生物可降解塑料厌氧消化降解研究进展

Research Progress on Degradation of Biodegradable Plastics During Anaerobic Digestion

生物可降解塑料作为传统石油基塑料的替代品具有广阔的应用前景。生物可降解塑料常被用作食品包装材料,因而易随城市生活垃圾中的有机组分一起进入厌氧消化系统,这对有机废物管理提出新的挑战。在众多种类的生物可降解塑料中,聚羟基脂肪酸酯(PHAs)和淀粉基塑料在厌氧条件下降解较快;而其余种类的生物可降解塑料在典型的厌氧消化厂水力停留时间下(15~30 d)均难以被有效降解。除塑料本身的物理化学性质外,外部因素如温度、pH和微生物等对于塑料的厌氧降解速率也有重要影响。介绍了常见的生物可降解塑料种类及其应用、厌氧降解性及降解影响因素,并总结了以预处理为代表的厌氧降解增强技术。最后,展望了生物可降解塑料厌氧消化降解的研究方向。

Biodegradable plastics have a promising application as an alternative to traditional petroleum-based plastics.Since biodegradable plastics were often used as food packaging materials,they tend to enter the system of anaerobic digestion along with the organic fraction of municipal solid wastes,which posed a challenge to organic waste management.Polyhydroxyalkanoates(PHAs)and starch-based plastics degraded faster under anaerobic conditions among wide variety of biodegradable plastics.The remaining types of biodegradable plastics were difficult to be effectively degraded under the biogas plants' typical hydrophilic residence time(15~30 days).In addition to the physicochemical properties of the plastic,external factors such as temperature,pH and microorganisms also had important effects on the anaerobic degradation rate of plastics.The common biodegradable plastic types and their applications,the anaerobic degradability and the factors influencing the biodegradability were reviewed.Also the technologies represented by the pre-treatment for enhancing the anaerobic biodegradability were summarized.Finally,the research direction on the anaerobic degradation of biodegradable plastics was prospected.