摘要
为得到合理有效、低成本的废水处理方法,利用凹凸棒石的离子交换特性和壳聚糖在酸性溶液中带正电荷的特点,以脱乙酰度90%的壳聚糖为原料,对用不同温度活化的凹凸棒石黏土作表面改性,制备了凹凸棒石黏土负载壳聚糖颗粒。壳聚糖包覆率的测定结果表明,活化温度为700℃时,凹凸棒石黏土的负载率达到最大值32.6%。凹凸棒石黏土负载壳聚糖吸附Cr(Ⅵ)的适宜条件为常温、pH值=4～6、吸附时间为35min、凹土-壳聚糖用量为12g/L,此时,凹土-壳聚糖吸附剂对质量浓度为40mg/L的Cr(Ⅵ)的吸附率可达90%。凹土-壳聚糖颗粒对Cr(Ⅵ)的吸附适合用Langmuir吸附等温方程来模拟。研究表明,凹凸棒石黏土经过改性制成的凹凸棒石-壳聚糖颗粒可用于含Cr(Ⅵ)废水的处理。
This paper is inclined to provide an innovated approach to controlling and remedying chromium（Ⅵ） contaminated sewage by attapulgite, especially, for the chromium （ Ⅵ ） contaminated sewage. So far as we know, although non-metallic mines are widely used as water amender, there are still a few reports on taking attapulgite, especially, chromium （Ⅵ） contaminated waste as remedy for heavy metal contaminated sewage. It is just for the purpose of providing a new way to control and remedy for such sewage, we have conducted the equilibrium adsorption isotherm experiments to investigate the effects of the adsorption behaviors toward chromium（Ⅵ） in the solution on the compound sorbent. In our experiments, the compound adsorbent was prepared through combination of chitosan and attapulgite, which are characteristic of natural attapulgite ions, with chitosan being positive in charge in the acid solution for its interchangeability. Based on the two properties mentioned above, attapulgite is added to the chitosan slurry of 90 % of deacetylation when the adsorbent is prepared with mass ratio being 1 ： 20 （ chitosan ： attapulgite） . Besides, experiments also prove that chitosan loading rate on attapulgite is 32.6 % at 700 ℃ . Its adsorption to Cr（Ⅵ） has also been found. And finally, the experimental results also indicate that the dosage of the adsorbent is 12 g/L, with the mass concentration of Cr（Ⅵ） in the sewage below 40 mg/L. While the pH = 4 - 6, the adsorption equilibrium time is expected to last about 35 min with Cr（Ⅵ） removal efficiency reaching 90 %. Thus, it can be inferred that the adsorption isotherm proves to follow Langmuir isotherm equation. The results show attapulgite-chitosan can used for remedying chromium（Ⅵ） contaminated waste water effectively.
出处
《安全与环境学报》
CAS
CSCD
2008年第3期52-55,共4页
Journal of Safety and Environment
基金
青岛市科技发展计划项目(05-1-NS-58)
