FORMULATION AND DEMONSTRATION OF A TECHNIQUE TO QUANTIFY LEACHATE POLLUTION POTENTIAL OF MUNICIPAL LANDFILLS

Transcription

1 FORMULATION AND DEMONSTRATION OF A TECHNIQUE TO QUANTIFY LEACHATE POLLUTION POTENTIAL OF MUNICIPAL LANDFILLS By DINESH KUMAR DEPARTMENT OF CIVIL ENGINEERING Submitted in fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY to the INDIAN INSTITUTE OF TECHNOLOGY, DELHI March, 2005

2 "I am enough of an artist to draw freely upon my imagination. Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world." Dedicated to ALBERT EINSTEIN (The Genius)

3 CERTIFICATE This is to certify that the thesis entitled "Formulation and Demonstration of a Technique to Quantify Leachate Pollution Potential of Municipal Landfills" being submitted by Dines h Kumar to the Indian Institute of Technology, Delhi, for the award of the Degree of Doctor of Philosophy is a bonafide record of research work carried out by him under my supervision and guidance. The thesis work, in my opinion, has reached the requisite standards fulfilling the requirement for the Degree of Doctor of Philosophy. The results contained in this thesis have not been submitted, in part or full, to any other University or Institute for the award of any degree or diploma. (Babu J. Alappat) Assistant Professor Department of Civil Engineering Indian Institute of Technology, Delhi Hauz Khas, New Delhi INDIA

4 ACKNOWLEDGEMENTS It gives me great pleasure in expressing my regards and profound sense of gratitude to Dr. Babu J. Alappat, for his perspective supervision, invaluable guidance and constant encouragement throughout my stay at Indian Institute of Technology, Delhi. My sincere thanks are also due to Prof. R. Kaniraj, Dr. A. K. Mittal, Dr. T. R. Sreekrishnan for their valuable supervision and constant encouragement and motivation. I would also like to thank Prof. Mukesh Khare, Prof. Rema Devi, Prof. Manoj Dutta, Dr. A. K. Nema and Dr. Rakesh Khosa for their valuable suggestions and moral support. I am thankful to Prof. K. G. Sharma, Head, Civil Engineering Department, Prof. A. K. Nagpal, Chairman, DRC, for their valuable guidance and constant support. I have great pleasure in expressing my sincere thanks to the staff members of Environmental Engineering Laboratory and the Department of Civil Engineering. I am also grateful to my fellow research scholars; especially Mr. Munish Chandel, Ms. Suman Mor, Mr. Amardeep Singh, Mr. Sumedha Chakma, Ms. Anju Pant, Mr. Sandeep Chaudhary, Mr. Nityanand Maurya and Mr. Sharad Gokhale. I am also thankful to Mr. Bharat Bhushan, Ms. Nathalene Christ. Mr. Atul Sharma, Mr. Rajesh Taneja and Mr. Sunil Kumar for their incredible help. ii

5 Finally, I would like to thank our panelists for their valuable comments, guidance and support without which this work might not have been completed. I would like to extend my indebtedness to Sh. Ravi Dass ji, Director-in-Chief, CSE Department, Sh. V. K. Mehrotra, Chief Engineer III, Engineering Department, MCD, Sh. Sanjay Jain, Director (T), Sh. R. C. JaM, Sh. P. K. Khandelwal, Sh. Surinder Pal, Sh. Arun Kumar, Sh. Tufel Ahmed, Sh. Nitesh Gupta, Sh. Brahmanand, Sh. Pardeep Kapoor and all my colleagues who helped me in so many ways and made my research work a comfortable journey. I wish to record my deep sense of gratitude to my parents for their blessings and encouragement, my brother for the good wishes and the help rendered. Finally I acknowledge with love, the patience and co-operation of my wife Poonam and my beloved daughters Aditi and Simran. I am grateful to GOD, the creator and the saviour, who guided me through all the good and difficult times. March, 2005 (Dinesh Kumar) iii

6 ABSTRACT Landfilling is one of the most widely used techniques, despite its numerous environmental problems, for the treatment and disposal of solid wastes. Significant effort has been directed toward the development of improved landfill designs to reduce the negative environmental impacts. Still, at present, about three quarters of the countries and territories around the world use 'open dumping' method of disposal of municipal solid waste. Municipal solid waste landfills, either closed or active, pose threat to human health and the environment. The greatest concern is the potential of leachate from a landfill to pollute the valuable ground water or surface water supplies. Due to a large number of closed and active landfills in every country and the limited resources, decisions regarding landfill remediation have to be based on the comparative evaluation of leachate contamination potential of landfills on a case-by-case basis. An index for easy comparison of leachate contamination potential of different landfills in a given geographical area would be a useful tool in this regard. With this objective in view, a technique has been formulated to quantify the leachate pollution potential of landfills on a comparative scale using an index. The index termed as `Leachate Pollution Index' has been formulated based on the Delphi Technique. In-depth review of the existing environmental indices was performed to adopt an appropriate methodology for formulating the Leachate Pollution Index. A panel of experts from various professions with knowledge in environmental engineering and solid waste management was prepared. For formulating the index, eighteen leachate characteristics viz., Total Chromium, Lead, COD, Mercury, BOD5, Arsenic, Cyanide, iv

7 Phenolic Compounds, Zinc, ph, TKN, Nickel, Total Coliform Bacteria, Ammonia Nitrogen, Total Dissolved Solids, Copper, Chlorides and Total Iron were selected based on the panel's response and subsequent reasoning. Rating curves were developed for all the eighteen parameters based on the response of the panelists. The rating curves express the effect of variation of strength or concentration of an individual parameter on the overall leachate pollution. The eighteen leachate characteristics were given weightages based on their significance values. These eighteen leachate characteristics were integrated using weighted linear sum aggregation function. The weighted linear sum aggregation function for the Leachate Pollution Index was selected after analyzing all the possible aggregation functions. Sensitivity analysis of six short-listed aggregation functions was performed to arrive at the best possible aggregation function. Further, an error analysis was performed to check the suitability of the index in case of lack of information. The Leachate Pollution Index will have many possible applications including ranking of landfills, resource allocation, landfill leachate management, public information and research. Three case studies demonstrating the possible applications of the Leachate Pollution Index, using the data available in the literature, have been presented. In the first case study, four landfills of Hong Kong have been ranked based on their Leachate Pollution Index values. It has been observed that a closed landfill can be potentially more dangerous than an active landfill. In the second case study, the Leachate Pollution Index of an Indian landfill has been computed and a comparison of the Leachate Pollution Index value has been made with the Leachate Pollution Index value calculated for the discharge standards set by the Indian regulatory authorities. The comparison has been made with the discharge standards because, the leachate generated from the landfill is

8 allowed to flow freely on to the soil and adjoining properties without any treatment. The comparison of the two LPI values demonstrated that the leachate generated from the landfill is highly contaminated and shall not be allowed to discharge to the receiving bodies without treatment. In the third case study, wherein, the data generated from an experimental study has been used, Leachate Pollution Index values of the raw and recycled leachate have been calculated to ascertain the leachate recycling as a leachate management option. The study results demonstrate that leachate recycling can be an effective management option and can significantly reduce the leachate contamination potential. It is also observed that it may not be worthwhile to recycle leachate more than two cycles as the leachate contamination potential do not reduce significantly after two recycles. To make the Leachate Pollution Index more informative and useful to the scientific community and field professionals, the eighteen pollutants have been grouped into three groups to formulate three sub-indices viz. LPI-Organic, LPI-Inorganic and LPI- Heavy Metals. Two case studies demonstrating the use of sub-leachate Pollution Indices, using the data available in the literature, have been presented. In the first case study, leachate generated from a UK landfill has been analyzed. It was obs6rved that leachate generated from the landfill is rich in organic pollutants, and acetogenic in nature, while the heavy metal pollutants are low in concentration. In the second case study, the efficiency of a leachate treatment facility installed at an Irish landfill has been evaluated. The results show that the leachate treatment facility is effective in treatment of leachate. The treated leachate however needs some secondary treatment prior to final discharge. vi

9 Based on this study, it can be concluded that a single value index in the form of Leachate Pollution Index, which reflects the composite influence of significant pollutant variables of leachate, is possible. The weighted linear sum aggregation function is relatively more parsimonious and is an appropriate aggregation function for integrating the effect of various pollutants in evaluating Leachate Pollution Index. Leachate Pollution Index can be calculated with marginal error when data for some of the pollutants is not available. This Index can be divided into three sub-indices, LPI-Organic, LPI-Inorganic and LPI-Heavy Metals, and the three sub-lpis along with overall Leachate Pollution Index can be more informative and useful to the field professionals. This index can provide a meaningful and uniform method of assessing the leachate contamination potential of different landfills with respect to their leachate strength at a particular time and can serve as an important information tool for researchers, policy makers and public about leachate pollution potential of the landfills. vii

10 CONTENTS Page No Certificate Acknowledgements Abstract Contents List of Figures List of Tables (i) (ii) (iv) (viii) (xii) (xv) CHAPTER 1 INTRODUCTION General Problem Definition Objectives and Scope of the Study Objective Scope Overview of the Thesis 4 CHAPTER 2 LANDFILLS AND ENVIRONMENTAL PROBLEMS General Landfills Landfill Classification 2.4 Municipal Landfill Categorization Landfills and the World Scenario Landfill Scenario in Asia East Asia/Pacific South and West Asia Landfills in Delhi Landfill Scenario in Africa Landfill Scenario in Europe Landfill Scenario in Latin America and 20 Caribbean Manual landfills Landfill Scenario in North America Environmental Impacts of Landfilling Leachate Formation Mechanisms 27 viii

11 2.8 Leachate Characterization Human Health Effects Associated with Leachate Factors that Affect the Contamination by Leachate Leachate Management Leachate Treatment Leachate Evaporation Leachate Recycling Discharge to Municipal Wastewater Treatment 38 System 2.12 Municipal Solid Waste Management Decisions 39 CHAPTER 3 ENVIRONMENTAL INDICES Introduction Use of Indices Structure of Environmental Indices Sub indices Aggregation of Indices Indices in Use Air Pollution Indices Water Quality Indices General Water Quality Indices Special Use Water Quality Indices Planning Indices Statistical Approaches Decision Making by Delphi Technique Delphi Technique Delphi Procedure Delphi Applications Analysis of National Sanitation Foundation Water Quality 64 Index 3.12 Brown et al.'s Method for Formulating NSF-WQI Index Shortcomings in the Methodology Adopted by Brown 69 et al Proposed Methodology for Calculating Significance 71 Value Reversal of Significance Values Incorporating Experts Opinion Comparison of the Significance Values Calculation of Weightage for Variables Included 76 in NSF-WQI ix

12 CHAPTER 4 DEVELOPMENT AND FORMULATION OF 81 LEACHATE POLLUTION INDEX (LPI) 4.1 General Methodology for the Formulation of Leachate Pollution 81 Index Selection of Leachate Pollution Index Candidate 82 Variables Selection of the Variables Development of Sub-indices Functions Derivation of Weights Aggregation of Sub indices Procedure for Selecting Appropriate 94 Aggregation Function Selection of the Appropriate 96 Aggregation Function for LPI Results and Discussion Sensitivity Analysis Stepwise Procedure to Calculate LPI Step 1: Testing of Leachate Pollutants Step 2: Calculating Sub-index Values Step 3: Aggregation of Sub-index Values Errors Involved in Calculating LPI Due to Non- 113 Availability of Data Methodology Adopted Errors Introduced by Ignoring 114 Pollutant Data Based on the Weight Factor Errors Introduced by Ignoring 119 Pollutant Data Based on Sub-index Value Results and Discussion Error Analysis Using Different Data Set 128

13 CHAPTER 5 APPLICATIONS OF LEACHATE POLLUTION 129 INDEX 5.1 Possible Applications of Leachate Pollution Index (LPI) Case Study 1: Ranking of Four Municipal Landfills 130 Based on Leachate Pollution Potential 5.3 Case. Study 2: Comparison of Leachate Pollution Index 136 of a Landfill with the Standards Set by the Regulatory Authorities 5.4 Case Study 3: Evaluation of Leachate Recycling as a 138 Leachate Management Option using LPI CHAPTER 6 FORMULATION OF SUB-LEACHATE POLLUTION 145 INDICES AND THEIR TYPICAL APPLICATIONS 6.1 General Sub-Leachate Pollution Indices (Sub-LPIs) LPI-Organic (LPlor) LPI-Inorganic (LPIin) LPI-Heavy Metals (LPIhm) Calculation of Sub-LPIs and Overall Leachate 150 Pollution Index 6.4 Case Study 4: Analyzing Landfill Leachate Using Sub- 154 LPIs 6.5 Case. Study 5: Determining Efficiency of a Leachate 158 Treatment Facility CHAPTER 7 CONCLUSIONS Conclusions Future Scope 166 REFERENCES 169 ANNEXURE I 189 ANNEXURE II 203 BIO-DATA 225 xi