Effects Of Biochar And Microbial Agent On Form Transformation Of Heavy Metals In Pig Manure Compost

The research shows that the heavy metals in manure of livestock and poultry manure accumulate in the agricultural environment and pollute the environment,which has become one of the main sources of heavy metals pollution in farmland.In order to reduce the activities of heavy metals in livestock and poultry dung,the experiment was conducted with pig manure,microbial agents,biochar as the trial materials,to analyze of biochar and microbial add immobilization effect of heavy metals in pig manure composting,to determine immobilization effect of heavy metals with the addition proportion of biochar and microbial agents in the fermentation process,to optimize the production technology of coal-base organic fertilizers,to research the influence of modified biochar on immobilization effect of heavy metals during pig manure composting,to reduce the availability of heavy metals in pig manure.The results could provided theoretical basis and technical guidance for preventing and controlling heavy metals pollution with organic fertilizer source.The main results were as follows:?1?Study biochar,compound microbial agents added individually and at the same time add on the immobilization effects of heavy metals in pig aerobic fermentation process,the research results show that in the process of pig manure composting adding biochar and microbical agent can make the pile body temperature prolonged,and can promote the seed germination rate,at the same time to add biochar and the processing of fermentation bacteria agent effect is best,obviously increase the microbial diversity and fungal diversity index are higher than other treatment at all stages of the compost,and heavy metal Cu?Zn?Pb?Cd in the immobilization effect is better,The effect of immobilization was 65.14%?56.19%?67.40%and 20.95%,higher than the other groups.?2?The effects of biochar species,addition ratio and microbial agent addition on the morphological transformation of heavy metals in aerobic fermentation of pig manure were studied.The high temperature of nine treatments lasted for more than 8 days,the water content dropped below 35%,and the seed germination index reached over 80%,all of which achieved harmless treatment.Three dimensional fluorescence spectrum analysis showed that the PeakA and PeakB intensity is weak after the compos,shows that microbial metabolic activity frequently and make the protein type of material is A large number of decomposition,DOM elements gradually complicated.The optimal addition of Cu was 12%peanut shell biochar and 0.5%microbial agents?T8?,Compared with the pre-reactor,the interchangeable distribution rate decreased by 25.36%and the immobilization was 70.36%.The optimal treatment for Zn was 24%sawdust carbon and 1.5%microbial agents?T3?.The total distribution rate of exchangeable and reduced Zn was 34.57%lower than before the compost,and the immobilization was 40.76%.The optimal treatment for Pb was 24%peanut chitosan biochar and 1%microbial agents?T9?.The exchangeable distribution rate was 16.32%lower than before compost,and the immobilization was 74.60%.The best treatment for Cd immobilization was 24%sawdust carbon and 1.5%microbial agents?T3?.The combination of 24%peanut shell biochar and 1.5%microbial agents was used to improve the immobilization the heavy metals.?3?The effects of NaOH and FeCl₃ modified biochar on heavy metals immobilization were studied in order to improve the effect of biochar on heavy metals immobilization.Pig manure and straw as raw material,the modified peanut shell biochar additive?24%?,add 1.5%microbial agents of experiment,the results show that adding of peanut shell biochar modification can make heavy metal Cu?Zn?Pb?Cd by higher activity form to active low form transformation,the immobilization effect is not add biochar increased by 1.81⁵.76,NaOH and FeCl3 significantly improved the aerobic fermentation process heavy metal immobilization effect.Together,in the process of compost FeCl₃modified biochar(pig manure quality of dry matter 24%of heavy metal Cu?Zn?Pb?Cd has relatively good immobilization ability,the effect of immobilization of 78.70%?43.53%?66.45%?58.78%,compared with the test two immobilization effect increased by 5.50%¹4.13%.In this paper,biochar and complex microbial agents were added during the composting process of pig manure to clarify the types and proportions of biochar used and the proportion of microbial agents,and to modify the biochar to further enhance the immobilization of heavy metals.The effect provided a reference for the immobilization of heavy metals in pig manure composting.