Anaerobic degradation of tetrachlorobisphenol-A in river sediment

This study investigated the anaerobic degradation of tetrachlorobisphenol-A (TCBPA) in sediment samples collected at three sites along the Erren River in southern Taiwan. TCBPA anaerobic degradation half-lives (t1/2) in the sediment were 12.6, 16.9 and 21.7 d at concentrations of 50, 100, and 250 μg g−1, respectively. TCBPA (50 μg g−1) anaerobic degradation half-lives (t1/2) in the sediment were 10.1, 11.8, 11.0, 11.6, 10.8, 9.1, 8.5, 18.2, 19.3, and 16.1 d by the addition of yeast extract (5 mg l−1), cellulose (0.96 mg l−1), sodium chloride (1%), brij 30 (130 mg l−1), brij 35 (43 mg l−1), rhamnolipid (55 μM), surfactin (91 μM), phthalic esters (2 mg l−1), nonylphenol (2 mg l−1), and heavy metals (2 mg l−1), respectively. The degradation rate of TCBPA was enhanced by the addition of yeast extract, cellulose, sodium chloride, brij 30, brij 35, rhamnolipid, or surfactin. However, it was inhibited by the addition of phthalic esters, nonylphenol, or heavy metals. Also noted was the presence of dichlorobisphenol-A and bisphenol-A, two intermediate products resulting from the anaerobic degradation of TCBPA accumulated in the sediments.