## 3 Results
### Turbidity Reduction Analysis  
The results of the turbidity analysis obtained from the evaluation of _P. striatotes_, _S. molesta_, and _E. crassipes_ in a tertiary treatment of secondary treated domestic wastewater for two weeks with a retention time of 6, 12, and 24 h are presented in Figures 3-5, respectively. As seen in Figure 3, the turbidity level of the influent wastewater samples collected from STP varied throughout the sampling period and ranged from 14.9-30.6 NTU. It was observed that the reduction of the turbidity level for the influent wastewater samples by the test plants was obvious from the beginning to the end of the sampling duration. On the second day of the sampling period, the test plants lowered the turbidity value of the influent wastewater sample from 30.66 \(\pm\) 2.12 NTU to 10.3 \(\pm\) 0.1 (_P. stratites_), 15.63 \(\pm\) 0.06 (_S. molesta_), and 12.36 \(\pm\) 0.05 NTU (_E. crassipes_). The reduction efficiency ranges for the _P. stratites_, _S. molesta_, and _E. crassipes_ wastewater treatment systems were found to be 48-72.7%, 10.19-58.3%, and 28.3-58.88%, respectively. However, these results show that _P. stratites_ exhibited better absorption of the suspended particles at a short retention time of 6 h. Similarly, the average performance demonstrated by the _S. molesta_ can be attributed to the slow growth and shrinking of the leaves observed from the sixth day of the sampling period. Furthermore, a substantial variance (\(p<0.05\)) was observed between the average initial wastewater samples and the individual effluent wastewater samples. From Figure 4, it is evident that the selected test plants were effective in polishing the influent wastewater samples with a 12 h retention time. However, the turbidity level of the influent wastewater samples collected from STP varied throughout the sampling period and ranged from 20.7-41.8 NTU. It can be noticed that a high turbidity concentration of the influent wastewater samples was recorded on the second and sixth day of the sampling period with a value of 32.5 \(\pm\) 1.85 NTU and 41.8 \(\pm\) 0.37 NTU, respectively. Nevertheless, the introduction of the test plants in the influent wastewater samples led to the improvement of the effluent wastewater samples from 28.6 \(\pm\) 0.45 NTU to 10.7 \(\pm\) 0.2 NTU (_P. stratites_), 4.74 \(\pm\) 0.12 NTU (_S. molesta_), and 9.02 \(\pm\) 0.69 NTU (_E. crassipes_) on the fourth day of the sampling study. Furthermore, reduction efficiencies of 41.0% and 77.1%, 73.2% and 84.6%, and 53.0% and 73.6% for _P. stratites_, _S. molesta_, and _E. crassipes_, respectively, were observed for the same sampling periods (second and sixth day). Similarly, a turbidity value of 20.72 \(\pm\) 0.06 NTU was obtained for the influent sample on the 14 th day, which was reduced to 7.0 \(\pm\) 0.1 NTU, 4.03 \(\pm\) 0.055 NTU, and 5.27 \(\pm\) 0.27 NTU by _P. stratites_, _S. molesta_, and _E. crassipes_, respectively. Finally, maximum reduction efficiencies of 66.2%, 84.6%, and 74.6% were obtained for _P. stratites_, _S. molesta_, and _E. crassipes_, respectively. A significant variance (\(p<0.05\)) was observed between the influent and effluent wastewater samples. From Figure 5, it is obvious that the three test plants polished the influent wastewater samples, thereby showing a remarkable improvement in the effluent wastewater samples when compared with the influent sample during the 14-day sampling study with a retention time of 24 h. It can be observed that the influent turbidity varied throughout the sampling period, as this was determined from the operation of the STP. The average turbidity level of the influent wastewater samples was lowered  
Figure 5: Bar plot of the average turbidity vs. the sampling period at 24 h retention time. from the second day of the sampling period: from \(23.63\pm 0.18\) to \(9.5\pm 1.32\) NTU, \(4.06\pm 1.45\) NTU, and \(4.72\pm 0.03\) NTU by _P. stratiodes, S. molesta,_ and _E. crassipes_, respectively. This led to reduction efficiencies of 58% (_P. stratiodes_), \(82.8\%\) (_S.