Currently, the role of amorphous carbon structure (ACS) in sorption of chlorinated hydrocarbons (CHs) to biochars remains little known. Therefore, three CHs (1,1,2,2-tetrachloroethane, 1,3,5-trichlorobenzene and γ-hexachlorocyclohexane) with different molecular properties were selected as model adsorbates to investigate the effect of ACS on sorption of CHs to biochars produced at seven different pyrolysis temperatures (300–900 °C). There were two main mechanisms for ACS controlling the sorption of CHs. First, the polar sites on ACS are hydrophilic, CHs with greater polarity could strongly compete with the water molecule for the hydrophilic sites. Second, ACS of low temperature (300–400 °C) produced biochars possessing the natural organic matter (NOM)-like structure occupied some hydrophobic sites on condensed graphitic structure (CGS) of biochars. CHs with great hydrophobicity possibly seized the hydrophobic sorption sites on CGS from the NOM-like structure. Therefore, ACS of biochar was more benefit for sorption of strong polar CHs (1,1,2,2-tetrachloroethane: π^∗ = 0.95; LogK_ow = 2.39) or strong hydrophobic CHs (1,3,5-trichlorobenzene: π^∗ = 0.70; LogK_ow = 4.19) than CHs (γ-hexachlorocyclohexane: π^∗ = 0.68; LogK_ow = 3.72) with relatively low polarity and hydrophobicity. The result reflects that the interaction between NOM and natural black carbon/biochars in soil and water environment possibly plays the similar role in controlling the environmental behavior of various polar or hydrophobic organic pollutants. Moreover, with increasing concentration of adsorbate (C_e), the first mechanism enhanced, while the second mechanism weakened. This study gives a deep insight into the roles of ACS of biochars in controlling the fate and availability of CHs with different molecular properties in environment.

目前，关于无定形碳结构（ACS）在氯代烃（CHs）吸附到生物炭中的作用仍然鲜为人知。因此，选择了三种具有不同分子特性的CHs（1,1,2,2-四氯乙烷，1,3,5-三氯苯和γ-六氯环己烷）作为模型吸附物，以研究ACS对CHs吸附于生成的生物炭上的影响。七个不同的热解温度（300–900°C）。ACS控制CH吸附的主要机制有两种。首先，ACS上的极性位点是亲水性的，极性更大的CHs可能与水分子强烈竞争亲水位点。其次，低温（300-400°C）的ACS生产的生物炭具有类似天然有机物（NOM）的结构，在生物炭的冷凝石墨结构（CGS）上占据了一些疏水位。疏水性很强的CHs可能会从NOM样结构中抓住CGS上的疏水吸附位点。因此，生物炭的ACS对强极性CHs（1,1,2,2-四氯乙烷：π^∗  = 0.95；Log K _ow  = 2.39）或 比CHs（γ-六氯环己烷：π ^∗  = 0.68; Log K _ow  = 3.72）或强疏水性CHs（1,3,5-三氯苯：π ^*  = 0.70; Log K _ow = 4.19）低极性和疏水性。结果表明，NOM与天然黑碳/生物炭在土壤和水环境中的相互作用可能在控制各种极性或疏水性有机污染物的环境行为中起相似的作用。而且，随着吸附物浓度的增加（C _e），第一种机制得到增强，而第二种机制则被削弱。这项研究深入了解了生物炭ACS在控制环境中具有不同分子特性的CH的命运和可用性方面的作用。