ABSTRACT

Surface sediment is often used to monitor contamination and assess ecological risk. We used multiple indices to assess sediment condition and ecotoxicity caused by heavy metal(loid)s (HMs) in Zarivar International Wetland (Zarivar) of Iran. We sampled the wetland at 12 stations using a Grab sampler, during both rainy and dry seasons. Using an atomic absorption spectroscopy and a mercury analyzer, we measured As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn and Hg. HMs temporal and spatial changes and general features of sediment were analyzed. Except Fe and Mn, all metals appear to have anthropogenic sources. We calculated toxic units (TUs) and contamination factors (CF) for all HMs. ∑TU calculations showed As> Cd> Cr and Ni to have the highest contributions in succession. CF indicated Cd, As, Pb and Cr, to have the highest concentrations, respectively. As (38.54 ± 10 mg/kg ⁻¹) and Cd (5.75 ± 2.01 mg/kg ⁻¹) exceeded their probable effect levels in 100% and 90% of the stations, respectively. Zarivar is classified as “very highly polluted” in rainy season (755.34 ± 289.97) and “considerably polluted” in dry season (489.98 ± 232.62) based on risk index values we calculated.

摘要

地表沉积物通常用于监测污染和评估生态风险。我们使用多个指标来评估伊朗 Zarivar 国际湿地 (Zarivar) 中重金属 (类物质) (HMs) 引起的沉积物状况和生态毒性。在雨季和旱季，我们使用 Grab 采样器在 12 个站点对湿地进行了采样。使用原子吸收光谱仪和汞分析仪，我们测量了 As、Cd、Cr、Cu、Fe、Mn、Ni、Pb、Zn 和 Hg。分析了沉积物HMs时空变化及一般特征。除了铁和锰，所有金属似乎都有人为来源。我们计算了所有 HM 的毒性单位 (TU) 和污染因子 (CF)。∑TU计算表明As>Cd>Cr和Ni依次具有最高的贡献。CF 分别表示 Cd、As、Pb 和 Cr 的浓度最高。^-1 ) 和 Cd (5.75 ± 2.01 mg/kg ^-1 ) 在 100% 和 90% 的站点中分别超过了它们的可能影响水平。根据我们计算的风险指数值，Zarivar 在雨季（755.34 ± 289.97）和旱季（489.98 ± 232.62）被归类为“高度污染”和“严重污染”。