5:15 PM - 6:30 PM
[AGE28-P01] Assessment of Hydrophobicity/Oleophilicity for Artificially Coated Autoclave Aerated Concrete Grains
Keywords:Oily-wastewater, Oil/water separation, Autoclave aerated concrete, Hydrophobicity/Oleophilicity, Contact angle (deg)
Insufficient treatment of oily-wastewater generated from domestic sources and industries such as petrochemicals, food, textiles, and metal industries, biopharmaceutical, and oil/gas refineries cause serious water pollution and endanger aquatic-life, which affects human health and living nature. Due to economic and technical constraints, however, general advanced treatment systems for oily-wastewater are not common, especially in developing countries. The applicable system with cost-effective and high-performance are highly required. Moreover, most of industrial by-products (IBPs) are not fully recycled and stored/dumped without a suitable treatment in most of those countries.
In this study, therefore, with the viewpoints of utilization of, the potential use of hydrophobized porous grains made from IBPs were examined to develop a suitable oily-wastewater treatment technology. Especially, this study aims to assess porous grains of autoclave aerated concrete (AAC) grains coated by hydrophobic agents (HAs) and discuss the applicability to the oil/water separation technique. The AAC grains (0.106–0.250 mm) were prepared from waste-scrap along with the manufacturing process of AAC blocks that stored at stocking yard without reuse and recycling in Vietnam. They were coated with two types of hydrophobic agents (HAs), Oleic acid (OA) and Stearic acid (SA), at different concentrations ranging from 0 to 750 (g of HA / kg of AAC grains; hereafter, g/kg) based on a solvent-aided method. The degree of hydrophobicity/oleophilicity was assessed in the laboratory, by measuring contact angles of water in air (CAa) and soybean oil in water (CAo). Results showed that the measured CAa for both OA–and SA–coated AAC grains rapidly increased with increasing HA concentrations with CAa(max) = 135–145o at HA > 100 g/kg, while CAo decreased with increasing HA concentrations with CAo(max) = 130–140o at HA < 10 g/kg. Finally, a simple gravity-driven oil/water separation experiment was performed showing that the hydrophobized AAC grains have good separation efficiency/capacity. Thus, this novel and cost-effective AAC grains coated with suitable HAs concentrations have a high prospective as filtration media in the oil/water separation system.
In this study, therefore, with the viewpoints of utilization of, the potential use of hydrophobized porous grains made from IBPs were examined to develop a suitable oily-wastewater treatment technology. Especially, this study aims to assess porous grains of autoclave aerated concrete (AAC) grains coated by hydrophobic agents (HAs) and discuss the applicability to the oil/water separation technique. The AAC grains (0.106–0.250 mm) were prepared from waste-scrap along with the manufacturing process of AAC blocks that stored at stocking yard without reuse and recycling in Vietnam. They were coated with two types of hydrophobic agents (HAs), Oleic acid (OA) and Stearic acid (SA), at different concentrations ranging from 0 to 750 (g of HA / kg of AAC grains; hereafter, g/kg) based on a solvent-aided method. The degree of hydrophobicity/oleophilicity was assessed in the laboratory, by measuring contact angles of water in air (CAa) and soybean oil in water (CAo). Results showed that the measured CAa for both OA–and SA–coated AAC grains rapidly increased with increasing HA concentrations with CAa(max) = 135–145o at HA > 100 g/kg, while CAo decreased with increasing HA concentrations with CAo(max) = 130–140o at HA < 10 g/kg. Finally, a simple gravity-driven oil/water separation experiment was performed showing that the hydrophobized AAC grains have good separation efficiency/capacity. Thus, this novel and cost-effective AAC grains coated with suitable HAs concentrations have a high prospective as filtration media in the oil/water separation system.