An experimental study on release mechanism of iron and manganese from sediments to the water column in reservoirs

Yıl 2021, Cilt: 4 Sayı: 3, 190 - 198, 30.09.2021

Buse Vural Aydın Şebnem Elçi Hatice Eser Ökten

https://doi.org/10.35208/ert.833975

Cited By: 1

Öz

Iron and manganese accumulation in drinking water reservoirs is a challenging issue and should be controlled to prevent their adverse effects on human health. Accumulation of these elements not only clogs pipeline systems but also causes stains on fixtures and laundry. Also, high concentrations of iron and manganese may lead to various health problems when ingested. This study focuses on the release mechanism of iron and manganese from sediments to the water column in reservoirs and investigates methods to prevent this release. Effects of hypoxia, hypolimnetic aeration, alkalinity of water, and thermal stratification on iron and manganese concentrations were investigated through laboratory experiments. Experiments done simulating the water column showed that hypoxia caused more dissolution of ferrous iron when compared with that of manganese. Accordingly, aeration of the water column in hypoxic conditions lead to a significant decrease in ferrous iron concentrations (in our case reaching zero). However, manganese and total iron levels were not affected by the aeration of the water column. Alkalinity level of the water column was observed to have a great effect on the solubility of iron and manganese. Concentrations of total Fe and total Mn measured for acidic (pH=5) conditions were considerably greater than concentrations measured at neutral conditions. As for alkaline (pH=11) conditions, the opposite was observed with measured concentrations of total Fe and total Mn being lower than the ones measured for neutral conditions. Thermal stratification had an enhancing effect on the solubility of both iron and manganese ions. While aeration of the stratified water column slightly decreased the concentrations of Total Fe and Mn, it had a greater impact on decreasing Fe²⁺ concentrations.

Anahtar Kelimeler

Iron, Manganese, Stratification, Aeration, Water quality, Laboratory study, Hypolimnetic oxygenation

Kaynakça

• [1]. Yu, X., Yan, Y., Wang, W. The distribution and bioavailability of heavy metals in different particle size fractions of sediments from the Pearl River estuary and Daya bay South China.Mar Pollut Bull 60:1364-1371. 2010.
• [2]. Connel, D.W. and Miller, G.J. Chemistry and ecotoxicology of pollution (pp.444). New York:Wiley. 1984.
• [3]. Beutel, M.W., Leonard, T.M., Dent, S.R. and Moore, B.C. Effects of aerobic and anaerobic conditions on P, N, Fe, Mn, and Hg accumulation in waters overlaying profundal sediments of an oligo-mesotrophic lake. Water Res. 42, 1953-1962. 2008.
• [4]. Gantzer, P.A.,Bryant, L.D., Little, J.C. Controlling soluble iron and manganese in a water-supply reservoir using hypolimnetic oxygenation. Water Res. 43, 1285-1294. 2009.
• [5]. Davison, W. Iron and manganese in lakes. Earth-Sci. Rev. 34, 119e163. 1993.
• [6]. Munger,Z.W.,Carey ,C.C., Gerling ,A.B. Effectiveness of hypolimnetic oxygenation for preventing accumulation of Fe and Mn in a drinking water reservoir, Water Research,106 ,1-14. 2016.
• [7]. Bryant, L.D.,Hsu-Kim, H., Gantzer, P.A., Little, J.C..Solving the problem at the source: controlling Mn release at the sediment-water interface via hypolimnetic oxygenation., Water Res. 45, 6381-6392. 2011.
• [8]. Kawashima, M., Takamatsu, T., Koyama, M. Mechanisms of precipitation of manganese (II) in Lake Biwa, a fresh water lake. Water Res. 22, 613e618. 1988.
• [9]. Zaw, M.,Chiswell, B. Iron and manganese dynamics in lake water. ,Water Res. 33, 1900-1910. 1999.
• [10]. Liu, J. L., Fan, Y. G., Yang, Z. S., Wang, Z. Y., & Guo, C. Iron and Alzheimer's Disease: From Pathogenesis to Therapeutic Implications. Frontiers in neuroscience, 12, 632. https://doi.org/10.3389/fnins.2018.00632. 2018.
• [11]. Guilarte, T.R. Manganese and Parkinson’s Disease: A Critical Review and New Findings. Environmental Health Perspectives, 118, 8, 1071- 1080. https://doi.org/10.1289/ehp.0901748. 2010.