Treatment Of Acid Copper Palting Wastewater By Magnetic Combined Immobilized Microorganism Technique

In this paper, the treatment technology of acid copper plating wastewater was studied under the condition of combineing magnetic and immobilized microorganism. The microorganism domesticated by acidic copper plating wastewater was fixed on the carrier, which was used in the experiment. This study focused on the influence of the magnet on immobilized microorganism、the optimal operation condition、the reason of changing in p H,and the removal mechanism of copper ion was analysised by the results of SEM-EDS. The results of the study are as follows:(1)The adsorption was used to fix the microorganism domesticated by acidic copper plating wastewater. The speed, magnetic field strength, volume concentration, fixation time were taken as factors on the quality of immobilized microorganism, and then the orthogonal test of the L9(34) was employed for optimal conditions. Correlation analysis and variance analysis showed there was a linear relationship between magnetic field strength and the amount of immobilized microorganism, and that the magnet had a significant effect on immobilized microorganism.(2)Gas-water ratio、hydraulic retention time、magnetic field strength、concentration of influent were taken as factors on the removal rate of copper ion, and then the orthogonal test of the L9(34) was employed for optimal conditions. The sequence of factors influencing Cu2 + biosorption was gas-water ratio > magnetic field strength > hydraulic retention time > concentration of influent. The temperature had no influence on the results.(3)The experimental results showed the magnet had a significant effect on the microorganism immobilization and the treatment of acid copper plating wastewater, while the required magnetic field strength they need was different.(4)The p H value rises form 2.50 of the influent to 4.50-5.00 of effluent. Correlation analysis showed that the gas-water ratio was the main factor affecting the p H of the effluent.(5)The SEM was used to anysis the microorganism which did not absorb the copper ion and the microorganism which absorbed the copper ion in the wastewater, and the EDS was used to anysis the removal mechanism of copper ion. The results showed the absorption peak of copper appeared in the EDS of the surface and interior of the microorganism after absorbing the copper ion, and the peak increased with the concentration of copper ions in solution, which proved Cu2+ biosorption included surface adsorption,transmembrane active transport and bioaccumulation.