成型秸秆炭吸附剂对水中Cd2+的去除特性

以水稻秸秆为原料，制取对Cd2+去除效果最佳的成型生物炭吸附剂。采取限氧升温方法，分析不同热解温度和不同热解时间的成型炭对Cd2+去除规律和特性。研究结果表明：热解温度不变，热解时间90 min去除率最大；热解时间不变，热解温度550 ℃时去除率最大；去除速率分快、慢两阶段，快阶段2 h内去除率最低达到76.83%，慢阶段10 h去除率仅20%左右；该成型炭对Cd2+吸附规律可用准二级动力模型进行拟合，拟合度Rmax2=0.987 2，该成型炭对Cd2+吸附不是单层吸附过程，而存在大量的阳离子交换量，化学反应较强烈。

Removal characteristics of Cd2+ applied in straw molding carbon adsorbent

In order to removing Cd2+,the effective molding carbon adsorbent is available by rice straw..It applies Limited-oxygen technique to changing temperatures. It also helps to analyze Cd2+ removing characteristics and rules of molding carbon between different temperatures and various pyrolyzation times.The results show that when the pyrolyzation temperature is fixed, the removal rate is maximal for the pyrolyzation time is 90 mins;as the pyrolyzation time is constant, the maximal removal rate happens when the pyrolyzation temperature is 550℃. The whole process of removal rate is divided into fast and slow stages, and the least removal rate reaches 76.83 in 2 h for fast state, while only 20% in 10 h for slow progress. The quasi two stage dynamic mode is adopted to fit the adsorption role of Cd2+ onto carbon, the fitting value Rmax2 is equal to 0.987 2, The result indicates that Cd2+adsorption on the formed carbon is not simple mono layer adsorption process, but a lot of cation exchange exists with strong chemical reactions.