## 3 Results and Discussion
### Relationship between Physicochemical Parameters and Heavy Metals in Surface Water and Sediments
Elevated TP concentrations may exacerbate mercury contamination since elevated levels indicate eutrophication, and since this tributary is exposed to anthropogenic pollution, it could explain the reason behind the strong correlation [66]. However, for sediments, most heavy metals were found to have a significant positive correlation with each other and also with TN and TP, apart from Cd (positive but  
Figure 6: Pearson correlation between heavy metals and nutrient parameters in surface water. ** means \(p\leq\) 0.05”, *** means \(p\leq\) 0.01”, *** means \(p\leq\) 0.001”. non-significant), Hg (positive but non-significant), and OM (positive but non-significant) (Figure 7). The strong positive correlations among critical heavy metals, As, Cu, Pb, and Ni, indicate a potential convergence of sources or similar behavior patterns, likely occurring because of anthropogenic influences or geological attributes intrinsic to the river basin [7]. This observed clustering of correlations emphasizes the interlinked nature of these heavy metals in the sediment matrix, highlighting the necessity for a complete approach to source identification. Conversely, the marked positive association between Cd and Zn suggests shared origins, possibly attributable to industrial activities or human activities [67]. A separate cluster emerges with Cr exhibiting robust correlations with Cu and Pb, implying a degree of co-release, a phenomenon that may have sources in agricultural discharges within the river's catchment area [68]. The distinctive behavior of Hg, displaying only moderate correlations with its heavy metal counterparts, apart from Cd and Cr, is noteworthy. This abnormality suggests differentiated sources or factors governing its mobility in the sediment, warranting a focused examination of its intricate transport mechanisms and contamination sources [40]. We observed positive associations between Total Nitrogen (TN) and Total Phosphorus (TP) with heavy metals, hinting at potential nutrient-metal interplays or shared inputs, unveiling yet another layer of complexity in the sediment's elemental composition [69]. Such associations underscore the interdependent nature of nutrient and heavy metal dynamics, contributing to the intricate ecological balance in river ecosystems. Organic matter (OM) positively correlated with multiple heavy metals, notably Chromium. This underscores the pivotal role of OM as a binding agent, influencing the retention and distribution of heavy metals within the sediment matrix [70]. These findings accentuate the multifaceted nature of heavy metal interactions and underscore the potential significance of organic matter content in sediments as a regulator of metal mobility. The exploration of heavy metal concentrations and environmental parameters in water samples yields critical insights into aquatic health and possible contamination sources. A robust Pearson correlation analysis among heavy metals (Arsenic, Cadmium, Chromium, Copper, Lead, Nickel, Zinc, and Mercury) and other environmental parameters (pH, Temperature, COD, TN, TSS, TP, and Chl\(\alpha\)) exposes several noteworthy relationships. A profoundly strong correlation was observed between Nickel (Ni) and Chromium (Cr)  
Figure 7: Pearson correlation between heavy metals and nutrient parameters in sediments. _”_ means \(p\leq 0.05\)”, _”_ means \(p\leq 0.01\)”, _”_ means \(p\leq 0.001\)”. (r = 0.89 ****), suggesting their simultaneous presence and potential common source, which may be attributed to industrial discharge, given the ubiquity of these metals in several industries [71]. Simultaneously, the apparent strong association between Copper (Cu) and Lead (Pb) (r = 0.86 ****), metals often conjointly found in electronic wastes and industrial emissions, denotes an imperative need for scrutinizing industrial activities occurring within the watershed [48]. Interestingly, the relationships between certain metals and nutrients hint towards the intricate and multifaceted dynamics within the water body.