NANOFILTRATION COMPOSITE MEMBRANES USING LAYERED DOUBLE HYDROXIDES FOR WATER TREATMENT
Water purification is one of the most urgent tasks for solving global problems of fresh water supply and ecology. Special attention is paid to nanoporous membranes, which can be used to purify water from most of the pollutants, such as metal ions, organic molecules, salts and microbes. The development of highly effective nanoporous membranes for water purification is an extremely urgent task. Nanofiltration membranes made from 2D nanomaterials have a huge potential in desalting and purifying to the characteristics of drinking water. This article discusses the process of obtaining composite three-layer membranes, where aluminum oxide (Al2O3) is used as a substrate and intermediate layer, and layered double hydroxides (LDH) with intercalated oleate anions act as a selective layer in the interlayer space to expand it and, accordingly, increase the pore size. Synthesis and modification of LDH were performed by controlled precipitation from solution.After the co-deposition process, the precipitate must be thermally aged to increase the crystallinity of the final product. The temperature and time of synthesis vary depending on the composition of the compound.The resulting sdgs were analyzed by scanning electron microscopy. Thermogravimetric analysis was used to study the temperatures of the beginning of decomposition of SDG samples. The studies were performed in the range of 25-800°C, with a temperature heating rate of 20 deg. / min, in the air (air flow rate of 100 ml/min).The efficiency of the membrane was determined by measuring the conductivity of the solution (using a conductometric sensor). As a result of research on the process of desalination, the effectiveness of such membranes was shown.