Microbial evaluation for biodegradability of recalcitrant organic in textile wastewater using an immobilized-cell activated sludge process

Abstract

Textile wastewater is difficult to be treated because it contains recalcitrant matters. This study evaluated the performance of an immobilized-cell process using polyethylene glycol media and microbial properties of the immobilized-cells for biodegradation of recalcitrant organics. The immobilized-cell process could remove hardly-biodegradable soluble COD more than 50% at various Hydraulic Retention Times (HRTs) over 8 similar to 24 hours. Active microbial distribution was fluctuated at the start-up operation, but became stable at both lower and upper part of the reactor after 92 days of operation. Cell mass in the media at the bottom was higher than at the middle or top parts of the reactor. The microbial decay in the media was more dependent on oxygen than organics. Stentrophomonas sp. and Pseudomonas putida, known as aromatic and aliphatic compound degraders, were identified in the media, confirming spontaneous selection and growth of cells that could oxidize the hardly biodegradable contaminants in the textile wastewater.