Purpose of Review

Hydrothermal carbonization (HTC) is an innovative technique by which a wet feedstock is converting into valuable product, hydrochar, without drying as a pretreatment step. Over all other thermal converting process, HTC is counted as the most cost-effective and environmentally friendly technique. The purpose of this review is to highlight the current research trends of HTC and the application of hydrochar derived from biomass in heavy metal removal.

Recent Findings

This review provides an overview about HTC fundamentals including its ecotoxicology and the factors such as biomass type, reaction temperature, retention time, catalysis, and pH medium, which affect hydrochar composition and performance. Moreover, various modification agents in order to function the hydrochar was discussed. It is proposed that the co-hydrothermal carbonization of two or more biomasses with the addition of other materials can enhance the functional groups and change the features of the produced hydrochar. This paper also reviews the kinetic analysis and adsorption isotherm as well as the hydrochar applications in heavy metal removal.

Summary

Acacia arabica waste is produced annually in huge amount, which adversely affect the environment. Up to now, it has no specific reuse in a proper way. In this respect, biomass such as Acacia arabica wastes can successfully be valorized by converting into hydrochar via hydrothermal carbonization. Moreover, application as a green adsorbent to remove heavy metal contamination from wastewater due to its high porosity and great surface area is counted as a promising technique that contributes to this field of research.

Graphical abstract

中文翻译：

---

吸附生物质水炭去除废水中的重金属：当前应用和研究趋势

审查目的

水热碳化（HTC）是一项创新技术，通过该技术，湿原料无需预处理就可以干燥而转化为有价值的产品水炭。在所有其他热转换过程中，HTC被认为是最具成本效益和最环保的技术。这篇综述的目的是强调HTC的当前研究趋势以及源自生物质的水炭在重金属去除中的应用。

最近的发现

这篇综述概述了HTC的基本原理，包括其生态毒理学以及影响水炭成分和性能的因素，如生物质类型，反应温度，保留时间，催化作用和pH介质。此外，还讨论了各种使水炭起作用的改性剂。有人提出，在添加其他物质的情况下，两种或多种生物质的共水热碳化可以增强官能团并改变所产生的水炭的特性。本文还回顾了动力学分析和吸附等温线以及水炭在重金属去除中的应用。

概要

阿拉伯树胶废料每年产生大量，对环境造成不利影响。到目前为止，它还没有以适当的方式进行特定的重用。在这方面，可通过热液碳化转化为水焦，从而成功地对阿拉伯树胶等生物质进行增值。而且，由于其高孔隙率和大表面积而被用作绿色吸附剂以去除废水中的重金属污染被认为是有助于该研究领域的有前途的技术。

图形概要