COMPARISON OF BIOFILM MEDIA IN RECIPROCATING BIOFILTERS TREATING DAIRY FLUSHWATER

biofilters known as ReCip is a viable technology to manage nutrients, mainly nitrogen, problems at livestock operations such as swine farms and dairies. Past studies have demonstrated that ReCip is more adept at total nitrogen (TN) removal than traditional subsurface flow wetland systems. The traditional substrate used to attach biomass was rock aggregate; this media may be hard to obtain for some agricultural projects, so alternate substrates are tested and compared with the rock aggregate. The purpose of the study was twofold: first, different biofilm media were tested and compared in terms of treatment performance and, second, the long-term performance of a ReCip in continuous operation for 3 years was characterized. Four, 2.67 square meter ReCip systems with different treatment media – rock aggregate, recycled concrete aggregate (RCA), vertical-flow plastic media, and walnut shells – were operated at a 2-day THRT over the course of a 16 week study. The TN removal efficiencies for rock aggregate, RCA, plastic media, and walnut shell medi