Ming-Chun Yen

Abstracts

2 Recovery of Boron from Industrial Wastewater by Chemical Oxo-Precipitation

Authors: Yao-Hui Huang, Yu-Jen Shih, Jui-Yen Lin, Ming-Chun Yen

Abstract:

This work investigated the reclamation of boron in industrial wastewaters by a chemical oxo-precipitation (COP) technique at room temperature. In COP, the boric acid was pretreated with H₂O₂, yielding various perborate anions. Afterwards, calcium chloride was used to efficiently remove boron through precipitation of calcium perborate. The important factors included reacted pH and the molar ratio of [Ca]/[B]. Under conditions of pH 11 and [Ca]/[B] of 1, the boron concentration could be reduced immediately from 600 ppm to 50 ppm in 10 minutes. The boron removal was enhanced with a higher [Ca]/[B], which further reduced boron to 20 ppm in 10 minutes. Nevertheless, the dissolution of carbon dioxide potentially affected the efficacy of COP and increased the boron concentration after 10 minutes.

Keywords: Carbon Dioxide, Boron, Hydrogen Peroxide, chemical oxo-precipitation

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1 Copper Removal from Synthetic Wastewater by a Novel Fluidized-bed Homogeneous Crystallization (FBHC) Technology

Authors: Yao-Hui Huang, Yu-Jen Shih, Cheng-Yen Huang, Ming-Chun Yen

Abstract:

This research developed a fluidized-bed homogeneous crystallization (FBHC) process to remove copper from synthetic wastewater in terms of recovery of highly pure malachite (Cu2(OH)2CO3) pellets. The experimental parameters of FBHC which included pH, molar ratio of copper to carbonate, copper loading, upper flowrate and bed height were tested in the absence of seed particles. Under optimized conditions, both the total copper removal (TR) and crystallization ratio (CR) reached 99%. The malachite crystals were characterized by XRD and SEM. FBHC was capable of treating concentrated copper (1600 ppm) wastewater and minimizing the sludge production.

Keywords: Crystallization, Copper, carbonate, fluidized-bed, malachite

Procedia PDF Downloads 168