Abstract: The extraction process of heavy metals in fly ash from MSW incinerator using saponin was optimized by response surface methodology. The pH, saponin concentration, ionic strength, temperature, extraction time and solid-liquid ratio were selected for central composite design, the design-expert8.0 software was employed for data fitting to establish a mathematical model for total Cu, Zn, Pb and Cd removal. By analysis of mean square deviation the order of main factors affecting the removal of total heavy metals is: pH> solid-liquid ratio> ionic strength> the saponin concentration> temperature>extraction time. The experimental results show that when saponin concentration is 41.2g · L^-1, time 13.54 h, onic strength 0.64 mol · L^-1, pH 2, solid-liquid ratio 1% and temperature is 23.4℃, the total removal of heavy metals reaches the maximum and the removal rates for Cu, Zn, Pb and Cd are 55.12%, 6.20%, 17.80% and 78.11% respectively.

Key words: saponins, MSW incinerator fly ash, heavy metals, response surface methodology

摘要： 通过响应面法对皂角苷浸提飞灰中Cu、Zn、Pb和Cd 4种重金属的实验条件进行优化，选取pH、皂角苷浓度、离子强度、温度、时间和固液比6个因素进行中心组合设计，使用design-expert8.0软件进行数据拟合，建立了Cu、Zn、Pb和Cd去除总量的工艺数学模型，通过方差分析得到6个因素对浸提液中4种重金属去除总量的主效应关系为： pH>固液比>离子强度>皂角苷浓度>温度>时间。对重金属去除总量数据进行design-expert8.0软件优化，得到皂角苷浓度为41.2g·L^-1、时间为13.54 h、离子强度为0.64 mol·L^-1、pH为2、固液比为1%和温度为23.4℃时，重金属总去除量达最大值，Cu、Zn、Pb和Cd的去除率分别达到55.12%、6.20%、17.80%和78.11%。

关键词: 皂角苷, 焚烧飞灰, 重金属, 响应面法