Effect of tire rubber ash enriched municipal waste compost on decreasing spinach Cd concentration (a case study: Arak municipal waste compost

Background and Polltion of food chain components such as vegetables to heavy metals is one of the important environmental problems. Remediation management of these metals especially Cd is very important. Thus, this research was done to investigate the effect of Arak municipal waste compost enriched with tire rubber ash on decreasing spinach Cd concentration in a Cd polluted soil.
Treatments consisted of applying (0, 200 kg/ha) Arak municipal waste compost enriched with tire rubber ash and Cd pollution at the rates of 0, 10, 20 and 30 mg Cd (kg soil)-1. The plant used in this experiments was spinach.
Increasing application rate Arak municipal waste compost from 0 to 20 and 40 ton/ha in a Cd polluted soil (mg Cd (kg soil)-1) caused a significant reduction in DTPA extractable-Cd by16 and 45 %, respectively. Similar to this result, shoot Cd concentration was decreased. Applying tire rubber ash also had an important role on decreasing Cd concentration.
The results of this study showed that applying Arak municipal waste compost had an important role on decreasing Cd concentration. This was due to the application of the organic amendment on increasing soil sorption properties that it in turn decreased soil and plant Cd concentration. However, the role of plant type and soil physico-chemical properties on changes in Cd availability cannot be ignored.