# Nitrogen Removal Using a Membrane Bioreactor with Rubber Particles as the Fouling Reducer
## 4 Conclusions  
The research presented here focused on the simultaneous organic compound and nitrogen removal, as well as the fouling behavior, of single-chamber MBRs with intermittent aeration. Several conclusions were drawn: First, the fouling rate is higher when employing intermittent aeration in MBRs, compared to constant aeration. The addition of GAC tended to reduce TMP initially. However, these results were not maintained as the flux was reduced over a long time. Lower TMP values were achieved under intermittent aeration with the addition of rubber particles in the MBR. Second, MBR coupling with rubber particles from waste tires extended the effective filtration duration to 40 days without using any physical cleaning techniques. However, the addition of GAC did not result in the MBR maintaining the desired TMP due to the GAC breaking down into PAC with internal circulation. Third, simultaneous organic compound and nitrogen removal can be achieved by MBRs under intermittent aeration. With an aeration/non-aeration period of 10 min/50 min, the organic compound and T-N removal efficiencies were over 94% and 93.3%, respectively. Lastly, from the analysis of the DCGE profiles, three major bacterial taxa were identified, with four sequences related to the phylum proteobacteria, four affiliated with bacteria, four affiliated with _Firmicute_, and four affiliated with phylum _Acidobacteria_. _Dysgonomonas_, _Acidobacteria_, \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Band Name**} & \multicolumn{2}{c}{**Gen Band Search Result**} & \multirow{2}{*}{**Assession No.**} & \multirow{2}{*}{**Similarity**} & \multicolumn{2}{c}{**Taxonomic**} \\ \cline{2-2} \cline{5-5}  & **Phylogenetically Closest Relative** & & & **Description (Class)** \\ \hline A & Uncultured _Acidobacteria bacterium_ & & & \\  & clone AKYG487 & & & & \\ \hline B & _Erginia billingiae_ partial & FR695871.1 & 98\% & \(\gamma\)-proteobacteria \\ \hline C & _Dysgonomonas mossii_ strain Melo40 & KC866165.1 & 100\% & Bacteria \\ \hline D & _Eubacterium_ sp. oral clone JN088 & & & & \\ \hline E & _Lactobacillus harboniensis_ strain FQ003 & KF418816.1 & 100\% & Firmicutes \\ \hline F & Uncultured _Acidobacteria bacterium_ & & & \\  & clone Upland\_75\_7169 & & & \\ \hline G & _Erylthrobacter litoralis_ strain Gi-3 & KF444160.1 & 100\% & \(\alpha\)-proteobacteria \\ \hline H & Uncultured _bacterium_ clone SPESB2\_718 & KC327255.1 & 100\% & Bacteria \\ \hline I & _Bacteroides xylanolyticus_ partial & HF558386.1 & 100\% & Bacteria \\ \hline J & _Pantoa_ sp. A1059 & KC236721.1 & 100\% & \(\gamma\)-proteobacteria \\ \hline K & \
\begin{tabular}{c} _Endosymbiont of Sphenophorus levis_ clone \\ \end{tabular} & FJ626273.1 & 100\% & Actinobacteria \\  &
\begin{tabular}{c} Field\_clone\_A06 \\ \end{tabular} & & & \\ \hline L & _Gordonia_ sp. AmG & KF444801.1 & 64\% & Firmicutes \\ \hline M & _Eubacterium tarantellae_ partial & FR733677.1 & 100\% & Firmicutes \\ \hline N & _Pytbobacter diazotrophicus_ strain L8 & DQ821583.1 & 97\% & \(\gamma\)-proteobacteria \\ \hline O & _Mycobacterium_ sp. _arrichment_ culture & & \\  & clone GE10037 bofNNA & JX083129.1 & 100\% & Actinobacteria \\ \hline P & _Bacterium enrichment_ culture clone LE & JN982535.1 & 97\% & Bacteria \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Affiliation and similarity of DCGE bands based on 16S rDNA sequences. and _Pantoea_ sp. contributed to the nitrification process, while _Lactobacillus, Erythbroacter, Phytobacter_, and _Mycobacterium_ contributed to the denitrification process. Conceptualization, T.-J.L. ; methodology, M.-S.C. and Y.H. ; validation, T.-J.L. and Y.H. ; formal analysis, M.-S.C.; investigation, T.-J.L. and Y.H. ; resources, T.-J.L. ; data curation, M.-S.C.; writing--original draft preparation, M.-S.C.; writing--review and editing, T.-J.L. and Y.H. ; visualization, M.-S.C.; supervision, T.-J.L. ; project administration, T.-J.L. ; funding acquisition, T.-J.L. All authors have read and agreed to the published version of the manuscript.