## 3 Results and Discussion
### Stage 1--LF-DSS Treatment and M-BGS Production
#### 3.1.4. Pollutant Removal Rate  
The changes in the M-BGS proved to have a significant effect on organic matter removal from the LF-DSS. We found that the more bacteria and protozoa were in the biomass, the better the biodegradation of waste substances (COD and TOC) was. In phase 1 (P1) of H-PBR (_Chlorella_ sp.-dominated microbial community), COD and TOC removal was 61.4 \(\pm\) 2.3%, and 71.9 \(\pm\) 2.7%, respectively (Table 5). Nominal levels in the effluent were 277 \(\pm\) 22 mgO\({}_{2}\)/dm\({}^{3}\) and 147 \(\pm\) 17 mg/dm\({}^{3}\), respectively. P2 (days 16-30) and P3 (days 31-45) had similar organic biodegradation rates, which were, respectively, 73.1 \(\pm\) 1.7% and 75.8 \(\pm\) 3.2% for COD and 80.7 \(\pm\) 3.0% and 83.4 \(\pm\) 4.7% for TOC. COD in the effluent did not exceed 100 mgO\({}_{2}\)/dm\({}^{3}\), whereas TOC did not exceed 200 mg/dm\({}^{3}\)--significantly less than in P1 (Table 5). P4 (days 46 to 60 of H-PBR operation) performed the best in terms of organics removal--the COD in the treated LF-DSS was 114 \(\pm\) 9 mgO\({}_{2}\)/dm\({}^{3}\), meaning that 84.1 \(\pm\) 5.1% was biodegradable. TOC removal was 88.2 \(\pm\) 7.2%, leaving 61.8 \(\pm\) 7.4 mg/dm\({}^{3}\) in the effluent (Table 5). \begin{table} \begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Parameter**} & \multicolumn{4}{c}{**Final Concentration (mg/dm\({}^{3}\))**} & \multicolumn{4}{c}{**Removal (\%)**} \\ \cline{2-9}  & d 15 & d 30 & d 45 & d 60 & d 15 & d 30 & d 45 & d 60 \\ \hline COD & 277 \(\pm\) 22 & 193 \(\pm\) 15 & 174 \(\pm\) 14 & 114 \(\pm\) 9 & 61.4 \(\pm\) 2.3 & 73.1 \(\pm\) 1.7 & 75.8 \(\pm\) 3.2 & 84.1 \(\pm\) 5.1 \\ TOC & 147 \(\pm\) 17 & 99.0 \(\pm\) 12 & 87.0 \(\pm\) 10.3 & 61.8 \(\pm\) 7.4 & 71.9 \(\pm\) 2.7 & 80.7 \(\pm\) 3.0 & 83.4 \(\pm\) 4.7 & 88.2 \(\pm\) 7.2 \\ TP & 7.69 \(\pm\) 0.82 & 7.54 \(\pm\) 0.81 & 7.58 \(\pm\) 0.81 & 7.36 \(\pm\) 0.79 & 54.2 \(\pm\) 4.1 & 55.1 \(\pm\) 3.9 & 54.9 \(\pm\) 3.8 & 56.2 \(\pm\) 4.6 \\ P-PO\({}_{4}\) & 0.98 \(\pm\) 0.23 & 1.25 \(\pm\) 0.30 & 1.19 \(\pm\) 0.28 & 1.10 \(\pm\) 0.26 & 90.3 \(\pm\) 1.7 & 87.6 \(\pm\) 1.2 & 88.2 \(\pm\) 2.3 & 89.1 \(\pm\) 1.1 \\ TN & 15.2 \(\pm\) 1.3 & 15.6 \(\pm\) 1.4 & 17.4 \(\pm\) 1.6 & 16.5 \(\pm\) 1.5 & 71.3 \(\pm\) 3.1 & 70.5 \(\pm\) 2.9 & 67.2 \(\pm\) 2.4 & 68.9 \(\pm\) 3.1 \\ N-NH\({}_{4}\) & 5.00 \(\pm\) 0.42 & 4.31 \(\pm\) 0.36 & 5.93 \(\pm\) 0.50 & 5.51 \(\pm\) 0.46 & 89.2 \(\pm\) 1.4 & 90.7 \(\pm\) 1.7 & 87.2 \(\pm\) 1.3 & 88.1 \(\pm\) 1.6 \\ \hline \hline \multicolumn{9}{c}{**Load in**} & \multicolumn{4}{c}{**Load removed**} \\ \cline{2-9}  & d 15 & d 30 & d 45 & d 60 & d 15 & d 30 & d 45 & d 60 \\ \hline COD & & 71.9 \(\pm\) 5.7 & & 44.1 \(\pm\) 3.5 & 52.6 \(\pm\) 4.2 & 54.5 \(\pm\) 4.3 & 60.5 \(\pm\) 4.8 \\ TOC & & 52.4 \(\pm\) 6.2 & & 37.7 \(\pm\) 4.4 & 42.3 \(\pm\) 5.0 & 43.7 \(\pm\) 5.2 & 46.2 \(\pm\) 5.5 \\ TP & & 2.68 \(\pm\) 0.18 & & 1.45 \(\pm\) 0.14 & 1.48 \(\pm\) 0.11 & 1.47 \(\pm\) 0.09 & 1.51 \(\pm\) 0.16 \\ P-PO\({}_{4}\) & & 2.11 \(\pm\) 0.24 & & 1.91 \(\pm\) 0.22 & 1.85 \(\pm\) 0.20 & 1.86 \(\pm\) 0.18 & 1.88 \(\pm\) 0.32 \\ TN & & 5.29 \(\pm\) 0.47 & & 3.77 \(\pm\) 0.33 & 3.73 \(\pm\) 0.45 & 3.55 \(\pm\) 0.24 & 3.64 \(\pm\) 0.32 \\ N-NH\({}_{4}\) & & 4.63 \(\pm\) 0.39 & & 4.13 \(\pm\) 0.47 & 4.20 \(\pm\) 0.71 & 4.04 \(\pm\) 0.62 & 4.08 \(\pm\) 0.91 \\ \hline \hline \end{tabular}