Effluent Treatment For Chronic Toxicity Removal With the Suspended Carrier Biofilm Reactor, 2000 Environmental Conference Proceedings

- C. Asselin, D. Collin, S. Graff, J. Marquis, R. Paradis, S. Sirois -- An on-site pilot study was carried out on a new biological treatment technology, i.e., the suspended carrier biofilm (SCB) reactor, to remove chronic toxicity from a fine paper mill effluent. The process configuration tested was primary clarification followed by two SCB reactors in series and dissolved air flotation (DAF) clarification. The chronic toxicity concentrations (C-NOEC) achieved at proposed reactor design criteria (3 hour hydraulic retention time and 175 square meters of carrier media surface area per cubic meter of reactor volume) exceeded the state of Maine limit of 3.1%, ranging from 3.1% to 100% with an average of 65%. The system gave excellent safety margin in BOD5 and SS reductions bringing these discharge levels to less than 15% of the monthly average limits. Overall, the suspended carrier biofilm reactor has been proven to be an efficient and cost-effective technology to address the mill effluent's chronic toxicity.