Effects of Electroplating Effluents on Growth, Heavy Metals Accumulation and Concentrations in Amaranthus viridis Lin.

Abstract

Pollution in recent times has become prevalent due to industrial expansion, hence, releasing pollutants into the environment. Thus, this study aimed at investigating the effects of effluents from electroplating companies on growth, heavy metals accumulation and concentrations in Amaranthus viridis. Seeds of A. viridis were obtained from the National Institute of Horticulture, Ibadan. Loam soils were collected from Lagos State University and two samples of electroplating effluents were obtained from Oregun, Lagos. Seeds were sown, nursed, and transplanted in a uniform bucket filled with 5 kg loam soil and transplanted seedlings were treated with Effluent A (5 and 10% conc.) and Effluent B (5 and 10% conc.) and control respectively. Growth parameters such as plant height and so on were measured and plant samples harvested were analyzed for heavy metal concentrations using Atomic Absorption Spectrophotometer. Data collected were subjected to a one-way analysis of variance. Results revealed that Effluents A and B are highly acidic and above discharge limits. Also, the result revealed that 5% conc. of Effluents A and B had more effects on growth (p < 0.05) of A. viridis across the harvests than 10% conc. in relation to control. This result showed that the effluent samples affect the growth rhythms of plants. Results further revealed vigorous accumulation of the heavy metals: Zn (241.66 µg kg–1 ± 0.10 at third harvest in Effluent A: 10%), Cu (68.25 µg kg–1 ± 0.23 at first harvest in Effluent B: 5%), Cr (500 µg kg–1 ± 0.90 in harvests at all concentrations.) and Ni (500 µg kg–1 ± 0.90 at third harvest in Effluent B: 5%) and all these metals are far above the control and permissible limits of WHO/FAO recommendations. From this study, it could be concluded that electroplating effluents had adverse effects on growth and increased metals’ bioaccumulation in A. viridis. Therefore, the treatment of effluents to enhance an eco-friendly environment should be done.