ALAR Replaces Clarifier & Filter Press - Reduces Heavy Metal

Problem: A Midwestern metal finishing company, specializing in zinc plating, utilized a conventional clarifier and filter press to process overflow rinses and an occasional acid tank dump. Periodic spikes of floating solids in the clarifier effluent caused high zinc and chrome POTW discharge levels. The filter press required full-time attention and produced cake solids with high moisture content. The water weight of the solids caused high hauling costs. The filter press also took three (3) eight-hour days to process 1000-gallons of a chemical-treated acid tank dump.

ALAR Engineering Corporation introduced the Company to the ALAR Auto-Vac® rotary vacuum drum technology as an alternative to the clarifier/ filter press combo. The customer sent in wastewater samples for a free in-house bench test simulation, and, after receiving positive results, visited several finishing operations that run Auto-Vacs. Satisfied with what they saw, the Midwest Company shipped a tote of their wastewater to ALAR for a test bay demonstration. Grab samples of the dry solids and clear effluent were taken and sent to a certified lab for analysis. The Company purchased an ALAR Auto-Vac® Model AV360.

Result: Once installed, the Auto-Vac® produced zinc and chrome levels up to eight times lower than the clarifier and filter press. The around-the-clock labor was reduced to an hour a day. The solids from the Auto-Vac® are twice as dry as the filter press, and take up less space in the dumpster. The Auto-Vac® AV360 can filter 5000-gallons of chemically treated acid tank dump in one (1) eight-hour shift. The overall savings of the Auto-Vac vs. Clarifier & Filter Press is estimated at $6,000 per month.