Summary of Environmental engineering doctoral thesis: Research and development of the internal circulation (IC) high rate anaerobic treatment technology

This thesis focuses on simulating the internal circulation process (gas pulling water) to determine: The amount of water (QN) was pulled up by the amount of gas (QK); and mixing ability of generated gas and circulating water flow, from which to calculate the periodic structure in the IC system.
Nội dung trích xuất từ tài liệu:
Summary of Environmental engineering doctoral thesis: Research and development of the internal circulation (IC) high rate anaerobic treatment technology MINISTRY OF VIETNAM ACADEMY OF EDUCATION AND TRAINING SCIENCE AND TECHNOLOGY GRADUATE UNIVERSITY OF SCIENCE AND TECHNOLOGY Tran Manh Hai RESEARCH AND DEVELOPMENT OF THE INTERNAL CIRCULATION (IC) HIGH RATE ANAEROBIC TREATMENT TECHNOLOGY Major: Environmental Engineering Code: 9.52.03.20 SUMMARY OF ENVIRONMENTAL ENGINEERING DOCTORAL THESIS Hanoi - 2019 This thesis done at: - Department for Technology Application and Tranfer - Institute of Environmental Technology, Vietnam Academy of Science and Technology - Department of Enviromental Technology - Center for Environmental Technology & Sustainable Development (CETASD), Hanoi University of Science (HUS). - Graduate University of Science and Technology - Vietnam Academy of Science and Technology. Supervisor 1: Assoc.Prof., Dr. Cao The Ha Supervisor 2: Assoc.Prof., Dr. Nguyen Hoai Chau The dissertation will be defended at Graduate University of Science and Technology - Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet street, Hanoi. Time: .............,.............., 2019 This thesis could be found at: - National Library of Vietnam - Library of Graduate University of Science and Technology. 1 INTRODUCTION 1. Rationale In the history of development, there are 4 types of anaerobic treatment techniques that have been applied: (1) The continuous stirred-tank reactor - CSTR, (2) Anaerobic contact - AC, (3) Up-flow Anaerobic Sludge Blanket – UASB, and (4) Expanded Granular Sludge Bed - EGSB and Internal Circulation - IC. In the past 40 years, many high-rate anaerobic techniques have been applied with different designs [2]. The references show that IC and EGSB system are the most advanced and efficient one, the IC technology has the highest loading rate and productivity in current techniques [3]. Therefore the growth rate of IC systems is very high. In 1997 the world had 32 IC systems, up to 2007 there were 2266 all over the world and by 2015 the estimated number of installed high-load anaerobic systems exceeded 4.000 [4]. An important feature of microbiological treatment techniques is mixing, increasing mixing make to increase of contact and reaction ability of microorganisms with pollutants, so increase the efficiency of metabolism. The UASB and EGSB techniques use the energy of generated gas and circulating flow (using circulating pump) to increase mixing ability. IC technology uses gas generated to circulate water. This is the advantage that makes ICs highly efficient while consuming less energy (because of no use of circulating pump). In order to study the fabrication of IC systems, the key point is to study the fabrication of re-circulating structures that requires no external energy (circulating pumps), using the process of drawing water with self-generated gas to circulate mixed mud and sewage. 2 Currently, UASB design guidelines are relatively common while water circulation techniques such as ICs are rarely published. For example, the latest monograph on waste water biotechnological treatment Handbook of Biological Wastewater Treatment, 2012 [5] there are 14 examples of the UASB system design with detailed explanation of the UASB without any examples of advanced system of EGSB and IC types. Therefore, in order to promote IC system application in Vietnam, it is necessary to have researches to determine basic parameters for equipment design and manufacture. This thesis focuses on simulating the internal circulation process (gas pulling water) to determine: (i) the amount of water (QN) was pulled up by the amount of gas (QK); and (ii) mixing ability of generated gas and circulating water flow, from which to calculate the periodic structure in the IC system. This thesis also presents the results of fabrication experiment of IC model system at lab scale to determine the processing capacity of IC system when operating the system with pig-farming wastewater. 2. Research targets Study on application of the internal circulation anaerobic treatment system (IC) in the treatment of organic-rich wastewater, specifically: (i) Establishs the relationships between commonly used parameters (load, surge rate) and IC system design parameters (size of the riser, reaction area height). (ii) Determines the correlation between the load and processing capacity of the IC anaerobic system in case of swine wastewater. 3 (iii) Determines the mixing ability by generated gas in the system. (iv) Determine value parameters (equipment height, reaction area height, inside diameter, size of the riser) to serve the anaerobic IC design. 3. Research content Content 1: Experiment to determine the K ratio equal to the amount of water (QN) which was pulled up by the amount of gas (QK) depends on the riser cross section (S), submergence levels (H1), water discharge heigh (H2) at the constant viscosity and density solution Content 2: Create equations to represent the relationship of K with parameters: riser cross section (S), submergence depth (H1), water discharge height (H2) at the constant viscosity and density. Content 3: Fabrication and operation of the IC system with swine wastewater to determine the processing capacity of the IC system. Content 4: Calculation of mixing ability of generated gas and circulating water to determine IC system design parameters. CHAPTE I: REVIEW In the field of ...