Abstract
The effects of copper (Cu) and zinc (Zn) on the growth of tomato plants when grown in hydroponics were tested; whether the Cu and Zn is taken up into the tomato fruits to toxic levels; and to determine the suitability of both secondary treated wastewater and Cu and Zn contaminated water as a nutrient source for tomato plants. Good yields of tomato fruit were observed on the plants grown in the control media (CM), the Cu spiked media (0.5mg/L and 1.5mg/L Cu spiked) and the Zn spiked media (2.2mg/L and 2.6mg/L Zn spiked), whereas the secondary treated wastewater (WW) did not produce adequate yields and the plant growth was stunted. The stunted growth in the WW plants was found to be more likely due to lack of macronutrients rather than the presence of Cu and Zn. In all media, accumulation of Cu and Zn was observed to be more in the roots than in the fruits. The use of Cu and Zn contaminated nutrient sources could be feasible, but there is still cause for concern as the ability of the tomato plants to accumulate potentially toxic levels of Cu and Zn is possible.