Summary: | This study aimed at degrading sodium dodecyl sulphate (SDS), a surfactant in the presence of metals using metal-tolerant bacteria from a laundry site. Metal composition of wastewater and sediments from a laundry environment was determined using atomic absorption spectrometry (AAS). Paenibacillus amylolyticus BAL1 (PAB) and Bacillus lentus BAL2 (BLB), earlier reported to tolerate 1000 ppm SDS were screened for metal tolerance. The bacteria were employed in the simultaneous degradation of SDS and metal removal in a batch culture set-up containing SDS and metals for 14 days on a rotary shaker at 250 rpm. Residual SDS and metal concentrations were determined using high performance liquid chromatography (HPLC) and AAS. Copper (Cu), zinc (Zn), and cadmium (Cd) were detected in both laundry wastewater and sediment while chromium (Cr) and nickel (Ni) were only detected in the sediments. The MICs of metals on PAB were: Cu and Zn (500 µg/ml), and Cd (100 µg/ml), while for BLB: Cu (500 µg/ml), Zn (400 µg/ml), and Cd (100 µg/ml). PAB degraded 49.90% of SDS and simultaneously removed 8.3% of Cu, 5.1% of Cd, and 6.6% of Zn, while BLB degraded 54.9% of SDS and simultaneously removed 3.1% of Cu, 39% of Cd, and 3.1% of Zn. A combination of the two bacteria led to 44.3% degradation of SDS, and removal of 11% of Cu, 7.7% of Cd, and 9.8% of Zn. Bacteria from this study possessed both SDS-degradation and metal-removing abilities, and could be useful in the bioremediation of wastewater co-contaminated by surfactants and metals due to their dual tolerance to both compounds.
DOI: http://dx.doi.org/10.5281/zenodo.1494292
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