Department of Environmental Engineering, College of Engineering, Kangwon National University, Kangwondaehak-gil, 1, Chuncheon-si, Gangwon-do 24341, Republic of Korea.
Korea Hydro and Nuclear Power (KHNP) Central Research Institute, 50, 1312-gil, Yuseong-daero, Yuseong-gu, Daejeon 34101, Republic of Korea.
J Hazard Mater. 2020 Dec 5;400:123102. doi: 10.1016/j.jhazmat.2020.123102. Epub 2020 Jun 4.
This study investigated the single and competitive adsorption characteristics of micropollutants using the pristine and alkali-modified spent coffee grounds (SCG) biochars. The alkali modification substantially improved the physicochemical characteristics of the SCG biochars (specific surface area and pore volume), which may have led to differences in the adsorption behaviors of the micropollutants. The pseudo second order model (R ≥ 0.990) better described the single and competitive adsorption kinetics than the pseudo first order model (R ≥ 0.664). It is evident that chemisorption played a key role in the removal of the micropollutants by the pristine and alkali-modified SCG biochars. The single and competitive adsorptions of the micropollutants were highly dependent on the solution pH and ionic strength since the pore-filling effects, electrostatic and hydrophobic interactions governed their removal by the pristine and alkali-modified SCG biochars. The higher removal efficiencies of the micropollutants by the alkali-modified SCG biochars (≥ 44.5%) in the presence of dissolved organic matter compared to the pristine SCG biochars (≤ 18.5%) support the assumption that alkali modification could markedly reinforce the surface structural properties of the SCG biochars related to the adsorption capacities.
本研究利用原状和堿改性废咖啡渣（SCG）生物炭研究了微量污染物的单一和竞争吸附特性。堿改性显著改善了 SCG 生物炭的物理化学特性（比表面积和孔体积），这可能导致微量污染物的吸附行为存在差异。准二级模型（R≥0.990）比准一级模型（R≥0.664）更好地描述了单一和竞争吸附动力学。显然，化学吸附在去除微量污染物方面起著关键作用，由原状和堿改性 SCG 生物炭。微量污染物的单一和竞争吸附高度依赖于溶液 pH 值和离子强度，因为孔填充效应、静电和疏水相互作用控制著它们被原状和堿改性 SCG 生物炭去除。与原状 SCG 生物炭（≤18.5%）相比，在存在溶解有机物的情况下，堿改性 SCG 生物炭（≥44.5%）对微量污染物的去除效率更高，这表明堿改性可以显著增强与吸附能力相关的 SCG 生物炭的表面结构特性。
