Ballast Water Treatment Research Articles

Technology selection for ballast water treatment by multi-stakeholders: A multi-attribute decision analysis approach based on the combined weights and extension theory

This objective of this study is to develop a generic multi-attribute decision analysis framework for ranking the technologies for ballast water treatment and determine their grades. An evaluation criteria system consisting of eight criteria in four categories was used to evaluate the technologies for ballast water treatment. The Best-Worst method, which is a subjective weighting method and Criteria importance through inter-criteria correlation method, which is an objective weighting method, were combined to determine the weights of the evaluation criteria. The extension theory was employed to prioritize the technologies for ballast water treatment and determine their grades. An illustrative case including four technologies for ballast water treatment, i.e. Alfa Laval (T1), Hyde (T2), Unitor (T3), and NaOH (T4), were studied by the proposed method, and the Hyde (T2) was recognized as the best technology. Sensitivity analysis was also carried to investigate the effects of the combined coefficients and the weights of the evaluation criteria on the final priority order of the four technologies for ballast water treatment. The sum weighted method and the TOPSIS was also employed to rank the four technologies, and the results determined by these two methods are consistent to that determined by the proposed method in this study.

Combining ballast water treatment and ballast water exchange: Reducing colonization pressure and propagule pressure of phytoplankton organisms

Species richness and species abundance (colonization pressure and propagule pressure, respectively) are commonly used to characterize invasion risk for ballast-water-mediated introductions, which can be high if either parameter is high. For practical reasons, the adopted IMO-D2 standard for organisms in discharged ballast water only considers total abundance of biological indicators, without consideration of species richness or source community. Here we explore the effect of ballast-water source, ballast water exchange, chlorination, or a combination of both (hybrid treatment) on both colonization pressure and propagule pressure for one IMO-D2 size class (≥10 µm and <50 µm; phytoplankton). A strong reduction of propagule pressure was observed in all experimental trials and taxonomic groups, probably owing to environment conditions inside ballast tanks and treatment effects. However, only the hybrid treatment met the IMO-D2 standard for propagule pressure, while also significantly reducing colonization pressure, from 25 initial groups to 16 final groups. In this treatment, dinoflagellates and diatoms dominated final composition. The impact of different treatments on colonization pressure and propagule pressure was always lower when the vessel was ballasted in a brackish than freshwater port. Our study demonstrates that even treated ballast water compliant with the IMO-D2 standard may still harbor a diverse phytoplankton community, albeit with low individual species abundances. These results might be similar even using a type approved ballast water management systems which usually includes a filter for >50 µm organisms as a pre-treatment.

Detection of UV-treatment effects on plankton by rapid analytic tools for ballast water compliance monitoring immediately following treatment

Non-indigenous species seriously threaten native biodiversity. To reduce establishments, the International Maritime Organization established the Convention for the Control and Management of Ships' Ballast Water and Sediments which limits organism concentrations at discharge under regulation D-2. Most ships will comply by using on-board treatment systems to disinfect their ballast water. Port state control officers will need simple, rapid methods to detect compliance. Appropriate monitoring methods may be dependent on treatment type, since different treatments will affect organisms by a variety of mechanisms. Many indicative tools have been developed, but must be examined to ensure the measured variable is an appropriate signal for the response of the organisms to the applied treatment. We assessed the abilities of multiple analytic tools to rapidly detect the effects of a ballast water treatment system based on UV disinfection. All devices detected a large decrease in the concentrations of vital organisms ≥50μm and organisms <10μm (mean 82.7–99.7% decrease across devices), but results were more variable for the ≥10 to <50μm size class (mean 9.0–99.9% decrease across devices). Results confirm the necessity to choose tools capable of detecting the damage inflicted on living organisms, as examined herein for UV-C treatment systems.

Deactivating harmful marine microorganisms through photoelectrocatalysis by GO/ZnWO4 electrodes

Photoelectrocatalytic (PEC) technology can be applied to treat ballast water. In this study, graphene oxide/zinc tungstate (GO/ZnWO4) electrodes were prepared to inactivate marine microorganisms. Results showed that microorganisms could be deactivated by GO/ZnWO4 electrodes under ultraviolet light and low-bias voltage. In particular, harmful microorganisms were deactivated by GO/ZnWO4 electrodes at 2V bias in 8min under ultraviolet light irradiation, and this duration was economically half the time of deactivation performed by ZnWO4 electrodes. GO plays a key role in electron and hole separation at a low voltage potential to avoid chlorine production by electrolyzing seawater at a high voltage in PEC. A hybrid heterojunction was also formed between GO and ZnWO4. This heterojunction increased the separation efficiency of electron–hole pairs, eliminated the hydrogen-related defect on the ZnWO4 surface, and improved the inactivation efficiency with a low applied potential. PEC could also elicit a synergistic effect with photocatalytic and electrocatalytic oxidation, which resulted in a high-separation efficiency of electron–hole pairs. This effect could also produce active substances, such as superoxide and hydroxyl radicals, and increase the inactivation efficiency of GO/ZnWO4 electrodes against harmful marine microorganisms. This work demonstrated that PEC is an efficient method to treat ballast water.

The effects of chemical additives on the production of disinfection byproducts and ecotoxicity in simulated ballast water

The management of ship ballast water is essential to stemming the introduction of non-indigenous species. Approval for onboard installation of a system to treat ballast water requires rigorous land-based testing as dictated in the G8 guideline by the International Maritime Organization. However, this testing lacks standardization—most notably augmentation of organic carbon for influent water by adding chemical additives. Electrochlorination is a popular treatment method for ballast water, in which chlorinated oxidants react with organisms and organic matter in water. The additives could thus affect the treatment efficacy of the ballast water. Here, we examined the effects of several candidates of organic carbon additives on the consumption of total residual oxidant (TRO), the production of disinfection byproducts (DBPs), plankton survival, and ecotoxicity. The TRO consumption over five days of storage was higher in electrochlorinated seawater amended with lignin and Metamucil when compared with seawaters with other organic carbon compounds. DBP production varied by almost two orders of magnitude as a function of the various additives. This was largely attributed to the production of tribromomethane and dibromoacetic acid. The survival of Artemia franciscana was significantly different across waters of different organic carbon additives. Algal toxicity testing with the marine haptophyte Isochrysis galbana significantly reduced growth in lignin- and Metamucil-treated seawaters, but not with other organic carbon compounds. Bioluminescence in Vibrio fischeri sharply declined in electrochlorinated seawaters with all types of organic carbon compounds, but no toxicity was manifested once the electrochlorinated seawaters were neutralized with sodium thiosulfate. The varying degrees of outcome suggest that it might be better to eliminate the requirements of adding organic carbon to test water as long as natural water was used for land-based testing of BWMS. If needed, the additives could be used in proportion to the composition of the organic matter in water being tested.

현존선에 전기분해방식 선박평형수 처리장치 설치를 위한 위험도 평가 분석

현존선에 전기분해방식 선박평형수 처리장치 설치를 위한 위험도 평가 분석

Development of the Electrolysis Ballast Water Treatment System and Test

선박의 항해 안전성을 유지하기 위하여 평형수 탱크에 주입ㆍ배출되는 선박평형수는 그 안에 포함되어 있는 각종 수중생물로 인하여 지역 해양 환경에 부정적인 영향을 주고 있다. 국제해사기구(IMO)는 선박평형수를 통한 수중생물의 이동을 막기 위해, 2004년 선박평형수와 침전물 통제 및 관리를 위한 국제협약을 채택하고 2016년 9월에 발효하여, 2017년 9월...

Ships' Ballast Water Treatment by Chlorination Can Generate Toxic Trihalomethanes.

The International Maritime Organization (IMO) will enforce a new abundance-based performance standard for ballast water in September, 2017. Strong oxidants, like chlorine, have been proposed as a method for achieving this standard. However chlorine treatment of ballast water can produce hazardous trihalomethanes. We assessed maximum trihalomethane production from one chlorine dose for three types of ballast water (fresh, brackish and marine) and three levels of total organic carbon (TOC) concentration (natural, filtered, enhanced). While the current standard test considers a 5day voyage, there is a high possibility of shorter trips and sudden change of plans that will release treated waters in the environment. Water source and TOC significantly affected trihalomethane production, with the highest amounts generated in brackish waters and enhanced TOC concentration. The concentration of brominated trihalomethanes increased from background levels and was highest in brackish water, followed by marine and fresh water.

The practicability of ships arriving to the Great Lakes to conduct ballast water exchange plus treatment—Analysis of shipping patterns

Abstract Ballast water exchange (BWE) has historically been the most oft-used approach to manage ballast water with the goal of reducing biological invasions. Henceforth, most ships will exclusively perform ballast water treatment (BWT) to comply with limits on concentrations of living organisms in discharge water, although the combination of BWE and BWT may reduce the risk of invasion more than BWT alone, particularly for ships arriving to freshwater ports, such as those in the North American Great Lakes. Whether the BWE and BWT is practicable rests upon several factors, particularly the time available to perform both operations in the appropriate area and safely during a voyage. We investigated records of ships arriving to U.S. ports from 2004 through 2014 to characterize the frequency and location of BWE. The National Ballast Information Clearinghouse dataset contained information on 872 × 10 3 arrivals in the 11-year span, which is summarized herein. In U.S. ports within the Great Lakes, about 1% of vessels arriving—or 921 arrivals over 11 years—conducted BWE. Most vessels arriving to Great Lakes ports did not discharge ballast water, but of those that did, > 98% of the volume discharged was from coastwise voyages. In ships arriving from overseas, ballast water was held for at least 4 days after BWE. Ships performing BWE while offshore would still need to meet the limits for living organisms in discharged water, which would require BWT while underway doubling the use rate of the shipboard treatment system, but also making some BWE procedures (e.g., flow-through exchange) impracticable.

Prediction and Optimization for Wall-Flow Structure Porous Ceramic Filter on Ballast Water Treatment

In light of urgent requirement of onboard ballast water treatment, a novel wall-flow structure porous ceramic filter (PCF) has been applied with combination of UV light in our laboratory works. According to the strict criteria of International Maritime Organization (IMO) on ballast water treatment, removal efficiencies on indicator planktons should be almost 100% even at high initial densities. However, the treatment efficiencies of PCF may be greatly affected by operational conditions of the system. Hence response surface methodology (RSM) was used to evaluate the significance of the operational factors on algal removal efficiencies. Based on our previous works, flow rate, algal density and algal size were considered as three key conditional factors during PCF treatment. These three individual factors and interactive effects between each two facts were studied statistically by Minitab 15. Also, experimental studies were arranged according to full factorial design of a 6L PCF on simulated ballast water treatment at different flow rates, algal densities and algal sizes. By computational prediction and mathematical analysis, the operational conditions were optimized with first order derivation of predicted model. And by doing so, the utmost optimization was estimated to achieve higher performance of PCF system.

Evonik exits ship-water treatment

Evonik Industries will no longer sell peracetic acid-based ship ballast water treatment chemicals. Its dispensing equipment partner TeamTec is withdrawing from the market too. Long-term storage tests under marine conditions raised doubts about the stability of the chemical, sold as Peraclean Ocean, Evonik says. An international treaty ratified in 2016 requires oceangoing vessels to install systems that prevent invasive species from hitching a ride in their ballast water. Other treatment systems rely on onboard sodium hypochlorite generators and ultraviolet light disinfection.

Solid sand particle addition can enhance the production of resting cysts in dinoflagellates

Resting cysts are an important part of the life cycle for many harmful algal bloom-forming dinoflagellates, and play vital roles in the recurrence and geographical spread of harmful algal blooms. Numerous factors have been suggested to regulate the formation of resting cysts, although only a few have been proven to be significant. Cyst formation can be induced by adverse environmental conditions such as drastic changes in temperature, light, salinity, and nutrient levels, and by biological interactions. In this study, we evaluated the ability of an artificial factor (fine sand particles) to enhance the formation of resting cysts. Fine sand particles were added to cultures of dinoflagellates that are known to produce cysts. The addition of fine sand particles significantly increased both the production rate and final yield of cysts in cultures of Scrippsiella trochoidea, Biecheleria brevisulcata, and Levanderina fissa (=Gymnodinium fissum, Gyrodinium instriatum, Gyrodinium uncatenum). The largest increase in the final yield (107-fold) of cysts as a result of sand addition was in S. trochoidea. However, addition of fine sand particles did not induce cyst formation, or barely affected cyst formation, in Akashiwo sanguinea, Cochlodinium polykrikoides and Pheopolykrikos hartmannii, which are also known to be cyst-producing species. We speculated that addition of sand significantly increased the chances of cell collision, which triggered cyst formation. However, further research is required to test this idea. Importantly, our findings indicate that the addition of fine sand particles is a useful method to obtain a large quantity of cysts in a short time for laboratory studies or tests; for example, if a cyst viability test is being used to assess the effectiveness of ships' ballast water treatment.

Tetraselmis as a challenge organism for validation of ballast water UV systems

Transport and release of waterborne organisms as a result of ballasting and de-ballasting operations is widely acknowledged to represent an important mechanism for invasions by non-indigenous species. Regulatory requirements have been implemented globally to require treatment of ballast water before its release to the environment as a means of minimizing risks of invasion. UV-based processes represent an option for ballast water treatment; however, their use will require development of appropriate methods for reactor validation. To address this need, Tetraselmis was examined as challenge organism using a most probable number (MPN) assay for quantification of the concentration of viable (reproductively active) cells in suspension. A low pressure collimated-beam reactor was used to investigate UV254 dose-response behavior of Tetraselmis. Based on the experimental conditions applied, Tetraselmis indicated 4.5–5 log10 units of inactivation for UV254 doses of approximately 120 mJ/cm2, with no apparent change of resistance resulting from repeated exposure. A medium pressure UV collimated-beam reactor equipped with a series of narrow bandpass optical filters was used to investigate the action spectrum of Tetraselmis for wavelengths ranging from 228 nm–297 nm. Radiation with wavelengths in the range 254–280 nm was observed to be most efficient for inactivation of Tetraselmis. Additionally, DNA was extracted from Tetraselmis to allow measurement of its absorption spectrum. These results indicated strong absorbance from 254 nm to 280 nm, thereby suggesting that damage to DNA plays an important role in the inactivation of Tetraselmis sp. However, deviations of the action spectrum shape from the shape of the DNA absorption spectrum suggest that UV-induced damage to biomolecules other than DNA may contribute to Tetraselmis inactivation at some wavelengths in the UVC range.

Ballast Water Treatment Test at Pilot-Scale Using an Underwater Capillary Discharge Device

We demonstrated a pilot-scaled underwater plasma discharge device for the treatment of ballast water (5 ton/h). Phytoplankton and microorganisms in the ballast water were successfully removed using underwater plasma with capillary electrodes. Microorganisms between 10 and 50 μm in the ballast water were eliminated with an efficiency of 99.9% as well as heterotrophic bacteria with an efficiency of 92.7%.

Laboratory tests on heat treatment of ballast water using engine waste heat

ABSTRACTWaste heat recovery from shipboard machineries could be a potential source for heat treatment of ballast water. Similar to a shipboard schematic arrangement, a laboratory-scale engine-heat exchanger set-up harvesting waste heat from jacket water and exhaust gases was erected to test the level of species’ mortalities. Mortalities were also assessed under experimental conditions for cultured and natural plankton communities at laboratory level. Effect of pump impellers on species’ mortalities were also tested. Exposures between 60°C and 70°C for 60 sec resulted in 80–100% mortalities. Mortalities due to pump impeller effects were observed in the range of 70–100% for zooplankton. On the laboratory-scale arrangement, >95% mortalities of phytoplankton, zooplankton and bacteria were recorded. It was demonstrated that the temperature of tropical sea waters used as secondary coolant can be raised to cause species’ mortalities, employing engine exhaust gases. The results also indicated that pump impeller effects will enhance species’ mortalities. The limitations of the shipboard application of this method would be the large ballast volumes, flow rates and time for treatment.

Efficacy and residual toxicity of a sodium hydroxide based ballast water treatment system for freshwater bulk freighters

Abstract The efficacy and residual toxicity of a sodium hydroxide (NaOH) based ballast water treatment system (BWTS) were tested aboard the Great Lakes carrier M/V American Spirit in 1000 L mesocosms containing water from the ship's ballast tanks. NaOH was added to elevate the pH to 11.5 or 11.7 for 48 h, after which pH was reduced to 96% in pH 11.7 treated discharge water relative to uptake densities. Seven day whole effluent toxicity tests indicated pH 11.7 NaOH BW met the USEPA VGP daily maximum criteria for residual toxicity. Organism densities in uptake water did not meet the minimum densities for IMO G8 shipboard test validity in 2 of 4 trials for organisms ≥ 10 μm to

Ballast water compliance monitoring: A new application for ATP

The coming into force of the USCG ballast water regulations and the IMO ballast water management convention resulted in the development of several technologies approved for the treatment of ballast water. To ensure compliance of these technologies, the development of rapid and robust analysis methods was necessary.In collaboration with the SGS Group (Switzerland) and LuminUltra (Canada), Aqua-tools (France) has developed an innovative Ballast Water Treatment Monitoring (BWTM) kit for rapid onboard testing. The affordable kit provides results in less than 1h, is easy to use and durable ensuring that the ballast water treatment system on the ship is fully compliant with the discharge standards upon arrival in port.The core of this method is a combination of high-quality reagents (lysis solution and ATP 2G Luminase™ enzyme) not inhibited by salinity and a patented fast homogenizing method for ATP extraction developed for a higher ATP recovery from zooplankton and phytoplankton. Compared to traditional analysis methods, the BWTM Kit provides fast and accurate results for all three fractions of microorganisms (≥50μm, ≥10÷<50μm and bacteria). Preliminary tests carried out in cooperation with SGS showed that the proposed method was able to detect onboard the efficiency of the treatment systems used. Compliance limits were established for all size fractions and a correlation between the standard methods (microscopy, plate count, MPN) and ATP was evaluated. The BWTM kit can provide a fast indication of compliance or gross exceedance. The rare borderline cases, when encountered, of course require additional confirmation.

Potential use of an ultrasound antifouling technology as a ballast water treatment system

The aim of this study was to investigate, at a laboratory scale, the potentialities of an ultrasound-based treatment initially designed to eliminate fouling, as a ballast water treatment system. Therefore, early life stages of three different zooplanktonic species (Amphibalanus amphitrite, Brachionus plicatilis and Artemia salina) were exposed to ultrasound waves (20–22kHz). The experimental set up included static assays with variations of time exposure (30s, 60s and 30s on/60s off/30s on), material of tanks (stainless steel, galvanized steel and plastic) and position of the ultrasound source. Results showed that the treatment efficacy increased from 30 to 60s and no differences were registered between 60s-continuous exposure and pulse exposure. The highest efficacy was observed in Experiment I (metal-to-metal contact assay) with a mortality value of 93–95% for B. plicatilis and A. salina. It consisted of organisms located inside stainless steel tubes that were located in direct contact with the ultrasound source and treated for 60s. Further, we found that, generally, A. amphitrite and B. plicatilis were the most resistant species to the ultrasound treatment whereas A. salina was the most sensitive. We further discuss that US may unlikely be used for commercial vessels, but may be used to treat ballast water in smaller ballast tanks as on board of mega yachts.

Algal DNA Repair Kinetics Support Culture-Based Enumeration for Validation of Ultraviolet Disinfection Ballast Water Treatment Systems

To mitigate the potential spread of invasive species and pathogens, the International Maritime Organization and U.S. Coast Guard (USCG) adopted discharge performance standards for ballast water management that will take full effect in 2017. The USCG requires staining methods for enumerating ballast water treatment system (BWTS) efficacy. These stains do not detect DNA damage, the primary mechanism for ultraviolet (UV) disinfection, and neglect potential DNA repair after discharge. These factors necessitate investigation of enumeration methods for accurate validation and approval of UV-based BWTSs. To molecularly assess DNA damage and repair kinetics, UV-induced DNA lesions were quantified by an enzyme-linked immunosorbent assay in Tetraselmis suecica control and UV-treated samples that were cultured and tested over time. Most DNA repair occurred within 6 h, was essentially complete within 24 h, and was insensitive to light or nutrient conditions during incubation. Asymptotic repair kinetics indicated a ma...

Forecasting design and decision paths in ship design using the ship-centric Markov decision process model

This paper introduces a decision-making model for forecasting design and decision paths in ship design by applying eigenvector analysis to the ship-centric Markov decision process (SC-MDP) model. This paper uses the concept of composite reducible Markov processes to identify various independent design absorbing paths. An absorbing path represents the long term behavior of a temporal decision process. This method identifies the set of absorbing paths by decomposing the process into sets of inherently independent parts and thus also gives insight into the structure and relationships of the decision process. This is done by examining the set of principal eigenvectors. Two metrics are introduced. First, the set of principal eigenvectors is used to identify all independent design absorbing paths without the need for full examination of all initial conditions. Second, through the use of the Moore-Penrose pseudo-inverse, the set of principal eigenvectors is used to estimate the optimal life cycle strategy of the decision process. A case study is presented involving life cycle planning for ballast water treatment compliance of a notional container ship to show the utility of these methods and metrics.