Effect Of Different Propootions Of Oak Charcoal On Composting Of Pig Manure With Rice Husk Under Aerobic Conditions

The livestock manure has been the main pollution with the rapid development oflivestock breeding in China. So it is important to develop the technology of manure controland resource utilization. Composting is the effective method to realize the disposal andresource utilization of livestock manure. The experiments were carried out in an aerobicreactor for60days; pig manure was selected as raw material, and mixed with rice huskpowder, and the mixtures were amended with oak charcoal at0%,2.5%,5.0%,7.5%and10.0%in dry weight before composting. The effects of different amounts of oak charcoaladdition on the dynamic changes of temperature, pH, EC, water contents, NH4+-N, NO3--N,TN contents, the spectral characteristics and heavy metal(Cu,Zn) were evaluated. The studyimplicated that adding oak charcoal could accelerate the composting maturity; reduce nitrogenloss and improving the quality of compost.The results showed that:1. After60days composting, the effects of oak charcoal addition on temperature, watercontents, pH, EC, germination index, and germination rate were studied in compostingexperiment. The results showed that adding oak charcoal could extend high-temperaturephase of the compost piles by2~5d, and increased the water contents, and decreased the ECand increased the germination index value during composting.2. The SEM analysis showed that the organic matter decomposition during thecomposting process. Adding oak charcoal could accelerate the decomposition.3. The results showed that, the oak charcoal adding could increase the NH4+-Nconcentration at the range of92.22~261.29mg·kg-1, as well as increase the NO3--Nconcentration at55.86%~89.32%. After oak charcoal addition, TN contents of compostincreased throughout the composting process. After60d composting, the final TN contents incomposts were14.92、16.69、17.32、18.05and18.53mg·kg-1. Compared to the controltreatment, the TN contents in oak charcoal addition treatments increased by20.55%~53.07%.4. During the composting process, the total Cu and Zn concentration were concentrated while the percentages of DTPA extractable Zn and Cu were decreased. The Sposito’s chemicalspeciation analysis showed that the fractionation were mainly in residue, sulfide, organicbound form for Cu, and residue, organic complexed or carbonate, sulfide form for Zn.