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

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

WATER SCIENCE AND TECHNOLOGY

I W A PUBLISHING

Año: 2018

0273-1223

This work reports on the biodegradation of textile wastewater by three alternative microbialtreatments. A bacterial consortium, isolated from a dyeing factory, showed significant efficacy indecolourize wastewater (77.6± 3.0%); the decolourization rate was 5.80± 0.31 mg of azodye·L1·h1, without the addition of an ancillary carbon source (W). The degradation was 52%(measured as COD removal) and the products of the treatment showed low biodegradability(COD/BOD5 ¼ 4.2). When glucose was added to the wastewater, (Wþ G): the decolourizationefficiency increased to 87.24±2.5% and the decolourization rate significantly improved (25.67±3.62 mg·L1·h1), although the COD removal efficiency was only 44%. Finally, the addition of starch(Wþ S) showed both a similar decolourization rate and efficiency for the W treatment, but a higherCOD removal efficiency (72%). In addition, the biodegradability of the treated wastewater wasconsiderable improved (COD/BOD5 ¼ 1.2) when starch was present. The toxicity of the degradationproducts was tested on Lactuca sativa seeds. In all treatments, toxicity was reduced with respect tothe untreated wastewater. The Wþ S treatment gave the best performance.