Year

2006

Degree Name

Doctor of Philosophy

Department

School of Civil, Mining and Environmental Engineering

Abstract

Water is the basis of all life, human well-being and economic development. It links together all aspects of life on this planet- human and environmental health, food supply, energy and industry. Wastewater is one of the most important sources of surface and ground water pollution due to the chemical and biological pollutants that it contains and is the world’s greatest killer. Some 1.8 million child deaths each year as a result of diarrhoea, the loss of 443 million school days each year from water-related illness and close to 2.8 billion people in developing countries suffering at any given time from a health problem caused by wastewater. Proper wastewater collection and treatment, not only can avert these problems, but also can meet soaring demand- supply imbalances in fresh water through beneficial reuse of qualityeffluent produced at the wastewater treatment plants (WWTPs). Every $1 spent in sanitation and wastewater treatment creates on average another $8 in costs averted and productivity gained in the developing world.

In this study, endeavour is made to look for an approach to transform the operations and management of WWTPs from existing ‘command and control’ licensing to managing in compliance with ‘ecologically sustainable development (ESD)’ principle. This incremental improvement is described in three parts:

Part 1 deals with improving effluent quality by reducing concentration of total suspended solids (TSS) and oil & grease (O&G) using predictive artificial neural networks (ANN) models. It is demonstrated that WWTP ANN models are able to predict effluent TSS and O&G concentration, one to three days in advance, with fair degree of reliability for primary sedimentation, chemically assisted primary sedimentation, biological activated sludge and nutrient removal WWTPs, in spite of the very complex physical, chemical and biological processes involved in wastewater treatment.

Part 2 explains how a regulatory and economic instrument such as ‘load- based- licensing (LBL)’ can be used to measure ecological and human health impact for 25 major harmful chemicals, present in WWTP effluent on the receiving water in terms of a performance indicator, called ‘pollution unit (PU)’. PU takes into account the level of technology, effectiveness of process and resource management and discharge load of 25 pollutants in WWTP effluent and their harmfulness to human health and ecology, and the sensitivity of the receiving water. PU also can be used to measure the environmental damage cost and licence administration cost in $ for pollution caused by WWTPs. Under ‘polluter pays principle (PPP)’, higher the number of PUs generated by a WWTP, the higher would be the pollution damage cost to be paid by the WWTP.

In Part 3, an integrated ISO9001 quality (QMS), ISO14000 environmental (EMS) and AS4801 occupational health and safety (OHS) management system, called IMS, is developed to enable WWTPs to deliver improved environmental, economic and social performance (triple bottom line, TBL) complying ESD principles. IMS achieves improved TBL performance through: (i) identifying and defining customers, stakeholders, employees, regulators, processes, activities, inputs and outputs for a WWTP and their performance targets for quality, environmental and OHS; (ii) identifying, ranking and prioritising risks related to all elements in (i); (iii) developing and deploying policy, strategy and pla n to address the risks; (iv) developing systems, processes and procedures for operations and management of WWTPs; (v) monitoring and measuring performance of WWTPs including auditing, benchmarking and independent certification of IMS; and (vi) reviewing and continuously improving IMS to cost effectively produce quality effluent, biosolids and residuals for beneficial reuse with minimum adverse impacts on environment, human health and safety. In this way, IMS will enhance triple - bottom- line (TBL) performance of WWTPs.

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