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以壬基酚(nonylphenol,NP)为目标污染物,采用批量实验法研究其在添加不同温度制备的小麦秸秆生物炭的黄土中的吸附动力学、吸附热力学,以及粒径、pH等影响因素.结果表明,不添加生物炭黄土吸附NP的快反应时间为10 h,而加入生物炭后,黄土对NP吸附的快反应时间缩短,为6 h;且快反应阶段添加生物炭黄土明显比不添加生物炭黄土对NP的吸附量多,但碳化温度不同的生物炭在此阶段吸附量差别较小.黄土和添加生物炭黄土对NP的吸附平衡时间均为16 h且符合准二级动力学模型.无论是否添加生物炭,NP在黄土上的热力学吸附过程都较好地符合Freundlich等温吸附模型,符合L-型吸附等温模式;随着系统温度的升高,黄土和添加生物炭的黄土对NP的饱和吸附量都呈增大趋势;NP的吸附自由能ΔGθ<0,焓变ΔHθ>0,熵变ΔSθ>0,表明此吸附是一个自发吸热且混乱程度增大的吸附过程.在同一温度下,随着生物炭碳化温度的升高,NP在添加生物炭黄土中的吸附量逐渐增大.添加生物炭黄土的粒径越小,对NP的吸附量越大.pH值为4~7时,添加生物炭黄土吸附量随pH值的增大而增加;pH为7~10时,吸附量又随pH值增大而减小;表明添加生物炭黄土在中性范围内对NP的吸附效果最好,酸性和碱性都不利于NP的吸附.
Using nonylphenol (NP) as the target pollutant, the adsorption kinetics, adsorption thermodynamics, particle size, pH and other factors were studied by batch experiments on the loess of wheat straw biochar with different temperature. The results showed that the quick reaction time of NP adsorbing without biochar loess was 10 h, but the reaction time of loess adsorption to NP was shortened to 6 h after adding biochar, and the biochar loess addition was faster than that without adding biochar loess The adsorption capacity of biochar on biochar loess is larger than that of biochar on loessial soil, but the biochar with different carbonation temperature has little difference in adsorption capacity at this stage.The equilibrium adsorption time of NP on loess and biochar loess is 16 h and the quasi-second order kinetic model . Whether or not biochar was added, the thermodynamic adsorption process of NP on loess was in good agreement with the Freundlich isothermal adsorption model, which was in accordance with the L-adsorption isothermal model. With the increase of system temperature, the loess and biochar- The adsorption capacity of NP increased with the increase of the enthalpy change ΔHθ> 0 and the entropy change ΔSθ> 0, indicating that the adsorption was a spontaneous endothermic and chaotic increase in the adsorption process.In the same temperature , With the increase of biochar carbonization temperature, the adsorption amount of NP in biochar loess increased gradually.The smaller the biochar loess size, the greater the adsorption capacity to NP.The pH value is 4 ~ 7 , The amount of adsorbed biochar loess increased with the increase of pH value. When pH value was 7-10, the amount of adsorption decreased with the increase of pH value. It indicated that the biochar loess adsorbed NP in the neutral range The best, acidic and alkaline are not conducive to the adsorption of NP.