[ DRESDEN UNIVERSITY OF TECHNOLOGY VNU UNIVERSITY OF SCIENCE Le Quynh Dung DEVELOPMENT OF A SIMPLIFIED CONCEPT FOR PROCESS BENCHMARKING OF URBAN WASTEWATER MANAGEMENT MASTER THESIS Hanoi - 2011 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com [ DRESDEN UNIVERSITY OF TECHNOLOGY VNU UNIVERSITY OF SCIENCE Le Quynh Dung DEVELOPMENT OF A SIMPLIFIED CONCEPT FOR PROCESS BENCHMARKING OF URBAN WASTEWATER MANAGEMENT Major: Waste Management and Contaminated Site Treatment MASTER THESIS SUPERVISOR: PROF. C PETER WERNER MSC-ENG. PHAN HOANG MAI Hanoi - 2011 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com TABLE OF CONTENTS ABBREVIATIONS. 3 LIST OF FIGURES AND TABLES.
8 Theoretical Foundations of Urban Wastewater Management System .1 Characteristics of Urban Wastewater.1 What is Urban Wastewater? .2 Constituents of Wastewater .2 Overview of the Urban Wastewater Management System .1 Components of Urban Wastewater Management System .2 Types of Wastewater Management System .3 Sub-processes of Wastewater Management System .3 Sludge Treatment and Disposal .4 Effluent Disposal and Reuse .4 Current situation of Urban Wastewater Management in Vietnam .1 The Development of the Urban Drainage System .2 Current Structure and Operation of Urban Drainage Systems .3 The Organizations of Urban Drainage Services in Vietnam .4 Financial Aspects of Urban Drainage Companies .5 Legal and Institutional Frameworks .6 Investment and Management of Urban Drainage System. 42 Benchmarking in the Urban Wastewater Management Sector.1 Fundamentals of Benchmarking .1 Definition of benchmarking .2 Types and elements of benchmarking .2 International Benchmarking System in Water Industry .1 Benchmarking of large Municipal Wastewater Treatment Plants in Austria .2 Benchmarking in Canada .3 North European Benchmarking Co-operation .3 Process Benchmarking in Wastewater Sector.1 What is Process Benchmarking?.2 The Objectives of Process Benchmarking .3 Methodology in Process benchmarking.4 Different Process Benchmarking Concepts. 53 1 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com CHAPTER III. 55 Performance Indicators of Benchmarking in Wastewater Service .1 Basis of Performance Indicators .1 Systems of Performance Indicators .2 The Usage of Performance Indicators (PIs) .3 Performance Indicators – A component of Benchmarking .2 The System of IWA-PIs for Wastewater Services.
65 Performance Assessment and Data Collection for Benchmarking in Wastewater Services of Vietnam .1 Approach of the Performance Assessment .1 Classification of various Undertakings .4 Structure of Questionnaire .2 Questionnaire of Wastewater Management System .3 Performance Indicators for Wastewater Management System .2 Operation and Maintenance .3 Quality of services .5 Economic and financial aspects. 99 2 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com ABBREVIATIONS CSOs Combined Sewer Overflows CI Context Information EWA European Water Association IWA International Water Association NEBC North European Benchmarking Co-operation No. Number PIs Performance Indicators p. Population Equivalent WWTPs Wastewater Treatment Plants 3 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com LIST OF FIGURES AND TABLES Figures Figure 1.1 Representation of a Centralized Wastewater Collection and Treatment System Figure 1.2 Representation of a Decentralized Wastewater Collection and Treatment System Figure 1.3 Schematic of unit operations and processes in a wastewater treatment plant Figure 1.4 Schematic of plug flow and complete mix activated sludge process Figure 1.5 Schematic of trickling filter with rock packing and plastic packing Figure 2.1 Main steps of a benchmarking process Figure 2.2 Extended process model for wastewater treatment plants above 100,000 PE Figure 2.3 Methodology for the development of process performance indicators Figure 2.4 NEBC’s benchmarking model Figure 2.5 Procedure of process benchmarking Figure 3.1 Structure of Wastewater Context Information & Performance Indicator Figure 3.2 Wastewater undertaking context Tables Table 1.1 Principal constituents of concern in wastewater treatment Table 1.2 Important metals in Wastewater Management Table 1.3 Comparison of ratios of various parameters used to characterize wastewater Table 1.4 Typical wastewater flowrates from urban residential sources in the USA Table 1.5 Typical wastewater flowrates from commercial sources in the USA Table 1.6 Typical composition of untreated domestic wastewater Table 1.7 Typical wastewater constituent data for various countries Table 1.8 Major biological treatment processes used for wastewater treatment Table 2.1 Holistic approach versus Selective approach in Process benchmarking Table 3.1 Reliability bands of collected data Table 3.2 The IWA Performance Indicators Table 4.1 Summary of Performance Indicators for Urban Wastewater Management 4 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com ACKNOWLEDGEMENTS This thesis has been developed in Dresden, Germany with the support of some people to whom I would like to express my special thanks.
I would like to thank Prof. Nguyen Thi Diem Trang - Hanoi University of Science and Prof. Bernd Bilitewski - Institute of Waste Management and Contaminated Site Treatment (IAA), Dresden University of Technology (TUD) as well as DAAD because of giving me the chance to do my thesis in Germany. I would like to send my special thanks to Msc.
Phan Hoang Mai, (IAA-TUD), who gave me this topic, supervised and encouraged me to write my thesis. I have learnt some things for my studying from her. Also I would like to thank Dr. Catalin Stefan (IAA-TUD) because of his kind help during the time I was in Dresden.
Thanks are also expressed to Msc. Le Thi Hoang Oanh (IAA-TUD) who was always willing to help me as I need. Especially, I would like to thank my family and friends, who always support and encourage me to finish my thesis. 5 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com INTRODUCTION Wastewater Management is one of the most concerns in any urban area.
An efficient management contributes to the wealth of a community, never the less a poor management leads to unpredictable hazards related to health, environmental pollution, etc. In developed countries, the issues of water and sanitation are solved, floodings are well controlled. However, the issues of water supply and sanitation are not solved in developing countries, poor management of floodings as well as improper operation and maintenance of sewer systems are very popular. Therefore, it is an urgent requirement to improve the system of wastewater management in developing countries.
Benchmarking is promised to be a solution to this problem as it is always the useful tool for improvement in management. Benchmarking was first time introduced by Xerox Company in the late 1970s when their peer company Fuji produced the photocopiers with better quality and lower prices. Xerox was forced to critically review their products and production costs by adopting the Japanese philosophy: gaining the best of the bests by learning, adapting and improving (Parena et al. That was how benchmarking appeared.
In many countries experiences (Xerox model inspired) have been developed to adapt benchmarking procedures in the water context (Parena et al. Benchmarking has been conducted in many developed countries such as Australia, Canada, England, Germany etc. to assess the performance of water and wastewater service providers, to estimate the quality of services as well as the satisfaction of customers. These benchmarking projects have achieved initial success and are supposed to sustain.
Some systems of performance indicators have been developed with the purpose of large scale application such as the system International Water Association or Qualserve system, etc. In some developing countries such as India, Vietnam, etc. certain benchmarking projects regarding the issue of water and sanitation have been carried out under the support of the World Bank. Aiming at developing a simplified concept for process benchmarking of urban wastewater management which can be applied in developing countries, performance indicators and questionnaire prepared for benchmarking in Vietnam, a representative of developing 6 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com countries are adapted in this thesis based on the International Water Association (IWA) system of performance indicators for wastewater services.
There are four chapters in the thesis. Chapter I considers the foundation of urban wastewater management in general and the current situation of wastewater management in urban areas of Vietnam. In chapter II, fundamentals of benchmarking and process benchmarking for the water industry are discussed. To make clear the tool of performance assessment presented in the thesis the performance indicators for wastewater services of IWA as well as the basis of performance indicators are given in chapter III.
Chapter IV explains the performance indicators selected for process benchmarking in wastewater services of Vietnam; also, the questionnaire as well as the excel file to collect data from wastewater undertakings are presented. Benchmarking of wastewater utilities is emerging as an important tool of performance improvement by regular monitoring and analyses can be the solution to this reality. It can play a significant role in the sector as a tool for institutional strengthening. Sustained benchmarking can help utilities in identifying performance gaps and gaining improvements by the sharing of information and best practices, ultimately resulting in better services to people.
It is expected that benchmarking in wastewater services in developing countries will soon be supported to implement. 7 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com CHAPTER I Theoretical Foundations of Urban Wastewater Management System In this chapter the theoretical foundations of urban wastewater management will be considered, including: (1) characteristics of urban wastewater, (2) overview of the urban wastewater management system, (3) sub-processes of wastewater management system and (4) current situation of urban wastewater management in Vietnam.1 Characteristics of Urban Wastewater 1.1 What is Urban Wastewater? According to Tchobanoglous et al. 2003, urban wastewater components may vary depending on type of collection system and may include: 1. Wastewater discharged from residential areas, and from commercial, institutional and similar facilities.
Wastewater in which industrial wastes predominate. Runoff resulting from rainfall 4. Water that enters the collection system through indirect and direct means. Infiltration is extraneous water that enters the collection system through leaking joints, cracks and breaks, or porous walls.
Inflow is stormwater that enters the collection system from storm drain connections, roof leaders, foundation and basement drains, or through access port (manhole) covers.2 Constituents of Wastewater The constituents of wastewater can be classified as physical, chemical and biological. Of the constituents listed in table 1.1, suspended solids, biodegradable organics and pathogen organisms the most concerning ones are referred. All wastewater treatment facilities are designed to remove these constituents completely.1 Physical Characteristics Solids There are many kind of solids present in wastewater, varying from coarse to colloidal ones. Before any analysis of solids in wastewater the coarse material should be removed.
In wastewater treatment, the solids can be classified by their size and state (suspended solids & 8 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com dissolved solids), by their chemical characteristics (volatile & fixed solids) and by settleability (settable suspended solids & non-settable suspended solids) (Sperling, 2007) Table 1.1 Principal constituents of concern in wastewater treatment a Constituents Reason for Concern Total suspended solids Sludge deposits and anaerobic conditions Biodegradable organics Depletion of natural oxygen resources and the development of septic conditions Dissolved inorganics (e. total Inorganic constituents added by usage. Recycling and dissolved solids) reuse applications Heavy metals Metallic constituents added by usage. Many metals are also classified as priority pollutants Nutrients Excessive growth of undesirable aquatic life, eutrophication, nitrate contamination of drinking water Pathogens Communicable diseases Priority organic pollutants Suspected carcinogenicity, mutagenicity, teratogenicity, or high acute toxicity.
Many priority pollutants resist conventional treatment methods (known as refractory organics) a: From Crites & Tchobanoglous, 1998 Particle Size Distribution The determination of particle size is to understand more about nature of particles composing TSS in wastewater. In addition, this analysis is also used to assess the effectiveness of treatment process (biological treatment, disinfection process, sedimentation, etc). Turbidity Turbidity is a measure of the light-transmitting properties of water. Turbidity is used to indicate the quality of waste discharges and natural waters regarding colloidal and residual suspended matter (Tchobanoglous et al.
Color Color in wastewater is caused by suspended solids, colloidal matters and dissolved substances. With suspended solids, it is called apparent color whereas true color is caused by colloidal matters and dissolved substances. 9 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com The sources of color in wastewater include infiltration/inflow (humic substances), industrial discharges (e. dyes or metallic compounds, etc) and the decomposition of organic compounds in wastewater.