 杨德国; 于江; 杨少荣; 王磊

    2015-01-01

    A comparative domestication study was conducted in the closed recirculating aquaculture system and the boat -net trunk using wild Coreius guichenoti juveniles (about 150 ~400 g) captured from the Yangtze River.For each aquacul-ture facility, experimental fish were divided into two groups based on fish size .The stocking density of the two groups of ex -perimental fish in the closed recirculating aquaculture system were 11.48 kg/m 3 and 17.65 kg/m 3 , and applied for 279 days with a mean water temperature (14.5 ±3.4) ℃.The stocking density of the two groups of experimental fish in the boat -net trunk were 4.40kg/m 3 and 7.06 kg/m 3 , and applied for 244 days with a mean water temperature (20.0 ±3.1)℃.All experimental fish were fed to satiation with artificial fodder .The results showed that the survival rate of experimental fish in the closed recirculating aquaculture system and boat -net trunk were over 97.75% and over 83.78%, respectively, and also showed a trend that smaller experimental fish had higher mortality .The specific growth rate of body weight of the two groups of experimental fish in the closed recirculating aquaculture system were 0.08%/d and 0.11%/d, while 0.17%/d and 0.21%/d in boat -net trunk.The condition factor of the experimental fish in the boat -net trunk were gen-erally higher than that of the closed recirculating aquaculture system .No serious disease was happened in the closed recircu -lating aquaculture system during the experiment ,while in the boat -net trunk recorded a serious outbreak of parasitic disea -ses including Ichthyophthirius multifiliis and Trichodina.The present study indicates that Coreius guichenoti juveniles domes-ticated in the closed recirculating aquaculture system had high survival rate but slower growth rate ,while had faster growth rate and more vulnerable to parasitic diseases when domesticated in the boat -net trunk.In conclusion,both of the closed recirculating aquaculture system and the boat -net trunk

  20. Comparison of arteriovenous fistula recirculation by thermodilution and urea

    International Nuclear Information System (INIS)

    To compare arteriovenous fistula recirculation by thermodilution technique and urea based two needle slow flow method. Thirty one patients with end stage renal disease on maintenance hemodialysis through arteriovenous fistula were selected on purposive design. Hemodialysis was done on Fresenius 4008 S machines with in-built blood temperature monitoring module to measure recirculation by thermodilution method. Recirculation by the thermodilution method was calculated with the blood flow rate of 300 milliliter /minute and dialysate flow of 500ml /minute. Access recirculation by urea based method was calculated by taking three blood samples for blood urea nitrogen. Two samples were taken simultaneously from the arterial and venous ports respectively. Third sample was taken from the arterial port after slowing the blood flow pump to 50 milliliter/minute and waiting for 30 seconds. Relationship of thermodilution and urea based method was assessed by calculating Pearson correlation coefficient (r). Out of 31 patients, 18 (58.1%) were males, whereas 13 (41.9%) were females. Their mean age was 47.29 +- 13.42 years. Mean access recirculation by thermodilution method was 7.31+- 3.03 and by urea based method was 9.55 +- 6.64. Correlation coefficient (r) was 0.706 with p-value of < 0.001, which was highly significant. Arteriovenous fistula recirculation calculated by thermo-dilution technique has a strong correlation with the recirculation calculated by the two-needle urea based method. (author)