聚丙烯微塑料对污泥厌氧消化效能作用影响

Effect of polypropylene microplastics on the performance of sludge anaerobic digestion

以聚丙烯(PP)微塑料为研究对象,考察不同浓度PP微塑料对污泥厌氧消化产CH_(4)和产酸效能的作用影响,同时采用荧光定量PCR方法定量检测了乙酸激酶(AK)和mcrA基因在不同PP微塑料作用下的丰度变化.结果表明,PP微塑料对污泥厌氧消化产CH_(4)和产酸效能具有促进影响,CH_(4)和乙酸累计产量随PP微塑料投加量的增大而升高,当PP微塑料投加量为0.2g/g VSS时,CH_(4)和乙酸累计产量与空白对照相比分别提高148.2%和15.2%,达227.1mL/g VSS和1291.2mg/L.相应地,mcrA基因丰度随之提高98.2%,表明PP微塑料对产甲烷菌的生长和繁殖具有促进作用,进而强化污泥厌氧消化产CH_(4)效能.

Polypropylene(PP)microplastics(MPs)were used to investigate their effects on the production of methane(CH_(4))and volatile fatty acids(VFAs)in sludge anaerobic digestion.The abundances of acetate kinase(AK)and mcrA genes under stresses of different amounts of PP MPs were determined by quantitative real-time PCR methods.The results showed that production of CH_(4) and VFAs was enhanced by addition of PP MPs.The cumulative productions of CH_(4) and acetic acid increased with increasing dosages of PP MPs.When the addition of PP MPs was 0.2g/g VSS,the cumulative productions of CH_(4) and acetic acid increased by 148.2%to 227.1mL/g and 15.2%to 1291.2mg/L,respectively,compared with the controls.Correspondingly,the abundance of mcrA genes increased by 98.2%,which indicated that PP MPs had a promoting effect on the growth of methanogens,thereby enhanced CH_(4)production during sludge anaerobic digestion.