Multi-walled carbon nanotubes, zeolite and arbuscular mycorrhizal fungi can affect plant Ni concentration in a Ni-polluted soil that was naturally polluted with diesel fuel

Abstract

Remediation of soils polluted with heavy metals or petroleum hydrocarbons is one of the environmental problems. This research aimed to evaluate the effect of carbon nanotubes, zeolite and AMF on triticale Ni concentration in a soil co-contaminated with diesel fuel and Ni. Treatments consisted of applying multi walled carbon nanotubes (MWCNs) and zeolite at the rates of 0 , 1 and 2 % (W/W) in a Ni-polluted soil (0, 75 and 150 mg Ni/kg soil) which was naturally polluted with diesel fuel under cultivation of triticale plant inoculated with AMF. After 70 days, plants were harvested and soil and plant Ni concentration was measured using atomic absorption spectroscopy (AAS). Soil microbial respiration and degradation of diesel fuel were also measured. Applying 2 % (W/W) zeolite and MWCNs significantly increased the diesel fuel degradation in soil by 12.3% and 14.5 %, respectively, while the plant Ni concentration was decreased by 8.9 % and 13.1%, respectively. Increasing soil pollution with Ni from 0 to 75 mg/kg soil significantly decreased the degradation of diesel fuel in the soil under cultivation of plant inoculated with AMF by 14.4%. In addition, the soil microbial respiration was also decreased by 11.8%. The results of this study showed that application of zeolite and MWCNs had significant effect on increasing diesel fuel degradation in heavy metal polluted soil that is a positive point in environmental studies.