Reverse Osmosis Recovery Maximization

Introduction:  The world’s water consumption rate is doubling every 20 years, outpacing by two times the rate of population growth. The availability of good quality water is on the decline and water demand is on the rise. Worldwide availability of fresh water for industrial needs and human consumption is limited. Various industrial and developmental activities in recent times have resulted in increasing the pollution level and deteriorating the water quality. Water shortages and unreliable water quality are considered major obstacles to achieve sustainable development and improvement in the quality of life. The water demand in the country is increasing fast due to progressive increase in the demand of water for irrigation, rapid industrialization, and population growth and improving life standards. The existing water resources are diminishing (i) due to unequal distribution of rain water and occasional drought, (ii) excessive exploitation of ground water sources and its insufficient recharge, (iii) deterioration of water quality due to the discharge of domestic and industrial effluents without adequate treatment. This is resulting into water stress/ scarcity. Country is currently passing through social and economic transition. The proportion of the population which is urban has doubled over the last thirty years (and is now about 30%), agriculture now accounts for about 25% of GDP and the economy has been growing at around 7-9% a year. Country has a highly seasonal pattern of rainfall, with 50% of precipitation falling in just 15 days and over 90% of river flows in just four months

NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the panel responsible for the report were chosen for their special competences and with regard for appropriate balance. Support for this study was provided by the U.S. Bureau of Reclamation under Grant No. 06CS811198. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organizations or agencies that provided support for the project.

Abstract: The purpose of this research project was to identify the discharge information that permitting agencies need and the decision-making process they go through to permit discharge methods in order to help desalination project proponents focus and expedite their permitting efforts. The project documented seawater reverse osmosis (SWRO) discharge regulatory issues and provided a critical overview of facility discharge-related information required for permitting desalination projects in the United States and selected countries with advanced environmental regulations and experience in implementing seawater desalination projects. Information was gathered from the three key U.S. states (California, Florida, Texas) where interest in SWRO desalination has been highest. Due to the more extensive international experience with SWRO desalination, information was also obtained from the countries of Australia, Israel, and Spain – all countries of significant recent large-scale SWRO desalination projects. Case studies of 11 SWRO plants and analysis of regulatory systems and permitting processes supported detailed definition of the decision-making process to set discharge permit limits, as well as defining environmental and other regulatory issues associated with concentrate regulation.