scholarly journals Challenges and development directions of membrane bioreactors operated on passenger ships in international shipping

2021 ◽  
Vol 17 ◽  
pp. 42-47
Author(s):  
Karol Trzciński ◽  
Magdalena Zielińska
Keyword(s):  
Membrane Bioreactors ◽  
Solid Particles ◽  
Water Recovery ◽  
Modular Construction ◽  
International Convention ◽  
Effluent Quality ◽  
Discontinuous Flow ◽  
Engine Cooling ◽  
Passenger Ships ◽  
Main Engine

In membrane bioreactor (MBR) technology, the activated sludge method is integrated with the separation of solid particles by ultrafiltration (UF). The technology ensures a high effluent quality, a shortened hydraulic retention time and a long sludge age that promotes slowly growing microorganisms and low sludge production. These advantages and the modular construction mean that MBRs have started to treat wastewater generated on passenger ships to adjust the treatment systems to the International Convention for the Prevention of Pollution from Ships. The aim of this paper is to present operational aspects of MBRs treating wastewater generated on ships, which are different from the aspects of MBR operation on land. This paper describes the consequences of separate treatment of gray wastewater (from showers, washing machines and kitchens) and black wastewater (from toilets), and of discontinuous flow of wastewater resulting from very high variability in the passenger numer and the use of the MBR as a ship ballast element. The possibility of introducing a water recovery technology using the existing infrastructure on passenger ships as well as the hybrid UF/reverse osmosis technology is presented. The findings demonstrated that gray effluent may be reused for marine main engine cooling jackets of high and low temperature, ship boilers or ship laundry.

Feasibility of submerged anaerobic membrane bioreactor (SAMBR) for treatment of low-strength wastewater

2008 ◽  
Vol 58 (10) ◽  
pp. 1925-1931 ◽  
Author(s):  
Z. Huang ◽  
S. L. Ong ◽  
H. Y. Ng
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactors ◽  
Organic Loading Rate ◽  
Effluent Quality ◽  
Significant Difference ◽  
Anaerobic Membrane Bioreactors ◽  
High Purification ◽  
Low Strength ◽  
Set Up ◽  
Internal Pore

Two 6-L submerged anaerobic membrane bioreactors (SAMBR) with SRT of 30 and 60 d (denoted as R30 and R60, respectively) were set up and operated for five months, with a mixture of glucose as substrate. Feasibility of SAMBR was studied for treatment of low-strength wastewater. First two months were identified as acclimation stage. A COD removal efficiency was achieved stably at around 99% and biogas productions were maintained at 0.023 and 0.028 L CH4/gMLVSS∙d for R30 and R60, respectively. Even though R60 contained higher MLVSS concentration, no significant difference of treatment performances between both reactors was found due to the low organic loading rate and high purification function of membrane. In the investigation of membrane fouling, less irreversible fouling was observed for R30 compared to R60. High non-flocculent concentration of R60 would be responsible for membrane internal pore blocking and deteriorated effluent quality.

Performance of membrane bioreactors used for the treatment of wastewater from the chemical and textile industries

2006 ◽  
Vol 53 (3) ◽  
pp. 61-67 ◽  
Author(s):  
S. Baumgarten ◽  
H.Fr. Schröder ◽  
J. Pinnekamp
Keyword(s):  
Pilot Scale ◽  
Membrane Bioreactors ◽  
Small Scale ◽  
Waste Waters ◽  
Effluent Quality ◽  
Molecular Separation ◽  
Textile Industries ◽  
Membrane Modules ◽  
New Applications ◽  
Pilot Tests

Within the scope of the study, nine waste waters from the chemical and textile industries were treated in bench-scale (laboratory scale) and small-scale (pilot scale) membrane bioreactors. Depending on wastewater characteristics, the resulting performance varied significantly. It was observed that MBR effectiveness was determined primarily by the degree of biodegradability of the wastewater. In the course of several months of operation, no significant changes associated with the complete retention of the biomass by the membranes were observed. In some cases, it was possible to improve effluent quality by using smaller molecular separation sizes. The flux performance of the membrane modules was dependent on wastewater composition. Occasionally, non-degradable macromolecular substances concentrated in the bioreactor, resulting in strongly reduced filterability and flow performance of the membrane modules, consequently also reducing the economic viability of the process. The results demonstrate that wastewater-specific pilot tests are absolutely necessary, in particular if the technology is to be used for new applications.

scholarly journals Analisa Kegagalan Conrod Bearing Pada Kapal Cepat

2021 ◽  
Vol 3 (2) ◽  
pp. 87-98
Author(s):  
Dwi Tatang Yulianto Tatang ◽  
D.N. Adnyana
Keyword(s):  
Connecting Rod ◽  
Engine Cooling ◽  
Main Engine

Kerusakan conrod bearing pada main engine kapal cepat akibat design material, peningkatan panas yang berlebih pada sistem engine cooling (overheat)  dan pengeoperasian. Untuk mengidentifikasi penyebab kerusakan dilaksanakan beberapa pengujian  seperti pengamatan visual makro, analisis komposisi kimia, kekerasan mikro dengan vickers, fraktografi,metalografi, pengukuran ketebalan lapisan. Hasil analisis telah terjadi overheating dan deform pada conrod bearing akibat bergesekan dengan connecting rod dan terlihat pada daerah tepi alur adanya gesekan, dan tidak ditemukan lapisan babbit dikarenakan lapisan tersebut sudah lebur (fase liquid) pada temperature 354°C sesuai dengan standar logam babbit ASTM B23-00 2014 serta lapisan back steel mengalami deform.

scholarly journals Role of Mesh Pore Size in Dynamic Membrane Bioreactors

2021 ◽  
Vol 18 (4) ◽  
pp. 1472
Author(s):  
Pompilio Vergine ◽  
Carlo Salerno ◽  
Barbara Casale ◽  
Giovanni Berardi ◽  
Alfieri Pollice
Keyword(s):  
Pore Size ◽  
Membrane Bioreactors ◽  
Operating Conditions ◽  
Major Influence ◽  
Solid Retention Time ◽  
Dynamic Membrane ◽  
Effluent Quality ◽  
Set Up ◽  
High Suction

Two identical bench-scale Self-Forming Dynamic Membrane BioReactors (SFD MBR) were set-up and operated for the treatment of real urban wastewater. The two bioreactors were equipped with meshes of different mesh pore size. Meshes having pore size values of 20 and 50 µm were tested under solid retention time (SRT) of 15 d, whereas meshes with 50 and 100 µm pore sizes were compared under SRT of 50 d. The results of long-term experiments showed very good overall performances by all systems at the steady state. High flux (in the range 61–71 L m−2 h−1) and very good effluent quality were obtained, with average suspended solids and chemical oxygen demanding values below 10 mg L−1 and 35 mg L−1, respectively. The mesh pore size did not have a major influence on the average cleaning frequency. However, the pore size affected the effluent quality in correspondence of two particular conditions: (i) immediately after mesh cleaning; and (ii) during operation under high suction pressures (mesh clogging not promptly removed through cleaning). Moreover, the mesh cleaning frequency was observed to be dependent on the SRT. In tests with 50 d SRT, the cleaning requirements were very low (one every five days), and this limited the influence of the mesh pore size on the effluent quality. In conclusion, in SFD MBR, the role of the mesh pore size on the effluent quality may be more or less relevant depending on the operating conditions that directly influence the Dynamic Membrane formation.

A Scenario Simulation - Evaluating Evacuation Analysis for ro-ro Passenger Ship in MV Tai Hwa

2020 ◽  
Vol 36 (04) ◽  
pp. 240-249
Author(s):  
Hui-Chiao Wang ◽  
Chien-Hsing Wu
Keyword(s):  
Ship Design ◽  
International Maritime Organization ◽  
Scenario Simulation ◽  
Loss Of Life ◽  
International Convention ◽  
Effective Evaluation ◽  
Passenger Ship ◽  
Initial Stage ◽  
Passenger Ships ◽  
Evacuation Routes

The ro-ro passenger ship is a type of passenger ship which is commonly seen in Europe. After the tragedy of MV Estonia, an effective evaluation of escape routes in passenger ship in the initial stage of ship design has been required by International Convention for the Safety of Life at Sea (SOLAS) Convention. To reduce the loss of life in passenger ships at sea, the International Maritime Organization (IMO) has created the revised guidelines on evacuation analyses for new and existing passenger ships. This article followed IMO's mandatory guidelines via using the hydraulic model of emergency egress to scrutinize the evacuation routes, congestion points, and the total evacuation duration of MV Tai Hwa.

Ethinylestradiol removal in a conventional and a simultaneous nitrification–denitrification membrane bioreactor

2011 ◽  
Vol 64 (12) ◽  
pp. 2333-2337
Author(s):  
M. Paetkau ◽  
W. Yang ◽  
N. Cicek
Keyword(s):  
Membrane Bioreactor ◽  
Estrogenic Activity ◽  
Screen Test ◽  
Membrane Bioreactors ◽  
Solid Particles ◽  
Removal Mechanism ◽  
Partitioning Coefficient ◽  
Synthetic Estrogen ◽  
Significant Difference ◽  
Removal Efficiencies

The removal of a synthetic estrogen 17α-ethinylestradiol (EE2) was investigated in submerged membrane bioreactors (MBRs) with simultaneous nitrification–denitrification (SND) and conventional nitrification. The influent EE2 concentration was 500 ng/L as EE2. Using a yeast estrogen screen test, the conventional-MBR (C-MBR) and SND MBR (SND-MBR) removed 57 and 58% of the estrogenic activity (EA) respectively; there was no significant difference in their removal efficiencies. Biodegradation was the dominant removal mechanism for both reactors with KBIO coefficients of 1.5 ± 0.6 and 1.6 ± 0.4 day−1 for the C-MBR and the SND-MBR respectively. Sorption to solid particles removed approximately 1% of influent EA in each reactor; the particle partitioning coefficient, KD, was calculated to be 0.21 ± 0.07 L/(g MLSS) for the C-MBR and 0.27 ± 0.1 L/(g MLSS) for the SND-MBR. These findings suggest that conditions favoring SND in MBRs have no significant impact on EA reduction.

scholarly journals Potential energy recovery from LNG regasification in LNG-fueled ships

2019 ◽  
Vol 113 ◽  
pp. 02011
Author(s):  
Gianluca Pasini ◽  
Andrea Baccioli ◽  
Lorenzo Ferrari ◽  
Umberto Desideri
Keyword(s):  
Energy Recovery ◽  
Waste Heat ◽  
Rankine Cycle ◽  
Maximum Temperature ◽  
Working Fluid ◽  
International Convention ◽  
Engine Efficiency ◽  
Temperature And Pressure ◽  
Main Engine ◽  
Power Recovery

Recent regulatory initiatives regarding ships emissions raised the interest of maritime operators on cleaner fuels. The International Maritime Organization (IMO) with Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL) set strict limits on SOx , NOx and CO2 emissions. Many studies have been carried out to increase engine efficiency based on waste heat recovery such as ORC or turbo-compounding. Using LNG as a fuel opens new opportunities in this prospect. In this study, an energy recovery from LNG regasification process, through a dedicated and optimized cycle, is investigated. The system is made of an open supercritical Rankine cycle performed before engine injection and exploiting LNG as a working fluid. Results showed the influence of the maximum temperature and pressure of the cycle on the system performance. A maximum power recovery up to 2.2% of main engine power was found.

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