Effects Of Ignition On The Soil Organic Matters And The Adsorption Of Pahs(Phenanthrene)and Bioavailability In Ignited Soil

This paper studied the effects of ignition on the soil organic matters, and the adsorption of PAHs (Phenanthrene) and bioavailability in ignited soil. Through analysed the treatment methods of burning straw on the field, provide theoretical basis for its influence on soil and environment. At the same time, it have considerable benefits for predicate the fate of pollutant in the environment, risk assessment of crop contamination, and subsequent human exposure and the develpoment of phytoremediation. The main research content of the dissertation involves:The influence of compotent and content of soil organic matters under different igniting temperations; Adsorption behaviour of phenanthrene in different soils under the different temperatures; Uptake, accumulation and translocation behaviour of phenanthrene affected by humic acid in maize. The main valuable conclusions are shown as follows:(1) In setting temperature range, the component of soil organic matters is different under different igniting temperatures. With increasing igniting temperature, the content of DOC is increased first and then decreased, which reached to its peak at200℃, it is about3.68～7.45times to control. And compared with DOC, the change of carbon neutral sugar and uronic acid carbon have the same trend. At200℃the content of carbon neutral sugar reached its peak, it’s about4.44～12.77times control. And at300℃, the content is below common temperature, but when the temperature creased to360℃, we couldn’t test it.(2) The composed of humus and the degree of humification are change with soil igniting temperature. With the temperature increase, the content of humic acid(HA) and fulvic acid(FA) are increased first and then decreased. Expect Wu-he soil, the highest ration of humic to fulvic acid on300℃treatment condition, and at this condition the polymerization degree of soil humus is lowest. And with the temperature increase the ratio of E4/E6is also increased first and then decreased and the ratio of E4/E6is highest under 200℃, expect Wu-he soil. This showed that the humification degree of soil is lowest under200℃.(3) A comparative study on the igniting temperature of CK,200℃and300℃in sorption characteristics of phenanthrene. The rusults showed that sorption isotherms of phenanthrene were similar at different temperature. In the concentration range of settings, along with the concentration of phenanthrene increased, the adsorption capacity of phenanthrene in soil is increased too.The adsorption of PAHs(phenanthrene) exhibited closely to linearity sorption isotherms in ignited soils, which were due to partitioning mechanism. What is more, it fit for Langmuir model, and the correlation coefficients were higher than0.98.(4) After one week, different concentration of humic acid has no obvious effect on the biamoss of maize in phenanthrene contaminated soil. Under the same treatment condition, the content of phenanthrene in roots is far higher than shoots. And after plant cultivation, the concentration of phenanthrene in soil decreased significantly, but between different treatments it hasn’t obvious variation.(5) Along with the increased of humus acid concentration, plant availability of phenanthrene is decreased in soil, and the effect of humic acid is very obviously. The presence of fulvic acid with relatively low concentrations promoted maize uptake of phenanthrene, wheras fulvic acid with higer concentration would inhibit the plant uptake of the compound. And the uptake and accumulation of phenanthrene in shoots and roots from soil were reduced with the increase of humic acid concentrations.