Elucidating the positive influence of calcined clay on the retention of carbon components during chicken manure composting.

Composting is an efficient way of recycling wastes, serious mineralization will lead to loss of organic carbon components in the biodegradation process, which will affect the quality of composting products. Calcination technology was adopted to improve the ability of clay minerals to adsorb and retain organic carbon components, and was applied to chicken manure composting. Five treatments (control group (CK), calcined montmorillonite (M-), montmorillonite (M), calcined illite (I-) and illite (I)) were executed. The results indicated that calcined clay minerals significantly reduced organic carbon loss (CK: 57.22%, M-: 54.56%, M: 56.86%, I-: 52.39% and I: 56.08%) and most of them in the form of humic acids. Therefore, the properties of carbon components were more stable, and ultimately improved quality of final compost products. Meanwhile, the network complexity, interactions and contribution of core bacteria involved in the formation of organic carbon were enhanced in the calcined clay minerals treatments through microbial analysis. Moreover, a series of statistical informatics analysis verified that specific structure of calcined clay minerals could indeed retain organic carbon by enhancing role of core bacteria and physicochemical factors. Therefore, this article revealed mechanism of calcined clay minerals retained organic carbon and proposed rational recommendations for practice of composting. [Display omitted] [ABSTRACT FROM AUTHOR]