以猪粪为原料,小麦秸秆为调节物质,在小型厌氧发酵装置进行中温(37℃)厌氧发酵试验,研究了外源添加土霉素(OTC)对厌氧发酵过程中累积甲烷产量、脲酶活性和脱氢酶活性的影响以及土霉素的浓度变化情况.依据土霉素的添加量不同,试验共设置4个处理:CK处理,L处理(OTC质量分数60 mg·kg-1),M处理(OTC质量分数100 mg·kg-1),H处理(OTC质量分数140 mg·kg-1).结果表明:厌氧发酵初期,土霉素对甲烷累积产量有一定的促进作用,以后转变为抑制作用.厌氧发酵结束时,同对照相比,L至H处理甲烷累积产量依次减少了8.9%,4.6%,9.4%.厌氧发酵初期,土霉素对脲酶活性有一定的促进作用,随后转变为抑制作用;厌氧发酵前期,不同浓度土霉素对脱氢酶活性均表现为抑制作用,厌氧发酵后期,只有H处理的脱氢酶活性显著小于对照.土霉素含量在第10 d大幅度减少,30 d后土霉素含量基本维持不变.
The variation of methane production, enzyme activities and degradation rate of OTC (oxytetracycline) in pig manure spiked with different concentrations of OTC were studied during anaerobic fermentation process( 37 ℃ ). There were four treatments for OTC, including CK (0 mg· kg 1 ) , L (60 mg·kg-1 ), M( 100 mg·kg-1 ) , and H( 140 mg·kg- 1 ). The results showed that pig manure anaerobic fermentation spiked with OTC would promote methane production in the initial stage, but became inhibitory in the later stage. The accumulation methane production in L, M and H decreased by 8.9%, 4.6%,9.4% respectively compared with CK. Adding OTC would promote the urease activities in the first 5 days, but changed to inhibitory effect afterwards. Urease activities of CK were higher than the treatments spiked with OTC at the end of anaerobic digestion process. Urease activities of H were the lowest one during the treatments spiked with OTC. On the contrast, dehydrogenase activities were inhibited by OTC at the beginning of anaerobic digestion, and were only restrained by H later. OTC degraded significantly on the first 10 days for all OTC treatments, and kept constant afterwards.