多级厌氧系统对土霉素菌渣无害化处理的中试研究

Pilot study on the harmless treatment of oxytetracycline residues by multi-stage anaerobic system

目的研究多级厌氧系统对土霉素菌渣的减量化和无害化处理的水平以及沼泥对沙化土壤和紫花苜蓿的改良促进作用。方法以化学需氧量(COD)为减量化验证参数,土霉素含量为无害化验证参数,通过检测处理前后COD和土霉素的变化考察多级厌氧系统的降解效率。以土壤养分和植物萌芽率及株高为资源化验证参数,以土壤中土霉素抗性基因含量为无害化验证参数,通过检测施加沼泥前后各参数的变化考察沼泥的资源化和无害化利用。结果经3个周期的多级厌氧系统处理,土霉素菌渣中COD降解率达到87.58%,土霉素含量降解率达到99.44%;施加沼泥至沙化土壤后,有机质含量增加1645.74%,全氮含量增加3654.39%,全磷含量增加29.17%,全钾含量增加31.08%,紫花苜蓿株高提高166.16%,土壤中抗性基因intⅠ1、tetC和tetW含量下降,抗性基因tetM含量无明显变化,抗性基因tetQ含量显著上升。结论多级厌氧系统能够实现土霉素菌渣的减量化和无害化处理,沼泥具有改良沙化土壤养分和促进植物生长的效果,对部分抗性基因有促降解作用,但仍需关注抗性基因tetQ的变化。

Objective To study the level of reduction and harmless treatment of oxytetracycline residues by multi-stage anaerobic system and the improvement and promotion of sludge on desertified soil and alfalfa.Methods Taking chemical oxygen demand(COD)as a reduction verification parameter,and oxytetracycline content as a harmlessness verification parameter,the degradation efficiency of the multi-stage anaerobic system was investigated by detecting changes in COD and oxytetracycline before and after treatment.Taking soil nutrients,plant germination rate and plant height as resource verification parameters,and oxytetracycline ARGs content in soil as harmless verification parameters,resources and harmless utilization of the sludge is investiged by detecting the changes of various parameters before and after applying sludge.Results After 3 cycles of multi-stage anaerobic system treatment,the degradation rate of COD in the oxytetracycline residues reached 87.58%,and the degradation rate of oxytetracycline content reached 99.44%;after applying sludge to the sandy soil,the organic matter content increased by 1645.74%,total nitrogen content increased by 3654.39%,total phosphorus content increased by 29.17%,total potassium content increased by 31.08%,alfalfa plant height increased by 166.16%,and the contents of ARGs intI1,tetC and tetW in the soil decreased significantly,the content of tetM did not change significantly,and the content of tetQ increased significantly.Conclusion The multi-stage anaerobic system can achieve the reduction and harmless treatment of oxytetracycline residues.The sludge can improve the nutrients of sandy soil and promote the growth of plant,and it can promote the degradation of some ARGs’content,but still need to pay attention to the changes of tetQ.