Preparation of polylactic acid/ defatted rice bran particles mixed matrix membranes for adsorptive removal of herbicide from water

• Main Authors: Chi-Shiang Peng, 彭啓翔
• Other Authors: Shing-Yi Suen
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/65078003208356308424

碩士 === 國立中興大學 === 化學工程學系所 === 103 === In this study, pesticide was removed from water using polylatic acid (PLA)/ defatted rice bran particles mixed matrix membranes. The pesticide adopted was paraquat dichloride (1,1-dimethyl-4,4-bipyridyl dichloride), which is a well-known herbicide. A mixture of 50 wt% defatted rice bran and 50 wt% PLA was blended in NMP (N-methyl-2-pyrrolidone) to prepare the mixed matrix membranes. After washing several times, the content of defatted rice bran particles in the membrane was found to be 40 wt%. In the batch process, the adsorption isotherm results show that the time required to achieve equilibrium was 2 hr. Different desorption solutions were tested in the batch desorption process, and the best desorption performance (~95 %) was achieved with an aqueous solution containing 1 M NaCl in 50% methanol (v/v). In the flow process with one piece of 25 mm mixed matrix membrane disc for 10 ppm aqueous paraquat solution, the optimal flow rate was 1 mL/min and the related breakthrough time was 4.1 min. When five membranes were used, the dynamic adsorption amount was five fold of a single membrane result. At last, the adsorption/desorption cycle with one piece of 25 mm membrane disc was repeated three times at 1 mL/min. The membrane efficiency was a little bit deteriorated due to the repeated use.