改性壳聚糖处理微生物浸矿废水

为解决采矿行业微生物浸矿酸性废水中和处理沉渣多、固液分离困难的问题,采用柠檬酸钠和环氧氯丙烷改性处理的壳聚糖在pH=2.2条件下吸附模拟废水中的Cu²⁺和Fe³⁺,用正交实验优化了壳聚糖改性工艺条件。实验结果表明,最适宜的工艺条件为：处理100 mL壳聚糖质量分数为2%的壳聚糖-冰醋酸溶液,柠檬酸钠缓冲溶液加入量200 mL,环氧氯丙烷加入量300 mL,反应时间6 h。改性壳聚糖对Fe³⁺的最大吸附容量为6.703 7 mg/g,对Cu²⁺的最大吸附容量为4.378 7 mg/g,Fe³⁺和Cu²⁺在改性壳聚糖上的吸附是单分子层形式。

Treatment of microbial leaching solution emissions by modified chitosan

Generally,the “Neutralization” direct treatment of microbial leaching acid solution emissions is used in the mining industry. In order to deal with the existing problems of vast amounts of sediments and difficult solid-liquid separation in the process of neutralization treatment,this paper studies the experiment method of modification of chitosan and discusses the effects of the amount of sodium citrate buffer solution （V₁）,the amount of epichlorohydrin （V₂）and the crosslinking reaction time （T）on the modified chitosan for removal of Cu²⁺ and Fe³⁺under the condition of pH 2.2. By modifying 100 mL chitosan-glacial acetic acid solution in which the mass fraction of chitosan was 2%,the results showed that the best improvement conditions were as follows：V₁=200 ml,V₂=300 ml,and T=6 h. The maximum adsorption capacity of Fe³⁺ was 6.70371 mg/g and the maximum adsorption capacity of Cu²⁺ was 4.378 7 mg/g on the modified chitosan. The modified chitosan has a certain significance of application in the removal of heavy metals in microbial leaching acid solution emissions in future.