1.1 Background of Study
Pollution in the marine environment is considered to be one of the major ecological problems of the 21st century maritime industry. The pollution of the any marine environment is liable to cause lethal consequences onto the living conditions of the marine and underwater flora and fauna. A large number of national and international regulations has been set. Besides the international regulations for prevention of marine pollution from vessels, many maritime nations have set forth their own regulations in line with the international regulations.
Nowadays, wastewater treatment has become an important issue of modern society. The impact of sewage on marine environment is of great concern. Researching more about wastewater treatment in ship and to find answers to the questions like – what kind of wastewater can be purified on wastewater treatment plant in ship, what are the problems that can be encountered in wastewater treatment plants, which processes of wastewater treatment should be provided, what are obligatory legal standards required for discharging the wastewater into the natural recipient whether it is on the ocean or the Mediterranean sea – is important.
In ships, wastewater can be produced on land –based ship facilities (including restaurants, offices, shipyards and washing areas) or can be collected from different vessels (with different wastewater treatment plants onboard or without any kind of wastewater treatment plants onboard). In general, wastewater is divided into sanitary wastewater, industrial wastewater and wastewater from ships (black water –sewage, graywater or ballast water).
Sanitary (domestic) wastewater from the ship is usually fecal water from office buildings and other buildings with sewage systems which can be found in the ship including wastewater from showers and canteens (water from cooking, washing dishes, sinks etc.) as well as wastewater from restaurants that can be parts of ship intended for cruise ship passengers, skippers or tourists. The quality of sanitary (domestic) wastewater varies from location to location and quantity is within a narrow range. One of the biggest problems that occur in a narrow coastal area along the coast is the intrusion of salt water (NaCl) into the sewage system. Salt water together with sanitary water goes to a biological wastewater treatment plant situated at the end of sewage system where salt destroys bacteria (biomass) needed for the process of purification. NaCl has a negative impact on the purification process and can cause a delay in the treatment at the concentration is greater than 10 percent. Seawater typically has a salinity of around 35 percent which means that only ¼ salt water is allowed in sewage wastewater treatment plants, of the total incoming wastewater, so the waste water treatment plant can operate normally.
Industrial wastewater is usually wastewater produced in the washing areas and wastewater from different types of machines and devices as well as water which is used for cooling the devices and shipyard wastewater. Contaminated water from ship is often full of toxic heavy metals such as tin (Sn), copper (Cu), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe) etc., which are dangerous for human health and as such can’t be discharged without purification into the public sewage system or natural receiving waters in cities (sea, river). The most important thing with industrial wastewater is doing a very good analysis of quality of wastewater which has to be purified on wastewater treatment plant, in order to know exactly what kind of heavy metals it contains and in what quantities.
Wastewater onboard can be divided into “black water“ sewage containing feces and “graywater“ wastewater from washing of living quarters, Oily Bilge water mixture of water, oily fluids, lubricants, cleaning fluids and other similar wastes that accumulate the lowest part of vessel from a variety of different sources including engines and piping and ballast water. In most maritime nations, ships are not allowed to discharge untreated black water within 12 nautical miles off shore according to MARPOL. Moreover, port authorities have to deal with two different groups of regulations for wastewater treatment: with legal requirements for effluent from wastewater treatment plants based on land and legal requirements for effluent from vessels (e.g. from Waste Water Treatment Plant onboard), which are stricter than the requirements for wastewater treatment on land.
1.2 Statement of problem
Lack of adequate waste reception facilities in developing countries’ ports is such that vessels have no choice but to discharge waste at sea. However, some vessel operators prefer to dump waste at sea, where there is a low risk of being caught, rather than use the provided facilities and thus pay the required user fees. In West and Central African ports, facilities are becoming available in varying forms but remain inadequate hence ship waste collection processes in the ports are not only inefficient but also their management remains poor. In Nigeria for example, the Nigeria Ports Authority (NPA)—custodian of national ports does not own or operate waste reception facilities but outsources that responsibility to a private pollution control company. In the words of the port authority’s managing director, Mohammed (2008), the private pollution control company is to provide port reception facilities in all four navigational districts of Lagos, Port Harcourt, Warri and Calabar. The project is self-financing and contract tenure is 20 years beginning from the year 2006. In addition, this company is given the responsibility of monitoring waste discharge from vessels visiting the ports and reporting back to the authority. In this circumstance, no independent organization is put in place to audit the activities of pollution control contractors. Against this backdrop, this paper proposes a practical model for monitoring and controlling ship-source marine pollution based on laboratory analysis of effects of pollutants on discharge areas within the harbour. Specifically, analysis of physico-chemical and microbiological properties of ship generated waste water would provide scientific information on the level of pollution (or its risk level) in the marine port environment. Integrated within the regulatory framework existing at the port, continuous scientific analysis of ships’ berthing areas provides a robust model for monitoring and controlling marine pollution in the ports. In this study, we propose the analysis of ship generated wastewater as a proxy for the analysis of water quality in the berthing area exposed to pollution from ship-sources. A major assumption of this study therefore is that the analysis of the properties of wastewater collected at the source (ships at berth) provides a proxy medium for understanding the nature and extent of pollution in the port environment.
1.3 Aim and Objectives of the Study
The main aim of the study is to investigate the effect of ship waste water treatment on the marine environment. This actually involves comparing situational effects both treated and treated ship waste water on the marine environment. In the realization of the major aim, the set objectives for this research are as follows:
To determine the significant physico-chemical and microbiological parameters of ship generated wastewater from vessels berthed at the ports.
To compare the values of these parameters with Nigeria’s Department of Petroleum Resources (DPR) standards for Effluent Discharge from marine vessels.
To examine the significant effects of the parameters (by the type of wastewater) on the marine environment.