IMPACT OF NANOPARTICLES ON THE ANAEROBIC DIGESTION CHARACTERISTICS OF ENROFLOXACINCONTAINING MANURE OF LIVESTOCK AND POULTRY AND ANALYSIS OF MICROBIAL COMMUNITY EVOLUTION

Enrofloxacin-containing chicken manure was taken as the research object for a 55-day batch mesophilic anaerobic digestion experiment using carriers of 300 mg/kgTS nano-Fe2O3 and 100 mg/kgTS nano-C60.Based on the analysis of the biogas production characteristics, chemical parameters, microbial diversity, and changes in antibiotic content during the anaerobic digestion process, the impact of nanoparticles on the anaerobic system of antibiotic-containing chicken manure was clarified, and the degradation laws of antibiotic were extracted to shed light on the pollution reduction and energy production of livestock and poultry manure.The results showed that: (1) The adding of nanoparticles nano-Fe2O3 and nano-C60 had a promotion effect on the anaerobic biogas production with manure containing different concentrations of ENR (enrofloxacin).The cumulative biogas output from day 1 to 10 was in the following order: 2968 (R5) > 2490 (R4) > 1375 (R1) > 1216 (CK) > 1203 (R2) > 1121 (R3) mL, and the cumulative biogas output of R4 and R5 increased by 81.09 and 115.8%, respectively.The degradation rates reached 82.7%, 89.18%, 86.69%, 92.12%, and 94.33%, respectively; (2) On the first day of the reaction process, Firmicutes and Bacteroidota were the dominant bacterial phyla, with relative abundance of 46.56-66.18%and 29.32-49.52%,respectively.The bacterial communities in R4 and R5 containing nanoparticles did not significantly change; The quantity of Bacteroidota in the nanoparticle-containing groups was slightly larger than that in R2.On the 50th day, Firmicutes became dominant with a relative abundance of 83.81 to 93.44%, with small difference between the groups; (3) Euryarchaeota and Halobacterota were the dominant phyla of archaea in the groups during the experiment.On the first day, the relative abundance of Halobacterota in the CK group was 74.56%, 14.11-12.56%higher than that in the groups R2, R4, and R5.In the middle stage of the experiment, Euryarchaeota was dominant with a relative abundance of 71.36-99.01%.On the 50th day, Halobacterota became the dominant phylum in the CK group again, while Euryarchaeota was still dominant in the groups R2, R4, and R5.