本研究通過以磷酸鹽為沈淀劑的流化床均相造粒工藝，確定了絡合劑EDTA和檸檬酸鹽對合成廢水中鈷和銅的回收率的影響。在沒有絡合劑的情況下，最佳pH值為7.75的鈷的去除率和造粒效率分別為99.34％，98.87％，最佳pH值為6.50的銅的去除率和造粒效率分別為99.59％，89.09％。在EDTA存在下，隨著EDTA與Co2 +摩爾比從0.1增加到0.5，鈷的去除和造粒效率分別下降5.28％至30.45％和8.63％至31.10％。檸檬酸鹽的不利影響略有減少，效率分別下降4.17％至28.00％和7.72％至29.02％。兩種絡合劑也阻礙了銅的沉澱。隨著EDTA與Cu2 +的摩爾比從0.1增加到0.5，去除和造粒效率分別下降4.94％至29.29％和4.38％至34.41％。在檸檬酸鹽的情況下，在檸檬酸鹽與Cu 2+摩爾比為0.1時，兩種效率分別急劇下降至25.69％和36.93％。隨著摩爾比的增加，沒有磷酸銅沉澱出來。此外，發現EDTA和檸檬酸鹽顯著降低了顆粒大小。可與鈷和銅形成絡合物的氯化物也會干擾鈷和磷酸銅的沉澱。 This research determined the effect of the complexing agents, EDTA and citrate, on the recovery of cobalt and copper from synthetic wastewater by the fluidized bed homogeneous granulation process using phosphate as the precipitant. In the absence of the complexing agent, the removal and granulation efficiencies of cobalt at the optimum pH of 7.75 were 99.34%, 98.87% and of copper at the optimum pH of 6.50 were 99.59%, 89.09%, respectively. In the presence of EDTA, the removal and granulation efficiencies of cobalt dropped by 5.28% to 30.45% and 8.63% to 31.10%, respectively, as the EDTA to Co2+ molar ratio increased from 0.1 to 0.5. The adverse impact slightly lessened for citrate by which the efficiencies decreased 4.17% to 28.00% and 7.72% to 29.02%, respectively. Both complexing agents hindered the precipitation of copper as well. As the EDTA to Cu2+ molar ratio increased from 0.1 to 0.5, the removal and granulation efficiencies deteriorated by 4.94% to 29.29% and 4.38% to 34.41%, respectively. In the case of citrate, both efficiencies drastically decreased up to 25.69 % and 36.93 %, respectively, at the citrate to Cu2+ molar ratio of 0.1. As the molar ratio increased, no copper phosphate precipitated out. In addition, it was found that EDTA and citrate significantly reduced the granule sizes. Chloride which can form complexes with cobalt and copper interfered the precipitation of both cobalt and copper phosphate as well.
