ABSTRACT

Consumption of contaminated water may result in several water-borne diseases, including hepatitis, typhoid, cholera, dysentery and other diseases that cause diarrhoea. One of the ways this problem can be prevented is by the use of household water treatment and safe storage. As a result of this, the ceramic water filter, which is one of the effective water treatment techniques, was studied and evaluated to provide information that, will help improve their performance and promote their use.

In this project, two kinds of ceramic filters were fabricated; one without hydroxylapatite and the other with hydroxylapatite. Their flow rates were determined and their ability to remove E.coli was also tested. The ability to scale up these filters to achieve a system that will provide large volumes of water per filtration was also explored in this project.

The results showed that, the two kinds of filters did not indicate significant difference in their flow rates and the E.coli removal of the filters proved successful. It was also realized for the scale up that, it is possible to connect the ceramic filters to produce a system that can produce large volumes of filtered water. However, the effectiveness of the system depends largely on the individual flow rate of the filters used.

CHAPTER ONE

INTRODUCTION

1.1 Background

The human body is said to be made up of about 70% water. This shows how important water is to the survival of humans. The importance of water is such that life cannot be sustained beyond a few days, without water supply. Furthermore, the lack of adequate water supply leads to the spread of disease (Guy & Jamie 2003). Water is used in most human domestic activities including cooking, cleaning, and most importantly drinking, which is a means by which the water lever in the human system is maintained. In some of the non domestic uses of water, the purity of the water is not really an issue, e.g. in the case of washing. However, for domestic uses of water, the purity of water is very important, since it has a direct relationship with the health and wellbeing of the individual using the water. A very important example of this is when water is used for drinking.

Consumption of contaminated water may result in several water-borne diseases. These include viral hepatitis, typhoid, cholera, dysentery and other diseases that cause diarrhoea (Ashbolt 2004). In 1998, Gadgil reported that about half the people in developing countries suffer from at least one of the six main diseases caused by inadequate water supplies and sanitation practices (Gadgil 1998). Theses six diseases include; diarrhea, Ascaris,Dracunculisis, hookworm, Schistosomiasis and trachoma. The world Health Organisation (WHO) in 2004a, estimated that about 1.8 million people die per year from diarrheal disease (WHO 2004a). It was also estimated by Pruss et al. (2002) that 4.0% of all deaths and 5.7% of the burden of global are attributed to inadequate water purification, sanitation, and hygiene, largely due to diarrheal disease. This is particularly prominent in rural communities in developing countries, where the rural communities do not have any sources of clean water supply. They therefore depend on the natural sources of water, such as rivers, streams and dams. Most of these sources of water are contaminated by human activities such as farming, construction and sewage. These activities introduce harmful chemicals and bacteria into these water sources, therefore making them unsafe to drink, and leaving the people of these communities vulnerable to water diseases.

Due to the number of lives that are lost to the consumption of contaminated water, significant efforts are being made by various organisations and scientists to provide sustainable solutions to the problem of contaminated water. Due to the magnitude of the problem, the World Health Organisation (WHO) in 2006 stated that “Access to safe drinking water is essential to health, a basic human right and a component of effective policy health protection”. Nevertheless, more than 1.1 billion people of the world's population still lack access to any form of clean and safe drinking water. (Brikke & Bredero 2003; Smet & Wijk 2002; Visscher 2006). Most of these people live in Asia and Africa (WHO/UNICEF 2000).

The issue of unsafe drinking water is most evident in communities in the developing world, where there is inadequate clean water supply. This poses a great health risk to the individuals. In view of this problem, some methods have been developed for water treatment. These methods include, boiling (Miller 1986), the addition of chlorine (Heber 1985), SODIS UV-disinfection (Wagelin & Sommer 1998), bio-sand filtration (Heber 1985), ceramic silver impregnated filters (Roberts 2003) and adsorption filters (http://en.wikipedia.org/wiki/activated_carbon). All these mentioned methods of treatment have their advantages and disadvantages. However, since these methods will be used mostly in the rural communities, factors such as, affordability, assessability, the simplicity of the methods, and the potential for the incorporation of local materials are very important factors to be considered. In order address the problem associated with poor water supply and sanitation, the United Nations (UN) developed seven very ambitious targets (UN 2008; WHO & UNICEF 2004). These were established in the 'Millennium Development Goals' (MDG). Hence, goal number seven (MDG #7) is “halving proportion of people without sustainable access to safe water and basic sanitation by 2015” (UN 2008; WHO & UNICEF 2004).