F. Batubara - Department of Chemical Engineering, Universitas Sumatera Utara, Jalan Almamater Kampus USU, Medan, Indonesia
M. Turmuzi - Department of Chemical Engineering, Universitas Sumatera Utara, Jalan Almamater Kampus USU, Medan, Indonesia
I. Irvan - Department of Chemical Engineering, Universitas Sumatera Utara, Jalan Almamater Kampus USU, Medan, Indonesia
N. Yanqoritha - Department of Industrial Engineering, Universitas Prima Indonesia, Medan, Indonesia

This research aims to examine the varians of organic loading rate (OLR) on degradation of tofu wastewater using the hybrid upflow anaerobic sludge blanket (hybrid UASB) reactor using the modified kinetic model of Stover Kincannon. This reactor was operated at OLRs variation of ۱.۵-۱۲ kg COD m-۳ d-۱ and HRT of ۱۲ - ۲۴ hours for ۳۲۸ days. Higher COD removal efficiency of ۸۶.۴۱% and biogas production of ۷۷۰۰ mL were achieved at OLR ۴.۸ kg COD m-۳ d-۱ and HRT ۲۴ hours on ۱۴۰ days. Modified Stover-Kincannon model was observed and matched data sets were obtained.  The kinetic values of model obtained at HRT variations, the parameters KB and μmax were ۳.۷, ۱۲.۹۷, ۲.۴۲ mgL-۱ d-۱ and ۰.۵۹, ۹.۴۱, ۰.۰۱۴ mgL-۱ d-۱, respectively. This model was a plot of the inverse of the removal rate, versus inverse of the total loading rate resulted in a straight line. It showed that the Stover-Kincannon Model is the rate of substrate removal was affected by the organic load rate (OLR) that flowed into the hybrid UASB reactor.

Organic Loading Rate, Tofu Wastewater, Hybrid Upflow Anaerobic Sludge Blanket Reactor, Modified Stover-Kincannon Model