Recycle & Reuse of Industrial Wastewater: Considerations for Evaluation and Implementation

In the past, recycle and reuse programs have been implemented in arid climates and locations where water resources are limited. But more recently, evaluation and implementation of recycle/reuse programs in other regions are being considered by numerous industries. Although the primary consideration is still bottom-line economics, there are several other criteria that should be considered in the evaluation of recycle/reuse. This paper outlines the steps to be taken during to evaluate the overall feasibility of water recycle/reuse. Beyond bottom-line economics, key drivers presented in this paper are: •Increasing stringent regulatory impacts on plant effluent • Community relations/environmental stewardship • Limitations of plant expansion due to water consumption or discharge restrictions •Changes or variability in water quality A systematic methodology to evaluate potential recycle/reuse opportunities is the key to success. The approach presented in this paper comprises: Evaluating water sources. It is critical that an accurate water balance and mass balance for key parameters be developed. Procedures to develop an accurate water balance are presented. Both source water and effluent water quality and quantity should be identified. Key parameters are presented and discussed. Identifying water needs. The required quality and quantity of the receivers of recycled wastewater needs to be understood. Specific regulatory framework must also be considered (i. e., SDWA, FDA cGMP, etc.) as to the feasibility of recycling wastewater to certain re-users. Technology evaluations. Identifying what equipment or conditioning is required to recycle and reuse wastewater and what waste streams/residuals are generated. Limitations and key design parameters for each technology is discussed. Developing a recycle strategy By combining the information gathered and the technologies to be considered, mass balances for each alternative scenario should be developed. The mass/flow balance will provide information on percent of allowable recycle, required flowrates, and resulting equipment sizing. Capital and operating costs are developed to assess return on investment (ROI) or other key financial metrics.