Impact of pharmaceutical wastewater on phytochemical constitution of commonly consumed vegetables in Nigeria

Abstract

The manufacture of pharmaceutical medicines is a desired industrialisation process, though the production of wastewater during its operations and its release into surrounding water systems may pose environmental pollution challenges. The objectives of this study was to examine the effect pharmaceutical industrial processing wastewater on the phytochemical constitution of commonly consumed vegetables in Nigeria. A study was conducted at the University of Ilorin Botanical Garden, involving two commonly consumed vegetables, namely Amaranthus viridis (African spinach) and Corchorus olitorus (jute mallow) cultivated in soils treated with different concentrations of pharmaceutical wastewater (20, 40, 60, 80 and 100%). Phytochemical analyses included the test to determine the presence and quantities of alkaloids, saponins, tannins, glycosides and terpenoids. Results revealed that the alkaloid content was marginally present in spinach leaves from soil treated with 100% wastewater, but moderately present in Amaranthus viridis from other treatments. The study revealed that the alkaloid content in Amaranthus viridis ranged from 4.22 to 9.8 mg 100 g -1; while glycoside content in Corchorus olitorius leaves varied between 0.50 to 2.72 mg 100 g-1. On the other hand, low pharmaceutical wastewater concentrations enhanced phytochemicals, with high concentrations causing heavy metal stress, resulting in reduced phytochemical yields. Phytochemical yield is the amount of bioactive plant compounds (phytochemicals) extracted from a plant sample, and it is usually expressed as a percentage of the weight of the initial plant material.