Abstract

The main contributors to the contamination ofrivers with heavy metals include industrial manufacturing,domestic practices, and aquaculture. Based on contemporaryresearch, it has been identified that three primary mechanismsof surface flow facilitate the transportation of pollutants,specifically heavy metals. These mechanisms include dissolvedflow, Suspended Particulate Matter (SPM), and bottom flow,which is associated with sediment movement. The primaryobjective of this study was to assess the spatial distribution andlevels of heavy metals in the downstream region of the Thi VaiRiver. This investigation encompassed the examination of heavymetal concentrations in the dissolved, suspended, andsedimentary fractions. LogKd distribution coefficients and theGeographic Information System (GIS) were used in this studyto show how heavy metals were spread out in space along thethree sections of the Thi Vai River that flow downstream, whichincluded a total of 19 monitoring sites. The averageconcentrations of Fe, Mn, Zn, Cu, Ni, Pb, and Cd were 0.193,0.06, 0.092, 0.056, 0.0095, 0.0028 mg/L respectively in thedissolved phase; 405.7, 269.6, 225.1, 72.2, 61.1, 35.2, 4.7 mg/kgrespectively in the suspended phase and 9.8.9, 266.3, 152.7, 79.3,44.6, 42.2, 3.3 mg/kg respectively in the sediment phase whichachieved the national standard averages, except for Cd exceed.It is crucial to acknowledge that heavy metals tend toconcentrate predominantly in the suspended phase, resulting inthe presence of varied distribution coefficients. Research hasshown that anthropogenic activities located along the river aremainly responsible for the presence of heavy metals. The effectsof natural processes such as river hydrodynamics on thedispersion and transport of these pollutants remain unknown.