Wood Ash Based Treatment of Anaerobic Digestate: State-of-the-Art and Possibilities
Wood Ash Based Treatment of Anaerobic Digestate: State-of-the-Art and Possibilities
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DOI：
10.3390/pr10010147
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发表时间：
2022-01
期刊：
影响因子：
3.5
通讯作者：
A. Abelenda;F. Aiouache
中科院分区：
文献类型：
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作者：
A. Abelenda;F. Aiouache
当前农业做法的问题不仅限于土地管理，而且还包括对植物所需基本营养素（如磷）的不可持续的消耗。本文主要研究了利用木灰和厌氧消化液制备缓释肥料的方法。通过分析混合物的应用，阐明了这两种材料的混合物的基本化学性质。首先，采用低剂量（≤1克总固体（TS）灰/克TS固态）的木灰的可行性进行了解释，作为一种方式，以改善厌氧消化的原料的组成和提高沼气生产。其次，详细描述了高剂量的木灰及其在厌氧污泥的下游处理中的用途，以进一步提高其稳定性。在所涉及的所有物理化学现象中，吸附过程被细致地描述，因为它们负责制备颗粒肥料中的养分回收、脱水和自硬化。简单的激活程序（例如，碳化、碳酸化、煅烧、酸化、洗涤、研磨和过筛）来促进营养素的固定化。由于有限的信息结合处理的木灰和厌氧消化状态，类似的残留物的转化另外考虑。考虑到所有可能的协同作用，在厌氧消化和下游阶段，灰的剂量为5克TS灰/克TS厌氧状态，建议用于未来的实验。
The problem of current agricultural practices is not limited to land management but also to the unsustainable consumption of essential nutrients for plants, such as phosphorus. This article focuses on the valorization of wood ash and anaerobic digestate for the preparation of a slow-release fertilizer. The underlying chemistry of the blend of these two materials is elucidated by analyzing the applications of the mixture. First, the feasibility of employing low doses (≤1 g total solids (TS) ash/g TS digestate) of wood ash is explained as a way to improve the composition of the feedstock of anaerobic digestion and enhance biogas production. Secondly, a detailed description concerning high doses of wood ash and their uses in the downstream processing of the anaerobic digestate to further enhance its stability is offered. Among all the physico-chemical phenomena involved, sorption processes are meticulously depicted, since they are responsible for nutrient recovery, dewatering, and self-hardening in preparing a granular fertilizer. Simple activation procedures (e.g., carbonization, carbonation, calcination, acidification, wash, milling, and sieving) are proposed to promote immobilization of the nutrients. Due to the limited information on the combined processing of wood ash and the anaerobic digestate, transformations of similar residues are additionally considered. Considering all the possible synergies in the anaerobic digestion and the downstream stages, a dose of ash of 5 g TS ash/g TS digestate is proposed for future experiments.