三种大型海藻对对氯苯胺的去除行为及光合生理响应

The removal of PCA by three marine macroalgae and the photosynthetical responses

以龙须菜、坛紫菜和石莼3种大型海藻为实验材料,通过模拟实验,研究并比较了它们对不同浓度对氯苯胺(PCA)的去除行为,以及石莼对PCA的光合生理响应.实验结果显示,7d实验结束时,3种藻类对海水中PCA的最终去除率排序分别为:6mg·L-1PCA处理组,龙须菜(58.7%)<坛紫菜(75.7%)<石莼(94.9%);60mg·L-1PCA处理组,龙须菜(50.2%)<石莼(61.3%)<坛紫菜(74.9%);海藻的培植密度越大,PCA的去除率越高,在受PCA污染的海域中大面积种植大型海藻来有效地处理修复此类污染在理论上是可行的.在不同浓度PCA处理过程中,石莼的生长受到抑制,有效光化学效率、光合作用和呼吸作用呈现出低浓度(<5mg·L-1)促进、高浓度(>10mg·L-1)抑制的现象.叶绿素、类胡萝卜素和可溶性蛋白含量在各处理组之间没有表现出确定趋势,表明PCA对石莼生长的影响可能是由于呼吸速率的增加而引起的.

This study investigated the removal of different concentrations of PCA in seawater under simulation experiments with three marine macroalgae, Gracilaria lemaneiformis,Porphyra haitanensis and Ulva lactuca. The results showed that, after 7 days＇ experiment, the final removal rate with respect to 6 mg·L^-1 PCA was 58.7% by Gracilaria lemaneiformis, 75.7% by Porphyra haitanensis, and 94.9% by Ulva lactuca. For 60 mg·L^-1 PCA, the final removal rate was 50.2% by Gracilaria lemaneiformis, 74.9% by Porphyra haitanensis, and 61.3% by Ulva lactuca. The greater the cultivation density of algae was, the better the PCA removal. The response of growth, photosynthesis, respiration and biochemical components exposed to different concentrations of PCA in Ulva lactuca was also studied in this paper. Five different concentrations of PCA （0, 1, 5, 10, 25 mg·L^-1） were adopted. The results showed that the growth of Ulva lactuca was negatively affected by PCA and the relative growth of Ulva lactuca decreased with the increasing of PCA. In the treatment of PCA, effective quantum efficiencies （Yield）, photosynthesis and respiration of Ulva lactuca were significantly enhanced at low concentrations （〈5 mg·L-1） while was inhibited at high concentrations （〉10 mg·L-1）. The contents of pigments and solube proteins in Ulva lactuca were not significantly affected by PCA. The results suggested that reduced growth could be mainly ascribed to the increased respiration rates.