猪粪水热预处理和厌氧消化条件下的典型抗生素降解性能

Typical Antibiotics Degradability of Pig Manure under Hydrothermal Pretreatment and Anaerobic Digestion

畜禽养殖过程中排泄的粪污中残存大量抗生素给环境带来潜在风险。为进一步了解水热预处理和厌氧消化对畜禽粪污中典型抗生素降解变化特征,同时明晰抗生素与产甲烷性能的相关性,以猪粪为研究对象,考察了不同温度(70、90、120、150、170℃)水热预处理对3种抗生素(磺胺嘧啶、土霉素和恩诺沙星)的消减作用,研究了3种抗生素在中温厌氧消化过程中的降解规律及其对产甲烷性能的影响。结果表明,磺胺嘧啶和恩诺沙星在70℃水热处理条件下100%去除,而土霉素在90℃水热处理条件下100%去除;3种抗生素的去除率随着厌氧消化时间的延长而逐渐增加,恩诺沙星在厌氧消化5 d基本达到100%的去除;土霉素在厌氧消化15 d基本达到100%去除,而磺胺嘧啶在厌氧消化30 d去除率达52.9%;厌氧消化过程中磺胺嘧啶的去除率随着起始浓度的增加而降低,低浓度组(SDZ-1、SDZ-2和SDZ-3)在前12 d均能够完全降解,高浓度组SDZ-4和SDZ-5在厌氧消化36 d后的去除率分别为65%和71%。此外,猪粪中磺胺嘧啶为5~150 mg/kg范围内,未见对猪粪厌氧消化产甲烷性能产生负面影响作用,厌氧消化累积沼气和甲烷产量与磺胺嘧啶浓度呈负线性相关(R^(2)=0.9546和R^(2)=0.8654)。因此,水热预处理和厌氧消化对猪粪中磺胺嘧啶、土霉素和恩诺沙星具有明显的消减作用,可为后续水热预处理耦合厌氧消化处理含抗生素粪污的研究提供数据支撑。

For the treatment and prevention of animal diseases,antibiotics are commonly used in livestock and poultry farming.The large amount of antibiotics remaining in livestock and poultry manure brings a huge potential risk of the spread of antibiotic resistance genes.In order to further understand the degradation characteristics of typical antibiotics in livestock and poultry manure by hydrothermal pretreatment and anaerobic digestion,and clarify the correlation between antibiotics and methane production performance,pig manure was taken as the research object.The reduction effects of different temperatures(70℃,90℃,120℃,150℃and 170℃)by hydrothermal pretreatment on sulfadiazine,oxytetracycline and enrofloxacin were investigated.The degradation laws of sulfadiazine,oxytetracycline and enrofloxacin during mesophilic anaerobic digestion and their effects on methane production performance were studied.The results showed that the hydrothermal pretreatment had obvious reduction effect on the three antibiotics.Sulfadiazine and enrofloxacin were 100%removed by hydrothermal treatment at 70℃,while oxytetracycline was 100%removed by hydrothermal treatment at 90℃.During mesophilic anaerobic digestion,the removal rates of the three antibiotics were increased gradually with the prolongation of anaerobic digestion time.After 5 d of anaerobic digestion,enrofloxacin basically reached 100%removal,while the removal rates of oxytetracycline and sulfadiazine were 39.76%and 21.29%,respectively.After 15 d of anaerobic digestion,oxytetracycline basically reached 100%removal,while after 30 d of sulfadiazine,the removal rate reached 52.9%.The degradation characteristics of the three antibiotics were quite different in the process of anaerobic digestion,but there was no significant difference in the biogas and methane production of pig manure with different antibiotics(P>0.05).In addition,when the sulfadiazine in pig manure was in the range of 5~150 mg/kg,cumulative biogas and methane production from anaerobic digestion was negatively linearly correlated with sulfadiazine concentration(R^(2)=0.9546 and R^(2)=0.8654).However,there was no significant difference in biogas and methane production with different antibiotics(P>0.05).Therefore,hydrothermal pretreatment and anaerobic digestion can significantly reduce sulfadiazine,oxytetracycline,and enrofloxacin in pig manure,which can provide data support for the subsequent study of hydrothermal pretreatment combined with anaerobic digestion in the treatment of antibiotic-containing manure.