Abstract

Humic substances are the major constituents of the organic matter of soils and sediments and were adopted in different industrial applications for their high content of functional groups. Recently, the research interest is focused on the possibility of extract these substances also from organic wastes, such as biowastes. However, an interesting option could be to extract humic substances from other organic stabilized wastes that differently from compost has no further use. Namely, in this study the possibility of extract Humic Acids (HA) from the bio-stabilized waste produced from a Mechanical Biological Treatment plant adopting different maturation durations was evaluated. Furthermore, the effect of the main operating conditions applied during the alkaline extraction of the humic acids was also investigated (i.e. material particle size, liquid–solid ratio, NaOH concentration and extraction time), analysing the elemental composition, the main functional groups content and the optical properties of the extracted HA. The operating conditions that showed to improve the extraction extent were the NaOH concentration and the extraction time. Furthermore, the HA obtained in these specific conditions showed higher functional groups content and aromaticity, in agreement with the characteristics of the commercial HA, allowing to consider these substances for various industrial applications.

Graphic Abstract

中文翻译：

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采用不同操作条件从生物稳定废物中提取的腐殖质

摘要

腐殖质是土壤和沉积物有机质的主要成分，由于其官能团含量高，已在不同的工业应用中被采用。近来，研究兴趣集中在也从有机废物如生物废物中提取这些物质的可能性。但是，一个有趣的选择可能是从其他有机稳定的废物中提取腐殖质，这些废物与堆肥不同，不再使用。即，在本研究中，评估了从采用不同成熟时间的机械生物处理厂生产的生物稳定废物中提取腐殖酸（HA）的可能性。此外，还研究了在腐殖酸碱提取过程中应用的主要操作条件的影响（即，材料粒径，固液比，NaOH浓度和萃取时间），分析萃取的HA的元素组成，主要官能团含量和光学性质。可以提高萃取程度的操作条件是NaOH浓度和萃取时间。此外，在这些特定条件下获得的HA显示出更高的官能团含量和芳香性，与商业HA的特征一致，从而允许考虑将这些物质用于各种工业应用。

图形摘要