Optimization of Magnetic particles recovery and reuse using experimental design method – A Case Study of chemical mechanical polishing wastewater treatment

• Main Authors: Chia-Ling Lin, 林家綾
• Other Authors: Terng-Jou Wan
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/v3y95y

碩士 === 國立雲林科技大學 === 環境與安全衛生工程系 === 103 === With the rapid development of the situation in the semiconductor industry, a large amount of grinding wastewater, and most abrasive wastewater treatment methods are chemical coagulation, thus leading to excessive dosing and produced large amounts of sludge . In recent years, magnetic particles have been gradually used in wastewater treatment, the adsorption of the magnetic particles, the use of sedimentation to remove the external magnetic field to attract and the magnetic particles by the experimental design method, the optimum conditions selected, the magnetic particles are recycled, and treatment cost reduction. This study first adjusted pH, strength of mixing, magnetic field, magnetic particles dose and other factors to perform jar test. In the selected the most suitable parameters, and then the optimal combination of parameters by Plackett-Burman method, to select high level and low level of each parameter for 8 factors； Among many factors, the most influential of the coagulation factor experiment are pH and strength of mixing, then the best conditions by RSM experiment singled out two key factors of the applied magnetic particle recycling experiment, and found that pH 4.9 with Speed 68 rpm, turbidity removal efficiency can reach 90%, and therefore the re-use of recycled experiment, flocculation conditions are all pH 4.9 with a speed of 68 rpm. Recycling experiment, for desorption method, we divided into two part, one is pH, another is used by ultrasound, the experimental results can be found by using ultrasound desorption, magnetic particles can re-use the higher number, probably because by the ultrasonic vibration, the average particle size of the magnetic particles become smaller, the surface area available for adsorption relative becomes large, it can also improve the number of reused; results of study has show the polishing of the magnetic particles used in waste water treatment, the effect is good, and the recovery of up to 4 times the number of parts, so that the magnetic particles can be applied to not only significantly reduce the polishing waste the coagulant dosage can greatly reduce the waste water turbidity.