Upcycling pharmaceutical capsules into porous activated carbon and activated carbon ash for efficient emerging contaminant removal

IF 3.4 4区环境科学与生态学 Q2 ENVIRONMENTAL SCIENCES

International Journal of Environmental Science and Technology Pub Date : 2026-09-16 DOI:10.1007/s13762-026-07429-1

A. S. Giroto, K. Furukawa, B. I. M. Santos, C. I. Portela, C. Cortez, S. F. Valle, R. Borges, A. E. Nogueira, M. Gonçalves

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引用次数: 0

Abstract

The management of pharmaceutical waste remains a significant challenge and presents opportunities for the development of value-added materials. In this study, discarded pharmaceutical gelatin capsules were converted into activated carbons and Ti-rich inorganic residues through sequential carbonization (700 °C), CO₂ activation (850 °C), and calcination, enabling the simultaneous valorization of both the carbonaceous and inorganic fractions of the waste. The resulting activated carbons (AC_HC and AC_SC) exhibited well-developed micro/mesoporous structures and oxygen and nitrogen-containing surface functionalities, while the inorganic residues retained Ti-containing phases derived from capsule excipients. ACSC exhibited the highest surface area (675 m² g⁻¹) and adsorption capacities toward methylene blue, acetaminophen, and bisphenol A (225, 380, and 112 mg g⁻¹, respectively). Adsorption equilibrium data were best described by the Sips and Redlich–Peterson models, indicating heterogeneous adsorption behavior and a distribution of adsorption sites. The calcined ash fractions exhibited photocatalytic activity toward methylene blue degradation under UV irradiation, with AC_HC ash achieving approximately 70% removal after 350 min. Dark adsorption control experiments demonstrated negligible methylene blue uptake by the ash materials, indicating that the observed removal under irradiation was predominantly associated with photocatalytic degradation. The results demonstrate that both the carbonaceous and inorganic fractions generated during the thermal conversion of pharmaceutical capsule waste can be further utilized as functional materials for contaminant removal, highlighting the potential of this approach as an integrated waste valorization strategy.

Graphical abstract

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将药物胶囊升级为多孔活性炭和活性炭灰，以有效去除新出现的污染物

医药废物的管理仍然是一项重大挑战，并为开发增值材料提供了机会。在本研究中，废弃的药用明胶胶囊通过顺序碳化（700°C）、CO2活化（850°C）和煅烧，转化为活性炭和富钛的无机残留物，使废物的碳质部分和无机部分同时增值。所得活性炭（ACHC和ACSC）表现出良好的微孔/介孔结构和含氧、含氮表面官能，而无机残留物则保留了来自胶囊辅料的含钛相。ACSC对亚甲基蓝、对乙酰氨基酚和双酚A的吸附量分别为225、380和112 mg g−1，比表面积（675 m2 g−1）最高。Sips和Redlich-Peterson模型最能描述吸附平衡数据，表明吸附行为和吸附位点的分布是不均匀的。在UV照射下，煅烧的灰分对亚甲基蓝的降解表现出光催化活性，350 min后，ACHC灰分的去除率约为70%。暗吸附控制实验表明，灰材料对亚甲基蓝的吸收可以忽略不计，这表明在照射下观察到的去除主要与光催化降解有关。结果表明，在药物胶囊废弃物热转化过程中产生的碳质和无机组分都可以进一步用作去除污染物的功能材料，突出了该方法作为一种综合废物增值策略的潜力。图形抽象

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

International Journal of Environmental Science and Technology 环境科学-环境科学

CiteScore

5.60

自引率

6.50%

发文量

806

审稿时长

10.8 months

期刊介绍： International Journal of Environmental Science and Technology (IJEST) is an international scholarly refereed research journal which aims to promote the theory and practice of environmental science and technology, innovation, engineering and management. A broad outline of the journal''s scope includes: peer reviewed original research articles, case and technical reports, reviews and analyses papers, short communications and notes to the editor, in interdisciplinary information on the practice and status of research in environmental science and technology, both natural and man made. The main aspects of research areas include, but are not exclusive to; environmental chemistry and biology, environments pollution control and abatement technology, transport and fate of pollutants in the environment, concentrations and dispersion of wastes in air, water, and soil, point and non-point sources pollution, heavy metals and organic compounds in the environment, atmospheric pollutants and trace gases, solid and hazardous waste management; soil biodegradation and bioremediation of contaminated sites; environmental impact assessment, industrial ecology, ecological and human risk assessment; improved energy management and auditing efficiency and environmental standards and criteria.