Bioremediation of Heavy Metal Ions by Phosphate‐mineralization Bacteria and Its Mechanism

Bioremediation of heavy metal ions by phosphate‐mineralization bacteria (PMB), as a new green and en‐ vironmental method, relies on microbe‐inducing phosphate precipitation and can prevent heavy metal ions from transferring. The growth of PMB was investigated via four aspects respectively — the control of incubation time, pH value, environmental conditions, and heavy metal ions. At the same time, phosphate? mineralization precipitations and mechanism of four common kinds of heavy metal ions were analyzed. The experimental results indicated that PMB didn’t grow immediately in the first 5 hours, and they reached to the fastest reproduction rate after 13 hours. The pH value of PMB solution increased gradually from 7.0 to 8.6 when PM₀B grew, which plays an important role in the mineralization process. PMB could grow most rapidly at 30 °C, pH of 8 and low concentration of heavy metal ions. It showed that too high or too low temperature and pH, as well as high concentration of heavy metal ions, could inhibit the reproduction of PMB. Stable and large particles phosphate ‐ mineralization precipitation, whose particle size could be more than 10 microns, were obtained by the process that PMB induced substrate to decompose and thus mineralized heavy metal ions effectively.