Effect Of Hydrogen Peroxide On The Transport And Transformation Of Cu And Zn Of Manure In Soil And Crop System

Heavy metal pollution in soil is a hot topic of food safety and environmental safety, most of them focused on the effects of application of sewage sludge and sewage irrigation and there has been no comprehensive review on the input of metals via livestock and poultry manures. H₂O₂ is a common component in natural water, it is the product of photochemistry or the process of radiation decomposition specially is obvious in the geological environment containing radioactive substances or industrial waste dumps. The oxidative capacity of H₂O₂ is much stronger than that of O2, and this illustrates that H₂O₂ is likely to participate in the oxidation process of metals. When H₂O₂ contacts with Fe?II? in soil, it may trigger the Fenton or Fenton-like reactions and a much stronger oxidants, free radicals, may be produced accordingly, which could enhance the chemical oxidation process of metals. In the present study, three different manures including air-dry fresh swine manure?FM1?, air-dry swine manure compost?FM2?, pig bio-bed swine manure material?FM3? that contained excessive Cu and Zn were selected to investigate their effect on transport and transformation of heavy metals in vegetable soil and rice soil, metals accumulation of I. aquatica and Oryza sativa L., and further more to explore the effects of 20-100 ?m·L-1 H₂O₂ on the form and availability of heavy metals in soil and their accumulation in crops were systematically investigated in this study, in order to provide scientific foundation for the protection of farmland ecoenvironment, the improvement of vegetable and rice quality, the comprehensive utilization of poultry and livestock manure and the treatment of environmental pollution by using incubation experiment, pot experiment and plot experiment. The main results are summarized as follows:?1? Soil p H and the content of organic matter increased after the soil applied with manures, especially in the treatment of FM1 and FM2. Soil p H initially rose and then decreased, whereas the content of organic matter decreased with time. Soil p H and the content of organic matter increased with H₂O₂, especially in 20 ?m·L-1 of H₂O₂.?2? The nutrient status can be improved by using manure in soil and crops would increase, especially by using FM2. But the growth of crops would be inhibited if the manure was applied with a large quantity. The biomass of crops increased with H₂O₂, especially in low concentration of H₂O₂.?3? Soil p H, Cu and Zn concentrations in crop tissues increased after the soil applied with manures, especially in I. aquatica and grains of Oryza sativa L. in the treatment of FM3. Cu and Zn concentrations in decreased with H₂O₂, especially in low concentration of H₂O₂.?4? The the manure with high concentrations of Cu and Zn in agriculture may easily induce heavy metal accumulation in soil, especially application of FM3. As the time went on, exchangeable fraction of Cu and Zn transformed to more stable form gradually, while the concentration of carbonate fraction increased first and then decreased, Fe/Mn oxide and organic fractions increased sequentially during the experiment. Concentrations of exchangeable and carbonate fraction in decreased with H₂O₂, while the organic fractions rose, especially in low concentration of H₂O₂.