ABSTRACT

Coagulation is an effective, simple and widely practiced water treatment method. However, the usage of chemical coagulant pose detrimental effect on living organism and human health as well as producing large amount of toxic sludge. This study describes the utilization of banana peel as a natural coagulant for the treatment of household wastewater. The natural coagulant extracted from banana peel was prepared by using simple extraction method. wastewater was used in this study to imitate the medium strength household wastewater. The parameters investigated in this study were pH of wastewater, coagulant dosage, and solvent of extraction. The application of the natural coagulant was evaluated based on the reduction of turbidity during the treatment process. The treatment of wastewater using banana peel coagulant was found to be the most effective at pH 1 and dosage of 100 mg/l whereas the most effective solvent to extract this type of fruit waste is sodium hydroxide (NaOH). In present work, it can be concluded that the banana peel coagulant was highly feasible in removing turbidity of the wastewater with removal efficiency of 88% under optimum condition

 

 

 

 

CHAPTER ONE

INTRODUCTION

1.1 Background information

Water is one of the key factors for economic development worldwide as it is widely used in different productive sectors including industry, agricultural production, livestock and urban supply. The fastpaced industrialization, economic growth and population growth in developing countries has implicated in unpredicted water requirement in cities. In the last few decades, the water used capacity and wastewater production in domestic sectors has increased remarkably [1]. Wastewater treatment is a crucial process in sanitation system. Effective municipal wastewater resource treatment and contamination control are necessary to ensure compliance to environment compliance and reutilization of resources.

Amongst the wide range of existing methods accessible for wastewater treatment, coagulation and flocculation process is the most preferable. This treatment is commonly being practiced as it is cost effective, reliable, simple and best regarded as low-energy consuming process [2]. This established physical-chemical process removes colloidal, suspended and soluble particles efficiently by prompting aggregation of macro and micro particles into larger size proceeded by sedimentation [2]. In conventional treatment processes, various types of coagulants are often used depending on chemical traits of the contaminants present in the wastewater. The inorganic and  organic polymer coagulants include alum, ferric chloride, calcium carbonate as well as polyaluminium chloride were generally used in the wastewater treatment [3]. Despite that, such treatment leads to disposal problems as the sludge obtained after the treatment using aluminium salts risks accumulation in the environment [4]. At the same time,  organic polymers like acrylamide possess carcinogenic and neurotoxic effects [5]. The alternative solution to these problems is replacement of metal and  coagulants with natural coagulants which are more environmental friendly.

 

1.3 Problem statement and justification

Pollution of water sources due to dumping of untreated wastewater and chemical wastes directly into rivers, lakes and drains has been of great concern over the last few decades (Feng and Guo, 2012). Unlike organic wastes, heavy metals are non-biodegradable and they can be accumulated in living tissues, causing various diseases and disorders such as cancer; therefore the need for their removal before discharge (Liang et al., 2009). Decontamination of toxic pollutants from water poses a challenging problem, and therefore a wide range of approaches have been explored for their removal (Jaramillo et al., 2009). Bio-adsorption has shown promising results in removal of toxic ions from water (Babel and Kurniawan, 2002).

 

The adsorption properties of biological waste materials such as peat, wood, pine bark among others leaves have been mainly reported for carbonized samples (Pino et al., 2006). Activated carbon which is widely used adsorbent in treatment of wastewater is not affordable and there is need for alternative cheaper methods (Babel and Kurniawan,

2002).

 

The search for low cost and easily available adsorbents has led to investigation of agricultural waste materials as potential adsorbents (Hossain et al., 2012). Cactus mucilage from cactus a plant that can thrive in extremely dry environments have been found to possess the ability to remove turbidity, heavy metals and bacteria from contaminated water. However, no work has been reported on its dry mass and

derivatives (Mane et al., 2011).

 

Therefore, this study sought to investigate the application of Banana peel Coagulant and its combusted products on removal of colour, turbidity and selected heavy metals from contaminated water. This is expected not only develop cheaper materials for water treatment but also use natural coagulants that are locally available, abundant and inexhaustible to provide a solution to the need for clean water in the rural communities.

 

1.4 Objectives

1.4.1 General objective

The general objective was to investigate adsorption capacity and application of Banana peel Coagulant and its combusted products in removal of colour, turbidity and selected metal ions (Cd²⁺ and Pb²⁺) from contaminated water.

 

1.4.2 Specific objectives

1. to investigate the application of banana peel as a potential coagulant to reduce turbidity of wastewater by varying different pH of wastewater, dosage of coagulant and types of solvents for extraction.
2. To conduct the standard jar test for determining the performance of extracted banana peel with respect to its coagulation activity

 

1.6 Significance of the study

The purpose of this study was to develop an alternative and cheaper natural coagulant of cleaning contaminated water using locally available materials Banana peel.

 

 

 

CHAPTER TWO

LITERATURE REVIEW

2.1 Water scarcity

Water scarcity leads to a declining water quality and increased pollution which has direct adverse impact on poor people. Many, probably most of the poorest people in developing countries are forced to drink water that literally is unfit for human consumption. They suffer from skin and other forms of sanitary diseases because of use of polluted water in bathing and lack of sufficient water for washing (Seckler et al., 1999).