饮用水用竹炭重金属含量的影响因素研究

The Determinants of Heavy Metal Contents in Bamboo Charcoal Used for Purifying Drinking Water

选用不同立地条件、部位、竹龄的毛竹,在炭化温度650℃、750℃,反应时间3 h、5 h的条件下按照正交乘积法在自制机械炭化炉中制备竹炭,用湿法消化-电感耦合等离子发射光谱仪,对采竹地土壤、毛竹原材料和成品竹片炭重金属砷(As)、铅(Pb)、镉(Cd)的含量进行了检测,并分析其分布规律。结果表明:毛竹As、Pb、Cd含量与土壤中As、Pb、Cd含量密切相关,各因素影响程度从大到小依次为立地条件、毛竹部位和竹龄。毛竹炭化后其As、Pb、Cd含量都有一定程度的降低,其中Pb含量降低最大。炭化工艺与原料条件及其交互作用对竹炭As、Pb、Cd含量有不同程度的影响,炭化温度和反应时间对竹炭As、Pb、Cd含量的影响较大,毛竹的立地条件对竹炭As含量也存在着影响,炭化温度与毛竹部位的协同作用对竹炭Pb、Cd含量影响也明显,未经营的毛竹稍部在炭化温度750℃反应时间3 h下炭化As、Pb、Cd含量较少。

The bamboo charcoal were prepared using Moso bamboo of various origins,bamboo culm positions,and ages,under the conditions of carbonization temperature 650℃ and 750℃and reaction time 3 h and 5 h,according to the orthogonal multiplication method in the mechanical carbonizing kiln. The contents of heavy metal Arsenic（ As）,Cadmium（ Cd）,Lead（ Pb） in the sampling bamboo forest soils,Moso bamboo materials,and charcoal flakes were determined by the method of ICP-OES. The results showed that the As,Pb,Cd contents of the Moso bamboo were closely related to that of the soils. These factors were ranked as site conditions,longitudinal positions,and ages,in terms of their influence degree from large to small. The contents of As, Pb, Cd of Moso bamboo decreased in some degree after carbonization,of which,the Pb contents decreased the most. The As,Pb,Cd contents of bamboo charcoal were affected in various degrees by carbonization process,raw materials and their interactions. The influence of carbonization temperature and reaction time on the As,Pb,Cd contents of bamboo charcoal was the most obvious. The origin site conditions of moso bamboo also influenced on the As contents of the bamboo charcoal. The interactions of carbonization temperature and culm positions obviously influenced on the Pb,Cd contents of bamboo charcoal. The As,Pb contents of Cd in bamboo charcoal reached a minimum when the top section of the moso bamboo were carbonized under the conditions of carbonization temperature 750℃ and reaction time 3 h.