TECHNICAL AND ECONOMIC EVALUATION OF WATER REUSE FROM WASTEWATER TREATMENTS PLANTS

摘要

Water shortage in recent years has led to the development and application of various methods for water supply and conservation, in order to satisfy the continuously increasing demands especially in places with water shortage. Water recycle and reuse procedures and technologies are based on the idea of properly treating and reusing the water in industries, municipalities and various other cases.Domestic Wastewater Treatment Plants (WWTP) produce significant quantities of effluent water that could possibly be recycled and exploited for various purposes such as irrigation and other secondary uses. The quality specifications of the water for each distinct use are mainly determined by the national and/or locally specific legislation.The present study investigates the possibilities of water reuse from Wastewater Treatment Plants. It is known that most of the WWTPs produce effluent water that can not further be utilised, since most of the plants do not proceed the waste processing to the so called tertiary stage of treatment. Therefore, there is a wide scope of investigating the technologies, legislative framework and practices that need to be adopted in order to make the existing plants able to produce reusable effluent water. The work focuses on the development of an economic model for the evaluation of the feasibility of converting a wastewater treatment plant from secondary to tertiary treatment, calculating the investment required and the potential benefit from the water selling to various interested users.The proposed method is implemented in a representative size and technology case study with very promising results for the profitability of the method. The economic model can be implemented in various WWTPs and result in an integrated proposal concerning the locations of the plants that can be converted in tertiary treatment and sell the produced water afterwards. Furthermore, environmental impact analysis of various wastewater treatment technologies is also included in the present work.The results of the work include an integrated plan on which WWTPs should be converted and a comparison between this and various alternative methods for water supply.