Effect of irrigation with wastewater on lead and cadmium accumulations in the soils and plants of wheat and barley

By considering the lack of high-quality water resources, the use of refined sewage as cheaply available water resources can reduce the challenge for water demand in Iran. This research aimed to investigate the accumulation of lead and cadmium in soil and seed of wheat and barley crops that are irrigated by refined sewage and a mixture of unrefined sewage and well water, respectively, in Qods city. During two growth months (March and May 2017), every ten days, one sample of each treatment was investigated to evaluate the physical and chemical properties of incoming water (totally nine samples per treatment). Sixty samples (30 samples from each plant) were randomly harvested. For soil measurement, 30 samples were randomly sampled in each filed (May 2017). The results showed that the values of EC, biological and chemical oxygen demands, lead and cadmium concentrations were more in the mixture of well water and unrefined water than refined water. There was no significant difference between the cadmium concentrations in the seeds of the two plants; however, the lead concentration in the seeds of barely was significantly more than wheat. The differences in the mean of lead and cadmium concentrations in the soil of two plants were not significant. The results of the bioconcentration factor i showed that none of the plant’s ability to extract lead and cadmium. Only the concentration of lead metal in barley is higher than the World Health Organization standard, which indicates that the grain produced in this field is harmful to human consumption.