Evaluation of the Ecotoxicity Potentials of E-Waste Using Selenastrum capricornutum (Microalga), Eisenia fetida (Earth Worm) and Allium cepa (Onion Bulb) as Bioindicators

Abstract

Aims: This research work was designed to evaluate the ecotoxicity potentials of e-waste using Selenastrum capricornutum, Eisenia fetida and Allium cepa as bioindicators. Study Design: Selenastrum capricornutum and Allium cepa bulbs were exposed for 72 h at concentration ranging from 0 mg/L to 100 mg/L while Eisenia fetida were exposed for 48 h and 14 days at sub - lethal concentrations ranging from 0 mg/L to 8.54 mg/Lfor Hp laptop battery and 0 mg/L to 9.34 mg/L for Toshiba battery sample, respectively. Place and Duration of Study: Department of Microbiology, Chukwuemeka Odumegwu Ojukwu University (COOU), Uli Anambra State, Nigeria during May, 2019 - December, 2019. Methodology: A laboratory scale study was carried out on spent Hp and Toshiba laptop battery samples using microalgal toxicity test, earthworm mortality test and Allium cepa tests. Results: The result showed that the spent Toshiba battery sample had the most hazardous toxic effect (ErC50 19.58 mg/L; EC50 34.54%; LC50 3.60 mg/kg and 3.16 mg/kg) on the growth rate of S. capricornutum, root growth of A. cepa and E. fetid a survival after the treatment periods. Morphological abnormalities were also observed on the exposed roots of A. cepa. Inhibition (%), biomass change and mortality (%) of all species used were found to be concentration dependent with significant (P < 0.05) strong positive correlation at increasing concentrations. Conclusion: Thus, the government should enforce strict regulations and heavy fines on industries, which do not practice E - waste prevention and recovery in the production facilities.