好氧/厌氧环境对微生物降解典型微塑料效能影响研究  

EFFECTS OF AEROBIC/ANAEROBIC ENVIRONMENTS ON MICROBIAL DEGRADATION EFFICIENCY OF TYPICAL MICROPLASTICS

作　　者：毕鑫祺 龚志伟 马杰 周立昌 江锦琦 郭刚 BI Xinqi;GONG Zhiwei;MA Jie;ZHOU Lichang;JIANG Jinqi;GUO Gang(School of Environmental Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China;Faculty of Resource and Environmental Science,Hubei University,Wuhan 430062,China)

机构地区：[1]华中科技大学环境科学与工程学院,武汉430074 [2]中铁第四勘察设计院集团有限公司,武汉430063 [3]湖北大学资源环境学院,武汉430062

出　　处：《环境工程》2024年第7期88-97,共10页Environmental Engineering

基　　金：湖北省重点研发计划项目“工业含盐废水脱盐、重金属去除及深度脱碳关键技术研究”(2022BCA065);国家重点基础研究发展计划项目“长江经济带大中城市多源有机固废园区化协同处置及示范”(2019YFC1904005);国家自然科学基金项目“单质硫强化低碳源污水反硝化除磷机理及调控”(52100040)。

摘　　要：室温条件下,对比了3种典型微塑料:聚羟基脂肪酸酯(Polyhydroxyalkanoate,PHA)、聚乳酸酯(Polylactic acid,PLA)和聚氯乙烯(Polyvinyl chloride,PVC)在好氧和厌氧环境中被微生物降解的效能。扫描电子显微镜(SEM)、差示扫描热分析仪(DSC)、傅里叶红外光谱(FTIR)、平均质量及微生物作用占比实验分析结果表明:PHA在好氧和厌氧环境中的微生物降解速率相似,均约为25.72 mg C/d,降解后的PHA表面均会出现明显的沟壑和裂痕,且酯基等官能团的丰度、结晶度和平均质量均降低;PLA虽为可生物降解微塑料但结晶度高,同自身结构稳定的难降解微塑料PVC,均未能被降解。PHA降解产物的变化特征和碳平衡核算结果表明,PHA中的碳主要转化为CH3COOH、CH4和生物质中的碳,但在好氧和厌氧环境中产物占比差异明显,分别为5.23%vs.0.27%、4.28%vs.12.24%、87.05%vs.82.50%,这可能与好氧和厌氧环境中参与PHA降解的微生物丰度和关键酶活性不同有关。系统评估了3种典型微塑料在好氧和厌氧环境中降解速率和降解产物的差异,可为全面评价微塑料的环境风险提供重要理论指导。This study evaluated the degradation efficiency of three typical microplastics(PHA(polyhydroxyalkanoate),PLA(polylactic acid),and PVC(polyvinyl chloride))under different aerobic and anaerobic environments in ambient temperatures.The experimental results of scanning electron microscope(SEM),differential scanning calorimetry(DSC),Fourier transform infrared spectroscopy(FTIR),average mass,and microbial activity ratio analysis showed that PHA exhibited similar degradation rates in both aerobic and anaerobic environments,approximately 25.72 mg C/d.The surface of PHA microplastic exhibited prominent grooves and cracks,along with decreased ester group abundance,crystallinity,and average mass.On the other hand,PLA and PVC practically did not degrade due to their intrinsic structural stability and great crystallinity.Calculations of the carbon balance when PHA was degraded showed that the carbon was predominantly broken down into CH_3COOH,CH_4,and carbon in biomass.The proportions of these three products in aerobic and anaerobic environments differed significantly,namely 5.23%vs.0.27%,4.28%vs.12.24%,and 87.05%vs.82.50%,respectively.This may be due to different microbial numbers and critical enzyme activity involved in PHA breakdown between the aerobic and anaerobic environments.This study investigated the effects of aerobic and anaerobic settings on degradation rates and product variations of microplastics in detail,which may help formulate important theoretical guidelines for determining the environmental risk of microplastics.

关 键 词：微塑料 好氧环境 厌氧环境 聚羟基脂肪酸酯 微生物降解 

分 类 号：X703[环境科学与工程—环境工程] X172