Phaseolus vulgaris in the treatment of agricultural soil contaminated by hydrocarbons

Abstract

A soil polluted by waste motor oil (WMO) is inhibiting organic matter mineralization and caused losing its fertility. An alternative solution is to enrich soil and a plant to eliminate WMO at concentration value lower than 4400 ppm, maximum value accepted by the Mexican environmental regulation called NOM-138-SEMARNAT/SSA1-2003 (NOM-138). The objective of this research was to treat a soil polluted by 35,000 ppm of WMO with Phaseolus vulgaris inoculated with Azotobacter vinelandii and Paenibacillus polymyxa to reduce the WMO´s concentration at lower value than the maximum accepted by the NOM-138. The variable responses for recovering soil ‘fertility of this experiment was a) the initial and final concentration of WMO by Soxhlet, and b) for P. vulgaris the percentage (%) of germination, the phenology: height of plant, length of root; and biomass: aereal and radical fresh/dry weight at seedlings and reflooring stages. Experimental data were analyzed by Tukey 0.05%. Results showed that soil enriched to facilitate that P. vulgaris with A. vinelandii and P. polymyxa at e-flowering, could reducing ARA until 1152 ppm, lower concentration than the maximum allowed by NOM-138 for recovering soil´s fertility.

Keywords

• soil
• hydrocarbons
• biostimulation
• phytoremediation
• rhizobacteria.