Respirometric assessment of biodegradation for acrylic fibre-based carpet finishing wastewaters

The paper evaluates biodegradation characteristics of wastewaters generated from acrylic fibre-based carpet processing and manufacturing. It involves detailed characterisation, respirometric modelling and kinetic description of dyeing and softening wastewater streams and the composite effluent. The wastewaters exhibit different COD content and fractionation. The resulting composite effluent has a total COD of 775 mgL⁻¹, predominantly soluble and with a biodegradable fraction of 86%. In respirometric studies, the OUR profiles can only be calibrated with a dual hydrolysis model with rates significantly slower compared to domestic sewage and other textile plant effluents. Kinetic information derived from the experiments is applied for the conceptual evaluation of the treatability of the composite wastewater using two different continuous-flow activated sludge configurations.