title: Augmenting Lagoon Process Using Reactivated Freeze-dried Biogranules.
abstract: This study investigated the feasibility of using freeze-dried biogranules in lagoon basins. The effect of different operational conditions on treatment performance and detention time of granule-based lagoons was examined in a series of laboratory-scale batch studies. Optimal granule dosage was 0.1 g/L under anaerobic condition, resulting in 80-94% removal of 1000 mg/L chemical oxygen demand (COD) in 7-10 days. Under aerobic condition, granule dosage of 0.2 g/L achieved the best result for identical COD concentration. However, adequate amount of nutrients (optimal COD/N/P ratio of 100/13/0.8) should be supplied to encourage the growth of aerobic species. At optimal COD/N/P ratio, aerobic treatment interval significantly reduced to 2-3 days with corresponding COD removal efficiency of 88-92%. Inhibition of high concentrations of COD (5000 mg/L) and ammonia (480 mg/L NH4-N) was observed on microbial activity and treatment capacity of the biogranules. Mixing was a crucial measure to overcome mass transfer limitation. Onetime inoculation of lagoon with fresh granules was the best approach to achieve a satisfactory treatment efficiency. This study suggested that utilization of the biogranules is a feasible and sustainable technique for augmenting lagoon plants in terms of improved effluent quality and reduced retention time. Graphical Abstract ᅟ.
authors.affiliation: Department of Civil Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada. roya.pishgar@ucalgary.ca.
authors.forename: Roya
authors.initials: R
authors.lastname: Pishgar
authors.affiliation: Department of Civil Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
authors.forename: Rania Ahmed
authors.initials: RA
authors.lastname: Hamza
authors.affiliation: Department of Civil Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
authors.forename: Joo Hwa
authors.initials: JH
authors.lastname: Tay
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D005612:Freeze Drying; D012722:Sewage / Q000382:microbiology*
chemical_list: D012722:Sewage
keywords: Biological wastewater treatment; Detention time; Lagoon; Nutrients; Reactivated biogranules; Treatment augmentation