Faculty of Environment, Ho Chi Minh City University of Technology, 268 Ly Thuong Kiet, District 10, Ho Chi Minh City, Viet Nam.
Water Sci Technol. 2011;63(10):2231-7. doi: 10.2166/wst.2011.460.
High concentrations of manganese and iron in the Saigon River are major problems for the water supply in Ho Chi Minh City (HCMC), Viet Nam. To identify their sources and leaching processes, we surveyed water quality along the Saigon River and ran batch leaching tests using soil and sediment samples. Two important leaching processes were identified: acidic leaching from acid sulfate soil (ASS) in the middle reaches of the river, and Mn dissolution and Fe reduction from sediments in the downstream reaches. Low pH caused the concurrent release of Fe and Mn from the ASS. In contrast, anoxia caused the release of Fe but not Mn from the sediments, whereas low pH facilitated Mn dissolution. Sediments are a more important source of Mn because of their higher Mn contents (10 times) and release rates (14 times) than those from ASS.
西贡河的高浓度锰和铁是越南胡志明市供水的主要问题。为了确定它们的来源和浸出过程，我们调查了西贡河的水质，并使用土壤和沉积物样本进行了批量浸出试验。确定了两个重要的浸出过程：来自河流中游酸性硫酸盐土壤（ASS）的酸性浸出，以及来自下游沉积物的 Mn 溶解和 Fe 还原。低 pH 值导致 ASS 中的 Fe 和 Mn 同时释放。相比之下，缺氧导致 Fe 释放而 Mn 不释放，而低 pH 值有利于 Mn 溶解。由于沉积物的 Mn 含量（高 10 倍）和释放率（高 14 倍）高于 ASS，因此沉积物是 Mn 的更重要来源。
