Start-Up Of An Upflow Anaerobic Sludge Blanket Reactor Treating Low-Strength Wastewater Inoculated With Non-Granular Sludge

The upflow anaerobic sludge blanket (UASB) process is known to be energy conservative biotechnology. Its low cost and low skill requirement render it to be a viable technology for reducing organic pollution loads. However, this system is facing a challenge in the treatment of low-strength wastewater especially inoculated with non-granular sludge. This work was performed to emphasis an in-depth understanding of an UASB reactor start-up process inoculated with digested slurry for treating synthetic wastewater of chemical oxygen demand (COD) around 700-1000 mg/L. The lab scale reactor with an effective volume of 9.97 L was operated under ambient temperature (24-35 0 C). At the end of start-up period that lasted for 84 days, this system achieved 90.8% COD removal and a biogas evolution of 4.72 L/d (457 L / kg COD removal) at an organic loading rate (OLR) of 1.293 kg COD/ m 3 d. Concurrently, the volatile fatty acids (VFA)/ alkalinity ratio was found as 0.184. It confirms the stability of the reactor.