| As professionalization, intensity and enlargement of livestock level were continue increased, large amount of poutry manure were system discharged and seriously threaten enviroment development. At the same time, heavy metal content of poutry manure were greatly higher than standard indexes, that was because of heavy metal additive agent utilization in feed materials, soil and enviroment, human healthy will be influnced by long-term utilization. There is significant realistic meaning of heavy metal in poultry manure were passivated by passivator agent, and the bioavailability and activity were decreased. Pig manure was used as composting materials that was discharged by management poutry system, aerobic-high temperature composting were conducted as simulation in outside, study on concentration and forms transformation of heavy metal before and after composting, inspect bioavailabilty of heavy metal in pig nanure after composting, selected advantage passivator, passivator combination and addition proportion of heavy metal in pig manure composting. Results showed that,1. There are significant effective of physical passivator on heavy metal bioavalability in pig manure composting, and passivation effectives are depend on heavy metal types, in addition heavy metal passivation effective were greatly influnced by passivation proportion. There are different effects of 3 heavy metals (zeolite, sepiolite and bentonite) on combination forms of Zn, Cu, Cd, Pb, Cr and As in composting treatments, and its advantage passivator and addition amount are depend on heavt metal types. The advantage passivator proportion of As in pig manure composting is 5.0% sepiolite, and its passivation effective is 28.5%, advantage passivator proportion of Cr is 5.0% zeolite, and its passivation effective is 98.1%, advantage passivator proportion of Cd in pig manure composting is 2.5% zeolile, and its passivation effective is 37.5%, advantage passivator proportion of Cu in pig manure composting is 7.5% sepiolite, and its passivation effective is 50.8%, advantage passivator proportion of Zn in pig manure composting is 2.5% sepiolite, and its passivation effective is 72.1%, advantage passivator proportion of Pb in pig manure composting is 7.5% bentonite, and its passivation effective is 88.7%.2. There is significant effects of chemical passivator on heavy metals bioavailability in pig manure composting, and effects of four heavy metal passivators (fly ash, ground phosphate rock, Ca-Mg-P fertilizers and DBS) on heavy metals (Zn, Cu, Cd, Cr, Pb and As) are different, advantage passivator and proportion are depend on heavy metal types, all of heavy metal bioavailability were decresed by heavy metal passivators additive. Results showed that, advantage passivator proportion for Zn in pig manure composting is 5.0% Ca-Mg-P fertilizer, passivation effective is 68.0%, advantage passivator proportion for Pb in pig manure composting is 5.0% ground phosphate rock, passivation effective is 34.8%, advantage passivator proportion for Cu and Cr in pig manure composting is 2.5% fly ash, passivation effective is 71.5 and 77.5%, advantage passivator proportion for Cd in pig manure composting is 7.5% Ca-Mg-P fertilizer, passivation effective is 73.3%, there is no signigicant effective of passivator on Hg in pig manure composting.3. There are significant effective of passivators combination on heavy metal bioavailability in pig manure composting. Advantage passivators combination and additive proportion for As in pig manure composting is F2.5+M2.5 treatment (addition 2.5% zeolite and 2.5% fly ash), passivation effective is 65.49%, the following is H5.0+M2.5 treatment (addition 5.0% zeolite and 2.5% fly ash), passivation effective is 60.75%. Advantage passivators combination and additive proportion for Cd in pig manure composting is F2.5+G2.5 treatment (addition 2.5% zeolite and 2.5% Ca-Mg-P fertilizer), passivation effective for exchangable Cd is 89.4%, following is F2.5+M2.5 treatment, passivation effective for exchangable Cd is 84.47%. Advantage passivators combination and additive proportion for Cr in pig manure composting is F2.5+M2.5 treatment (addition 2.5% zeolite and 2.5% fly ash), passivation effective for exchangable Cr is 93.32%, following is F2.5+G2.5 treatment, passivation effective for exchangable Cr is 88.85%. Advantage passivators combination and additive proportion for Cu in pig manure composting is F2.5+L5.0 treatment (addition 2.5% zeolite and 2.5% ground phosphorus rock), passivation effective for exchangable Cu is 88.78%, compared with no passivator addition treatment (41.75%), passivation effective was increased by 47.03%. Advantage passivators combination and additive proportion for Pb in pig manure composting is F2.5+L5.0 treatment (addition 2.5% zeolite and 5.0% ground phosphorus rock), passivation effective for exchangable Pb is 88.05%, following is F2.5+M2.5 treatment, passivation effective for exchangable Pb is 85.98%. Advantage passivators combination and additive proportion for Zn in pig manure composting is H5.0+L5.0 treatment (addition 5.0% sepiolite and 5.0% ground phosphorus rock), passivation effective for exchangable Zn is 97.07%. There is no signigicant effective of passivator on Hg in pig manure composting also.4. Heavy metal utilization in plant experiment results showed that, Zn, Cu, Cd, Cr and As content in vegetable tissues were decresed significantly. The best passivation agent for As is H5.0+M2.5 (82.16%) treatment, the best passivation agent for Cd is F2.5+G2.5 (92.70%) treatment, the best passivation agent for Cr is F2.5+M2.5 (77.42%) treatment, the best passivation agent for Cu is F2.5+L5.0 (70.03%) treatment, the best passivation agent for Pb is F2.5+L5.0 (81.16%) treatment, the best passivation agent for Zn is H5.0+L5.0 (75.65%) treatment.5. Heavy metal utilization in animal experiment results showed that, Cr, Cd, Cu, Pb and Zn bioavailability were decresed significantly by passivators additive in pig manure composting, results of earthworm breeding experiment showed that, Cr, Cd, Cu, Pb and Zn content in body of earthworm were decresed significantly. Heavy metal contents in earthworm can be decreased significantly by zeolite, sepiolite, bentonite, fly ash, Ca-Mg-P fertilizer and ground phosphorus rock, the best effective for Cd bioavailability decreasing is H7.5 treatment and passivation effective is 64.14%, the best effective for Cu bioavailability decreasing is F7.5 and passivation effective is 88.34%, the best effective for Pb bioavailability decreasing is L5.0 and passivation effective is 73.84%, the best effective for Cr bioavailability decreasing is M2.5 and passivation effective is 74.48%, Zn content in earthworm can be decreased by the 6 passivators treatment in composting, the differences of Zn content between CK and treatments are significant, advantage treatements are 7.5% zeolite and 7.5% sepiolite treatments, effective are 73.77% and 72.80% respectively.In brief, effects of heavy metal passivators combination and proportion on bioavailability and activity of heavy metals (Zn, Cu, Cd, Cr and As) were conducted in this experiment, the best generally effective is 2.5% zeolite+2.5%fly ash treatment in composting, in addition zeolite is advantage heavy metal passivator with large specific surface area, high adsorbability, low price and aboundance resources, and fly ash is producation discharge of thermal power companies, its utilization in composting as passivator for heavy metal is not only develop fly ash advantage, heavy metal pollution in pig manure composting can be allevaited also. |
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