Impact of treated municipal wastewater irrigation on turnip (Brassica rapa)

The effect of treated municipal wastewater on the roots and the leaves of turnip was studied to compare the 50% and 100% wastewater of 34 ml/d Sewage Treatment Plant (STP) with different doses of potassic fertilizers. Turnip (Brassica rapa) was used as a test plant. A pot experiment was conducted, using a factorial randomized block design to investigate the growth and translocation of heavy metals to the leaves and the roots of turnip. The concentration of heavy metal in wastewater used for irrigation was within the limits. However, the concentration in the plant parts showed a significant rise due to continuous use of wastewater. The concentration of heavy metals in leaves and roots was at excessive levels at 40 and 55 days after sowing (DAS), while at 70 DAS, metal concentration was comparatively low. The range of heavy metals in wastewater irrigated plants was Cd = 1–16.3, Ni = 0–136, Fe = 263–1197, Cu = 0–18, Mn = 37–125, and Zn = 42–141 mg/kg. Concentration of heavy metals in plants was found in the order of Fe>Zn>Ni>Mn>Cu>Cd.