to achieve closed cycle operation and subsequent reuse of treated effluent, individual streams of pulp and paper mill effluents are being evaluated for their suitability for in-mill treatment. this thesis includes two individual studies. the first part focused on the feasibility of thermomechanical pulping (tmp) condensate treatment using thermophilic and mesophilic sequencing batch reactors (sbr). the second part of this thesis, based on the results of the first part and literature, developed an improved fundamental understanding of how environmental (temperature) and operating (dissolved oxygen (do)) conditions affecting sludge properties and their role in bioflocculation and settling using a synthetic wastewater of glucose.