Assessment of pollution and sources of heavy metals in the sediments of the Shitalakhya river, Bangladesh

Abstract

The Shitalakya River, located near Dhaka City of Bangladesh, supplies water to the city dwellers and hence it is essential to determine pollu-tion condition, ecological risk and sources of heavy metals in the river sediments. Sediment works as the sink and source of heavy metals in the riverine ecosystem. The samples collected from the ten sites of the Shitalakhya River were investigated in the study. Average concentra-tion of different heavy metals in the sediments are Cu>Zn>Ni>Pb>Cr>Cd. Geo-accumulation index reveals moderately pollute Cu concen-tration, unpolluted to moderately pollute Ni concentration and unpolluted for the rest of the heavy metals. The order of geo-accumulation index are Cu>Ni>Pb>Cd>Zn>Cr. Overall, the heavy metals render low potential ecological risk and the order of potential ecological risk index are Cd>Cu>Ni>Pb>Cr>Zn. Though the concentration of Cd is low in sediment, it poses higher ecological risk. Positive matrix factor-ization (PMF) identifies two sources of pollution, S1 and S2. Where, S1 consists with Cu, Ni, Pb, Zn; which come from industrial wastewater. S2 consists with Cr, Cd, Pb, Zn; which originate from natural sources. The outcomes of the study provide as a reference to plan, control and manage heavy metal pollution and protect the water source of the Shitalakhya River.

Risk Assessment of Heavy Metals in Sediment Samples from the Mae Chaem River, Chiang Mai, Thailand

“…Additionally, it is important to point out that the concentrations of As, Cd, Cr, Ni, Cu, and Zn observed in the present study were comparatively lower than the values reported in previous studies conducted on the Xiangjiang River, Majiagou River, and Yunliang River in China [50,51]. Furthermore, it is interesting that the concentrations of heavy metals observed in the current study were found to be higher compared with the values reported in previous studies carried out in the Batin River in Turkey and the Shitalakhya River in Bangladesh [44,52]. The results obtained from previous studies conducted on heavy metal concentrations in river sediments in Thailand [53][54][55] demonstrate that the heavy metal concentrations observed in this study during the dry season were 1-4 times higher than what was reported for the Lam Plai Mat River, Chao Phraya River, and Mae Klong River in Thailand, as shown in Table 2.…”

Indexical and statistical approaches to investigate the integrated origins of elements in the sediment of Teesta River, Bangladesh: sediment quality and ecological risk assessment

“…In comparison with the standardized elemental ratio of U/Th (>1.25: anoxic or <0.75: oxic), the average U/Th ratio in this study is found to be 0.18 (<0.75) which rather indicated a swily oxidizing environment with substantially adsorbed as well as deployed sediment deposition. 14,[68][69][70][71] The felsic source origin of the minerals mainly contains Al and K (this study) according to the analyzed immobile trace elements' mean elemental ratio (Cr/Th = 1.24, Th/Co = 3.26, and Th/Cr = 0.81). The calculated elemental ratios of Cr/Th and Th/Cr were lower and higher than the UCC normalized data, respectively, suggesting considerable geochemical sorting, a high rate of transportation, and relatively low solubility.…”