有机改性膨润土治理压载水有害生物的初步研究

Removal of harmful organisms using organobentonite

船舶压载水造成的有害生物外来入侵问题已经引起世界性关注,本研究以阳离子表面活性剂十六烷基三甲基溴化铵(HDTMAB)为改性材料,通过膨润土颗粒的表面吸附及离子交换作用对膨润土进行了改性,并以常见于我国沿海的海洋生物种小球藻(Chlorellasp.)、新月菱形藻(Nitzchia closterium)为目标生物,研究了有机膨润土对压载水中有害生物的去除作用。实验结果表明膨润土与HDTMAB发生了有效结合,微观结构和形貌发生改变。当有机膨润土的用量为0.02 g/L时,在24 h内小球藻的去除率大于85%,新月菱形藻的去除率大于90%,而未经改性处理的原土在相同用量下没有表现出明显的去除作用,这表明膨润土通过有机改性除藻能力显著增强。同时对有机膨润土除藻机理进行分析,有机膨润土表面静电作用和季铵盐离子亲脂性长脂肪链的网捕作用及灭杀作用是有机改性膨润土去除微藻细胞的主要原因。

WTBZThe Biological invasions from Ballast water had caused a variety of problems for aquatic life and human activity throughout the world. In this study, Hexadecyltrimethylammonium bromide （ HDTMAB）, a kind of cationic surfactants, was chosen to improve bentonite by surface sorption and cationic exchange, and was applied to remove the Chlorella sp. and Nitzchia closterium, the common phytoplankton in the Sea. The results indicated that HDTMAB was integrated with bentonite, and the microstructure of the orgaobentonite had been changed. Also, the organobentonite had an excellent ability to remove the organisms, and could kill more than 85% Chlorella sp. and 90% N. closterium under the application of 0. 02g/L in 24 h. The reason for the efficient algae removal by organobentonite might be the reversal of the surface electric charge on bentonnite particles, the net capture by the long lipoid chains of HDTMAB, and the local high density of HDTMAB on particles surface, which could effectively kill algal cells.