Comparison of clinoptilolite with gravel in a recirculating course media biofilter treating simulated septic tank effluent.

摘要

The main objective of the pilot scale study was to compare total inorganic nitrogen removal and COD removal in a recirulating clinoptilolite bioflter with a course gravel biofilter used to treat simulated septic tank effluent by simultaneous nitrification and denitrification. Both the biofilters were operated with a recycle ratio of 6 and a surface hydraulic loading rate of 7.5 gal/ft2/day without recycle throughout the duration of the research. Results of the composite sample analysis establish that better nitrification of the influent was achieved in the clinoptilolite biofilter. Average total inorganic nitrogen removal of 80.4% was achieved in the clinoptilolite biofilter as compared to 73% removal in gravel biofilter. Analysis of the results showed 77% COD removal for the biofilters. The performance of both biofilters was affected by excessive biomass generation in the biofilter leading to biological clogging. However more severe clogging occurred in the clinoptilolite biofilter due to disintegration and breakage of clinoptilolite media.