Testing the Efficiency of Biofilms Formed on Natural Substratum,Coyonoxtle (Opuntia Imbricata), for the Anaerobic Degradation of Aromatic Compounds

In this study, previously developed anaerobic microbial consortia capable of degrading aromatic compounds were used to develop biofilms on a natural material, coyonoxtle (Opuntia imbricata), which is abundantly available in North Mexico. The developed biofilms were evaluated for their efficiency in the biodegradation of different aromatic compounds, viz., phenol, catechol, 4‐aminobenzoic acid and p‐phenylenediamine in batch reactors. It was observed that in reactors with biofilms a more than 90 % COD removal and a concomitant production of methane could be obtained. But the rate of COD removal and methane production varied depending upon the type of biofilm used. Rumen‐derived biofilms demonstrated a lag phase of 7 to 14 days, whereas sludge‐derived biofilms exhibited a lag phase of more than three weeks. Between the biofilms from two sources, rumen‐derived biofilms showed a higher COD removal and methane production than sludge‐derived biofilms. When biofilm reactors were compared with reactors containing freely suspended consortia, it was evident that both rumen– and sludge‐derived biofilm reactors exhibited a two‐fold higher COD removal and methane production. Based on the results obtained, it can be concluded that coyonoxtle has the potential for use as a substratum.