A mechanistic model that describes the bulk breakdown rate, accumulation, and leaching of copper (Cu), lead (Pb), and zinc (Zn) is presented.
Leaching of copper and other metals (i.e., Ni, Ag and Pd) from waste printed circuit boards (WPCBs) in acidic ferric sulphate solutions was studied.
Although leaching of copper differs considerably between the series of experiments, the emissions of copper decreased with increasing L/A ratios in both series of experiments (see Figure 2b).
Fig. 2 Time period evaluation of pH (a), Fe2+ concentration (b), copper recovery (c), and Fe3+ concentration (d) in leaching of copper from PCBs by bacteria-free cultural supernatant.
Fig. 3 Time period evaluation of Cu2+ concentration at the conditions of bacteria-free cultural supernatant, ferric sulfate solution, pure water, and pure medium in leaching of copper from PCBs.
Leaching of copper is strongly related to the concentrations of DOC and TN in the eluates, whereas co-elution with organic substances is less important for tebuconazole (see Table 4).
Our previous studies have demonstrated leaching of copper ions when water is stored at 35°C at pH 7.0.
Under the conditions, the leaching efficiency of copper was 89.39%.
Although bacterial oxidation of sulfide materials results in the undesirable formation of acid mine drainage, the same reaction has been put to use for microbial leaching of copper, uranium, and other valuable metals from low-grade sulfide-containing ores.
Additional experiments were performed to further investigate unexpected effects of L/A ratio on leaching of copper and duration of storage of treated test specimens.
