Binary iron cobalt oxide silica membrane for gas separation

Development of Hybrid and Templated Silica-P123 Membranes for Brackish Water Desalination

Water scarcity is still a pressing issue in many regions. The application of membrane technology through water desalination to convert brackish to potable water is a promising technology to solve this issue. This study compared the performance of templated TEOS-P123 and ES40-P123 hybrid membranes for brackish water desalination. The membranes were prepared by the sol–gel method by employing tetraethyl orthosilicate (TEOS) for the carbon-templated silica (soft template) and ethyl silicate (ES40) for the hybrid organo-silica. Both sols were templated by adding 35 wt.% of pluronic triblock copolymer (P123) as the carbon source. The silica-templated sols were dip-coated onto alumina support (four layers) and were calcined by using the RTP (rapid thermal processing) method. The prepared membranes were tested using pervaporation set up at room temperature (~25 °C) using brackish water (0.3 and 1 wt.%) as the feed. It was found that the hybrid membrane exhibited the highest specific surface area (6.72 m²·g⁻¹), pore size (3.67 nm), and pore volume (0.45 cm³·g⁻¹). The hybrid ES40-P123 was twice thicker (2 μm) than TEOS-P123-templated membranes (1 μm). Lastly, the hybrid ES40-P123 displayed highest water flux of 6.2 kg·m⁻²·h⁻¹. Both membranes showed excellent robustness and salt rejections of >99%.

Interlayer-free Silica Pectin Membrane for Wetland Saline Water via Pervaporation

Wetland in South Kalimantan is one of surface water sources to provide clean water. However, seawater intrusion has spread into the wetland aquifer and reduce the quality of water. Silica-pectin membrane is a promising technology for desalination. The membranes were tested for desalination by pervaporation at room temperature (~25 °C). During pervaporation process, the water contacts to membrane and the separation is started to occurs as vapour phase by maintaining vacuum pressure (~1 bar). The permeate was collected in the cold trap after condensed using nitrogen liquid. The purpose of this research was to investigate the performance of interlayer-free silica pectin membrane for wetland saline water. Experimental results shows the fluxes of membrane are 0.35 and 0.19 kg.m-2 h-1 ( pectin 0%wt); 0.23 and 0.16 kg.m-2 h-1 (pectin 0.1%wt); 0.58 and 3.63 kg.m-2 h-1 (pectin 0.5%wt); 3.40 and 0.12 kg.m-2 h-1 (pectin 2.5%wt) calcined at 300 and 400 °C, respectively. Natural organic matter (NOM) and salt concentration in wetland saline water can reduce the fluxes up to (~98%). Nevertheless, overall salt rejection of membranes achieved >99%. It was found that low calcination gives better performance at high pectin concentration. While pectin concentration was limited at high calcination.

Synthesis and use of bimetals and bimetal oxides in contaminants removal from water: a review

This paper gives an overview of the recent advances of the synthesis methods of bimetals and bimetal oxides and applying them in contaminant removal from water.

Tailoring the structure and gas permeation properties of silica membranes via binary metal oxides doping

The incorporation of binary Co–Mn or Co–Cr oxides within the silica matrix leads to the formation of silica structures with different networks, which allows tuning of the gas separation properties.