铜藻中有害元素的脱除工艺优化及脱除前后砷形态的变化

为降低铜藻中有害元素铬、砷、镉、铅含量,对最佳脱除剂进行选择,通过单因素实验、正交试验优化脱除工艺,以及采用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)联用技术分析脱除前后铜藻中砷形态的变化,并将优化后的工艺应用于羊栖菜、马尾藻。结果表明,以1.5% EDTA-2Na作为脱除剂,在料液比为1:30 g/mL,时间为4 h,温度为30 ℃的工艺条件下,对铬的脱除率为71.34%;对总砷的脱除率为66.32%,其中对毒性较大的As3+、As5+脱除率分别为100%、91.43%;对镉的脱除率为87.40%;对铅的脱除率为87.64%,脱除后铅的含量低于GB 2762-2017《食品中污染物限量》的限量规定,脱除后铜藻中岩藻黄质损失率在可接受范围内。该工艺对羊栖菜中的有害元素铬、砷、镉、铅的脱除率分别为57.27%、66.00%、87.14%、88.88%;对马尾藻中有害元素铬、砷、镉、铅的脱除率分别为55.56%、56.89%、87.14%、96.44%。此工艺简单易操作,能脱除大部分毒性较大的无机砷,且具有一定的适用性,为工业上降低海藻中有害元素的含量提供思路。

Optimization of Removal Process of Harmful Elements in Sargassum horneri and Changes of Arsenic Species before and after Removal

The pollution of harmful elements has restricted the development and utilization of Sargassum horneri. In order to reduce the content of chromium, arsenic, cadmium and lead in Sargassum horneri, the best remover was selected. The removal process was optimized through single-factor experiments and orthogonal experiments. And high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was used to analyze the change of Arsenic species in Sargassum horneri before and after removal, and the optimized process was applied to Hizikia fusifarme and Scagassum. The results showed that with 1.5% EDTA-2Na as the remover, the removal rate of chromium was 71.34% under the process conditions of 1:30 g/mL, 4 h, and 30℃. The removal rate of total arsenic was 66.32%, among which the more toxic As3+ and As5+ was 100% and 91.43%. The removal rate of cadmium was 87.40%, and the removal rate of lead was 87.64%. The content was lower than the national standard limit, and the loss rate of fucoxanthin in the Sargassum horneri was within an acceptable range. The removal rate of harmful elements such as chromium, arsenic, cadmium and lead in the Hizikia fusifarme was 57.27%, 66.00%, 87.14% and 88.88%;The removal rates of harmful elements such as chromium, arsenic, cadmium and lead in Scagassum were 55.56%, 56.89%, 87.14% and 96.44%.The process is simple and easy to operate, which can remove most of the more toxic inorganic arsenic with certain applicability. It provides an idea for industrially reducing the content of harmful elements in seaweed.