CHAPTER ONE
1.0 INTRODUCTION
1.1 Background of the study
` Chlorine is a greenish-yellow gas that dissolves easily in water. It has a pungent, noxious colour that some people can perceive smell at concentrations above 0.3 part permillion. Chlorine is an excellent disinfectant commonly added to drinking water supplies to kill harmful micro-organism. Chlorine is not only an effective disinfectant but it also reacts with ammoniamiron and other metal s and some organic compounds to improve overall water quality (white, 2000).
In parts of the world when chlorine is not added to drinking water, thousands of people die each day from waterbone disease like typhoid and cholera according to (Darnail 1999). However, the addition of chlorine in water has its limitations but its dangers, are relatively shortlived compared to the dangers of most other highly poisonous substances. Rideal et al, (2005) suggests that this is because chlorine reacts quickly with other substance in after (and forms combined chlorine) or escapes as a gas into the atmosphere. The free chlorine test measures only the amount of free or dissolved chlorine in water, but the total chlorine test measures both free and combined of chlorine.
According to Richardson et al (2007), if the water contains a lot of decaying materials, free chlorine can combine with them to form disinfection –by- products like tribhalomethanes. Though there is a limit to the use of chlorine as negative results are possible with the addition of too odour in water are often enhanced.
Fair et al, (2000) states that less than one half (0.5mg/L) of free chlorine is needed to kill bacterial without causing water to smell or taste unpleasant. Most people cannot detect the presence of chlorine on water amount (1.0mg/l). although 1.0mg/l chlorine in water is not harmful to people, it does cause problems to fish and other aquatic animals when they are expose to it over along period of time. It is very important for water suppliers to monitor closely the level of chlorine present in the water (Hodges 1997).
RISK OF WATERBORNE DISEASE
Where adequate water treatment is not readily available, the impact on public health can be devastating (White, 2002), would. Worldwide, about 1.2 billion people lack access to safe drinking water and twice that number may have adequate sanitation (Christian et al, 2001). As a result the World Health Organization (WHO) estimates that 3.4 million people mostly children die, every year from water related diseases. Ridealetal (2005). Even where treatment is widely practiced constant vigilance is required to guard against waterborne disease outbreaks.
Well known pathogens such as Ecoli are easily controlled with chlorination but can cause deadly outbreak give condition if inadequate or disinfection (Richardson, et al 2007). Some emerging pathogens like osporiolianare resistance to chlorination and can appear even in high quality water supplies. Cryptosporidium was the cause of the longest reported drink water in United state (Craun et al, 2002). The new regulation from U.S Environmental Protection Agency will require water system to monitor cryptosporidium and adopt a range of treatment options based on source water cryptosporidium concentrations. Most water systems are expected to meet EPA requirement while continuing to use chlorination.
1.2 STATEMENT OF PROBLEM
There has been high prevalence of water borne disease in Enugu metropolis judging from the hospital statistics hence the need to know if the cause has been from the method of water treatment employed in the purification of drinking water supplied to the municipality.
1.3 AIMS OF THE STUDY
· To determine the chlorine content to water from Ajalli water source.
· To compare the chlorine content in the drinking water in Enugu metropolis with World Health Organization standard.
· The study will also evaluate the effect of bad water chlorination and the harms of indisinfecter drinking water.
1.4 SIGNIFICANCES OF THESTUDY
This research work is meant to elucidate the actual concentration of chlorine in Enugu drinking water and to make known the processes or steps taken in the treatment of the water. Also to establish whether some prevalent disease could be traced to the way drinking water in Enugu is treated.
1.5 SCOPE OF THE STUDY
This research work is limited to the determination of the chlorine content in raw Ajalli water source the treatment of water and the tap water within Enugu.