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Description of key information

C12-16 ADBAC is expected to biodegrade almost completely in conventional biological waste water treatment plants. The same biodegradation behaviour is expected for C12-14 ADMAES.

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Additional information

A guideline study was performed to determine the biodegradation of the read-across substance C12-16 ADBAC in a continuous activated sludge test (CAS). The microorganisms obtained by addition of domestic wastewater were exposed to a nominal concentration of 49 mg/L (36 mg/L carbon) of the test substance for an exposure period of 58 days. A control fed with domestic wastewater only was included in the test. With non purgeable organic carbon (NPOC) contents in the control and test units, a strong increase of NPOC concentration was noted on Day 2. The high NPOC concentration was likely caused by toxic effects of the test substance. The activated sludge acclimatized to the test substance within a few days resulting in a decrease of the NPOC concentrations. After 3 weeks, high carbon removal percentages were achieved. The mean removal percentage of test substance-carbon calculated over 15 measurements during the last three weeks (Days 48 to 58) was 99.8%. This indicates that the test substance is ultimately biodegraded. Specific analyses were performed to assess the removal of the parent compound. The mean removal percentage in the test unit assessed with a HLPC-MS/MS method was 99.998%. This analysis demonstrated that the primary biodegradation of the test substance was practically complete. Removal of the test substance from the influent through adsorption onto sludge was only 0.016 to 0.023% at Days 57 and 58, respectively, demonstrating that the test substance was removed and almost completely biodegraded (van Ginkel CG and Geerts R, 2007).