Research on the Preparation of Organic Modified Bentonite and the Control of Biological Invasion in Ballast Water

Abstract

In this research, the effect of modified bentonite on removing harmful organisms in ballast water was discussed using HDTMA+ modified bentonite as flocculating material, and Alexandrium tamarense, Nitzchia closterium, and Photobacterium phosphoreum as the objects of harmful organisms, and also through an observation of the reaction mechanism between HDTMA+ and bentonite with Fourier transform infrared spectroscopy (FTIR). The result showed that there was an effective combination of HDTMA+ with bentonite, and the modified organic bentonite possessed a powerful ability to remove harmful organisms. The removal rate against Alexandrium tamarense within 24h was greater than 85% if the dosage of the organic bentonite was 0.03 g/L; the removal rate against Nitzchia closterium was approximate to 80% if the dosage was 0.06 g/L; the luminous intensity could not be displayed by luminescent bacteria under the condition of concentration 0.30 g/L, and also the original soil with modification did not shown a significant removal effect under the same dosage. Therefore, it was concluded that the conditions such as aging time, organic bentonite’s particle size, and HDTMA+ dosage were the important factors affecting the harmful biological removal efficiency.