จำนวน Repository ( 7 )
การประดิษฐ์เซรามิกเฟร์โรอิเล็กทริกไร้ตะกั่วในระบบบิสมัทโซเดียมโพแทสเซียมไททาเนตเป็นองค์ประกอบหลัก
The research project investigated the effects of CoO additive on dielectric ferroelectric physical and mechanical properties of modified Bi0.5(Na0.81K0.19)0.5TiO3 ceramics were investigated. The samples were synthesized by solid state reaction technique where powders were calcined at 850 °C for 4 h and ceramics were sintered at 1050 °C for 4 h which difference heating rate controlled i.e. 100 300 and 600 °C/h for. The ceramics of BNKT/x wt.% CoO was added CoO by various x=0.00 0.10 0.20 0.30 0.60 and 0.90. Phase formation was determined by X-ray diffraction technique (XRD). The X-ray diffraction analysis of the ceramics suggests that all samples exhibited a perovskite structure. The dielectric properties under room temperature and various temperatures were also determined. Dielectric measurement data showed that the additive and heating rate controlled influenced dielectric constant and dielectric loss. Furthermore the hysteresis loop behaviors slightly changed with increasing the CoO contents.
การดัดแปลงพื้นผิวตัวดูดซับสำหรับกำจัดไอออนตะกั่วจากสารละลาย
The objective of this work was to study the adsorption efficiency of natural clay and its surface modified with manganese oxide for removal of Pb( II) ion. The adsorption of Pb( II) from aqueous solution onto raw natural clay (NC) and manganese oxide-modified natural clay (MnO-NC) was evaluated based on batch experiment. The adsorption efficiency of MnO-NC onto Pb( II) was investigated as a function of the initial pH of 6 equilibrium time of 30 min adsorbent concentration of 5 g/L and initial concentration of Pb(II) solution in the range of 50- 500 mg/L. The adsorption isotherms of Langmuir Freundlich and Dubinin-Radushkevich were used to describe the equilibrium isotherm. It is observed that the data from MnO-NC adsorbents fitted well to the Langmuir isotherm. The maximum monolayer adsorption capacities of MnO-NC were estimated as 38. 76 mg/ g. By comparing with NC the amount of Pb( II) adsorbed onto MnO-NC was more than NC by about 38 times under the optimized adsorption condition. According to Dubinin-Radushkevich isotherm the adsorptive mechanism of Pb(II) onto MnO-NC was chemisorption whereas the NC showed the mechanism as physical in nature. The kinetic studies of Pb( II) demonstrated that the adsorption of Pb( II) onto MnO- NC and NC adsorbents followed a pseudo second- order model with a good correlation. The adsorption mechanism was processed via chemical ion exchange between H+ and bonded MnO groups and Pb(II) ions in solution.
ประสิทธิภาพการดูดซับไอออนตะกั่วจากสารละลายโดยใช้อิฐมวลเบาเป็นตัวดูดซับ
In this study autoclaved aerated concrete (ACC) were investigated as low-cost andsimple adsorbents for removal of Pb(II) from aqueous solution. The adsorption of Pb(II) wascarried out by batch experiments as a function of solution pH adsorbent dosage contacttime initial Pb(II) concentration and temperature. The experimental data were analyzed bythe Langmuir Freundlich Temkin and D-R isotherm models. The Langmuir isotherm modelis more suitable. The monolayer adsorption capacity of ACC was found to be 3.99 mg g−1.The adsorption of Pb(II) onto ACC was physical in nature. The kinetic studies of Pb(II)demonstrated that the adsorption of Pb(II) onto ACC adsorbents followed a pseudosecond-order model with a good correlation.
การเพิ่มมูลค่าของเปลือกกล้วยเหลือทิ้ง เพื่อกำจัดสารพิษในน้ำ
An ability of fresh banana peel without surface modification was evaluated for the removal of lead ions from aqueous solution. Batch adsorption was performed at room temperature. The experimental conditions including dosage contact time initial concentration of lead( II) ion were studied. The characterization of fresh banana peel was carried out by Fourier-transform infrared spectroscopy (FTIR) and energy dispersive X-ray fluorescence ( ED-XRF) . The isotherm models of Langmuir and Freundlich were used to describe the adsorption mechanism involving the relationship between adsorbent surface capacity and adsorbed degree of lead(II)ion in the equilibrium conditions. The experimental data fitted well to the Langmuir isotherm with a correlation coefficient of r2 greater than 0.86. The Maximum adsorption capacity (qm) was found to be 0.9151 mg/g. The results of ED-XRF of fresh banana peels before and after treatment with lead( II) ion confirmed that lead( II) ion was occupied onto the surface of fresh banana peel. Moreover the inside of fresh banana peels was found the lead(II)ion larger than the outside peels. It was concluded that waste of banana could be used as a low-cost adsorbent for removal of lead(II)ion from aqueous solution based on a simple adsorption method.
การดูดซับโลหะหนักโดยใช้เรซินแลกเปลี่ยนไอออนที่ทำจากผงไผ่และการดัดแปรพื้นผิวด้วยแมงกานีสออกไซด์
The objective of this work was to study the adsorption efficiency of bamboo and its surface modified with manganese oxide for removal of Pb(II) ion. The adsorption of Pb(II) from aqueous solution onto bamboo (BB) and manganese oxide-modified bamboo powder (MnO-BB) was evaluated based on batch experiment. The adsorption efficiency of MnO-BB onto Pb(II) was investigated as a function of the initial pH of 6 equilibrium time of 30 min adsorbent concentration of 5 g/L and initial concentration of Pb(II) solution in the range of 50-500 mg/L. The adsorption isotherms of Langmuir Freundlich and Dubinin-Radushkevich were used to describe the equilibrium isotherm. It is observed that the data from MnO-BB adsorbents fitted well to the Langmuir isotherm. The maximum monolayer adsorption capacities of MnO-NC were estimated as 38.76 mg/g. By comparing with BB the amount of Pb(II) adsorbed onto MnO-BB was more than BB by about 40 times under the optimized adsorption condition. According to Dubinin-Radushkevich isotherm the adsorptive mechanism of Pb(II) onto MnO-BB was chemisorption. The kinetic studies of Pb(II) demonstrated that the adsorption of Pb(II) onto MnO-BB adsorbent followed a pseudo second-order model with a good correlation. The adsorption mechanism was processed via chemical ion exchange between H+ and bonded MnO groups and Pb(II) ions in solution