Abstract:

This paper studied and analyzed the physicochemical properties, molecular characteristics and correlation of volatile organic compounds (VOCs) of liquid digestate of anaerobic digestion (ADLD) from putrescible waste, in order to provide basic properties for the utilization of ADLD resources. The study found that the seasonal differences of biogas slurry physical and chemical indicators were small, and the differences of each biogas slurry were large. Different ions existed in different forms in ADLD. The content of heavy metals in ADLD was much lower than the stipulated limits of heavy metals in the domestic and foreign standards. A total of 304 kinds of VOCs were detected in each ADLD sample, mainly including aromatic compounds (30%—83%) and olefins (5%—44%). There were differences in VOCs produced by different anaerobic digestion processes. The dry anaerobic digestion ADLD contained more aromatic VOCs (32%—83%), while the wet digester contained more alcohols (1%—20%) and others (1%—30%). 14 kinds of plant sensitive VOCs, such as methyl salicylate, 2-butanone and so on, were found in ADLD (0.05%—15.42%). These compounds could promote plant physiological activities. Common compounds (1.09%—41.54%) were found in the 19 VOCs samples, such as flavor additives and food flavor compounds that were not anaerobic degraded.

Key words: putrescible waste, liquid digestate, volatile organic compounds, land application

摘要：

解析了易腐垃圾厌氧消化沼液(ADLD)理化性质及其挥发性有机化合物VOCs的分子特征与关联性，以期为沼液资源化利用提供基础性质依据。研究发现，沼液理化指标的季节性差异较小，各沼液的差异较大。不同离子在沼液中的存在形式不同。沼液中的重金属含量远低于国内外相关标准限值。共检测304个VOCs分子，主要是芳香族(30%~83%)、烯烃(5%~44%)类化合物。不同厌氧消化工艺产生沼液的VOCs存在差异，干式厌氧消化沼液中芳香族类VOCs较多(32%~83%)，而湿式含有更多的醇(1%~20%)和醚(1%~30%)。从沼液中发现了14种植物敏感性VOCs分子(0.05%~15.42%)，如水杨酸甲酯、2-丁酮等，这类化合物可以促进植物生理活性。鉴定出共有化合物(1.09%~41.54%)，如香料添加剂、食用香精类化合物等。

关键词: 易腐垃圾, 厌氧消化沼液, 挥发性有机化合物, 土地利用