Effect of Water Hardness on Acute Aquatic Toxicity of Fatty Acid Salts
-
- Takada Noriko
- Graduate School of Environment and Information Sciences, Yokohama National University
-
- Kobayashi Takeshi
- Graduate School of Environment and Information Sciences, Yokohama National University
-
- Oya Masaru
- Graduate School of Environment and Information Sciences, Yokohama National University
この論文をさがす
説明
<p>The acute aquatic toxicity of anionic surfactants, including fatty acid salts, changes depending on water hardness. Generally, the acute aquatic toxicity of Daphnia magna is caused by the adsorption of surfactants and other substances. Despite the low environmental risk, the effect of water hardness on the acute aquatic toxicity of soap should be discussed to improve the assessment accuracy. Previously, we evaluated the effects of water hardness and the presence of an adsorbent on the acute aquatic toxicity of soap by performing an immobility test using D. magna in accordance with Japanese Industrial Standards (JIS) K 0229. Immobility was low at 50 ppm and a higher water hardness was indicated owing to the loss of interfacial activities caused by the formation of insoluble fatty acid calcium or magnesium complexes (soap scum). In the current study, we evaluate the effects of water hardness on the acute aquatic toxicity of C10, C12, C14, C16, and C18 saturated and C18:1 unsaturated fatty acid sodium salts. The EC50 is measured via an immobility test in accordance with JIS K 0229 using D. magna, and the surface tension is measured as an indicator of surface activity. Results show that the EC50 and surface tension curves change with water hardness in single and mixed solutions. C18:1 indicates the least change and the highest surface activity. Moreover, immobility change is not observed when C18:1 is filtered, whereas the immobility of other solutions decreased significantly. This implies the effect of soap scum on immobility, such as the clogging of gills by soap scum. Based on quantitative analysis, the percentage of C18:1 that transformed soap scum to its initial concentration exceeds 80%. This implies that calcium deficiency under 5 and 25 ppm water hardness affects the immobility of larval D. magna. The effects of soap scum clogging and calcium deficiency on D. magna should be considered before assessing the soap.</p>
収録刊行物
-
- Journal of Oleo Science
-
Journal of Oleo Science 72 (11), 1005-1014, 2023
公益社団法人 日本油化学会
- Tweet
キーワード
詳細情報 詳細情報について
-
- CRID
- 1390016515857577344
-
- NII書誌ID
- AA11503337
-
- ISSN
- 13473352
- 13458957
-
- NDL書誌ID
- 033134447
-
- PubMed
- 37914262
-
- 本文言語コード
- en
-
- データソース種別
-
- JaLC
- NDL
- Crossref
- PubMed
-
- 抄録ライセンスフラグ
- 使用不可