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铝与胡敏酸之间的相互作用的研究,对于了解铁铝质土胡敏酸复合体的特性极为重要。本研究中的胡敏酸铝制法是先从铁铝质土中提取胡敏酸,然后加入各种形态铝离子的AlCl_3溶液。试验是在不同pH条件下,测定胡敏酸铝的生成量和由此引起的胡敏酸阳离子交换量下降情况。试验着重注意半中和铝离子和氢氧化铝对胡敏酸的反应。胡敏酸的提取和制备法如下:风干细土100克放入盛有5升NaOH 0.1M Na_4P_2O_7的大玻瓶中,用NaOH调节悬浊液的pH至12.5。振荡30分钟后再加饱和Na_2SO_4溶液300毫升。经离心操作使上层溶液澄清。加HCl(pH1.5)于浸提液中使胡敏酸沉淀,将上部澄清液(富啡酸)用虹吸管吸出,余下的沉淀物再加HCl振荡混匀静置,再用虹吸管吸出上部澄清液。如是反复冲洗到上部溶液成为无色为止。将沉淀物再加NaOH 0.1M Na_4P_2O_7(pH12.5)溶液
The study of the interaction between aluminum and humic acid is of great importance for understanding the properties of Fe-Al-rich humic acid complexes. In this study, the humic acid aluminum method is to extract humic acid from ferro-aluminum soil and then add AlCl 3 solution of various forms of aluminum ions. The test was to determine the amount of humic acid aluminum produced and the resulting drop in humic acid cation exchange at different pH conditions. The experiment focused on the reaction of half-neutralized aluminum ions and aluminum hydroxide on humic acid. Humic acid extraction and preparation method is as follows: 100 g of air-dried fine soil into 5 L NaOH 0.1M Na_4P_2O_7 large glass bottle, with NaOH to adjust the pH of the suspension to 12.5. After shaking for 30 minutes, add 300 ml of saturated Na 2 SO 4 solution. The supernatant was clarified by centrifugation. Add HC1 (pH1.5) to the leachate to precipitate humic acid, aspirate the supernatant (fulvic acid) through a siphon tube, add the rest of the precipitate to HC1 and mix well and allow to stand still before siphoning off the upper clarification liquid. If so repeatedly washed into the upper solution to become colorless so far. The precipitate plus NaOH 0.1M Na_4P_2O_7 (pH12.5) solution