Co culture of microalgae and bacteria for wastewater treatment coupling with biomass recovery

VIETNAM NATIONAL UNIVERSITY HO CHI MINH CITY HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY NGUYEN HONG HAI CO-CULTURE OF MICROALGAE AND BACTERIA FOR WASTEWATER TREATMENT COUPLING WITH BIOMASS RECOVERY NUÔI CẤY VI TẢO - VI KHUẨN CỘNG HỢP ĐỂ XỬ LÝ NƯỚC THẢI KẾT HỢP VỚI THU HỒI SINH KHỐI Major: Environmental Engineering Code: 8520320 MASTER THESIS HO CHI MINH CITY, February 2022 THIS RESEARCH IS COMPLETED AT HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY – VNU-HCM Instructor: Assoc Prof Dr Bùi Xuân Thành Examiner : Assoc Prof Dr Nguyễn Thị Thanh Phượng Examiner : Assoc Prof Dr Lê Đức Trung Master’s Thesis defended at HCMC University of Technology, VNU-HCMC on February 18, 2022 The Board of The Master’s Thesis Defense Council includes: Chairman: Prof Dr Nguyen Van Phuoc Secretary: Dr Vo Thanh Hang Examiner 1: Assoc Prof Dr Nguyen Thi Thanh Phuong Examiner 2: Assoc Prof Dr Le Duc Trung Member: Assoc Prof Dr Nguyen Nhat Huy Verification of the Chairman of the Master’s Thesis Defense Council and the Dean of the Faculty of Environment & Resource after the thesis being corrected (if any) CHAIRMAN Prof Dr Nguyễn Văn Phước DEAN OF FACULTY OF ENVIRONMENT & RESOURCE VIETNAM NATION UNIVERSITY HCMC HCMC UNIVERSITY OF TECHNOLOGY SOCIALIST REPUBLIC OF VIETNAM Independence – Liberty - Happiness THE TASK SHEET OF MASTER’S THESIS Full name: Nguyễn Hồng Hải Learner ID:1970162 Day of birth: 24/01/1996 Place of birth: Ho Chi Minh city Major: Environmental Engineering Major code: 8520320 I THESIS TOPIC: Co-Culture Of Microalgae And Bacteria For Wastewater Treatment Coupling With Biomass Recovery/ Nuôi Cấy Vi Tảo - Vi Khuẩn Cộng Hợp Dể Xử Lý Nước Thải Kết Hợp Với Thu Hồi Sinh Khối II TASKS AND CONTENTS: The study includes the following mission with relating contents as below: Evaluate the formation and characterization of activated (microalgae + sludge) granule in PBR with SBR mode Definition of optimal operating conditions for cultivation of activated granules in photobioreactor Evaluation of batch MPBR for granular activated algae on biomass recovery and wastewater treatment III TASKS STARTING DATE: 05/09/2022 IV TASKS ENDING DATE:18/12/2022 V INSTRUCTOR: Assoc Prof Dr Bùi Xuân Thành Tp HCM, ngày tháng năm 20 INSTRUCTOR HEAD OF DEPARTMENT Assoc Prof Dr Bùi Xuân Thành DEAN OF FACULTY OF ENVIRONMENT & RESOURCE i ACKNOWLEDGEMENT First of all, I would like to express my deep respect and appreciation to Assoc./Prof Bui Xuan Thanh, my career father, my inspirational advisor who gave me valuable advice during my time studying and researching at Ho Chi Minh City University of Technology Without his dedication, enthusiasm, and erudite knowledge, I would not be able to overcome the difficulties to complete this thesis and this study Thank you so much my team Bird Fighter, Kim Qui – Hong Ngoc – Phuong Uyen, for helping me so much from the very beginning of this study Thanks guys, always by my side to work with me during years It was a lot of memory with you, I never forget Thank you, my seniors, my fellows in BIOSEP Research Group for helping me improve my knowledge and practical skills during my time working with the group A special thanks to VINIF fund for granting me Master Scholarship which supported me so much during my study time ii ABSTRACT In this study, activated algae granule was achieved by cultivated mixed culture inside PBR Granulation and wastewater treatment of activated algae from Chlorella vulgaris microalgae strain and bacteria from AS was investigated through different agitation speeds of 80, 120, 160, 200 rpm (shear stress of 0.04-0.69 Pa) The stable ability in treating COD, ammonium, TP of activated algae, with the highest achieved removal efficiency were 92%, 85% and 91%, respectively During granulation process, EPS and filamentous microalgae are the main observed factors contribute to the granule formation Shear stres below 0.15 Pa could not form granule The largest granule was achieved at R200 – shear stress of 0.69 Pa (339.1 µm), but R160 (shear stress 0.35 Pa) gave optimal results in terms of granule formation time, as well as wastewater treatment efficiency Shear stress from 0.04 – 0.15 Pa could guarantee mass transfer for the entire co-culture without aeration Shear stress from 0.15 – 0.69 Pa is a suitable range for the granulation process of activated algae The different strategy of EPS in the microbial community also affected by various hydraulic shear force combining with the stress caused by retention time The hydrodynamic shear by agitation was found to determine the structure of granules and regulated the granulation including its transformation stage, the EPS regulation and dominant microbial community Therefore, the present study adds insight into the comprehensive understanding of the effect of hydraulic shear stress induce granulation formation on activated microalgae iii TÓM TẮT Trong nghiên cứu này, kích hoạt hạt tảo đạt nuôi cấy hỗn hợp nuôi cấy bên PBR Quá trình tạo hạt xử lý nước thải tảo hoạt tính từ chủng vi tảo Chlorella Vulgaris vi khuẩn AS khảo sát thông qua tốc độ khuấy trộn khác 80, 120, 160, 200 vòng/phút (ứng suất cắt 0,04-0,69 Pa) Khả xử lý COD, amoni, TP tảo hoạt tính ổn định với hiệu suất xử lý đạt cao 92%, 85% 91% Trong trình tạo hạt, EPS vi tảo dạng sợi yếu tố quan sát góp phần hình thành hạt Lực cắt 0,15 Pa tạo thành hạt Hạt lớn đạt R200 – ứng suất cắt 0,69 Pa (339,1 µm), R160 (ứng suất cắt 0,35 Pa) cho kết tối ưu thời gian tạo hạt hiệu xử lý nước thải Ứng suất cắt từ 0,04 – 0,15 Pa đảm bảo chuyển khối cho tồn hệ thống đồng ni cấy mà khơng cần sục khí Ứng suất cắt từ 0,15 – 0,69 Pa khoảng thích hợp cho q trình tạo hạt tảo hoạt tính Chiến lược khác EPS cộng đồng vi sinh vật bị ảnh hưởng lực cắt thủy lực khác kết hợp với ứng suất gây thời gian lưu Lực cắt thủy động lực học cách kích động tìm thấy để xác định cấu trúc hạt điều chỉnh trình tạo hạt bao gồm giai đoạn biến đổi nó, quy định EPS cộng đồng vi sinh vật chiếm ưu Do đó, nghiên cứu bổ sung nhìn sâu sắc hiểu biết toàn diện ảnh hưởng ứng suất cắt thủy lực gây hình thành hạt vi tảo hoạt hóa iv LỜI CAM ĐOAN Tôi tên Nguyễn Hồng Hải, học viên cao học ngành Kỹ thuật Mơi trường khóa 2019, mã số học viên 1970162 Tôi xin cam đoan: Luận văn cao học cơng trình nghiên cứu khoa học thực thân tôi, thực dự hướng dẫn PGS.TS Bùi Xuân Thành Các hình ảnh, số liệu thông tin tham khảo luận văn thu thập từ nguồn đáng tin cậy, qua kiểm chứng, công bố rộng rãi tơi trích dẫn rõ ràng phần Tài liệu tham khảo Các đồ, đồ thị số liệu tính tốn kết nghiên cứu thực nghiêm túc trung thực Tôi xin lấy danh dự uy tín thân để đảm bảo cho lời cam đoan GUARANTEE My name is Nguyen Hong Hai, I am a graduate student in Environmental Engineering, class of 2019, student number 1970162 I hereby declare that this master thesis is my own true scientific research work carried out under the guidance of Assoc.Prof.Dr Bui Xuan Thanh The images, data and reference information in this thesis are collected from reliable, verified, widely published sources and are clearly cited by me in the References section The maps, graphs of calculated data and research results are done seriously and honestly by me I pledge my honor and reputation to back this statement Master Student Nguyễn Hồng Hải v TABLE OF CONTENT ACKNOWLEDGEMENT i ABSTRACT ii GURANTEE ii TABLE OF CONTENT viii LIST OF FIGURES viii LIST OF TABLES x ABBREVIATIONS xi CHAPTER INTRODUCTION 1.1 General context 1.2 Objectives of the study 1.3 Research scope 1.4 Research content 1.5 The meaning of the topic CHAPTER LITERATURE REVIEW 2.1 Co-culture of Microalgae-Bacteria 2.1.1 Wastewater treatment using microalgae-based systems 2.1.2 Interactions within co-culture .7 2.1.3 Wastewater treatment by co-culture 11 2.1.4 Co-culture systems and configurations in wastewater treatment 13 2.1.5 Challenges and operational conditions of co-culture system 14 2.2 Microalgae – Bacteria flocculation 15 2.2.1 Bio-flocculation 15 2.2.2 Factors influencing bio-flocculation 17 vi 2.2.3 Flocs structure 18 2.2.4 Challenges in bio-flocculation 19 2.3 Activated Microalgae granules 19 2.3.1 Characteristics of Activated Microalgae granules (AMGs) 19 2.3.2 Influence factors on AMGs 23 CHAPTER MATERIALS AND METHOD 28 3.1 Overall reseach content 28 3.2 Microbial and synthetic wastewater 29 3.2.1 Microalgae and symbiotic bacteria strain 29 3.2.2 Wastewater 31 3.3 Experimental set-up and operating conditions of photobioreactors (PBR) system32 3.3.1 Experimental set up 32 3.4 Analysis methods: 35 CHAPTER RESULTS AND DISCUSSION 44 4.1 Treatment performance 44 4.2 Microalgae activity profile 51 4.3 Impact of shear stress on granulation process of AMGS .55 4.3.1 Size distribution 56 4.3.2 Settleability 60 4.3.3 EPS secretion 60 4.3.4 Granulation mechanism 66 CHAPTER CONCLUSIONS AND RECOMMENDATIONS 77 5.1 Conclusions .77 vii 5.2 Recommendations 77 REFERENCES 78 PROFILE (Phần Lý Lịch Trích Ngang) 100 TRAINING PROCESS 100 WORKING PROCESS 100