UNIT ENVIRONMENTAL PROFILE APPROACH FOR WASTE MINIMIZATION AND TREATMENT

Effective and efficient solutions for waste minimization and waste treatment are the product of evaluating the elements of the hierarchy for waste minimization/pollution prevention. This hierarchy usually flows from source reduction to the disposal step. These steps include: source reduction; reuse; recycle; treatment; and disposal. The highest benefit typically is achieved by addressing the source reduction opportunities and sequentially evaluating reuse, recycle, treatment, and disposal options. In practice, the focus of attention typically is reversed, in that treatment and disposal are the driving forces, and reducing these costs is the initial focal point. To understand and achieve the opportunities and benefits for pollution prevention and waste minimization, the “Unit Environmental Profile” approach is a useful tool. This provides a mass balance on the total production unit or facility and integrates the raw materials and products with the emissions to the various disposal receptors – air, water, or land. The Unit Environmental Profile allows the identification of the major impact areas for particular production units or for the production facility, and it incorporates the management and control elements for a complete solution.This paper discusses these key elements and provides examples of pollution prevention/ waste minimization case studies and how they integrate with waste treatment. Three chemical production case studies are summarized. Two case studies of process change and one of focused pretreatment are presented for illustration. The case studies for the process change are: 1. improved recovery of unreacted raw material to minimize loadings on a biological wastewater treatment plant; and, 2. changes in a batch distillation to prevent the production of a EPA characteristic hazardous waste condition in the water cut. The case study for the focused treatment is the preliminary treatment of a waste constituent in a nitrations process, which created issues for discharge to, and treatment in, the activated sludge biological treatment process for the wastewater, and concern about eventual impacts in the surface water receptor.