Exploiting the efficacy of Lysinibacillus sp. RGS for decolorization and detoxification of industrial dyes, textile effluent and bioreactor studies

Abstract

Complete decolorization and detoxification of Reactive Orange 4 within 5 h (pH 6.6, at 30°C) by isolated Lysinibacillus sp. RGS was observed. Significant reduction in TOC (93%) and COD (90%) was indicative of conversion of complex dye into simple products, which were identified as naphthalene moieties by various analytical techniques (HPLC, FTIR, and GC–MS). Supplementation of agricultural waste extract considered as better option to make the process cost effective. Oxido-reductive enzymes were found to be involved in the degradation mechanism. Finally Loofa immobilized Lysinibacillus sp. cells in a fixed-bed bioreactor showed significant decolorization with reduction in TOC (51 and 64%) and COD (54 and 66%) for synthetic and textile effluent at 30 and 35 mL h⁻¹ feeding rate, respectively. The degraded metabolites showed non-toxic nature revealed by phytotoxicity and photosynthetic pigments content study for Sorghum vulgare and Phaseolus mungo. In addition nitrogen fixing and phosphate solubilizing microbes were less affected in treated wastewater and thus the treated effluent can be used for the irrigation purpose. This work could be useful for the development of efficient and ecofriendly technologies to reduce dye content in the wastewater to permissible levels at affordable cost.

Keywords:

• Decolorization and degradation
• fixed bed reactor
• Luffa cylindrica
• photosynthetic pigments
• phytotoxicity
• Reactive Orange 4
• textile effluent

Funding

The project was supported by the Fundamental Technology R & D Program for Society of the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (Grant number: 2013 M3C8A3078596 and 2009-0083527).

Supplemental material

Supplemental data for this article can be accessed at http://dx.doi.org/10.1080/10934529.2014.975536.