土壤重金属的竹基活性炭吸附及近红外光谱预测

Bamboo activated carbon adsorption and near infrared spectroscopy prediction of heavy metal in soil

为探究竹基活性炭对土壤的修复及改良效果,用水蒸气活化法制备出竹基活性炭,分析其孔结构特性,采用盆栽实验的方法,研究不同添加量(0%、10%、20%)的竹基活性炭对土壤性质、土壤重金属含量、植物株高和生物量以及植物地上和地下部分重金属含量的影响,研究发现随着竹基活性炭添加量的升高,土壤p H和有机质逐渐上升,且土壤中的重金属含量下降明显。其中,添加量高的竹基活性炭对土壤中的重金属Cu、Pb、Zn的去除率可达94.8%、82.1%、87.7%。添加竹基活性炭可增加百日草株高及生物量,其根和茎叶部分的重金属浓度有所降低,表明竹基活性炭吸附土壤重金属性能显著。同时,利用近红外光谱技术结合偏最小二乘法建立了不同竹基活性炭添加比例的土壤中的铜离子含量预测模型。该模型相关系数R^2达到0.995 9,相对分析误差RPD大于10,模型相关性好,具有良好的预测性能。

Bamboo activated carbon （BAC） was prepared by the steam activation method and its pore structure characteristics were analyzed. In order to investigate the effect of bamboo activated carbon on soil remediation and improvement, a pot experiment was carried out. After cultivation soil heavy metal content, plant height, biomass, the heavy metal content in plant and underground adding bamboo activated carbon with different ratios （0%, 10% and 20%） were analyzed. The results showed that the pH value and organic matter of soil gradually increased, the content of heavy metal decreased obviously with an increase of the amount of bamboo activated carbon. Moreover, the removal rates of heavy metal Cu, Pb and Zn in soil were 94.8%, 82.1% and 87.7% with a high amount by adding 20% ratio of bamboo activated carbon in soil. The height and biomass of zinnia elegans were increased and the content of heavy metals in root and shoot were reduced. The effect of bamboo activated carbon was remarkable to remove copper ions for remediation and improvement of soil. Meanwhile, a prediction model for the content of copper ions in soil with different ratios of bamboo activated carbon combined with PLS （partial least square） was created by using near-infrared spectroscopy technique. The R2 was 0.995 9 and RPD was greater than 10 which indicated that the model had a good correlation and excellent accuracy for Cu2＋ prediction in soil.