Selenastrum capricornutum Prinz, Zea mays L. and Phaseolus vulgaris L. Biomonitors: Natural Monitors of Spent Phone Battery Toxicity

Aims: This study was undertaken to monitor the different effects of spent Toshiba and Dell laptop battery on the growth and germination indices of Selenastrum capricornutum Prinz, Zea mays L. and Phaseolus vulgaris L. Study Design: Five treatments and the controls designs designated as 6.25%, 12.5%, 25%, 50%, 100% and CTRL were set up in triplicates and incubated at 25 ± 2°C for 72 h and 5 days. Place and Duration of Study: Department of Microbiology, Chukwuemeka Odumegwu Ojukwu University (COOU), Uli Anambra State, Nigeria during May, 2019 - December, 2019. Methodology: The algal growth inhibition was analyzed using spectrophotometric method while growth and germination indices were adopted for the seed growth inhibition. Results: The result revealed that the positive control K2Cr2O7 had the lowest ErC10 (-86.65 mg/L) and the highest ErC90 (130.92 mg/L) while the spent Dell battery sample had the highest ErC10 (10.18 mg/L) and spent Toshiba battery sample had the lowest ErC90 (75.52 mg/L) on Selenastrum capricornutum growth rate, respectively. Boric acid standard toxicant had the highest EC50 (-12.62 mg/kg and -14.30 mg/kg) on Z. mays and P. vulgaris while Toshiba and Dell battery samples had the lowest EC50 (-73.03 mg/kg and -22.37 mg/kg) on Z. mays and P. vulgaris, respectively. Conclusion: The study revealed that both S. capricornutum, Z. mays L. and P. vulgaris L. were very good bio-monitoring models for spent Toshiba and Dell laptop battery contamination assessment; and are therefore recommended for E-wastes bioassays.