Preparation of red mud-modified sludge char through microwave-assisted one-step pyrolysis and steam activation and its adsorption properties for hydrogen sulfide

IF 8.1 2区环境科学与生态学 Q1 ENVIRONMENTAL SCIENCES

Chemosphere Pub Date : 2024-11-01 DOI:10.1016/j.chemosphere.2024.143723

Mengyao Zhu, Mingtao Hu, Wenyi Deng, Yaxin Su

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Abstract

To improve the hydrogen sulfide (H₂S) adsorption performance of sludge-derived char, a type of red mud-modified sludge char (RSC) was prepared through microwave-assisted one-step pyrolysis and steam activation of sludge and red mud (RM). The effects of pyrolysis temperature, RM mass percentage, and steam flow rate on the cumulative adsorption capacity of H₂S were systematically investigated using response surface method. The results indicated that the sludge char showed a significant increase in cumulative adsorption capacity from 1.47 mg/g to 22.83 mg/g when it was modified with RM at a pyrolysis temperature of 625 °C, a mass percentage of RM of 20%, and a steam flow rate of 0.46 mmol/min. The XRD and XPS analysis results indicated that the RM doping generated abundant iron oxides on the surface of RSC, which is beneficial for the adsorption of H₂S. Adsorption thermodynamics, isotherm fitting and thermodynamic calculations indicate that the adsorption mechanism of H₂S on the RSC surface was attributed to the combined effects of physisorption and chemisorption. Additionally, the material exhibited reliable reusability, retaining more than 80% of its initial breakthrough capacity after three adsorption-regeneration cycles. Therefore, the RSC prepared in this study can be regarded as a promising adsorbent due to its low cost, effective adsorption capabilities, and reusability. The developed method is promising as it achieves environmental remediation through the utilization of waste sludge and RM.

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通过微波辅助一步热解和蒸汽活化制备赤泥改性污泥炭及其对硫化氢的吸附性能。

为了提高污泥制备的炭对硫化氢（H2S）的吸附性能，研究人员通过微波辅助一步热解和蒸汽活化污泥和赤泥（RM）制备了一种赤泥改性污泥炭（RSC）。采用响应面法系统研究了热解温度、赤泥质量百分比和蒸汽流量对 H2S 累积吸附量的影响。结果表明，在热解温度为 625 ℃、RM 质量百分比为 20%、蒸汽流速为 0.46 mmol/min 的条件下，用 RM 对污泥炭进行改性后，污泥炭的累积吸附容量从 1.47 mg/g 显著增加到 22.83 mg/g。XRD 和 XPS 分析结果表明，RM 的掺杂在 RSC 表面生成了丰富的铁氧化物，有利于 H2S 的吸附。吸附热力学、等温线拟合和热力学计算表明，H2S 在 RSC 表面的吸附机理归因于物理吸附和化学吸附的共同作用。此外，该材料还表现出可靠的可重复使用性，经过三次吸附-再生循环后，其初始突破能力仍保持在 80% 以上。因此，本研究制备的 RSC 因其低成本、有效的吸附能力和可重复使用性，可被视为一种前景广阔的吸附剂。所开发的方法通过利用废弃污泥和 RM 实现了环境修复，因此前景广阔。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Chemosphere 环境科学-环境科学

CiteScore

15.80

自引率

8.00%

发文量

4975

审稿时长

3.4 months

期刊介绍： Chemosphere, being an international multidisciplinary journal, is dedicated to publishing original communications and review articles on chemicals in the environment. The scope covers a wide range of topics, including the identification, quantification, behavior, fate, toxicology, treatment, and remediation of chemicals in the bio-, hydro-, litho-, and atmosphere, ensuring the broad dissemination of research in this field.