Effects of Cu and CuO on the preparation of activated carbon from waste circuit boards by H3PO4 activation

- Activated carbons were prepared from waste circuit boards by H3PO4 activation.
- Cu and CuO powder were introduced in the activation process, respectively.
- Three activated carbons were named AC, AC/Cu and AC/CuO.
- AC/CuO showed the best pore characteristic and adsorption capacity for cephalexin.
- The adsorption-regeneration cycle experiment of adsorbents were studied.

In order to study the effects of Cu and CuO on the activated carbon synthesized from waste circuit boards, we choose non-metal part without metal as the precursor, H3PO4 as the activating agent, Cu and CuO were added in the preparation process respectively. One was only activated by H3PO4, one was activated by H3PO4 and Cu powder, and another was activated by H3PO4 and CuO powder, which were named AC, AC/Cu and AC/CuO, respectively. Thermo-gravimetric analysis detected that the introduction of Cu and CuO powder into the activation process accelerated the decomposition of organic matter in the precursor. The BET surface area followed an order of AC/CuO > AC/Cu > AC. Compared with AC, the graphitization degree of AC/Cu and AC/CuO decreased, the amorphous carbon content increased, implying the introduction of Cu and CuO powder changed the activation reaction process. For these three adsorbents, the Langmuir model was better to describe the equilibrium data with a higher R2 value. The maximal adsorption capacity followed an order of AC/CuO > AC/Cu > AC. Besides, the adsorptions of cephalexin (CEX) on these three adsorbents were dependent on pH values. The adsorption-regeneration cycle experiment showed they were stable for CEX removal. The characterization and adsorption experiment proved the introduction of Cu and CuO could improve the properties of activated carbon. The results of cost analysis suggested these three adsorbents were practical for producing activated carbons.