Textile Wastewater Treatment Using Biogranules Under Intermittent Anaerobic/Aerobic Reaction Phase

Abstract

Granular sludge was successfully cultivated under intermittent anaerobic and aerobic reaction phase strategy using synthetic textile wastewater for 72 days. The granules were developed under superficial air velocity of 2.4 cm/s in the SBR system that operated at hydraulic retention time of 8 hours. The unique feature of the granules is that they were cultivated using anaerobic granules as seeding material. The microscopic examination showed clear, smooth and spherical shape of mature granules with diameters ranging from 0.85 to 1 mm after 60 days of operation. The particle size distribution has shifted from less than 0.3 mm in the beginning to about 1 mm with some reaching 2.5 mm. The granules had good settling properties indicated by their high settling velocity reaching up to about 42 m/h and low sludge volume index (SVI) of 61 mL/g. The MLSS has also increased from 4.8 g/L to 7 g/L while the granular strength has also increased with time. During the development process, the granular sludge system was capable of treating synthetic textile dyeing wastewater containing mixed dyes with 93% of COD and ammonia removal and 56% of color removal.