Ballast Tanks Research Articles

Ballast Water Treatment with Heat Exchanger Modeling Simulation

Pollution of the marine environment has become a global issue, including marine pollution from ballast water. The impact is it can damage ecosystems and even affect humans. Therefore, pollution from ballast water is something that must be prevented by ballast water treatment. In this research, the author carried out a modeling simulation on a heat exchanger with a mechanical-type ballast water treatment method by utilizing the heat generated by the ship’s engine. Heat is used to kill microorganisms. So that the ballast water becomes cleaner than without treatment. In this research, the calculation of the need for heat exchangers on certain types of ships with certain sizes is carried out. In this calculation, the ship used is a container type with 3 categories based on cargo capacity and ballast tank capacity. Then the heat from the exhaust gases is used to heat the ballast water of the ship. The simulation results show that the maximum ballast water temperature of each ship category is in the range of 68-75 C. With this temperature, it is sufficient to kill and reduce microorganisms in the ballast water.

Radio-Controlled Submarine using a Water Bottle with an Integrated Camera

Abstract: We aim to make a wireless remote-control model of a submarine whose motion can be controlled from outside of the water with the help of a transmitter and receiver. Today, RC (radio-controlled) submarines can be used for underwater surveillance. The project is cost-optimized and uses readily available parts. The most important thing in an RC submarine is the control system and waterproofing of the electronic components. The key components of the control circuit are the ESC, radio control module, and propeller motor. Direction control uses servo motors to navigate the surface unit. The ballast tank is a PVC water bottle of cylindrical shape. Building a control system for the ballast system is a major challenge for this project. Circuits are sensitive and prone to interference. The submarine can be controlled with a remote control, and an onboard wireless camera can broadcast underwater scenes.

Modification of Ballast Filtering Device on John Lie Training Ship to Prevent Marine Pollution

This study aims to present appropriate selection methods for evaluation, analysis, and comparison between different ballast water treatment technology systems in order to make good decisions in selecting the most optimal treatment system. This research designed a ballast water filter device on the John Lie training ship to prevent marine pollution due to species movement through the ballast water transfer process by referring to the D2 standard of the IMO Ballast Water Management Convention. During the ballasting process, ballast water contains thousands of species of marine animals and plants that are carried in ballast tanks, causing problems for the marine environment and human health. The modification of the filtration tool designed by the researcher used a 0,1 mm and 0,01 mm net tied to the ballast tank inlet pipe using a clamp on the ballast pipe of the John Lie training ship. This can fully be used during the process of filling ballast water from port seawater to enter the ballast tank through this filtration system. The results shown after passing the filter with a total plate count of 36 microorganisms indicate that the filtration system designed by the researcher can meet the D2 standard of the IMO BWM Convention Regulation.

An Improved Emergency Blow Theoretical Model for Naval Submarine Blowing System and Experimental Verification

_ An improved emergency blow model is proposed, which is based on the traditional emergency blow model and takes into account the influence of compressed air overflows from flood holes in the later stage of blowing. In order to verify the prediction accuracy of the improved emergency blow model for tank blowing, the full-scale model experiment of tank blowing was conducted to investigate the effects of air source volume, air source initial pressure, and flood holes diameters on blowing. The process of air release from bottle and main ballast tank drainage can be accurately simulated by the improved emergency blow model, and the prediction error of tank air peak pressure is shown to be <10%. Additionally, it is found that the air source volume has no effect on the tank’s air peak pressure or tank drainage rate. By analyzing the dynamic characteristics of tank air pressure, it is found that the dynamic change trend of air pressure differs between flood holes with small and large diameters. In the small diameter conditions, the air pressure reaches the maximum when the compressed air just enters the tank; however, under large diameter conditions, the peak pressure comes before the accumulated air pressure is released. The experiment and simulation demonstrate that increasing the area of the flood holes has a decreasing effect on the amount of air accumulated in the tank, and that the decreasing effect becomes more pronounced as the air source initial pressure increases. Introduction To carry out military operations, submarines are deployed both underwater and close to the open surface. About 170 submarines have sunk since they were originally created as a result of an accident, such as a fire, explosion, malfunction, grounding, or collision (Park & Kim 2017). Submarines run the risk of losing safety control in these critical situations. The best method of self-rescue is emergency floating to the surface to prevent bottoming or going deeper than allowed (Liu et al. 2009). A key factor in emergency rising to the water’s surface is the compressed air blowing mechanism. In such an operation, supplying air to the main ballast tank and blowing out ballast water should be used to achieve positive buoyancy or recover a positive pitching moment, which can be used to restore the safe depth of the submarine. Emergency blow is the term used to describe the process of directly supplying air to the main ballast tank without using a high-pressure valve column. The emergency blow is explored in this work because its influence is significantly greater than that of usual blowing, or traditional blowing.

Assessing the effectiveness of filtration + UV-C radiation for the treatment of simulated ballast water at various holding times.

In recent years, the issue of invasive alien species brought on by ballast water has drawn increasing attention, and advances in ballast water treatment technologies have been made. One of the most popular combined ballast water treatment technologies utilized in ballast water management systems (BWMSs) globally is filtration + UV-C radiation. During the actual voyage of the ship, ballast water is treated by the BWMS and then enters the dark ballast tanks until the ballast water is discharged. Marine organisms are able to complete DNA damage caused by UV radiation in dark ballast tanks. Therefore, the length of holding time affects the effectiveness of the BWMS in treating ballast water. The objective of this study was to examine the efficacy of filtration + UV-C irradiation treatment at different holding times for the removal or inactivation of phytoplankton and zooplankton populations during simulated ballast water treatment. Results indicate that the holding time after the filtration + UV-C radiation treatment increased the inactivating efficacy, especially for zooplankton in natural seawater. For phytoplanktons in ballast water, the strongest impact on the treatment efficacy was reached with a holding time of 24 h.

Impact of Red Sludge Dumps, Originating from Industrial Activity, on the Soil and Underground Water

In the aluminum industry, one of the most sensitive economic and environmental problems is the management of resulting waste such as slag, ash and sludge, which become potential sources of pollution. Red sludge, which results from the aluminum industry, is a mixture made up of different forms of iron and aluminum oxides, sodium and aluminum silicates, various titanium compounds, constituted in the residue left after the alkaline solubilization of alumina. The Purpose of this research is to quantify the environmental aspects involved in the storage of sludge in a landfill that has an area of 381,189 square meters and is located in the hearth of a former ballast tank in the western industrial area of the town of Oradea, Romania. The objective of the research was to determine the impact of red sludge dumps, which originated from industrial activity, on the soil and groundwater. The degree of degradation of the soil cover was highlighted by analyzing a number of 12 soil samples (4 collection points, at 3 depths). A total of 14 samples (7 samples on 2 depths) were investigated to monitor the migration mode of the sludge in the structure of the dam. In order to monitor the quality of groundwater, samples from 3 observation boreholes were analyzed. Soil monitoring results did not indicate values of the analyzed parameters above the values imposed by the national legislation on soil quality. Since the dumps were not waterproofed, the quality parameters of the water from the observation boreholes were exceeded, and gravity caused the water to drain into the underground water network in the area. Based on the samples from the observation boreholes, several measurements exceeded allowable values: pH values of the water sample taken from upstream of the dump exceeded the value limits by about 7%, and both upstream and downstream, water samples indicate an excess of 13.60% in the aluminum indicator, 267% in the sulfate ion, and 417% in the sodium ion. This shows a risk of pollution which requires additional monitoring.

Statistical Approaches to Optimize the System to Reduce Sediment Accumulation in Ballast Tanks

Deneysel çalışmalar mühendislik alanında sistem ve yapıların tasarımı, optimizasyonu, tasarımın iyileştirilmesi faaliyetlerinin vazgeçilmez ögelerindendir. Ancak özellikle birden çok faktörün performans ölçümleri üzerindeki etkisinin değerlendirilmesi amacıyla yapılan deneysel çalışmalarda elde edilen bulguların işaret ettiği sonuçlar, istatistiksel olarak anlamlı bir şekilde yorumlanamayabilir. Buna ek olarak, kaynakların (zaman, iş gücü ve maddi kaynaklar vb.) kısıtlı oluşu ise deneysel çalışmaların en önemli sınırlılıkları arasında yer almaktadır. Bu çalışmada, gemilerin balast tanklarında sediman birikimini azaltmak için geliştirilen pnömatik sistemin çalışma koşullarını belirleyen üç temel faktör ele alınmış ve bu faktörlerin sedimanın azaltılmasına etkisi istatistiksel açıdan irdelenmiştir. Çalışma kapsamında uygulanan klasik istatistiksel yaklaşımlarla, deneysel veriler istenilen düzeyde anlamlı bir şekilde yorumlanamamıştır. Bu nedenle deney setinden elde edilen veri kümesindeki ilişkileri istatistiksel bir model üzerinden yorumlamak yerine doğrudan veri üzerinden değişkenler arasındaki ilişkinin ortaya çıkarılması değerlendirilmiştir. Bunun için her ne kadar veri kümesindeki veri sayısı sınırlı olsa da Yapay Sinir Ağları (YSA) yaklaşımı uygulanmıştır. YSA girdi setinde veri sayısı bu yaklaşımın doğruluk ölçüsü (accuracy) üzerinde büyük bir öneme sahiptir. Söz konusu deneysel çalışmada veri setinin sonsuz sayıya çıkarılması teorik olarak mümkün olsa da kaynak kısıtları nedeniyle bunun gerçekleştirilmesi uygulanabilir değildir. Bu nedenle YSA modeli oluşturulurken deneysel çalışmanın amacı dikkate alınmış ve farklı bir yaklaşım uygulanmıştır. Deney verisinin bir kısmı YSA modelinin eğitim aşamasında kullanılmış, YSA modelinin optimum bir çalışma koşulu önermesi sağlanmıştır. YSA eğitim aşamasına dahil edilmemiş olan deneysel sonuçlar ise model tarafından önerilen optimum çalışma koşulunun deneysel olarak karşılaştırılmasında kullanılmıştır. Söz konusu çalışmada YSA optimizasyon için bir araç olarak kullanılmış ve model tarafından önerilen optimum çalışma koşulu, tüm deney verileri arasında sediman birikimini azaltılması açısından en uygun sonucu vermiştir. Bu çalışmada, gemilerin balast tanklarında sediman birikimini azaltmak için geliştirilen sistemin işletme parametresinin optimizasyonu için yapılan deneysel çalışma sonuçlarının istatistiksel olarak yorumlanmasında yaşanan sorunlar ve YSA kullanılırken uygulanan yaklaşıma yer verilmiştir.

A Study on Design Investigation Method for Drainage Plan in Ship’s Ballast Tanks by Hydraulic Model Experiment

A Study on Design Investigation Method for Drainage Plan in Ship’s Ballast Tanks by Hydraulic Model Experiment

Ballast Water Problem: Current Status and Expected Challenges

Transporting non-native species in ballast tanks has been a major challenge over the years. The number of surviving species in the host environment is quite small compared to those of all introduced. However, even a single species can cause great harm to the environment, economy, and public health. Ballast water treatment issues are difficult and complex as the performance of the treatment is highly affected by the variable characteristics of the seawater. In addition, targeted organisms are in a wide spectrum. The International Convention on the Control and Management of Ship Ballast Water and Sediments requires ships to manage ballast water with a Type Approved System in compliance with the Ballast water discharge standard defined in the Convention. The Ballast Water Management Systems Approval (G8) Guide was revised in 2016 and accepted as the BWMS Code (Ballast Water Management Systems Approval Code) as the mandatory regime in 2018. According to the implementation schedule of this mandatory approval regime, the ballast water management system installed on or after 28 October 2020 must be type-approved according to the IMO’s revised G8 requirements. Several systems use different methods with their limitations. However, the ballast water problem does not seem to end only with the installation of the systems on ships. Although substantial international progress has been made in ballast water management (both technically and regulatory), there are still several issues regarding effectiveness, compliance monitoring, and the environment.

Operation cost analysis of UV-based ballast water treatment system used on a bulk carrier ship

According to IMO rules, when a new machine system needs to be integrated into the ship, it is required to have low fuel consumption in terms of energy efficiency and emissions. The same is true for ballast treatment. Many different types of ballast water treatment systems (BWTS) are available on the marine market. Ship operators want to choose BWTS that will consume minimum fuel and operate at maximum efficiency. Therefore, in this study, fuel consumption under both IMO and USCG conditions, and hence the operational cost, is calculated if the UV-based BWTS system is integrated into a bulk carrier ship. As a result, the highest cost is $9773 when the most expensive fuel, MGO, is used and operation is performed with a single ballast pump. In USCG mode, the minimum cost is $6382 and the maximum cost is $18929 under the same conditions. It is seen that if the fuel price increases to 1.4 $/kg, the cost of using BWTS in IMO mode can increase to $11392, and if it drops to 0.3 $/kg, the cost of using BWTS in IMO mode can decrease to $1826. It is seen that the highest cost can go up to $22066 and the lowest cost can go down to $3983, with the change of fuel prices in the use of BWTS in USCG mode. With the resulting formulation, with the power consumption of the BWTS and the diesel generator shop trail test fuel consumption values, researchers or shipping companies can repeat the calculations for all kinds of different fuels and different amounts of ultraviolet (UV) chambers for variable ballast operations with different ballast tank capacities. Consequently, it is thought that this study is useful in determining the additional operational cost of UV-based BWTSs.

IDENTIFICATION OF VIBRIO CHOLERAE IN THE PORT OF THE CITY OF RIO DE JANEIRO: A CONTRIBUTION TO THE PROBLEM OF BALLAST WATER AND THE POSSIBLE INTERACTION WITH HUMAN HEALTH

Cholera, caused by Vibrio cholerae O1 and O139, has high incidences in regions with neglected populations, especially in terms of sanitation. V. cholerae can be transported by ship ballast water which makes it a D2 standard evaluation bioindicator for the International Convention for the Control and Management of Ship´s Ballast Water and Sediments. The objective of this is to identify the presence of the organism in the port area of the City of Rio de Janeiro (Brazil), in samples of surface water and ballast tanks, contributing to the analysis of the ballasting process and its interactivity with human health. In superficial and vessel sampling campaigns, the non-toxic form of the organism was detected. The conclusive facts suggest the vulnerability of the area, methodological elaboration for the selection of ships to be sampled, incentives for installation, inspection of the D2 standard and constant monitoring of port waters and vessels, aiming to prevent possible cholera outbreaks caused by the ballast of the modal maritime in region.

손상 선박 기름 유출량 추정을 위한 수치해석과 이론식의 비교 연구

This paper provides the results of numerical and theoretical predictions of oil outflows from damaged single-hull and double-hull ships.Theoretical equations derived from the unsteady Bernoulli equation and a CFD method for multi-phase flow analysis were used to estimate the oil outflow rate from cargo tank. The predicted oil outflow rate from a single-hull cargo tank damaged due to grounding and collision accidents showed a good agreement with the available experimental results in both numerical and theoretical analyses. However, in the case of the double-hull conditions, the time variation of the amount of water and oil mixture inside the ballast tank predicted by the theoretical equation showed some different behavior from the numerical results. The reason was that the interaction of the oil flow with the water inflow in the ballast tank was not reflected in the theoretical equations. In the problems of the initial pressure condition in the cargo and ballast tanks, the oil outflow and water inflow were delayed at the pressure condition that the tanks were sealed. When the flow interaction between the oil and water in the ballast tank was less complicated, the theoretical and the numerical results showed a good agreement with each other.

The prevalence of potential pathogens in ballast water and sediments of oceangoing vessels and implications for management

Ballast water and sediments can serve as prominent vectors for the widespread dispersal of pathogens between geographically distant areas. However, information regarding the diversity and distribution of the bacterial pathogens in ballast water and sediments is highly limited. In this study, using high-throughput sequencing and quantitative PCR, we investigated the composition and abundance of potential pathogens, and their associations with indicator microorganisms. We accordingly detected 48 potential bacterial pathogens in the assessed ballast water and sediments, among which there were significant differences in the compositions and abundances of pathogenic bacterial communities characterizing ballast water and sediments. Rhodococcus erythropolis, Bacteroides vulgatus, and Vibrio campbellii were identified as predominant pathogens in ballast water, whereas Pseudomonas stutzeri, Mycobacterium paragordonae, and Bacillus anthracis predominated in ballast sediments. Bacteroidetes, Vibrio alginolyticus, Vibrio parahaemolyticus, and Escherichia coli were generally detected with median values of 8.54 × 103−1.22 × 107 gene copies (GC)/100 mL and 1.16 × 107−3.97 × 109 GC/100 g in ballast water and sediments, respectively. Notably, the concentrations of Shigella sp., Staphylococcus aureus, and V. alginolyticus were significantly higher in ballast sediments than in the water. In addition, our findings tend to confirm that the indicator species specified by the International Maritime Organization (IMO) might underestimate the pathogen risk in the ballast water and sediments, as these bacteria were unable to predict some potential pathogens assessed in this study. In summary, this study provides a comprehensive insight into the spectrum of the potential pathogens that transferred by ship ballast tanks and emphasizes the need for the implementation of IMO convention on ballast sediment management.

Sequential matching optimization for lifting trajectory and ballast water allocation of the intelligent revolving floating crane

Revolving floating crane (RFC) is one of the core equipment applied to major offshore lifting operations due to its strong working ability. Its operation safety is directly determined by the collaborative matching between the lifting trajectory and the ballast water allocation. However, such matches are accomplished manually in the actual operations, leading to low efficiency, high energy consumption, etc. To address these problems, the unattended intelligent operation mode is an inevitable solution for the RFC. Therefore, a novel sequential matching optimization (SMO) method for the lifting trajectory and the ballast water allocation of the RFC is proposed in this study. The SMO method is proposed based on the point to point (PTP) method and the corresponding principles are firstly explained in great detail. Then, the SMO model is established for searching the optimal scheme with the lowest energy consumption of the lifting and ballast systems. Furthermore, to explore the corresponding superiority, the proposed SMO method is compared with the conventional method, finding that the proposed SMO method can perfectly achieve better lifting performances. Finally, numerical experiments regarding different lifting positions, crane loads, and quantities of the ballast tanks are performed to verify the feasibility of the SMO method.

Biofilms as potential reservoirs of stony coral tissue loss disease

Since 2014, corals throughout Florida’s Coral Reef have been plagued by an epizootic of unknown etiology, colloquially termed stony coral tissue loss disease (SCTLD). Although in Florida the movement of this waterborne coral disease has been consistent with natural transport via water currents, outbreaks in the Caribbean have been more sporadic, with infections occurring in locations inconsistent with spread via natural means. Often Caribbean outbreaks have been clustered near ports, potentially implicating ships as mediators of SCTLD into new regions. Biofilms attached to ship hulls, ballast tank walls, or other surfaces could represent a possible vector for the disease. We investigated whether bacteria shed by healthy and SCTLD-diseased corals would form distinct biofilms, and whether a SCTLD signal would be detectable within biofilm bacterial communities. Stainless steel plates serving as proxies for ship hulls, ballast tank walls, and other colonizable surfaces were incubated for three days in filtered seawater mesocosms containing healthy or SCTLD-infected corals. Resulting biofilm bacterial communities were characterized through sequencing of the V4 region of the 16S rRNA gene. We determined that bacteria shed by healthy and diseased corals formed significantly different biofilms consisting of highly diverse taxa. Comparison with 16S data from previous SCTLD investigations spanning different coral species, collection locations, years, and source material revealed the presence of numerous genetically identical sequences within the biofilm bacterial communities formed during exposure to SCTLD-infected corals, including several previously identified as possible SCTLD bioindicators. These results suggest ship-associated biofilms may have the potential to be vectors for the transmission of SCTLD into new regions.

Optimization method and experimental research on attitude adjustment scheme of attitude adaptive rescue robot

To improve the space attitude adjustment efficiency of the robot designed in this study, the average water level height variation of each ballast tank during the rescue process and the ballast water filling mass before the rescue process are taken as optimization variables, the minimal ballasting time during rescue process as the optimisation objective, and the heel and trim inclination angle, and stability in the rescue process as the constraint conditions. For the first time, an optimization method of a rescue robot space attitude adjustment scheme based on a dynamic programming algorithm is proposed. Relevant experiments and data collection were carried out with a model robot with a physical ratio of 1:2. MATLAB simulation and model robot experimental results show that compared with an empirical scheme, the total deployment time and ballast water total allocation mass are reduced by 11.07% and 30.79%, respectively, and the heel and trim angle variation stability is increased by 4.18% and 8.67%, respectively. The optimization model and algorithm are beneficial to improve the space attitude adjustment efficiency and stability of the rescue robot in this paper, and it is also easier to transfer to other fields of ballast water allocation, which has strong practical engineering significance.

Analysis Of The Placement And Needs Of General Cargo Ship Tanks With DWT 3650 Tons

The double bottom can enhance the ship's safety and a ballast tank. If the ship crashes into a rock and the outer bottom plate is torn, the watertight top tank will limit/protect the cargo from damage caused by water. The tank is a cargo storage container and is the central part of the liquid and gas transport vessel so that the cargo is maintained and safe. As a storage medium, the tank will always get a load from inside or outside the tank—calculating tank requirements using Simpson's approach. From the calculation results obtained fuel tank obtained 68,354 m3, and the diesel oil tank obtained 14,758 m3. The lubricating oil tank obtained 17,566 m3. The freshwater tank obtained 72,815 m3, and the Ballast tank obtained 356,098 m3.

Bacterial communities in ballast tanks of cargo vessels - Shaped by salinity, treatment and the point of origin of the water but “hatch” its typical microbiome

Ballast water is a main vector of introduction of potentially harmful or pathogenic aquatic organisms. The development of genetic tools for ballast water monitoring has been underway and highlighted as a source for accurate and reliable data for decision making. We used 16S rRNA gene amplicon sequencing to analyze the microbial communities found in the ballast water of fifteen commercial ships routed through two Estonian ports. In parallel, samples from the port area were collected at the same time each ship visited. Fluorescence microscopy was utilized to assess the effectiveness of the treatment applied to ballast water. In addition, supplemental samples were collected from Hamburg Port (Germany) and a ballast tank decontamination system used at this port. The composition and diversity of bacterial communities varied greatly between obtained samples. The application of UV treatment did not demonstrate significant reduction in species richness estimates. The composition of microbial communities was significantly influenced by salinity, treatment (mainly untreated or UV treated) and the point of origin of the ballast water. Over a hundred potentially pathogenic bacterial taxa were found in relatively high abundance, including in ballast water that had received UV treatment. These shortcomings of stand-alone UV treatment of ballast water, especially when weak treatment is applied insufficiently, highlight the danger of possible harmful effects arising over time and the need for genetic tools for ballast water monitoring and management.

Ballast Water Dynamic Allocation Optimization for Revolving Floating Cranes Based on a Hybrid Algorithm of Fuzzy-Particle Swarm Optimization with Domain Knowledge

Ballast systems and ballast water dynamic allocation between ballast tanks are very important for ensuring the offshore operation efficiency and safety of the revolving floating crane (RFC). Its modeling and solving have multiple difficulties such as modeling complexity, solving complexity and engineering practicability. Early studies showed that domain knowledge is of great significance for the optimization of the design quality and innovation of such complex engineering issues. By analyzing the coupled operation process characteristics among the floating crane, ship hull and ballast system, a ballast water allocation optimization model based on dynamic programming strategy is established. The domain knowledge of ship ballasting is extracted, and a domain knowledge base of expert experience rules for the ballast water allocation is established. A Fuzzy-Particle Swarm Optimization (FPSO) algorithm is given to obtain the optimal allocation scheme, which uses fuzzy logic inference to process domain knowledge and improve the solving quality. Three different cases are given to illustrate the validity of the proposed model and algorithm by comparing it with other algorithms. The analysis results show that the established optimization method can effectively improve the operation efficiency and reduce the calculation time and the number of ballast tanks involved in allocation, which makes the optimal scheme more suitable for engineering applications.

Evaluation of the Corrosion Depth of Double Bottom Longitudinal Girder on Aging Bulk Carriers

The longitudinal girder (LG) between fuel oil tanks (FOT) and water ballast tanks in the double bottoms of ships represent critical structural parts whose watertight nature could be harmed by corrosion, thus, causing the pollution of water ballast tanks and adjacent areas. The new common structural rules (CSR) define the minimum thickness values of structural elements and corrosion margins. The assessment of the deviations from the prescribed values during ship operation could optimize the prescribed criteria. Assuming that corrosive processes begin after four years of operation, the paper analyzes a linear model that describes the percentage of plate wear as a function of the built-in thickness of LG of FOT. The research included 20 ships and provided the database for 1918 corrosion depth values. The gauging records included the average values of the original thickness of steel plates grouped in three intervals (11–13 mm, 13–15 mm, 15–18 mm). Based on the difference between the built-in and subsequently measured values, the paper analyzes the percentage of thickness reduction due to corrosion, concerning the original plate thickness. The findings of the research should facilitate the optimization of corrosion margins and prevent potential structural collapse and pollution.