Explaining widely varying biofilm‐process performance with normalized loading curves

Abstract

ABSTRACT: The goal of the research was to evaluate whether the method of normalized loading curves could explain the performance differences among three steady‐state biofilm processes that had nearly identical loadings and process configurations. Three methanogenic fluidized‐bed biofilm reactors were challenged with a range of surface loadings of three distinctly different organic substrates: acetate, phenol, and glucose. Normalized loading curves were generated from the four fundamental parameters ( S min , S * min , K * , J R ) and compared to the experimental performance. The curves and the fundamental parameters explained why effluent concentrations of acetate and phenol were sensitive to loading, while the glucose concentration was insensitive; why effluent concentrations were much lower for phenol than for glucose at similar surface loads; and why acetate required a much higher surface loading to give similar performance trends.