摘要:
在本研究第二篇中,我们通过实验室模拟研究,发现海水中Fe+++或Al+++离子在适当pH条件下生成Fe(OH)3或Al(OH)3胶体沉淀后,对活性硅有相当大的吸附能力;同时还通过吸附热计算、淋洗脱附实验和重溶解实验,判断上述吸附并不是一般可逆的离子交换吸附,而比较可能是化学吸附,吸附后基本上不转化为高聚硅酸结构,而比较可能进行结构重排转入内部结构中去.根据这些结果,我们提出一个关于河口活性硅地球化学转移的理论图象:即活性硅主要通过由于pH和盐度提高而生成的铁、铝等元素氢氧化物胶体沉淀的吸附而转移,再进一步转化为比较稳定的铁、铝的硅酸盐化合物形式,沉积到海底.为了进一步验证这个理论图象的现实性,我们再度在九龙江口进行了一些现场取样分析研究,试图通过河口各处海水悬浮物中各化合形式硅、铁、铝的分布变化资料,加以初步归纳总结,并和理论图象相对照.
Abstract:
In situ observations were conducted to verify the nrechanisrn and geochertrical pattern proposed previously by the authors. her ies of samples of suspended matter in estuarine waters wore collected along Jiulong River, Fujian. The part which can be dissolved by hot 0.43 N HCl was considered as the "anthigenie" inorganic silicate constituent of the suspended matter, and the filtrates were analyzed for reactive silicate, Fe and Al. the part of the residue whicki can be further dissolved by concentrated HNO3and then by 0.48 N HCl was analyzed for reactive silicate and considered as the organic Si content of the suspended matter. It is assmned that the "authigenic" inorganic silica comes from the inorganic chemical removal of the reactive silicate from the water phase.