COD fractionation based biological treatability assessment of segregated & recovered wastewater streams from denim processing plant

Abstract

This study evaluated the biological treatability of overall wastewater generated from a denim processing plant located in Corlu, Tekirdag, in the NW of Turkey, before and after sub-stream wastewaters' recovery alternatives were performed in the plant processes. It was determined that there are 5 segregated sub-streams composed of 11 segregated single sub-stream wastewaters contribute overall wastewater of the plant. The plant overall wastewater reflects the typical character of denim processing effluents which have a high level of chemical oxygen demand (CODTot) 1200-1577 mg.l(-1) (1390 mg.l(-1)), CODSol 700-1210 mg.l(-1) (955 mg.l(-1)), TSS 2840-6800 mg.l(-1) (4820 mg.l(-1)) and quite acidic/neutral pH value such as 5.8-6.5 (6.2). According to the segregated stream characters, 6 segregated single sub-stream wastewaters fitted to be suitable for recovery. After recovery, it was observed that the remaining wastewater character changed as COD Tot 1750-2295 mg.l(-1)(2020 mg.l(-1)), CODSol 1080-1695 mg.l(-1) (1390 mg.l(-1)), TSS 3330-9735 mg.l(-1) (6535 mg.l(-1)) and pH value 5.3-6.5 (5.9). According to the biodegradability experimental data, the soluble inert fraction (S-I) of the initial total (COD) (S-I/C-T) remain steady by the ratio 3% before and after recovery while particulate inert fraction (X-I/C-T) increased from 1.6% to 3.4% ratio, as it can be considered as a specific case of COD fractions for recovery. But when the all biological treatability characteristics were evaluated as a private for this plant, it was observed that there is no any difficulty for biological treatability of remaining wastewater after recovery.