**1. Introduction**

Shipping has a vital role in developing human society over the years, at which the shipping activities have linked the widely separated parts of the world through commercial relationships. In fact, the shipping industry is still developing from time to time with rapid industrial and digital economy growth. In Canada, the shipping industry has been established since 1840 and now undergone significant technological advances, where the size of ships that carry containers for international use continues to increase [1]. Even in Malaysia, the government has launched an initiative, namely, Malaysia Shipping Master Plan, that ensures the shipping industry is focused on developing itself and has a guide for future development. This initiative takes place from 2017 until 2022 with a "Revitalizing Shipping for a Stronger Economy" theme [2].

Generally, there are three main classifications for the global cargo shipping industry, which are:


Each of wet bulk, dry bulk, and liner shipping needs their specialized vessels, which are tankers, bulkers, and container ships, respectively [3].

on the surface of the water and is carried into the shoreline, causing life cycles of

Hence, many governments and international industries are working on the marine pollution issue, mainly originated from the shipping industry, such as the Marine Environmental Protection Committee (MEPC), the International Convention for the Prevention of Marine Pollution from Ships (MARPOL), and the Department of Environment (DOE), Malaysia. In order to solve the problem, oily wastewater separator is essential and needs to be installed and operated effectively to prevent the pollution as well as to ensure that the water discharged overboard

The lowest compartment of the vessels and directly above the keel is known as bilge, where water that drains off from various sources is captured. The water might be originated from rain, interior spillage, rough seas, or minor leakage in other main parts of the vessel. Depending on a few factors such as ship size, design of engine room, and components' age, the amount of accumulated bilge water onboard varies from one to another. In order to maintain the stability of the vessel and to avoid conditions that can cause hazard (such as vessel's propulsion systems and ancillary machinery damage and fire hazard) due to too much of bilge waste accumulation, it is crucial to remove the bilge water into a holding tank, periodically [9]. There are two options to manage the bilge water, which are whether installing bilge separator to treat it onboard or holding it in a tank on the vessel before discharging it to the shore's treatment facility. Somehow, treating it onboard has an advantage where a smaller volume of oily bilge water has to be stored in the vessel. Meanwhile, the treated wastewater can be removed according to the related regulations and

The composition of bilge water depends on the design and function of the ship. The wastewater is commonly comprised of water, oily fluids, cleaning fluids, lubricant, and grease as well as other wastes that originated from piping, engines, and other operational and mechanical sources in the vessel's machinery spaces [9] as well as urine and chemicals. Other than that, extra waste streams in massive vessels contain sludge, waste oil, and oily water mixtures. Sludge is formed from the continuous fuel purification to remove contaminants in order to enhance lowquality fuels as well as to avoid ship's engines and highly machined components

The regulation stipulated by the International Maritime Organization (IMO) highlighted on the oil content of the bilge water discharged to the sea. The International Convention for the Prevention of Pollution from Ships (MARPOL 73/78) has set the maximum limit of 15 mg/L for the oil content in the wastewater to be discharged to the sea. According to the US EPA (2008), passenger ships produce the highest amount of bilge water with huge difference as compared to the other types of ships. This is due to their more complex constructions and support for crowds of

Typically, the small volumes of treated bilge water are released above the water line and instantly diluted in the sea water. Hence, the obvious effects of oil spill is most likely not going to occur. However, a long-term effect might happen to the marine living organisms around the shipping lanes. The negative consequences that will take place may be due to the excessive concentration of biodegradable compounds, including oil, as well as continuous increment of nondegradable compound

the plant and the respiration of the animals be interfered [10].

*Oil–Water Separation Techniques for Bilge Water Treatment*

*DOI: http://dx.doi.org/10.5772/intechopen.91409*

is within legal limits.

standards.

from being damaged.

passengers [9].

**149**

concentration such as metals [11].

**2. Impact of bilge on marine pollution**

Firstly, for wet bulk shipping, approximately a quarter of the goods transported by sea is dominated by crude oil [4]. The oils are transported from its production point to the purchasers by the wet bulk shipping or known as tankers. Majority of the crude oil is moved from the most significant oil-producing region, which is the Middle East, to the dominant importers like the European Union, Japan and the United States of America. Other than that, North America imports oil from the Caribbean and West America meanwhile West and North Africa export their oils to Europe [4].

Next, the largest group out of these three classifications is dry bulk shipping, where more than 50% of all loaded goods are handled by the bulkers, while 30 and 16% are for tankers and containers, respectively [5]. There is a vast range of solid cargoes transported by containers. Generally, there are five primary crucial bulk goods, which are coal, grain, iron ore, bauxite, and phosphates, in which iron ore and coal are the two goods that are transported the most [4]. Meanwhile, chemical packages and steel products are the example of the shipped minor bulk goods [6]. The main routes for iron ore transportation are from Australia and Brazil to Japan as well as from Brazil to Western Europe. While for coal, which is commonly used as steam coal in power stations to generate electricity, the leading exporters are from South Africa, Australia, Colombia, the East and West Coast of the United States, as well as Indonesia. Moreover, Australia, South Africa, Colombia, and the East Coast of the United States export their coal to Western Europe, whereas Japan receives the coal from the West Coast of the United States, Australia, and South Africa [4].

Liner shipping, also known as container shipping, provides services by transporting goods in containers with scheduled sailings. The variety of goods transported by liner shipping are packed in a smaller unit. One of the contributors to the continuation and development of liner shipping is the increment of the digital economy. According to Ref. [7], companies that produce and process raw materials, commodities, and manufacturing goods are the previous world's fastest-growing and biggest corporations. However, currently, Internet-related service and technology-based manufacturers, such as Alibaba, Amazon, Apple, and Microsoft, have become the world's most valuable and most prominent companies, where ecommerce, online communication and cashless Business to Business (B2B) and Business to Consumer (B2C) transactions are practiced [7]. This development has contributed more to the growth of the shipping industry, where it is considered as a catalyst for economic development by facilitating world trade, due to the cheaper mode of transportation.

However, aside from on-the-ground activities such as lubricants, refineries, and petrochemical industries, it is undeniable that shipping activities have contributed to marine pollution, especially in this twentieth century where carriage of the cargoes by the ships is increasing. According to [8], millions of tons of oily wastes and waste oils are generated as the by-products of the ships, every year. One of the contributors to water pollution by the operating marine vessels is the discharging of oily bilge water. Typically for marine vessels, the oily wastes and waste oil that come from various sources accumulate in the bilge space, which is the lowest part of the vessel.

Routinely, the accumulated oily bilge water must be discharged out of the bilge spaces to maintain the stability of the vessel, hence eliminating the possibility of the ship to be in the conditions that can cause a hazard to it [9]. The wastes discharged can eventually cause water pollution, which leads to many negative impacts on the human, environment, and marine populations. Oily bilge water may poison marine organisms because it might cover plants and tiny animals when it floated

## *Oil–Water Separation Techniques for Bilge Water Treatment DOI: http://dx.doi.org/10.5772/intechopen.91409*

Each of wet bulk, dry bulk, and liner shipping needs their specialized vessels,

Next, the largest group out of these three classifications is dry bulk shipping, where more than 50% of all loaded goods are handled by the bulkers, while 30 and 16% are for tankers and containers, respectively [5]. There is a vast range of solid cargoes transported by containers. Generally, there are five primary crucial bulk goods, which are coal, grain, iron ore, bauxite, and phosphates, in which iron ore and coal are the two goods that are transported the most [4]. Meanwhile, chemical packages and steel products are the example of the shipped minor bulk goods [6]. The main routes for iron ore transportation are from Australia and Brazil to Japan as well as from Brazil to Western Europe. While for coal, which is commonly used as steam coal in power stations to generate electricity, the leading exporters are from South Africa, Australia, Colombia, the East and West Coast of the United States, as well as Indonesia. Moreover, Australia, South Africa, Colombia, and the East Coast of the United States export their coal to Western Europe, whereas Japan receives the coal from the West Coast of the United States, Australia, and South Africa [4]. Liner shipping, also known as container shipping, provides services by transporting goods in containers with scheduled sailings. The variety of goods transported by liner shipping are packed in a smaller unit. One of the contributors to the continuation and development of liner shipping is the increment of the digital economy. According to Ref. [7], companies that produce and process raw materials, commodities, and manufacturing goods are the previous world's fastest-growing and biggest corporations. However, currently, Internet-related service and

technology-based manufacturers, such as Alibaba, Amazon, Apple, and Microsoft, have become the world's most valuable and most prominent companies, where ecommerce, online communication and cashless Business to Business (B2B) and Business to Consumer (B2C) transactions are practiced [7]. This development has contributed more to the growth of the shipping industry, where it is considered as a catalyst for economic development by facilitating world trade, due to the cheaper

However, aside from on-the-ground activities such as lubricants, refineries, and petrochemical industries, it is undeniable that shipping activities have contributed to marine pollution, especially in this twentieth century where carriage of the cargoes by the ships is increasing. According to [8], millions of tons of oily wastes and waste oils are generated as the by-products of the ships, every year. One of the contributors to water pollution by the operating marine vessels is the discharging of oily bilge water. Typically for marine vessels, the oily wastes and waste oil that come from various sources accumulate in the bilge space, which is the lowest part of

Routinely, the accumulated oily bilge water must be discharged out of the bilge spaces to maintain the stability of the vessel, hence eliminating the possibility of the ship to be in the conditions that can cause a hazard to it [9]. The wastes discharged can eventually cause water pollution, which leads to many negative impacts on the human, environment, and marine populations. Oily bilge water may poison marine organisms because it might cover plants and tiny animals when it floated

Firstly, for wet bulk shipping, approximately a quarter of the goods transported by sea is dominated by crude oil [4]. The oils are transported from its production point to the purchasers by the wet bulk shipping or known as tankers. Majority of the crude oil is moved from the most significant oil-producing region, which is the Middle East, to the dominant importers like the European Union, Japan and the United States of America. Other than that, North America imports oil from the Caribbean and West America meanwhile West and North Africa export their oils to

which are tankers, bulkers, and container ships, respectively [3].

Europe [4].

*Resources of Water*

mode of transportation.

the vessel.

**148**

on the surface of the water and is carried into the shoreline, causing life cycles of the plant and the respiration of the animals be interfered [10].

Hence, many governments and international industries are working on the marine pollution issue, mainly originated from the shipping industry, such as the Marine Environmental Protection Committee (MEPC), the International Convention for the Prevention of Marine Pollution from Ships (MARPOL), and the Department of Environment (DOE), Malaysia. In order to solve the problem, oily wastewater separator is essential and needs to be installed and operated effectively to prevent the pollution as well as to ensure that the water discharged overboard is within legal limits.

The lowest compartment of the vessels and directly above the keel is known as bilge, where water that drains off from various sources is captured. The water might be originated from rain, interior spillage, rough seas, or minor leakage in other main parts of the vessel. Depending on a few factors such as ship size, design of engine room, and components' age, the amount of accumulated bilge water onboard varies from one to another. In order to maintain the stability of the vessel and to avoid conditions that can cause hazard (such as vessel's propulsion systems and ancillary machinery damage and fire hazard) due to too much of bilge waste accumulation, it is crucial to remove the bilge water into a holding tank, periodically [9]. There are two options to manage the bilge water, which are whether installing bilge separator to treat it onboard or holding it in a tank on the vessel before discharging it to the shore's treatment facility. Somehow, treating it onboard has an advantage where a smaller volume of oily bilge water has to be stored in the vessel. Meanwhile, the treated wastewater can be removed according to the related regulations and standards.

The composition of bilge water depends on the design and function of the ship. The wastewater is commonly comprised of water, oily fluids, cleaning fluids, lubricant, and grease as well as other wastes that originated from piping, engines, and other operational and mechanical sources in the vessel's machinery spaces [9] as well as urine and chemicals. Other than that, extra waste streams in massive vessels contain sludge, waste oil, and oily water mixtures. Sludge is formed from the continuous fuel purification to remove contaminants in order to enhance lowquality fuels as well as to avoid ship's engines and highly machined components from being damaged.
