Ship Ballast Water Research Articles

Preparation of double-doped Cu, N-nano-TiO2 photocatalyst and photocatalytic inactivation of Escherichia coli in ballast water

With more and more international economic exchanges, ship transport becomes more and more frequent, which further increases the exchange capacity of ship ballast water in different sea areas, thus causing more and more serious marine problems of alien microbial invasion. Therefore, in this paper, on the basis of microbial inactivation of ship ballast water treated by uv irradiation, the influencing factors of its catalytic activity were explored by adding photocatalyst TiO2 into the bacterial suspension, That is to change the catalytic activity of titanium dioxide noble metal and other modified substances and doping amount. Firstly, the UV-sterilization was used as a control, and the modified photocatalyst nano-TiO2 was added. It was found that the sterilization rate increased greatly, indicating that the photocatalyst-modified nano-TiO2 has a very strong reinforcing effect on ultraviolet sterilization. Secondly, the photocatalyst itself was changed. It was found that the amount of photocatalyst nano-TiO2 had a great influence on UV sterilization. Within a certain range, the more the photocatalyst nano-TiO2 is, the better the sterilization effect is. Finally, changing the external conditions of the photocatalyst, it was found that the photocatalyst nano-TiO2 had the best activity at higher temperature (33 °C), alkaline (pH=8.5) or neutral (pH=7.5) and long-wave ultraviolet radiation.

Rapid detection method of ship ballast water biomass based on spectrophotometry

Rapid detection method of ship ballast water biomass based on spectrophotometry

A Microfluidic Prototype System towards Microalgae Cell Separation, Treatment and Viability Characterization.

There are a huge number, and abundant types, of microalgae in the ocean; and most of them have various values in many fields, such as food, medicine, energy, feed, etc. Therefore, how to identify and separation of microalgae cells quickly and effectively is a prerequisite for the microalgae research and utilization. Herein, we propose a microfluidic system that comprised microalgae cell separation, treatment and viability characterization. Specifically, the microfluidic separation function is based on the principle of deterministic lateral displacement (DLD), which can separate various microalgae species rapidly by their different sizes. Moreover, a concentration gradient generator is designed in this system to automatically produce gradient concentrations of chemical reagents to optimize the chemical treatment of samples. Finally, a single photon counter was used to evaluate the viability of treated microalgae based on laser-induced fluorescence from the intracellular chlorophyll of microalgae. To the best of our knowledge, this is the first laboratory prototype system combining DLD separation, concentration gradient generator and chlorophyll fluorescence detection technology for fast analysis and treatment of microalgae using marine samples. This study may inspire other novel applications of micro-analytical devices for utilization of microalgae resources, marine ecological environment protection and ship ballast water management.

Mechanism and influence of removing algae with chlorine dioxide treatment for ship ballast water

This study aims at examining the performance of the ClO2 on treating ballast water of Dalian new port area foreign trade oil pool in the cases of different experimental parameters, and Cylindrospermopsis raciborskii (CR), Gymnodinium catenatum (GC) and Gymnodinium cf. mikimotoi (GCM) are used for this experiment. The results shows that under certain test condition, the removal rates are in proportion to the dosage of ClO2 and reaction time, and inversely proportion to pH value, humic acid and ammonia nitrogen content. Accordingly, on operating at the optimal dosage of ClO2 and parameters of experiment, this process is proven to be an effective technology to remove these three algae and organic compounds in ballast water. In ballast water, the removal ability of ClO2 for these three algae is less sensitive to pH value, humic acid and ammonia nitrogen content than to ClO2 dosage and reaction time. Removing GC, GCM and CR with ClO2 are attributed to the second order reaction. Investigating the performance of such process, could serve to develop management strategies that enable mitigating the impacts of harmful substance in ballast water and help improving and ensuring quality of ballast water.

Технологическое и нормативное обеспечение обезвреживания судовых балластных вод

Технологическое и нормативное обеспечение обезвреживания судовых балластных вод

Phylogeographic characteristics of hypervariable regions in the mitochondrial genome of a cosmopolitan, bloom-forming raphidophyte, Heterosigma akashiwo.

The global distribution of phytoplankton is defined by many events, including long-term evolutionary processes and shorter time span processes (e.g., global climate change). Furthermore, human-assisted, unintentional dispersion, including the transport of live fish and spat for aquaculture, and transfer of aquatic microorganisms contained in ship ballast water, may aid the spread of phytoplankton. To understand the phylogeographic history of a species, the development of useful molecular markers is crucial. We previously reported a hypervariable mitochondrial gene in the cosmopolitan bloom-forming alga, Heterosigma akashiwo. In this study, we identified two additional hypervariable segments in the H.akashiwo mitochondrial genome, one a protein coding sequence, and the other an intergenic region, by comparing the whole mitogenomes of strains obtained from various geographic origins. Interestingly, the newly identified hypervariable protein coding sequence was a paralogue of the previously identified gene, and both sequences showed tendencies to correlate with latitude of geographic origin. However, the hypervariable intergenic sequence did not show a clear correlation with origin. Our results demonstrated that the protein coding sequences may serve as useful tools for understanding the phylogeographic history of H.akashiwo, and they may crucially function in adaptation of the species to the environment.

Operational and environmental factors affecting disinfection byproducts formation in ballast water treatment systems

To prevent the worldwide spread of invasive aquatic species, the ballast water of ships may be disinfected with either physical or chemical treatment systems. Excess chemicals, such as chlorine, are neutralized before the ballast water can be discharged. Unfortunately, disinfection byproducts (DBPs) formed during treatment are not neutralized and remain potentially toxic. In this study, DBPs obtained from land-based tests of seven different ballast water treatment systems (BWTSs) have been statistically analyzed. Effect of operational factors (treatment type, holding time, source of carbon and active substance dosages) and environmental variables (salinity, pH, temperature, organic matter) were related to the formation of DBPs, such as trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs) and aldehydes. THMs and HAAs were the groups with major occurrences and concentrations detected in all BWTSs. Treatment type and source of carbon were the operational factors with major significance on DBP production, especially in chlorination systems. Salinity is the main variable determining DBP composition, as it differs between brominated-DBPs and chlorinated-DBPs. Concentration and type of organic matter (dissolved and particulate) have also a significant influence on the formation of total DBPs. According to the specific group of DBPs, some factors get significance. For instance, THMs are significantly affected by pH, and the production of aldehydes correlates positively with oxidant dose.

An unexpected advantage

Evolutionary Rescue Human activities are altering Earth's environment in many ways. Will other species be able to adapt in the face of rapid change? Adaptation requires genomic variability, but declining populations lose diversity, which casts doubt on adaptation as a survival mechanism in today's world. Oziolor et al. report a case of rapid adaptation to pollution in killifish, apparently enabled by introduction of a non-native congener within the last 30 generations (see the Perspective by Pfennig). This related species, possibly carried in ship ballast water, appears to have provided advantageous genetic variability that has allowed the native fish to adapt to its increasingly polluted environment. Science , this issue p. [455][1]; see also p. [433][2] [1]: /lookup/doi/10.1126/science.aav4155 [2]: /lookup/doi/10.1126/science.aax3713

Adaptive introgression enables evolutionary rescue from extreme environmental pollution.

Radical environmental change that provokes population decline can impose constraints on the sources of genetic variation that may enable evolutionary rescue. Adaptive toxicant resistance has rapidly evolved in Gulf killifish (Fundulus grandis) that occupy polluted habitats. We show that resistance scales with pollution level and negatively correlates with inducibility of aryl hydrocarbon receptor (AHR) signaling. Loci with the strongest signatures of recent selection harbor genes regulating AHR signaling. Two of these loci introgressed recently (18 to 34 generations ago) from Atlantic killifish (F. heteroclitus). One introgressed locus contains a deletion in AHR that confers a large adaptive advantage [selection coefficient (s) = 0.8]. Given the limited migration of killifish, recent adaptive introgression was likely mediated by human-assisted transport. We suggest that interspecies connectivity may be an important source of adaptive variation during extreme environmental change.

Study on the Influence of Galvanic Corrosion on Ship Structural Materials

In order to study the effects of galvanic corrosion on the structural materials of ships, the effects of metal corrosion and ballast tank coating failure on ships are discussed. The electrolytic treatment technology of ship ballast water is one of the mainstream technologies for ship ballast water treatment. The new corrosion system was carefully explored. The galvanic corrosion rate is related to the nature of the material itself, including the corrosion potential, corrosion current, and polarization properties of the metal before coupling. In addition, it is affected by factors such as the area ratio of the cathode and the anode, dissolved oxygen in the seawater environment, temperature, and flow rate. The results showed that the research on the galvanic corrosion behavior of typical structural materials of ships in the marine environment provided economic and effective protection measures for the protection of ship materials. Therefore, this method is of great theoretical and practical significance for the protection of metal structural materials in other industries.

First record of the fiddler crab Leptuca ([formula omitted]Uca) uruguayensis in the Bahía Blanca Estuary (Buenos Aires, Argentina) with comments on its biology in South America

The occurrence of the fiddler crab Leptuca (=Uca) uruguayensis (Brachyura: Ocypodidae) in the Bahía Blanca Estuary (Buenos Aires, Argentina) is reported for the first time. The organisms had a small patchy distribution with high densities in an environment with silty-sandy sediments and low organic matter content, near the population of the dominant varunid crab Neohelice granulata. The presence of this species suggests that larvae of L. uruguayenesis may have been introduced into the estuary via the ballast water of ships. The field sampling was extended to other sites closer to this harbour to assess if the species was inhabiting other places within the estuary, but with no results. Within this framework, the monitoring of this population is fully recommended; moreover, it is necessary to keep monitoring other sites in order to assess if this species could settle in other places in the future.

Methods of decontamination of ship ballast water with polyguanidine disinfectant

Methods of decontamination of ship ballast water with polyguanidine disinfectant

The Efficiency of Application of UV + VUV Radiation for Preventing Unicellular Invasions Transported with Ballast Waters of Ships

The results of an experiment on modeling the neutralization of ship ballast waters (BWs) contaminated with unicellular halophilic alga Dunaliella terricola using the radiation of a low-pressure mercury arc lamp with wavelengths of 254 and 185 nm are presented. The experiment models the filling of the BW tank with seawater contaminated with D. terricola using a ballast water decontamination unit, followed by the storage of the water in the BW tank for 5 days, thereby simulating ship navigation, and BW discharge at the port of arrival through the unit. Contaminated BW was neutralized according to the technology of advanced oxidative processes (AOPs) using ozone and hydrogen peroxide which were generated in the water by radiation of a 185 nm line. It is experimentally established that the proposed method of treating model ballast water stops the reproduction of a test object. The conducted research shows prospects of application of UV + VUV (ultraviolet + vacuum ultraviolet) radiation for preventing the transfer of alien unicellular organisms by BWs and their invasions into local biocenoses.

Economic viability of treating ballast water of ships by ultrafiltration as a function of the process position

Ballast water is fresh or seawater taken onboard to stabilize a ship. By traveling with the vessels, different species can be introduced into a new area with potentially high impact on health, economy, and environment. Some conventional treatments may reach their limit because of the high variability of water quality found worldwide: for example, UV treatments efficiency can be low for highly turbid water. Currently, 30% of ballast water treatment uses UV, while 45% use a chlorine generation process. Membrane filtration could be a promising alternative, or complementary treatment. An efficient ballast water management system is required to discharge treated water into the environment. The aim of this paper is to compare, from an economic perspective, ultrafiltration with UV treatments applied to fresh and seawater. This comparison takes into account the location of the treatment, and the specific challenges associated with each location. This modeling, based on feedback from various ship-owners, includes ballast water discharge flow, as well as ballast loading and discharge times. These operations stop the ship and increase its annual down time. Several scenarios of ballast water treatment were studied following the various condition: during ballast loading or ballast water discharge; on-board processing with batch treatment; barge-based processing with semi-continuous treatment, or with continuous treatment to ballast several ships per day; with or without UV post-treatment. The on-board ultrafiltration installation does not appear economically viable, whereas the barge-based installation is very competitive and retains better suspended matter and organisms.

Dielectrophoretic separation of microalgae cells in ballast water in a microfluidic chip.

The composition of the ship's ballast water is complex and contains a large number of microalgae cells, bacteria, microplastics, and other microparticles. To increase the accuracy and efficiency of detection of the microalgae cells in ballast water, a new microfluidic chip for continuous separation of microalgae cells based on alternating current dielectrophoresis was proposed. In this microfluidic chip, one piece of 3-dimensional electrode is embedded on one side and eight discrete electrodes are arranged on the other side of the microchannel. An insulated triangular structure between electrodes is designed for increasing the inhomogeneity of the electric field distribution and enhancing the dielectrophoresis (DEP) force. A sheath flow is designed to focus the microparticles near the electrode, so as to increase the suffered DEP force and improve separation efficiency. To demonstrate the performance of the microfluidic separation chip, we developed two species of microalgae cells (Platymonas and Closterium) and a kind of microplastics to be used as test samples. Analyses of the related parameters and separation experiments by our designed microfluidic chip were then conducted. The results show that the presented method can separate the microalgae cells from the mixture efficiently, and this is the first time to separate two or more species of microalgae cells in a microfluidic chip by using negative and positive DEP force simultaneously, and moreover it has some advantages including simple operation, high efficiency, low cost, and small size and has great potential in on-site pretreatment of ballast water.

Challenges in Managing Marine Bio-invasions via Shipping in Singapore

The economic, social and environmental impacts arising from the transfer and establishment of non indigenous marine species (NIMS) mediated through ship hull biofouling and ballast water discharges in the coastal marine environment require a regional approach to manage bio-invasions. As the coordinating body for maritime shipping affairs and protection of the marine environment, the International Maritime Organization (IMO) has been working with member states to adopt and ratify global conventions aimed at preventing invasive species transfer through shipping. As a major shipping hub and port-of-call in Southeast Asia, Singapore faces multiple challenges in managing marine bio-invasions including managing the transit of high risk vessels to environmentally sensitive areas beyond national borders. In this article, global frameworks for managing bio-invasions and its challenges for marine invasive pest management are discussed.

Application of Fluorescence in situ hybridization-Flow cytometry (FISH-FCM) technique to detect and quantify Vibrio cholerae population from different geographic regions

Rapid and species-specific detection, and quantification of pathogenic bacteria are fundamental for monitoring and assessment of the risk they pose to any ecosystem. The study employed Vibrio cholerae, a human pathogen responsible for the life-threatening diarrhoeal disease, cholera and one among the most unwanted from marine bioinvasion point of view. The present study coupled fluorescence in situ hybridization (FISH) technique, a powerful tool in molecular phylogenetic discrimination, with flow cytometry (FCM), a technique used for rapid and accurate quantification of both viable but non-cultivable and non-viable microorganisms. The FISH-FCM technique was used for the first time to quantify V. cholerae (includes cultivable and non-cultivable) from different geographic regions of Southeast Asia (Brunei, Indonesia, Lao PDR, Myanmar, Philippines, Singapore, Thailand, Vietnam) and India (Goa, west coast of India). The data acquired from the analyses provides a snap shot view of the total bacterial abundance with special reference to V. cholerae. As the method developed, it was evaluated with bacterial samples collected from different sites in Southeast Asia and India, and the application of this technique to different geographical regions appears feasible. Considering that the continuous growth of the shipping industry and ballast water as one of the primary vectors responsible for the global transport of pathogenic microorganisms, the risk they present needs immediate attention. This technique will be useful in the quick and accurate detection of specific pathogens. It may also provide significant insights to quarantine measures for Ballast Water Management.

Potential application of SMART II for Vibrio cholerae O1 and O139 detection in ship's ballast water

Ballast water is used to safely stabilize and operate shipping vessels worldwide, in a multitude of aquatic settings, including inland, coastal and open oceans. However, ballast water may pose ecological, public health, and/or economic problems as it may serve as vehicles of transmission of microorganisms. Current ballast water regulations include limits of Escherichia coli, Enterococcus spp. and toxigenic Vibrio cholerae. Several United States Environmental Protection Agency approved standard operating protocols (SOPs) exist for detection of E. coli and Enterococci, yet none exists for V. cholerae. Current V. cholerae detection methods include colony blot hybridization, direct fluorescent antibody test (DFA), and/or polymerase chain reaction (PCR), which can be time consuming and difficult to perform. This study utilizes Cholera SMART II to determine its potential use in detection of V. cholerae. Validation of this method would help provide quick and accurate analysis for V. cholerae in ballast discharge waters in the field.

An Examination of the Validity of MRPS Method for the Detection of Label-free E. Coli and Enterococci in Ships Ballast Water

To test for compliance with the D-2 standard for ballast water management convention of the International Maritime Organization, the bacteriological quality of ship’s ballast water is determined to evaluate the risk of invasion of non-indigenous species both onboard ship and in Port. In this article, hydrodynamic flow focusing particles viewed through a microfluidic resistive pulse sensor (MRPS) was used to detect the pathogenic bacteria from ship’s ballast water. Escherichia coli and Enterococci were addressed as bacterial indicators to determine of their characteristic and concentration. The system provided the individual particle-by-particle readout in rather large 20 μm x 10 μm x 8 μm (length x width x height) horizontal rectangular microchannel duct. The average volume flow rate was 4.5 μl/min. However, it returned online and real time results for a complete of 30 μl sample volume during 15 min. The system was low maintenance, high in sensitivity, good accuracy and reliable. Targeted bacteria needed neither labelling nor extracting DNA.

선박평형수 처리장치의 스크린 필터 성능 최적화 연구

선박평형수는 선박 운항 시 복원성 또는 균형 유지를 위해 사용된다. 장거리 선박의 선박 평형수는 해양 생태계 교란으로 인한 해양 오염의 주요 원인이다. 스크린 필터는 수처리 시스템의 전처리로 고형물을 제거하는 데 사용된다. 스크린 필터는 반영구적으로 사용하기 위해 역세정 메커니즘이 요구된다. 즉, 스크린 필터는 세정 시간은 길어야 하며, 역 세정 횟수와 시간은 최소화하도록 설계되어야한다. 따라서 본 연구에서는 수직 방향 스크린 필터의 반경 변화와 하우징의 반경 변화에 대한 유동 특성을 분석하였다. 결과적으로, 하우징 각도가 출구 측으로 갈수록 좁아지고, 필터 각도는 넓어지는 인자를 조합한 모델이 여과 및 역세척 효율이 높게 나타났다.