Ecotoxicological Effect of Aged Wood Leachates to Aquatic Organisms

• Main Authors: Lyndon N. A. Sackey, Klára A. Mocová, Vladimír Kočí
• Format: Article
• Language: English
• Published: MDPI AG 2020-07-01
• Series: Water
• Subjects: aged wood leachate; toxicity; aquatic organisms; ecotoxicity; Ghana
• Online Access: https://www.mdpi.com/2073-4441/12/8/2091

Wood is an important natural resource used for various human activities. Toxicity of wood leachate in aquatic organisms has been previously established, but whether storage over time has an impact on the quality of leachate has not been assessed. Hence, this research seeks to assess the toxicity of aged wood leachate in aquatic organisms. Five fresh wood samples were randomly selected from the Oboyow forest reserve in the eastern region of Ghana: Mahogany (<i>Khaya ivorensis</i>), Cedrela (<i>Cedrela odorata</i>), Emire (<i>Terminalia ivorensis</i>), Wawa (<i>Triplochiton scleroxylon</i>), and Ceiba (<i>Ceiba pendandra</i>) to assess their toxicity to aquatic organisms. Algal (<i>Desmodesmus subspicatus</i>) duckweed (<i>Lemna minor</i>) and daphnia (<i>Daphnia magna</i>) were carried out using exposures to concentrations of 20%, 30%, 45%, 67%, and 100% <i>v/v</i> of wood leachate with control media, because they represented various concentration rate levels of wood leachate toxicity in the test organisms. The toxicity of the various wood leachates might be due to high levels of biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total organic carbon (TOC), i.e., metals and phenols. The % IC₅₀ of the various wood leachate ranged from 21.51–66.77% with mahogany exhibiting the highest toxicity and wawa the lowest. It was also observed that toxicity of wood leachates decreased as the wood leachate aged. The % IC₅₀ showed both confirmed and potential toxicity among the various wood leachates.