Chapter 8 - Industrial Water Reuse Technologies

Abstract

This chapter focuses on industrial water reuse. Industrial wastewater treatment is undertaken to meet regulatory compliance. The treatment of wastewater effluent has been seen more as the cost of doing business rather than as a valuable resource. In recent years there is the realization that security of water supply, drought, scarcity of water and increased costs for potable water and sewer discharge are forcing some companies to rethink this minimalist strategy. This chapter provides a step-by-step approach to water reuse and examines the current technologies for water reuse applications. The steps for water reuse projects are: establish the goals of the project, define the project boundaries, gather data, identify and evaluate the water reuse projects—relative to goals, conduct a water reuse technical assessment—desk top as well as a pilot study, implement the new water-reuse model or design, commission new system, monitor operation and review and update the model or design as needed. For a project to be feasible, the proposed treatment technologies need to be reliable, economical, meet water-quality specifications and be safe to use, as determined by regulatory authorities. The potential volume of water available for reuse is dictated by the type of industry sector, the achievable cost savings and the prevailing regulatory environment that enables the reuse of water. The recovery rates fall into three distinct groups. Over 80% of water used is recovered in the steel, chemical and transport machinery sectors. In some industries technological advances such as alkaline sizing are enabling greater mill closure with consequent higher recovery levels of water and fiber.