Abstract

We determined the physicochemical regularities of the process of purification of an alkaline solution of a cationic dye (Methylene Blue) and anionic dyes (Direct Brown and Direct Red) using a microfiltration ceramic membrane based on clay minerals, which is dynamically modified with montmorillonite. This membrane retained 99.6% of Methylene Blue at specific productivity of 0.08 m³/(m² h) at an initial concentration of the dye of 50 mg/dm³, pH₀ 12.5, P 1.0 MPa, and a permeate selection factor of 80%. The high retention capacity of the ceramic membrane to Methylene Blue is due to the presence of a modifying layer of montmorillonite on its surface, ensuring the adsorption of dyes in the form of an additional retention gel-like layer of dye associates. The modified microfiltration ceramic membranes made of clay minerals, developed at the Dumansky Institute of Colloidal Chemistry and Water Chemistry, National Academy of Sciences of Ukraine, are comparable to modified microfiltration membranes of oxide ceramics from Rauschert (Germany) in the efficiency of water purification from cationic dyes but are much more productive and cheaper than the latter. Under similar conditions, the modified membrane of clay minerals also showed a high retention capacity to Direct Brown and Direct Red anionic dyes. The mechanism of their retention is associated with the electrostatic repulsion of like-charged anions of dyes and montmorillonite particles. A clay-based ceramic membrane modified with montmorillonite is proposed for the pretreatment of alkaline washing solutions of banknote factories.

中文翻译：

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蒙脱土修饰的粘土矿物微滤陶瓷膜从染料中纯化碱性溶液

摘要

我们确定了使用基于粘土矿物的微滤陶瓷膜对阳离子染料（亚甲基蓝）和阴离子染料（直接棕和直接红）的碱性溶液进行纯化的过程的物理化学规律，该膜经蒙脱土动态改性。该膜在染料的初始浓度为50 mg / dm ³，pH ₀ 12.5，P时以0.08 m ³ /（m ² h）的比生产率保留99.6％的亚甲蓝。1.0 MPa，渗透物选择系数为80％。陶瓷膜对亚甲蓝的高保留能力是由于其表面上存在蒙脱土改性层，从而确保了染料以附加的类似染料缔合的保留凝胶状层的形式吸附。乌克兰国家科学院杜曼斯基胶体化学和水化学研究所开发的由粘土矿物制成的改性微滤陶瓷膜，与德国Rauschert氧化物陶瓷的改性微滤膜相比，其净化水的效率可与之媲美。阳离子染料，但比后者具有更高的生产率和价格。在相似的条件下，粘土矿物的改性膜对直接棕和直接红阴离子染料也显示出很高的保留能力。它们的保留机理与染料和蒙脱石颗粒的带负电的阴离子的静电排斥有关。提出了一种用蒙脱土改性的粘土基陶瓷膜，用于钞票工厂的碱性洗涤液的预处理。