# A Snapshot on the Occurrence and Risk Assessment of Organic Pollutants in an Urban River
## 3 Results and Discussion
### CECs Monitoring in Sediment Lixivivates  
The results seem to indicate that the presence of CECs in sediments might be independent of the distance and discharge from WWTP (Table 2; Figure 2). Ibuprofen, diclofenac, clorfibric acid, carbamazepine, caffeine, and BPA were trapped in the sediments (lixiviates). In F1 and F3 an accentuated divergence in concentrations between water and sediment. [79] also observed that sites with higher concentrations of CECs in sediment generally exhibit lower concentrations in water and vice-versa. Ibuprofen was found in F1 (10.36 ng\(\cdot\)L\({}^{-1}\)) and in F2 (18.80 ng\(\cdot\)L\({}^{-1}\)). Diclofenac and clorofibric acid were detected only in the F1 sediment. Ibuprofen was found both in F1 (10.36 ng\(\cdot\)L\({}^{-1}\)) and F2 (18.80 ng\(\cdot\)L\({}^{-1}\)). The observed concentrations for diclofenac and ibuprofen in F1 can be related with the sandy nature of the sediments, as [80] demonstrated that diclofenac and ibuprofen exhibit significant sorption to sandy sediments. Carbamazepine was found in similar concentrations to those \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline  & \begin{tabular}{c} **F1** \\ **MEC** \\ **ng\(\cdot\)L\({}^{-1}\)** \\ \end{tabular} & \begin{tabular}{c} **F2** \\ **HQ** \\ **ng\(\cdot\)L\({}^{-1}\)** \\ \end{tabular} & \begin{tabular}{c} **F3** \\ **HQ** \\ **ng\(\cdot\)L\({}^{-1}\)** \\ \end{tabular} & \begin{tabular}{c} **L-F1** \\ **HQ** \\ **ng\(\cdot\)L\({}^{-1}\)** \\ \end{tabular} & \begin{tabular}{c} **L-F2** \\ **HQ** \\ **ng\(\cdot\)L\({}^{-1}\)** \\ \end{tabular} & \begin{tabular}{c} **L-F3** \\ **HQ** \\ **ng\(\cdot\)L\({}^{-1}\)** \\ \end{tabular} & \begin{tabular}{c} **L-F3** \\ **HQ** \\ **ng\(\cdot\)L\({}^{-1}\)** \\ \end{tabular} & \
\begin{tabular}{c} **L-F3** \\ **HQ** \\ **ng\(\cdot\)L\({}^{-1}\)** \\ \end{tabular} &
\begin{tabular}{c} **HQ** \\ **ng\(\cdot\)L\({}^{-1}\)** \\ \end{tabular} \\ \hline \multicolumn{10}{c}{Pharmaceuticals} \\ Paracetamol & 0.05 & 0.002 & 0.05 & 0.002 & 0.05 & 0.002 & 0.05 & 0.002 & 0.05 & 0.002 & 0.05 & 0.002 \\ Ibuprofen & 7.56 & 0.756 & 6.94 & 0.694 & 21.81 & 2.181 & 10.36 & 0.006 & 18.80 & 0.011 & 0.05 & 0.005 \\ Diclofenac & 0.05 & 0.001 & 0.05 & 0.001 & 398.35 & 7.967 & 92.63 & 0.142 & 0.05 & 0.001 & 0.05 & 0.001 \\ Clofibric Acid & 0.05 & 0.000 & 0.05 & 0.000 & 0.05 & 0.000 & 21.47 & 0.033 & 0.05 & 0.000 & 0.05 & 0.000 \\ Carbamazepine & 0.05 & 0.000 & 0.05 & 0.000 & 52.10 & 0.021 & 0.05 & 0.000 & 0.05 & 0.000 & 47.10 & 0.019 \\ Ofloxacin & 0.05 & 0.002 & 0.05 & 0.002 & 376.16 & 2.589 & 0.05 & 0.002 & 0.05 & 0.002 & 0.05 & 0.002 \\ \hline \multicolumn{10}{c}{Stimulant alkaloid} \\ Caffeine & 3.17 & 0.058 & 10.23 & 0.205 & 167.38 & 3.348 & 14.43 & 0.030 & 92.60 & 0.191 & 20.41 & 0.042 \\ \hline \multicolumn{10}{c}{Musk fragracies} \\ Galaxolide (HHCB) & 0.05 & 0.000 & 0.05 & 0.000 & 224.36 & 0.151 & 0.05 & 0.000 & 0.05 & 0.000 & 0.05 & 0.000 \\ Tonalide (AHTN) & 0.05 & 0.000 & 207.92 & 0.059 & 231.45 & 0.068 & 0.05 & 0.000 & 0.05 & 0.000 & 0.05 & 0.000 \\ \hline \multicolumn{10}{c}{Plasticizers} \\ Bisphenol A (BPA) & 642.69 & 0.47 & 90.95 & 9.095 & 212.18 & 1.218 & 134.92 & 0.957 & 149.27 & 1.059 & 772.85 & 5.484 \\ \hline \multicolumn{10}{c}{Toxic units (without BPA)} \\ Total Toxic units & 0.824 & 0.964 & 0.16 & 0.178 & 0.185 & 0.207 & 0.071 \\ \hline \multicolumn{10}{c}{Limit of quantification (LOQ) = 0.1 ng\(\cdot\)L\({}^{-1}\) (concentrations below LOQ were considered as LOQ/2); Green: Negligible risk; Yellow: Low risk; Orange: Moderate risk and Red: High risk.} \\ \end{tabular}
\end{table} 
Table 2: Measured mean environmental concentrations (MEC) and Hazard Quotient (HQ) for CECs dissolved in water and lixiviates from sediments in F1, F2, and F3. Figure 2: Relative percentage of CECs found in water (**A**) and in sediment (**B**) in F1, F2, and F3. found in water in F3. Reference [79] also observed that carbamazepine was in elevated concentrations in sediments located downstream from WWTP, probably with high sorption and low migration rates [81].