## 3 Results and Discussion
### Effect of Different Glucose Concentration on Microalgal Growth, Pigments, and Nutrient Removal
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Glucose** & **Biomass Production** & **Biomass** & **Maximum Biomass** & **Specific Growth Rate** & **Maximum Specific Growth Rate** \\
**Concentration** & **(g/L)** & **Productivity** & **Productivity** & **(/d)** & **(/d)** & **Growth Rate** \\ \hline
0 & 0.58 \(\pm\) 0.07 \({}^{\circ}\) & 40.36 \(\pm\) 6.84 \({}^{\circ}\) & 75.00 \(\pm\) 14.14 \({}^{\dagger}\) & 0.31 \(\pm\) 0.07 \({}^{\circ}\) & 0.88 \(\pm\) 0.24 \({}^{\rm{b}}\) \\
2 & 1.40 \(\pm\) 0.06 \({}^{\ddagger}\) & 98.45 \(\pm\) 4.17 \({}^{\ddagger}\) & 240.00 \(\pm\) 13.23 \({}^{\circ}\) & 0.35 \(\pm\) 0.09 \({}^{\rm{a}}\) & 0.85 \(\pm\) 0.01 \({}^{\rm{b}}\) \\
5 & 1.70 \(\pm\) 0.02 \({}^{\circ}\) & 119.17 \(\pm\) 1.09 \({}^{\circ}\) & 724.17 \(\pm\) 92.38 \({}^{\rm{b}}\) & 0.30 \(\pm\) 0.06 \({}^{\rm{a}}\) & 1.24 \(\pm\) 0.15 \({}^{\rm{ab}}\) \\
8 & 1.84 \(\pm\) 0.03 \({}^{\circ}\) & 129.29 \(\pm\) 1.29 \({}^{\circ}\) & 383.75 \(\pm\) 90.16 \({}^{\ddagger}\) & 0.33 \(\pm\) 0.08 \({}^{\ddagger}\) & 1.62 \(\pm\) 0.29 \({}^{\rm{a}}\) \\
10 & 3.04 \(\pm\) 0.12 \({}^{\rm{b}}\) & 213.21 \(\pm\) 13.27 \({}^{\rm{b}}\) & 506.67 \(\pm\) 62.77 \({}^{\ddagger}\) & 0.31 \(\pm\) 0.07 \({}^{\rm{a}}\) & 0.99 \(\pm\) 0.47 \({}^{\rm{ab}}\) \\
20 & 3.81 \(\pm\) 0.21 \({}^{\rm{a}}\) & 277.31 \(\pm\) 18.02 \({}^{\rm{a}}\) & 1350.00 \(\pm\) 91.92 \({}^{\rm{a}}\) & 0.42 \(\pm\) 0.05 \({}^{\rm{a}}\) & 1.00 \(\pm\) 0.17 \({}^{\rm{ab}}\) \\
30 & 1.92 \(\pm\) 0.10 \({}^{\rm{c}}\) & 135.71 \(\pm\) 8.92 \({}^{\rm{c}}\) & 601.67 \(\pm\) 25.66 \({}^{\rm{bc}}\) & 0.37 \(\pm\) 0.07 \({}^{\rm{a}}\) & 1.45 \(\pm\) 0.56 \({}^{\rm{ab}}\) \\ \hline \hline \end{tabular} Note: Values with different letters represent significant difference (\(p\) < 0.05) between treatments.  
\end{table} 
Table 4: Biomass growth profiles of FACHB-8 cultivated in ADSW supplemented with varying concentrations of glucose. Figure 4: Biomass growth of FACHB-8 cultivated in ADSW supplemented with varying glucose concentrations. Figure 5: Time course profile of chlorophyll \(a\) concentration (**a**) and carotenoid concentration (**b**) for FACHB-8 cultivated in ADSW supplemented with varying glucose concentrations. The 20 g/L glucose group exhibited a relatively higher TN removal rate (88.70%). TP removal rates generally increased with higher glucose concentrations. Nitrogen is critical for cell growth, as microalgae assimilate NH4\({}^{+}\)-N and NO3\({}^{-}\)-N to synthesize proteins and nucleic acids [13]. The limited improvement in the TN removal with the increasing glucose may result from an energy reallocation toward biomass accumulation rather than nitrogen assimilation. In contrast, the phosphorus (essential for ATP and nucleic acids) uptake improved significantly in glucose-supplemented groups, likely due to the enhanced biomass production (Table 5). The 20 g/L glucose group achieved the highest TP removal (82.93%). Given its balanced TN removal (88.70%) and optimal TP removal, the 20 g/L glucose group demonstrated a superior wastewater purification efficiency. In summary, the 20 g/L glucose supplementation group demonstrated an optimal algal growth and superior nutrient removal efficiency. Therefore, 20 g/L was selected as the optimal glucose concentration for ADSW treatment and was applied in subsequent studies. Biomass Growth and Nutrient Removal Capacity of FACHB-8 in ADSW with Optimized Glucose Supplementation  
Based on the previous results, this study evaluated the growth of FACHB-8 in ADSW with an optimized glucose supplementation (20 g/L). Compared to the control (CK, no glucose), the optimized group exhibited a dramatic biomass accumulation on day 4, entering the exponential phase (Figure 6a). The specific growth rate under optimized conditions (0.42/d) exceeded that of the control (0.31/d). After 14 days of cultivation, the biomass productivity reached 271.31 mg/L/day in the optimized group--6.72 times higher than the control (40.36 mg/L/day). At the same time, a TN removal of 88.70% and a TP removal of 82.93% was observed (Figure 6b).