CHAPTER ONE
INTRODUCTION
1.1 Background of Study
Fresh drinking water is a necessity in life for optimal health. Not only does fresh drinking water taste better, it’s safer as well. Most water supply are contaminated by organic compounds, metals etc. which affects health or cause taste and odour problem. Sources of these contaminants includes; solvents, pesticides, industrial waste, or contaminants from leaking underground storage tanks etc. Contaminants such as benzene, trichloroethylene etc. may pose threat to the human health when consumed continuously. Drinking water disinfected with chlorine or chloramine react with organic contaminants to form compounds such as trihalomethanes (THMs) as by products and can cause cancer. In addition, lead from water pipes, and joints may be present in water from taps.
There are several methods of treating drinking water (dechlorination, filtration, activated carbon filters, etc.). Among all these available methods, activated carbon filter can effectively reduce certain contaminants in water.
Activated carbon can be used to purify liquids and gases in a variety of applications, including municipal drinking water, food and beverage processing, odour removal, industrial pollution control, and point-of-use filters in the home. Activated carbon is a material that is produced from carbonaceous source materials, such as coal, coconut shell, rice husk, nutshells, peat, wood, and lignite. Activated carbon consist of a wide range of amorphous based materials prepared to possess a high degree porosity and an extended interparticulate surface area. Activated carbon is a form of carbon that is processed to have small and low volume pores that could increase the surface area available for adsorption. These qualities give activated carbon excellent adsorbent characteristics that make carbon very useful for a wide range of processes including filtration, deodorization, decolourization, purification, and separation.
Activated carbon filters are designed using carbon as the primary filtering agent. The carbon in many cases is solid and the water runs through it and is purified. This filtering process removes bad taste and more importantly dangerous contaminants that affects human health. Activated carbon filter can operate as a filter and adsorber simultaneously. The Activated carbon filter is able to carry this function because of its ability to adsorb the contaminants and its affinity for the contaminants is stronger than the bond the contaminants have for the water molecule.
1.2 Statement of Problem
There can be no life without water. Human survival depends heavily on water. The use of water includes; water for drinking, cooking, bathing, washing and other purposes. Today, 1.1 billion people have no access to improved water resource and over 3 million people, mostly of which are children die yearly from water related diseases (Anon 2008). Therefore, it’s of great importance that water treatment is carried out to improve the health status of human existence.
This present work proffers solution by construction of an activated carbon filter that removes most of contaminants found in water.
1.3 Aim and Objectives
The aim of this research work is to design and fabricate a laboratory scale activated carbon filter for water treatment. The objectives are:
- Preparation of activated carbon from coconut shells by carbonization and subsequent activation
- Construction of a test column
- Choosing appropriate materials of construction
- Characterization
- Adsorption experiment
- Specification of design parameters
- Determination of breakthrough points.
1.4 Significance of Study
Through this research work, the department of Chemical Engineering will have a laboratory scale activated carbon filter to demonstrate water treatment and serve as evidence of the department’s research abilities.
1.5 Scope of Study
This work is restricted to the design and fabrication of a laboratory scale activated carbon filter for treating contaminated water.
