DEFLUORIDATION OF DRINKING WATER USING INEXPENSIVE ACTIVATED CARBONS AS ADSORBENTS By BHARATH G. BHAT Md RASHEEL ASHTHAF ALI C ALTHAF AHMAD P P ABDUL KHADAR SHADAF Guide: Prof. M.N. HIREMATH
AGENDA • Introduction • Fluoride • Literature Review • Theory of Adsorption • Materials and Method • Experimentation • Result and Discussion • Conclusion • Reference
1. INTRODUCTION • Importance of Water • Hydrologic Cycle
2. FLUORIDE • Fluoride in Drinking Water • Origin, Occurrence and Distribution of Fluoride • Distribution of Fluoride in Water • Chemistry of Fluoride • Effects of Fluoride
FLUORIDE IN DRINKING WATER Health impacts from long-term use of fluoride-bearing water have been summarised below • <0.5 mg/l: dental caries • 0.5-1.5 mg/l promotes dental health • 1.5-4 mg/l dental fluorosis • >4 mg/l dental, skeletal fluorosis • >10 mg/l crippling fluorosis Dental fluorosis is by far the most common manifestation of chronic use of high-fluoride water.
EFFECTS OF FLUORIDE • Fluoride Accidents & Poisonings • Fluoride & Dental Fluorosis • Fluoride & Allergy/Hypersensitivity • Fluoride & The Kidneys • Fluoride & The Brain • Fluoride & The Pineal Gland • Fluoride & The Thyroid Gland • Fluoride & Bone Disease • Fluoride & Cancer • Fluoride & Tooth Decay
DEFLUORIDATION TECHNIQUES • Activated Alumina • Coagulation Techniques • Reverse Osmosis and Nanofiltration Processes • Lime Softening • Anion Exchange • Adsorption Technique
3. THEORY OF ADSORPTION • Adsorption • Types of Adsorbents • Manufacture of Activated Carbon • Adsorption Isotherm • Application of Activated Carbon Treatment • Treatment with Granular Activated Carbon (GAC) • Treatment with Powdered Activated Carbon (PAC)
Treatment with Granular Activated Carbon (GAC) Fixed Bed Reactor
4. MATERIALS AND METHODS • Materials • Instruments
Methods • Preparation of activated carbon • Characteristics of activated carbon • Preparation of fluoride solution • Methodology • Optimization of various operation conditions
Characteristicsof activated carbon SEM IMAGE • Above figure shows SEM Image of activated carbon. • Surface area of activated carbon 850 meter square per grams.
Optimization of Various Operation Conditions • Optimization of pH • Optimization of dosage • Optimization of temperature • Optimization of initial fluoride ion concentration • Optimization of flow rate
5. EXPERIMENTATION • Experimental Setup • Development of low cost defluoridation filter unit • Cost Analysis
6. RESULT AND DISCUSSION • Initially the operating parameters were obtained by conducting separate experiments with prepared activated carbon for dosage, pH, flow rate, initial fluoride ion concentration and temperature and finally fluoride removal efficiencies were compared with PAC and CAC.
a. Optimization of Dosage • The raw water sample of known concentration (2mg/l) was passed through the different bed height column. • The filter rate and bed height which gives maximum removal of fluoride efficiency will be the optimized dosage. • Then same procedure was repeated for commercial activated carbon (CAC). • In the present study 8cm bed height gives the optimum dosage for both PAC and CAC i.e. optimum dosage. Fluoride Removal (%) Bed Height
b. Optimization of pH • In this study obtained optimum dosage i.e. 8cm bed height was kept constant and raw water were introduced and there filter rate were analyzed for fluoride ion concentration. • pH which gives maximum removal of fluoride will be the optimum pH. • Then same procedure was repeated for commercial activated carbon (CAC). • In the present study 4 pH gives the optimum pH for both PAC and CAC i.e. optimum pH. Fluoride Removal (%) pH
c. Optimization of Flow Rate • In this study, obtained dosage, i.e., 8 cm bed height and pH 4 was kept constant and raw water sample of known concentration (2mg/l) was passed through the different bed height column. • The flow rate which gives maximum removal of fluoride will be the optimum flow rate. • Then same procedure was repeated for commercial activated carbon (CAC). • In the present study, 20mg/l gives maximum removal efficiency for both PAC and CAC i.e. optimum Flow Rate. Fluoride Removal (%) Flow Rate
d. Optimization of Initial Fluoride Ion Concentration • In this study, obtained optimum dosage i.e., 8cm and optimum pH 4 and optimum flow rate of 20ml/min was kept constant and raw water of different initial fluoride ion concentration. • Then filter rate were analyzed for fluoride ion concentration. • Then same procedure was repeated for commercial activated carbon (CAC). • In the present study, 2mg/l gives maximum removal efficiency for both PAC and CAC i.e. optimum initial fluoride ion concentration. Fluoride Removal (%) Initial Fluoride Ion Concentration
e. Optimization of Temperature • In this study, obtained optimum dosage i.e., 8cm and optimum pH 4, optimum flow rate of 20ml/min and optimum initial fluoride ion concentration 2mg/l was kept constant and raw water of same initial fluoride ion concentration was introduced. • Then filter rate were analyzed for temperature. • Then same procedure was repeated for commercial activated carbon (CAC). • In the present study, 30ºC gives maximum removal efficiency for both PAC and CAC i.e. optimum temperature. Fluoride Removal (%) Temperature (°C)
FINAL ANALYSIS • Final Analysis of raw water sample of known fluoride ion concentration (2mg/l) and using all optimized parameters as discussed above i.e., optimized dosage is 8cm, optimized pH is 4, optimized flow rate is 20ml/min, optimized initial fluoride ion concentration is 2mg/l and optimized temperature 30ºC is kept constant and is analyzed over single column. • The result obtained by using optimized parameters and inexpensive activated carbon i.e., by using PAC and CAC proves that it can efficiently remove 63% and 78% respectively.
7. CONCLUSION • From the experiment investigation of defluoridaton of drinking water using in expensive activated carbon prepared from corn cob an agro byproduct, following conclusion were drawn, • Inexpensive adsorbent prepared from corn cob can be used in the treatment of defluoridation. • The prepared activated carbon has surface area of 850m2/g. • It showed 63% using PAC and 78% using CAC removal efficiency of fluoride.
8. FUTURESCOPE Undoubtedly the low cost adsorbent offer a lot of promising benefits for commercial purpose in future and the same study can also be carried out using different impregnation ratio and carbonization temperature.
9. FUTURESCOPE • We are grateful to our institution for having provided the facilities that have made this project a success. • We express our heartfelt thanks to Dr. R. Noor Ahmed, Principal for providing a congenial atmosphere to work in. • We are deeply indebted to our honorable HOD of Civil Engineering Prof. H. M. Phalachandra who has supported and advised us throughout the preparation of the project. • Also our grateful thanks to the Project guide Prof. M. N. Hiremathwho gave valuable guidance and support to complete the project work with ease. • We are also grateful to the teaching and non-teaching staff members of Civil Department for their timely help and advice provided towards the preparation of the project. • This acknowledgement will be incomplete without admitting our insolvency towards the co-operation from ourbelovedparents, friends and well wisherswithout which I would not have completed this task.
10. REFERENCES • D. J. Killedar and D. S. Bhargava, An overview of defluoridation methods, Part- 2, J.Inst. Publ. HlthEngng, 2, 37 (1988). • Bulusu, Fluorides in water-defluoridation methods and their limitations, J. Inst. Engng, 60, 2–6 (1979). • APHA, Standard methods for examination of water and wastewater, American Public Health Association, Washington DC, 18th edn (2000). • D. J. Killedar and D. S. Bhargava, Fluoride adsorption on adsorption on fishbone charcoal through a moving media adsorption column, Wat. Resources, 26, 781–788 (1992). • D. S. Bhargava and D. J. Killedar, Batch studies of water defluoridation using fish bone charcoal, Res. J. Waste Process. Chem. Engrs, 63, 848–858 (1991). • M. Rao and A. G. Bhole, Removal of chromium using low cost adsorbents, J. Indian Ass. Environ. Mgmt, 27, 291–296 (2000). • A. K. Bhattacharya and C. Venkobachar, Removal of cadmium (2) by low-cost adsorbents, J. Env. Engng ASCE, 11, 110–122 (1984).
REFERENCES (contd…) • APHA, AWWA and WEF (2005) Standard methods for the examination of water and wastewater. 21st edition. • American Public Health Association, American Water Works Association, and Water Environment Federation. • Aschengrau, A., Zierler, S. and Cohen, A. (1989) Quality of community drinking water and the occurrenceof spontaneous abortion. Arch. Environ. Health, 44: 283–290 [cited in Department of National Health andWelfare, 1993]. • Aschengrau, A., Zierler, S. and Cohen, A. (1993) Quality of community drinking water and the occurrence of lateadverse pregnancy outcomes. Arch. Environ. Health, 48: 105–113 [cited in Department of National Health andWelfare, 1993]. • D. Barkin and C. Pailles, Water and forests as instruments for sustainable regional development, Int. J. Wat., 1, 71–79 (2000). • D. J. Killedar and D. S. Bhargava, An overview of defluoridation methods, Part-I, J. Inst. Publ. HlthEngng, 1(6), 41–44 (1998). • R. Piekos and S. Paslawska, Fluoride uptake characteristics of fly ash, Fluoride, 32, 14–19 (1999).