Different Heavy Metal Concentrations in Plants and Soil Irrigated with Industrial / Sewage Waste Water

摘要

Application of waste water for irrigation purposes has increased over the past years. This waste water contains high amount of trace elements and heavy metals. Objectives of this study were to evaluate the concentration of iron (Fe), lead (Pb) and manganese (Mn) in soil irrigated with waste water at different depths and also in the leaves and flowers of vegetables grown in that soil. Samples were collected from vegetable farms located along drain where vegetables were grown by untreated sewage water. Plant samples were washed and cut into pieces, air dried in fluidized bed dryer. After digestion, concentration of heavy metals was detected by atomic absorption spectrophotometer (AAS). The results revealed that heavy metals concentration in soil irrigated with waste water was higher the toxicity level at depth of 0-15cm than the lower layer 16-30cm while the leaves and fruits of vegetables also showed higher concentration of heavy metals. The maximum concentration of lead, iron and manganese was recorded in soil samples taken from Nawabanwala, Malkanwala and Sheikhanwala respectively.