Bioremediation Experiment Of Soil Contaminated By Organic Pollutants In Field

Organic compounds,especially pesticide,contaminated soil is a very preminent problem which affected product safety of agriculture and food at present time. Bioremediation of soils contaminated with organic compounds become a research hotspot in the domain of agriculture,environmental science, ecology and other areas of research in recent years. The research in this paper adopt P.chrysosprium to progress degradation experiment of contaminated soil with organic compounds in field, in order to provide a bioremediation gist for a large-scale bioremediation of contaminated soil under natural conditions.First of all, the paper cultivated microbial agent using of solid-state fermentation culture, and further optimize the white-rot fungus solid culture conditions, it can be suitable for the needs of large-scale production; Secondly, the effect factor to the proliferation of white rot fungi was researched in the field bioremediation test, such as the capacity,time,way of infliction etc. At the same time, PCP was studied as a representative of organic pollutants.it was confirmed that the optimal degradation condition and the main operation rules has monitored the degradation of contamination in soil.Finally, the overall capability which the white rot-fungus agent degradated PCP and nirobenzene compounds was analyzed in mixture compounds contaminated soil. These teachnical research have laid down the foundation to large-scale bioreme- diation of contaminated soil in natural environment in the future.The results are as follows:So to produce more spores, using bag-batch culture at prophase, and using shallow tectorial culture at anaphase, and drying of solid culture in a low temperature around 50℃. The spores amount of dry microbial agent per gram reached to 280 million around. This provide a good condition for proliferation of white rot-fungi in soil. The microbial agent which was produced through this method have a lot of merits such as lower cost,shorter production cycle,higher output. Single-batch production capacity have reached about 120kg.After experimented in field,the pH,temperature,fillers and other key factors that were suitable for growth of white rot-fungi in soil were found. The CFU of P.chrysosporium can reach to 8.8×104 in each gram soil, at pH 5.6, the ground temperature being about 28℃, the mass ratio of fillers and soil being about 1:200. At the aspect of degradation research, degradation experiment have been performed separately in different plot of 160cm*80cm in different season, and each plot are all contaminated by PCP which concentration is about 200ppm. These plots have been treated by P.chrysosporium for 2 months. Degradation rate is reach to 84% in winter and spring, 90% in summer, 93% in autumn. It is obvious that degradation effect is best in autumn other than in other season. In autumn, the degradation experiment are also performed to soil which contaminated by commixture pollutant,in order to validating that P.chrysosporium have a wide range to degradate pollutants. Its result show that the plot, which contaminated by commixture pollutants of 150ppm, has been treated by P.chrysosporium for about one month, and the whole degradation rate is kept above 85%.