State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University , Beijing 100875, China.
Stockbridge School of Agriculture, University of Massachusetts , Amherst, Massachusetts 01003, United States.
Environ Sci Technol. 2016 Dec 20;50(24):13274-13282. doi: 10.1021/acs.est.6b02401. Epub 2016 Dec 1.
This study investigated the sorption potential of hydrochars, produced from hydrothermally carbonizing livestock wastes, toward organic pollutants (OPs) with a wide range of hydrophobicity, and compared their sorption capacity with that of pyrochars obtained from conventional dry pyrolysis from the same feedstock. Results of SEM, Raman, and C NMR demonstrated that organic carbon (OC) of hydrochars mainly consisted of amorphous alkyl and aryl C. Hydrochars exhibited consistently higher log K of both nonpolar and polar OPs than pyrochars. This, combined with the significantly less energy required for the hydrothermal process, suggests that hydrothermal conversion of surplus livestock waste into value-added sorbents could be an alternative manure management strategy. Moreover, the hydrochars log K values were practically unchanged after the removal of amorphous aromatics, implying that amorphous aromatic C played a comparable role in the high sorption capacity of hydrochars compared to amorphous alkyl C. It was thus concluded that the dominant amorphous C associated with both alkyl and aryl moieties within hydrochars explained their high sorption capacity for OPs. This research not only indicates that animal-manure-derived hydrochars are promising sorbents for environmental applications but casts new light on mechanisms underlying the high sorption capacity of hydrochars for both nonpolar and polar OPs.
本研究考察了水热碳化牲畜废物制备的水炭对疏水性范围广泛的有机污染物（OPs）的吸附潜力，并将其吸附能力与相同原料通过传统干热解制备的热炭进行了比较。SEM、拉曼和 C NMR 的结果表明，水炭中的有机碳（OC）主要由无定形烷基和芳基 C 组成。水炭对非极性和极性 OPs 的 log K 均明显高于热炭。这与水热过程所需的能量显著减少相结合，表明将多余的牲畜废物转化为增值吸附剂可能是一种替代粪便管理策略。此外，在去除无定形芳烃后，水炭的 log K 值几乎保持不变，这意味着与无定形烷基 C 相比，无定形芳环 C 在水炭的高吸附能力中发挥了类似的作用。因此，可以得出结论，水炭中与烷基和芳基部分相关的主要无定形 C 解释了它们对 OPs 的高吸附能力。这项研究不仅表明动物粪便衍生的水炭是有前途的环境应用吸附剂，而且为水炭对非极性和极性 OPs 的高吸附能力的机制提供了新的认识。
