Monitoring of Zinc Profile of Forages Irrigated with City Effluent

Abstract

Wastewater contains a surplus amount of trace metals that contaminate the soil and crops. A pot trial was performed to determine the impact of wastewater on the zinc accumulation in forages and their associated health risk. Forages both of summer (Zea mays, Echinochloa colona, Pennisetum typhoideum, Sorghum vulgare, Sorghum bicolor, Sesbania rostrata, and Cyamopsis tetragonoloba) and winter (Trifolium alexandrinum, Medicago sativa, Brassica campestris, Trifolium resupinatum, Brassica juncea, and Brassica napus) were grown with sewage water and tap water treatment. The experiment was laid down in a completely randomized design with five replicates. The concentration of zinc in water, root and forage samples were analysed by atomic absorption spectrophotometer. In tap water, the zinc value was 0.498 mg/L and in wastewater 0.509 mg/L, respectively. The maximum level of zinc in the forages leaves was 3.582 mg/kg found in Brassica napus grown in the winter season. The maximum observed value for zinc bioconcentration factor in Brassica juncea was (2.88) grown in winter. The values of pollution load index for zinc were found less than 1. The values of daily intake of metal and health risk index for zinc in all forages were less than 1 indicated that consumption of these forages was free of risk.

Keywords

• bioaccumulation
• pollution load index
• forage
• health risk index