LABORATORY WASTEWATER TREATMENT USING CLAY BIOCHAR COMPOSITES IN BIO-GEO FILTERS Vinitha Pathinayaka (168419L) Master of Science in Building Services Engineering Department of Mechanical Engineering University of Moratuwa Sri Lanka August 2021 LABORATORY WASTEWATER TREATMENT USING CLAY BIOCHAR COMPOSITES IN BIO-GEO FILTERS Vinitha Pathinayaka (168419) Thesis submitted in partial fulfillment of the requirements for the degree Master of Science in Building Services Engineering Department of Mechanical Engineering University of Moratuwa Sri Lanka August 2021 i DECLARATION "I declare that this is my own work, and that this thesis does not incorporate without acknowledgement any material previously submitted for a Degree or Diploma at any other University or institute of higher learning, and that it does not contain any material previously published or written by another person to the best of my knowledge and belief, except where acknowledgement is made in the text." In addition, I grant the University of Moratuwa the non-exclusive right to reproduce and disseminate my thesis in whole or in part in print, electronic, or other media. I reserve the right to use this content in whole or in part in future works (for example, articles or books)." Signature: Date: Under our direction, the aforesaid applicant conducted research for her master's thesis. Name of the supervisor: Name of the supervisors: Prof. Bandunee Athapattu Dr.M.M. Inoka D. Manthilake Signature of the supervisor: Date : ii ABSTRACT Laboratory waste is overlooked because of its low flow rate, despite the fact that it has a negative influence on the human and environmental systems. As a result, the focus of this research is on using clay biochar composites in horizontal flow bio geo filters to treat university laboratory wastewater in an environmentally acceptable manner. The composite was made with a 1:5, 1:3, 1:1, 3:1, and 5:1 mass ratio of Cinnamon biochar and Neem biomass to clay from Giant tank, Murunkan, Mannar for laboratory research experiments, and then treated with slow pyrolysis at 400°C. To determine the hydraulic retention period, adsorption kinetic studies and isotherms were performed, followed by the m/v ratio and COD test. For both Neem and Cinnamon, the Clay: Biochar mass ratios, 1:1 ratio composite exhibits superior efficacy in COD elimination. To ensure the presence of Montmonolite, clay samples were analyzed by Laser diffraction particle size analysis. As a result, clay samples taken from the Giant tank contain 3.42% and 4.99% nano clay, respectively. The existence of MMT in Murunkan clay is confirmed by FTIR readings of clay samples from Murunkan, which reveal a distinct and strong band at 998.03 cm -1 and 3620 cm -1 . XRF analysis was used to assess the chemical composition of biochar samples. The use of biochar with a greater K content supports heavy metal sorption and phosphors retention. H/C ratios of Cinnamon and Neem biochars were 0.06 and 0.02 respectively, according to CHN analyses. BET study revealed that the specific surface area (SSA) of gasified Cinnamon Biochar was 563m 2 /g. As a result, it has a higher adsorption affinity. Kinetic model parameters for COD adsorption onto Neem - BC and Cinnamon - BC composites were determined using the most commonly utilized adsorption kinetic mathematical models. The removal effectiveness of adsorbent constructed of Neem biochar composite is better than that of Cinnamon biochar composite. The Bio Geo Filter was created using Subsurface Flow Constructed Wetlands design principles. For the treatment system, a composite sample of on-site stored wastewater was diluted to 1:100. The system is based on a mix of physical, chemical, and biological processes that occur naturally in wetlands and are linked to vegetation, sediments, and the microbial populations that live there. The removal effectiveness of the system for heavy metals (Cd, Cr, Hg, and Mn) was investigated, and all heavy metal concentrations in effluent were much lower than in influent. The effluent quality was assessed and compared to CEA criteria for inland surface discharge. When water travels through the systems and into the tanks, only phosphate levels increase. As a result, methods for using this by-product (Phosphate) as fertilizer must be developed. As a result, our newly designed cost-effective bio-geo filter treatment system is highly recommended for laboratory wastewater purification. Keywords: Laboratory wastewater, Murunkan Clay, Biochar, Constructed wetland, Bio-geo composite, Kinetic models & Isotherms iii ACKNOWLEDGEMENT First and foremost, I want to thank my advisors, Dr. Inoka Manthilaka, Course Coordinator, MSc in Building Engineering Services, Department of Mechanical Engineering, University of Moratuwa, and Prof. Bandunee Athapattu, Professor in Environmental Engineering, Department of Civil Engineering, The Open University of Sri Lanka, for their unwavering patience, motivation, enthusiasm, and immense support throughout my MSc study and research. Their advice aided me in finishing my research and producing this thesis on deadline. Prof. T. Mangaleshwaran, Vice Chancellor, University of Vauniya, and the Dean and Academic Coordinators of Faculty of Sciences (formerly Vauniya Campus, University of Jaffna) deserve special thanks for their support and sponsorship in putting this treatment system in place to treat their laboratory wastewater. My sincere thanks goes to lectures of MSc in Building Services Engineering Prof. R.A.Athalage, Prof. Mahesh Jayaweera, Dr. Asanka Rodrigo, Dr. Anusha Wejewardana, Dr. Chatura Ranasinghe, Dr. Narein Perera, Eng. Samantha Gunawardana, Eng. J.P. Premarathna, Eng. Indradeva Mendis and Eng. Prasanna Narangoda for guiding me to improve the subjects relevant to MSc in Building Services Engineering which leads me working on diverse exciting project. I'd like to thank the OUSL undergraduate students who helped me with this project, Ms. Karthika, Mr. Nimantha, Mr. Niruparan, and Ms. Sashika. Ms. Pradeepa Rajaguru, Senior Technical Officer, Department of Civil Engineering, OUSL, who assisted with this project also deserves my gratitude. I am grateful to the Engineering Testing Laboratories and the employees of the Sri Lanka Institute of Nanotechnology, Homagama, and the Industrial Technology Institute for providing correct testing data in order to evaluate this research. iv TABLE OF CONTENTS DECLARATION i ABSTRACT ii ACKNOWLEDGEMENT iii TABLE OF CONTENTS iv LIST OF FIGURES viii LIST OF TABLES xi LIST OF ABBREVIATIONS xiii Chapter 1 INTRODUCTION 1 1.1 Introduction 1 1.2 Background 2 1.3 Problem Statement 4 1.4 Aim 5 1.5 Objectives 6 1.6 Methodology 6 Chapter 2 LITERATURE REVIEW 8 2.1 Laboratory Wastewater 8 2.1.1 Research Area of Concern 8 2.1.2 Pollutants in Laboratory Wastewater 8 2.1.3 Laboratory Wastewater Generation in Sri Lanka 9 2.1.4 Present Practice of University Laboratories 9 2.1.5 Roles of Analytical Laboratories 10 2.1.6 Effects of Heavy Metals in Laboratory Wastewater 11 2.1.7 Laboratory Wastewater Disposal Practices in Sri Lanka 12 2.2 Methods of Wastewater Treatment 12 2.3 Pollutant Removal Wetland Plants 15 2.4 Study of Biochar as Pollutant Remover 21 2.4.1 Properties of Biochars 21 2.4.2 Biochar Aromaticity and Elemental Ratios 22 2.4.3 Removal Mechanism of Heavy Metal by Biochar 24 2.4.4. Preparation Methods of Biochar 25 2.4.5. Characteristics 26 2.5 Study of Clay as Filter Media 28 2.5.1 Montmorillonite (MMT) 29 2.5.2 Characteristic of Murunkan Clay 30 2.6 Clay –Biochar Composite 31 2.6.1 Clay-Biochar Composite 31 2.6.2 Isotherm 32 v 2.6.3 Kinetics 33 2.6.4 Modifying Biochar 34 2.7 Constructed Wetlands 35 2.7.1 Constructed Wetland Systems 35 2.7.2 Classification of Constructed Wetland Systems 36 2.7.2.1 Surface Flow Systems 37 2.7.2.2 Subsurface Flow Systems 39 2.7.3 Metal Removal Mechanism in Wetlands 41 2.7.4 Design Approach for Horizontal Flow Constructed Wetland 42 2.8 Bio-Geo Filters 44 2.9 Conclusion of Literature 44 Chapter 3 MATERIALS AND METHODS 46 3.1 Methodology 46 3.2 Sample Collection of Raw Materials 47 3.2.1 Clay 47 3.2.2 Cinnamon Biochar 48 3.2.3 Neem Biomass 48 3.2.4 Calicut Tile 49 3.2.5 Wetland Plants 49 3.2.6 Aggregates 51 3.2.7 Data Collection of Laboratory Wastewater 51 3.3 Preparation of Sample 51 3.3.1 Preparation of Clay Biochar Composite 51 3.3.2 Adsorption Isotherm and Kinetic Studies 51 3.4 Characterization of Materials 52 3.4.1 Characterization of Clay 52 3.4.2 Characterization of Biochar 52 3.4.3 Characterization of Wastewater 52 3.4.4 Characterization of Filter Media 53 3.5 Methods 53 3.6. Design Approach 53 3.6.1 Hydraulic Design of Filter Media 54 3.6.2 Vegetation in Constructed Wetland 54 Chapter 4 RESULTS AND DISCUSSION 58 4.1 Characterization of Material 58 4.1.1. Characterization of Murunkan Clay 58 4.1.1.1. Laser Diffraction Particle Size Analysis 58 4.1.1.2 Fourier Transform Infrared Spectorscopy (FTIR) Analysis 58 4.1.2. Characterization of Biochar 60 vi 4.1.2.1. X-Ray Florescence Analysis (XRF) 60 4.1.2.2. Carbon Hydrogen and Nitrogen (CHN) Analysis 61 4.1.2.3. Brunauer-Emmett-Teller (BET) Analysis 62 4.1.3. Characterization of Laboratory Wastewater 62 4.2. Design of the Treatment System 64 4.2.1. Design of the Filter Media 64 4.2.1.1. COD Removal Efficiency of Clay Biochar Composite 64 4.2.1.2. Adsorption Studies 65 4.2.1.3. Phosphate Releasement 70 4.2.2. Hydraulic Design of Prototype Treatment System 71 4.2.2.1. Subsurface Flow (SSF) Constructed Wetland System 71 4.2.2.2. Hydraulic Detention Time 71 4.3 Checking the Efficiency of the System 72 4.3.1 COD removal efficiency in the treatment system 72 4.3.2. Characterization of Treated Laboratory Wastewater 73 4.4 Checking the Efficiency of the System for Heavy metal Removal 73 Chapter 5 DESIGN AND IMPLEMENTATION OF BGF 76 5.1 Location and Area 76 5.2 Existing Condition of the Site 76 5.3 Design of Treatment System 79 5.4 Implementation 83 5.4.1 Preparation of Filter Media 83 5.4.2 Clay Biochar Composite Tiles Preparation 84 5.4.3 Preparation of Absorption Unit 84 5.4.4 Progress of the Implementation Work 85 5.4 5 Wetland plants 85 5.5 Monitoring of the performance 87 5.6 The implemented System 87 5.5 performance of the Treatment System 88 5.6 Cost Estimation 90 Chapter 6 CONCLUSIONS AND RECOMMENDATIONS 91 6.1 Conclusions 91 6.2. Recommendation 92 REFERENCES 93 vii ANNEXURES 102 Annex.1 General Standard Criteria (CEA) 102 Annex.2 Biochars' Basic Utility Properties (Test Category A) 103 Annex.3 Under the EBC Specification Following Parameters Have to be Tested for Biochar 104 Annex.4 Usage of Chemicals in Laboratory in University of Vauniya 105 Annex.5 Design Calculation for laboratory wastewater – University of Vauniya 111 Annex.6 Construction Drawings 115 Annex.7 Test Results 117 Annex.8 Cost Estimation 119 viii LIST OF FIGURES Figure 1.1 Location Map of State Universitiesof Sri Lanka 3 Figure 2.1 A Typical Waste Chemical Neutralization System's Process Flow Diagram 13 Figure 2.2 Types of phytoremediation 16 Figure 2.3 Van Krevelen Diagram for Biochar and Biomass 23 Figure 2.4 Based on the Oxygen to Carbon Ratio in the Residual Solid Product, a Spectrum of Black C Products 24 Figure 2.5 Heavy metal removal using conventional methods 24 Figure 2.6 Schematic representation of the MMT structure 29 Figure 2.7 3D view molecular structure of MMT 30 Figure 2.8 Scanning Electron Microscope image of MMT 30 Figure 2.9 Biochar modification processes are classified using classification systems 35 Figure 2.10 Classification of Constructed Wetlands 37 Figure 2.11 Constructed Wetlands with Free Water Surface 38 Figure 2.12 Floating Treatment Wetlands 38 Figure 2.13 Constructed Wetlands with Horizontal Subsurface Flow 39 Figure 2.14 Constructed Wetlands with Vertical Flow 40 Figure 2.15 Hybrid CWs made up of a variety of different CW types 41 Figure 3.1 Flow Diagram of Research Methodology 46 Figure 3.2 Google Image of Sample Collected Location 48 Figure 3.3 Gasifier of the Heritance Kandalama 49 Figure 3.4 Image of Cyperus corymbosus (Gal ehi) 49 Figure 3.5 Image of Vetiveria zizanioides (Savandara) 50 Figure 3.6 Image of Cannas 50 Figure 3.7 Image of Cosmos Sulphureus 50 Figure 3.8 Image of Mustard 50 Figure 3.9 Image of Cattail 50 Figure 3.10 General Arrangement of Wastewater Treatment Tank 56 Figure 3.11 Image of Arrangements to Treatment 57 Figure 3.12 Treatment System Flow Diagram 57 Figure 4.1 Sample 01 Particle Size Analysis Graph 59 Figure 4.2 Particle Size Analysis Graph for Sample 02 59 ix Figure 4.3 Clay Sample from the Murunkan Area FTIR Spectroscopy 60 Figure 4.4 ppm Concentration there are fewer hazardous components 63 Figure 4.5 ppm Harmful and Toxic Elements Found in Lab Wastewater Concentration 63 Figure 4.6 Heavy Metal Concentration in the Laboratory Wastewater in ppm 64 Figure 4.7 Different Composites' Influence and Effluent Concentration on Cinnamon Biochar Composites 65 Figure 4.8 Different Composites' Influence and Effluent Concentration on Neem Biochar Composites 65 Figure 4.9 COD adsorption kinetic model parameters on Neem-BC and Cinnamon-BC composites at 320°C 66 Figure 4.10 For Neem – BC and Cinnamon –BC composites Pseudo First Order Kinetic Model was developed 67 Figure 4.11 For Neem – BC and Cinnamon –BC composites, a pseudo second order kinetic model was developed 67 Figure 4.12 For Neem – BC and Cinnamon –BC composites, the Freundlich Isotherm model was used 68 Figure 4.13 The Variation in COD Concentration over Time 69 Figure 4.14 COD Removal Efficiency with Time 70 Figure 4.15 Dissolved Phosphate Variation over Time in Various pH Conditions 70 Figure 4.16 The Treatment System in Cross Section 71 Figure 4.17 Percentage of removal effectiveness with tanks 72 Figure 4.18 Batch 15 & 16 Effluent 73 Figure 4.19 The Treatment System in Cross Section 74 Figure 5.1 Images of the Laboratory Building and Available land 77 Figure 5.2 Layout Plan of Ground Floor in Chemistry Laboratory 77 Figure 5.3 Layout Plan of 1 st Floor in Chemistry Laboratory 78 Figure 5.4 Layout Plan of Existing Sewerage System 78 Figure 5.5 Layout Plan of the Treatment Plant 81 Figure 5.6 Details of Elements of the treatment system 82 Figure 5.7 Cross section of absorption unit 83 Figure 5.8 Biochar prepared at the site 84 Figure 5.9 Preparation of composite tiles 84 Figure 5.10 R/F work for the absorption unit 85 Figure 5.11 Formwork for the absorption unit 85 x Figure 5.12 Completed structure for the absorption unit 85 Figure 5.13 Laying of filter media 86 Figure 5.14 Before implementation of the treatment system 87 Figure 5.15 After implementation of the treatment system 87 Figure 5.16 After implementation of the treatment system at the rear 87 Figure A.5.1 Longitudinal section of absorption unit 115 Figure A.5.2 Cross section 5-5 of Absorption unit 116 Figure A.5.3 Cross section 4-4 of Absorption unit 116 xi LIST OF TABLES Table 2.1. Chemicals Used in Analytical Laboratories 10 Table 2.2. Different Types of Technology for Wastewater Treatment in the Laboratory 14 Table 2.3 Minimization Programs for Laboratory Wastewater 15 Table 2.4 List of research that have been undertaken to remove H/M from contaminated soil 17 Table 2.5 Different types of adsorption 25 Table 2.6 Removal Mechanisms for Biochar-Based Adsorbents 25 Table 2.7. Comparison of Biochar Production Techniques 26 Table 2.8 Previous Studies of Biochar Preparation Method and Removed Heavy Metals 27 Table 2.9 Heavy Metal Removal Using Clay-Biochar Composites in the Previous era 34 Table 2.10 Heavy Metal Removal Mechanisms in Constructed Wetlands (Summary) 43 Table 2.11 Heavy Metal Concentration in Roots and Shoots of Vetiveria zizanioides 44 Table 3.1: Coordinates of Extracted Place 47 Table 4.1 Chemical Composition of Biochar Sample in Relation to Prominent Elements' Mass Percentage 61 Table 4.2 Elemental Concentrations of Carbon, Hydrogen, and Nitrogen in Relation to Mass Percentage 61 Table 4.3 Important Parameters of the Influent Wastewater 62 Table 4.4 Adsorption of COD onto Neem-BC and Cinnamon-BC composites kinetic model parameters 68 Table 4.5 Influence Sample Test Results 74 Table 4.6 Effluent Sample Test Results 74 Table 4.7 Tolerance limits for treated wastewater effluents under the Central Environmental Authority's General Standards 75 Table 5.1 Existing Fittings 79 Table.5.2 Additional Facilities for the Bio Chemistry Building 79 Table. A.1 General Standard Criteria for the Discharge of Industrial Effluent into Inland Surface Waters 102 Table. A.2 Test Category A: Basic Utility Properties (Required for All Biochars) 103 Table. A.3 Under the EBC Specification Following Parameters Have to be Tested for xii Biochar. 104 Table. A.4 Usage of Chemicals - Laboratory in Vavuniya University 105 Table. A.7 Test Results 117 Table. A.8 Cost Estimation 119 xiii LIST OF ABBREVIATIONS UGC - University Grant Commission SLSI - Sri Lanka Standard Institute NBRO - National Building Research Organization NWS&DB - National Water Supply and Drainage Board ITI - Industrial Technology Institute CEA - Central Environmental Authority SLLDC - Sri Lanka Land Development Corporation CECB - Central Engineering Consultancy Bureau NERD - National Engineering Research and Development OUSL - Open University of Sri Lanka COD - Chemical Oxygen Demand BOD - Bio Chemical Oxygen Demand TDS - Total Dissolved Solids TSS - Total Suspended Solids SSA - Specific Surface Area BC - BioChar WHO - World Health Organization UV - Ultra Violet HDPE - High Density Polyethylene IBI - International Biochar Initiative MMT - Montmorillonite XRD - X-ray diffraction DTA - Differential thermal analysis TGA - Thermogravimetric Analysis FTIR - Fourier transform infrared spectroscopy BET - Brunauer-Emmett-Teller (BET) XRF - X-Ray Florescence Analysis SEM - Scanning Electron Microscopy CEC - Cation Exchange Capacity FWS CW - Free water surface constructed wetlands FTWs - Floating Treatment Wetlands HSF CW - Horizontal Subsurface Flow Constructed Wetland VF CWs - Vertical Flow Constructed Wetlands HFSS - Horizontal flow subsurface