有机酸介质作用下大米中镉元素的释放及其在工艺脱除中应用初探

Release of cadmium from rice under the action of organic acid medium and its application in technological removal

中文关键词:  有机酸  镉元素  大米  脱除

英文关键词:organic acid  cadmium element  rice  removal

中文摘要:

      目的 研究不同有机酸介质条件下对大米中镉元素释放的影响及其在脱除中的应用。方法 在不同浓度的有机酸介质溶液的作用下, 测定镉元素从含镉大米中释放到浸提溶液的含量。通过测定酸性溶液中镉元素浓度与大米中镉元素含量的比值, 评估其浸提释放效果。结果 不同浓度的有机酸对大米中镉元素的释放有明显影响, 固液比1:10时, 1%浓度的有机酸对镉大米的浸提率平均高达97.3%, 将有机酸浓度降低到0.01%, 仅有少量的镉会被浸出, 平均浸提率为16.7%。脱除效果与大米的形态和有机酸浓度有关, 固液比1:4时, 采用整粒浸泡法(10 h), 糙米去除率可达25.1%, 精米可达58.0%, 物料损失率小于1.4%; 采用粉状振荡浸提法(30 min), 去除率最高可达82.9%, 其物料损失率小于3.4%。结论 通过控制不同有机酸溶液的浓度, 能够显著释放出大米中的镉元素, 本研究可为镉污染大米的工艺化合理处理提供一种途径。

英文摘要:

      Objective To investigate the effects of different organic acids on the release of cadmium from rice and its application in the removal of cadmium from rice. Methods The content of cadmium released from cadmium-containing rice into the leaching solution was determined under the action of organic acid medium solutions with different concentrations. The ratio of cadmium concentration in acid solution to cadmium content in rice was determined to evaluate the extraction and release effect. Results Different concentrations of organic acids had obvious effects on the release of cadmium in rice, When the solid-liquid ratio was 1:10, the leaching rate of 1% organic acid to cadmium rice was as high as 97.3% on average, and the organic acid concentration was reduced to 0.01%, only a small amount of cadmium was leaching, and the average leaching rate was 16.7%. The removal effect related to rice morphology and organic acid concentration, when the solid-liquid ratio was 1:4, the removal rate of brown rice could reach 25.1% by using the whole grain soaking method (10 h), that of polished rice was 58.0%, and the loss rate of materials was less than 1.4%. The removal rate of powder rice could reach 82.9% by shock leaching (30 min), and the loss rate of materials was less than 3.4%. Conclusion Cadmium in rice can be released significantly by controlling the concentration of different organic acid solutions. This study can provide a way for the reasonable processing of cadmium-contaminated rice.