Contamination of water sources by contaminants of emerging concerns, including pharmaceutical compounds, threatens the well-being of human who relies on the water sources. Development of cost-effective adsorbents for maximum removal of these contaminants is important to ensure clean and safe water access. This study demonstrates the reusability of activated carbon synthesized from spent tea leaves (STL-AC) for aspirin adsorption at optimized conditions. The maximum aspirin removal was 98.97% after optimization of process conditions using Response Surface Methodology. The adsorbent can be reused up to five cycles via solvent elution, with aspirin removal percentage above 85%. The repeated adsorption–desorption cycles affected the adsorbent textural properties, however the adsorbent surface chemistry was not affected by the regeneration. The aspirin adsorption proceeds via pore filling together with hydrogen bonding and π–π interaction between the aspirin molecules, however electrostatic repulsion between the deprotonated aspirin molecules and negatively charged STL-AC resulted in reduced removal percentage at high solution pH. This study signifies the superior property of STL-AC in adsorptive removal of aspirin, therefore the potential of such adsorbent in treatment of municipal wastewater, as well as hospital and pharmaceutical manufacturing effluents will be investigated.

新兴问题污染物（包括药物化合物）对水源的污染威胁到了依赖水源的人类的健康。为了最大程度地去除这些污染物，开发具有成本效益的吸附剂对于确保清洁安全的取水非常重要。这项研究证明了在优化的条件下，用废茶叶合成的活性炭（STL-AC）可用于阿司匹林吸附。使用响应表面方法优化工艺条件后，最大阿司匹林去除率为98.97％。吸附剂可通过溶剂洗脱重复使用多达五个循环，阿司匹林去除率可达到85％以上。重复的吸附-解吸循环影响了吸附剂的质地，但是吸附剂的表面化学不受再生的影响。阿司匹林通过孔填充，氢键结合以及阿司匹林分子之间的π-π相互作用进行吸附，但是去质子化的阿司匹林分子与带负电荷的STL-AC之间的静电排斥导致在高溶液pH下去除率降低。这项研究表明STL-AC在阿司匹林的吸附去除中具有优越的性能，因此，将研究这种吸附剂在处理市政废水以及医院和制药生产废水中的潜力。