ABSTRACT
The current method used in the treatment of Cr(VI) uses biosorbents that are expensive hence the need for cheaper available biosorbent. In this study,potential use of corn cob powder biomass, as a bioremediation agent for the removal of Cr(VI) was investigated in a packed bed column bioreactor. The effects of the operating parameters such as influent Cr(VI) concentration, pH, biomass concentration, flow rate and temperature, on the Cr(VI) removal were investigated in the continuous system using a packed-bed reactor. Percentage removal curves were obtained for different flow rate, pH, temperature, biomass concentration and initial concentration of Cr(VI). It was found that the adsorption of Cr(VI) to the biomass was strongly dependent on these parameters, as expected. In particular, the influent pH and temperature were most significantly affected leading toa high percentage removal of Cr(VI); a decrease in the influent pH of 2, and an increase in the temperature up to 70°C enhanced the Cr(VI) reduction in the column significantly (P<0.05) up to 70 ± 11.39 %. A flow rate of 5min/ml was optimum for higher removal percentage. FTIR spectra analysis carried out on the biosorbent showed the presence of some functional group; hydroxyl (OH), carboxylic (COOH), ethyne (CH), and ethane (CH2) groups which are responsible for the biosorption reaction in the column. Both Langmuir and Freundlich adsorption isotherms fitted reasonably well with the data and showed high correlation coefficient (R2) values of 0.993 and 0.985 respectively. These results show that, the adsorbent can be used as a low cost alternative in biosorption of wastewaters containing lowerconcentrations of Cr(VI).Finally, the potential of the column packed with corncobbiomass for Cr(VI) detoxification has been found to be a good biosorbent in removal of Cr(VI) from aqueous solutions and also in the treatment of Cr(VI) containing industrial waste
TABLE OF CONTENT
Title Page
Abstract
Table of Content
List of Abbreviations
CHAPTER ONE: INTRODUCTION
1.1 Background of Study
1.2 Statement of Research Problem
1.3 Justification
1.4 Aims and Objectives
1.4.1 Aims
1.4.2 Specific Objectives
CHAPTER TWO: LITERATURE REVIEW
2.1 Biosorption
2.1.1 Mechanism of Biosorption
2.1.2 Factors Affecting Biosorption
2.1.3 Advantages of Biosorption
2.2 History of Corn
2.2.1 Classification of Corn
2.2.2 Biosorbent Properties of Corncob
2.3 Chemistry and Characteristic of Chromium
2.4 Hexavalent Chromium
2.4.1 Toxicity of Chromium (VI)
2.4.2 Chromium (VI) andthe Environment
2.4.3 Health Hazards of Chromium (VI)
2.5 Packed Bed Column Reactor
2.5.1 Benefits of Continuous Reactors
2.6 The Adsorption Isotherm of Metal Removal
2.6.1 Freundlich Adsorption Study
2.6.2 Langmuir Adsorption Study
CHAPTER THREE: MATERIALS AND METHODS
3.1 Materials
3.1.1 Biosorbent
3.1.2 Reagents and Equipment Used
3.1.3 Continuous Reactor System
3.2 Methods
3.2.1 Pre-Treatment of Biosorbent
3.2.2 Preparation of Chromium (VI) Solution
3.2.3 Preparation of DiphenylCarbazideSolution (Developing Reagent)
3.2.4 Determination of Chromium (VI) Concentration
3.2.5 Preparation of Standard Curve
3.2.6 Determination of the Effect of Mass of Biosorbent on Chromium (VI) Removal
3.2.7 Determination of the Effect of Flow Rate on Chromium (VI) Removal
3.2.8 Determination of the Effect of Temperature on Chromium (VI) Removal
3.2.9 Determination of the Effect of Initial K2Cr2O7 Concentration on Chromium (VI) Removal
3.3.0 Determination of the Effect of pH on Chromium (VI) Removal
3.3.1 The Use of Activated Carbon as Adsorbent For Chromium (VI) Removal
3.3.2 The Used of Waste Water Containing Chromium(VI) from a Leather Tanning Industry
3.3.3 FTIR Analysis of Biosorbent
3.3.4 Statistical Analysis
CHAPTER FOUR: RESULTS
4.1 Effect of Mass of Corncob on Chromium (VI) Removal
4.2 Effect of Flow Rate on Chromium (VI) Removal
- 3 Effect of Temperature on Chromium (VI) Removal
4.4 Effect of Initial K2Cr2O7 Concentration on Chromium(VI) Removal
4.5 Effect of pH On Chromium (VI) Removal
4.6 Use of Activated Carbon as aAdsorbent In The Column
4.7 The Used of Waste Water Containing Chromium(VI) from NILEST
4.8 FTIR Analysis of Biosorbent
4.9 The Adsorption Isotherm Studies
CHAPTER FIVE: DISCUSSION
CHAPTER SIX: SUMMARY, CONCLUSION AND RECOMMEMDATION
6.1 Summary
6.2 Conclusion
6.3 Recommendation
REFERNCES
APPENDICES