| The soil was collected in the farmland around a Xinjiang petrochemical industry wastewater reservoir and the experiments were carried out on indoor potted plants. We conducted the flowing work in this paper:The relationship of vanadium concentration in the soil and the absorption of vanadium(V) in alfalfa was studied. The effect of alfalfa’s growth time on the ion state of vanadium in the soil. How the amount of EDTA in the soil effected the absorption of vanadium in alfalfa. Different concentration of EDTA、citric acid and gallic acid were used to study how it can effect the distribution of vanadium ion state in the soil. The following conclusions were included:(1)Based on the investigation of vanadium(V) aging time,20days was chosen as the aging time in this work. The distribution form of vanadium(V) would be influenced by the adding amount of vanadium(V), and the results were:RF> OM> EX>Fe-Mn>CARB.(2) The alfalfa height and biomass reached to the maximum when the adding amount of vanadium(V) was80mg/kg. With the increase of vanadium (V) contents, the absorption of vanadium(V) in leaf of alfalfa increased accordingly. And the absorption of vanadium(V) reached to maximum in root when the adding amount was80mg/kg. The order of vanadium(V) in various forms in the soil was as follows: Fe-Mn> EX> OM> RF> H2O> CARB. The best relevance in EX, Fe-Mn,OM and the amount of vanadium(V) contents in soil was positively correlated.(3)The best absorption of vanadium(V) in alfalfa was reached when adding5mmol/kg of complexing agent EDTA. Compare with the soil without adding EDTA agents, the adsorption of vanadium(V) was enhanced after adding EDTA.The overall order for the various forms of vanadium(V) in the soil except RF as follows was: OM> EX> Fe-Mn> CARB> H2O. With the increase of planting time, the relevance of the vanadium(V) and the chemical form of the vanadium(V) in the planting soil was significant growing increasingly.(4) The vanadium(V) content in the root, sten and leaf of alfalfa in cobalt-vanadium combined pollution soil, the maximum of the content of cobalt was 30mg/kg in the soil, no matter EDTA was added or not.(5) By adding different concentrations of citric acid, gallic acid, citric acid and EDTA, gallic acid and EDTA into the soil. Through biological effectiveness coefficient calculation, the result showed that:the biological effectiveness coefficient of vanadium(V) was0.283without chemical enhanced treatment of vanadium(V) in soil. With adding the same amount (5mmol/kg) of chemical amendments, namely EDTA, citric acid, gallic acid, the biological effectiveness coefficient of vanadium(V) increased to0.449,0.355and0.320, separately. When7mmol/kg citric acid and5mmol/kg EDTA were added together, the biological effectiveness coefficient of vanadium(V) was0.339. And it increased to0.435when7mmol/kg gallic acid and5mmol/kg EDTA were added. As a consequence, the best chemical amendments effect was reached by adding5mmol/kg of EDTA. |
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