The characteristics of acid-activated raw bentonite (RB) activated with binary acid solutions sulfuric acid + nitric acid, nitric acid + phosphoric acid, and phosphoric acid + sulfuric acid, at a concentration of 5 mol/L (denoted as 5-SN, 5-NP, and 5-PS), were evaluated. Moreover, its application for improving the electrical conductivity in tap water was demonstrated. Acid activation induced the partial destruction of RB; subsequently, there was a significant release of sodium ions from the RB. In addition, the specific surface area and pore volume of 5-SN, 5-NP, and 5-PS were higher than those of RB. Next, the electrical conductivity when using RB increased with adsorption treatment because sodium ions were released from the RB. However, the electrical conductivity significantly decreased with adsorption treatment when using acid-activated RB. Specifically, magnesium ions, calcium ions, and potassium ions were removed into 5-SN, 5-NP, and 5-PS, and sodium ions were not released from the RB simultaneously. The removal percentage of the electrical conductivity using 5-SN, 5-NP, and 5-PS was approximately 31% to 36%. The results indicated that employing acid-activated RB with a binary acid solution is a useful method for decreasing the electrical conductivity in tap water.

中文翻译：

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二元酸溶液酸活化膨润土的制备和表征及其在降低自来水电导率中的应用

用硫酸+硝酸、硝酸+磷酸、磷酸+硫酸二元酸溶液活化的酸活化原膨润土（RB）的特性，浓度为5mol/L（记为5-SN， 5-NP 和 5-PS) 进行了评估。此外，还展示了其在提高自来水中电导率方面的应用。酸活化诱导RB的部分破坏；随后，RB 大量释放钠离子。此外，5-SN、5-NP和5-PS的比表面积和孔容均高于RB。其次，使用 RB 时的电导率随着吸附处理而增加，因为钠离子从 RB 中释放出来。然而，当使用酸活化的 RB 时，电导率随着吸附处理而显着降低。具体而言，镁离子、钙离子和钾离子被去除到 5-SN、5-NP 和 5-PS 中，钠离子不会同时从 RB 中释放出来。使用 5-SN、5-NP 和 5-PS 的电导率去除百分比约为 31% 至 36%。结果表明，将酸活化的 RB 与二元酸溶液一起使用是降低自来水中电导率的有效方法。