RENOVATION OF ALUMINUM PLANT WASTEWATER
FOR NONPOTABLE REUSE
James Kane, Research Engineer
Richard Osantowski, Research Engineer
Environmental Research Center
Rexnord, Inc.
Milwaukee, Wisconsin 53214
This project was undertaken to evaluate the effectiveness of selected advanced waste
treatment technologies for renovating industrial process waters to meet nonpotable reuse
applications. The project was funded by the Office of Water Research and Technology
under Contract No. 14-34-0001-7805 to demonstrate the feasibility of supplementing
existing water supply sources by wastewater reuse, thereby conserving limited national
water resources. Specifically, the purpose of this project was to determine the most feasible
approach to treat and reuse the wastewaters generated by a high water usage industry,
namely the primary aluminum industry. There are 12 companies in the United States operating 32 plants engaged in primary aluminum production. Annual gross water usage for this
industry is estimated at 2.732 x 10*' liters (722 billion gallons) with 6.55 x 1010 liters
(173 billion gallons) discharged.
The project objective was achieved through the performance of an in-depth pilot plant
program investigating the applicability of the advanced treatment methods reverse osmosis
and electrodialysis for renovating the aluminum products wastewater. The pilot program
goal was to put 3000 operating hours on the membrane processes, reverse osmosis and
electrodialysis. This goal was established to provide long-term operating data that could be
used to predict membrane life for this wastewater. The study was performed using mobile
treatment facilities containing pilot scale desalting and pretreatment equipment. The portable waste treatment systems were field operated for six months at the research site. The
pilot scale systems were of sufficient size to permit scale-up of performance and basic
design criteria to full size equipment.
The advanced waste treatment trains investigated on a pilot basis included the following:
1. chemical flocculation/clarification (CF) + multimedia filtration (F) + reverse osmosis
(RO); and
2. CF + F + electrodialysis (ED).
For each treatment train investigated, samples and operational data were obtained for
later use in evaluating and comparing the adequacy of the individual advanced waste treatment methods.
Evaluation and comparison of the data were performed using the criteria: (1) process
and/or treatment train performance; and (2) residual or side-stream characteristics and
disposal options.
DESCRIPTION OF PILOT EQUIPMENT
This investigation was conducted using the Rexnord Advanced Waste Treatment (AWT)
van in conjunction with the Office of Water Research and Technology's (OWRT's) mobile
desalting treatment system. These mobile pilot treatment systems are housed in two semitrailer vans and are shown in Figures 1 and 2.
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