Biodegradation of textile wastewater: enhancement of biodegradability via the addition of co-substrates followed by phytotoxicity analysis of the effluent

ANA MICAELA FERRO OROZCO; MARIA BELEN CERETTA; JORGE FROILÁN GONZÁLEZ; IGNACIO DURRUTY; ERIKA ALEJANDRA WOLSKI

WATER SCIENCE AND TECHNOLOGY

I W A PUBLISHING

Año: 2018 vol. 2 p. 516 - 526

0273-1223

This work reports on the biodegradation of a real textile wastewater under three alternative treatments by a microbial consortium isolated from a dyeing factory. The microbial consortium showed a high efficiency to decolorize the wastewater (77.6 ± 3.0 %), with a decolorization rate of 5.80 ± 0.31 mg of azo dye.L-1.h-1, without the addition of an ancillary carbon source (W). The degradation was 52.32% (measured as COD) and the products of the treatment showed low biodegradability (COD/BOD5= 4.2). When glucose was added to the wastewater (W+G): the decolorization efficiency increased to 87.24 ± 2.5 % and the decolorization rate was significantly improved (25.67 ± 3.62 mg.L-1.h-1), although the COD removal efficiency was 44.02 %. Finally, the addition of starch (W+S) showed a similar decolorization rate and a similar decolorization efficiency than that obtained for the W treatment, but a higher COD removal efficiency (72.52 %) and the biodegradability of the treated wastewater was considerable improved (COD/BOD5= 1.2). The toxicity of degradation products was tested on Lactuca sativa seeds. All the treatments reduced the toxicity respect to the untreated wastewater. The W+S treatment showed the best performance.