Chiang Mai Journal of Science

     This research aims to study the sustainability of celadon glazes by using lampang kaolin waste and longan wood ash as substitutes for rare wood ashes, such as kha and rok fa wood, as well as for replacing silica and feldspar, which are chemicals. The celadon glazes was fired at lower temperatures of 1230°C and 1250°C in a reducing atmosphere. The analysis of the specific characteristics revealed that the glazes formula CG25-20, consisting of 30 wt.% Lampang kaolin, 20 wt.% Lampang kaolin waste, and 50 wt.% longan wood ash, with the addition of 1 wt.% sankamphaeng red clay for coloring, fired at 1250°C, had a chemical composition dominated by CaO, followed by SiO₂, Fe₂O₃, Al₂O₃, K₂O, TiO₂, SO₃, and MnO, respectively. The glaze exhibited a complete glassy morphology, with crack patterns limited to the upper surface, and the glazes adhered well to the clay body. The property tests showed that cracks decreased when 20% silica from Lampang kaolin waste was used. After firing, the glaze exhibited a green-yellow tone with L = 67.41, a = -2.13, b = +14.96, and a gloss level of 40 GU. The glazes demonstrated heat resistance, with a MOR loss percentage of 0.48, based on thermal shock testing, and had a low thermal expansion coefficient in relation to the clay body. Therefore, it is feasible to use lampang kaolin waste and longan wood ash to enhance the sustainability and heat resistance of environmentally friendly celadon glazes for ceramic ware from the sankamphaeng kiln site in Chiang Mai province.

     The large volume of wastewater produced by food factories in western Thailand has increasingly impacted the ecosystem. This study aimed to isolate lipid-degrading bacteria from household and industrial wastewater in Nakhon Pathom Province, Thailand, and to treat oil-contaminated wastewater from a vitamin E manufacturing plant under aerobic conditions. Out of 120 isolates, two strains (1W51 and 1W52) were selected for their strong ability to degrade lipids, as demonstrated on tributyrin media. 16S rRNA sequencing identified strains 1W51 and 1W52 as closely related to Bacillus nitratireducens and Bacillus paranthracis, respectively. Both strains produced hydrolytic enzymes including amylase, protease, and lipase on selective media. They also demonstrated beta-hemolysis, positive drop collapse results, and clear halo zones in oil displacement tests. The emulsification index (E24) of both strains exceeded 50%. After treatment with these strains, the chemical parameters in wastewater showed notable improvement: total suspended solids (TSS) and chemical oxygen demand (COD) decreased by 50% and 75%, respectively, while dissolved oxygen (DO) and biological oxygen demand (BOD) increased by 67% and 73%, respectively. The addition of B. nitratireducens 1W51 and B. paranthracis 1W52 significantly improved wastewater quality, indicating their potential for use in environmentally friendly biological wastewater treatment.