中文摘要：

将芦苇秸秆在500℃下缺氧热解4 h制备成生物炭.采用批量平衡实验法,考察溶液p H值、生物炭投加量、溶液离子强度以及生物炭灰分对芦苇生物炭吸附水中Pb（2＋）的影响.结果表明：溶液p H值在2.0—5.5范围内,芦苇生物炭对Pb（2＋）的吸附量随着p H值升高而增加;生物炭最佳投加量为1.8 g·L-1,Pb（2＋）的去除率为96.6%;溶液中Na＋、Ca（2＋）的存在会抑制芦苇生物炭对Pb（2＋）的吸附;去除灰分后的生物炭对Pb（2＋）的吸附量降低.不同温度下的吸附等温线更符合Langmiur方程.在283、298、313 K下的最大实际吸附量分别为21.89、24.06、24.95 mg·g（-1）.热力学研究结果为ΔGθ0和ΔSθ＆gt;0,说明该吸附是自发、熵增的吸热过程.吸附动力学线性拟合结果更符合假二级动力学方程.芦苇生物炭吸附前后的红外光谱和XRD衍射谱图分析表明吸附过程存在离子交换和阳离子-π作用.去除灰分的生物炭吸附Pb（2＋）后溶液中Na＋、K＋、Ca（2＋）、Mg（2＋）浓度升高,表明离子交换是主要吸附机制.

英文摘要：

Biochar was prepared by pyrolyzing reed straw at 500 ℃ for 4 h under oxygen-limited condition. The effects of initial solution pH value, biochar dosage, ionic strength and biochar ash on the adsorption of Pb2＋ were investigated by batch adsorption experiments. The results showed that when solution pH value was between 2--5.5, the adsorption capacity increased with the solution pH. When the biochar dosage was 1.8 g·L-1, the removal rate reached 96.6%. It was observed that Na＋ and Ca2＋ in aqueous solution inhibited the adsorption and the adsorption capacity of the de-ashed biochar decreased. The adsorption isotherms at different temperatures were fitted better to Langmiur equation. When the temperatures were 283, 298 and 313 K, the maximum adsorption capacities were 21.89, 24.06, 24.95 mg·g-1 respectively. The thermodynamics parameters of △G θ〈0, △H θ〉0 and △S θ〉0 demonstrated that the adsorption was a spontaneous, entropy increasing and endothermic process. The kinetics data were fitted better to the pseudo-second-order equation. The analysis by FTIR and XRD of reed biochars before and after adsorption indicated that the adsorption process involved ion exchange and cation-π interaction mechanisms. After adsorption of Pb2＋ by de-ashed biochar, the concentrations of Na＋, K＋, Ca2＋, Mg2＋ in aqueous solution increased, which indicated that ion exchange was the main adsorption mechanism.