Effective adsorption of non-biodegradable pharmaceuticals from hospital wastewater with different carbon materials

- Different carbon adsorbents were tested for the removal of pharmaceuticals.
- Adsorption tests for the removal of carbamazepine and ciprofloxacin were developed.
- The mixture of carbamazepine-ciprofloxacin in water was treated by adsorption.
- TOC, TN, carbonates and aromaticity was removed from a hospital effluent by carbon adsorbents.
- Pharmaceuticals in the real effluent, at ng L−1, was efficiently treated by adsorption onto carbon materials.

Adsorption on carbon materials (AC-F400, AC-PS, AC-RH, CNF and MWNT) has revealed as an effective treatment for the removal of two representative pharmaceutical compounds (carbamazepine, CBZ, and ciprofloxacin, CPX) in ultrapure water, as isolated compounds and as a mixture of both of them. Accordingly, a real pharmaceutical effluent containing these substances was efficiently treated by adsorption with the tested carbon adsorbents. A relatively high adsorption rate (equilibrium time of 4 h) and large carbamazepine and ciprofloxacin adsorption capacities (qCBZ = 242 mg g−1, qCPX = 264 mg g−1) were found, using adsorbent doses ranging from 2 to 3 g L−1, natural pH, temperature of 30 °C and stirring rate of 250 rpm. Thus, the decreasing in the adsorption removal was observed for both contaminants when the mixture CBZ-CPX was treated, reaching up to 80.5% of decreasing in CBZ adsorption (in presence of CPX) onto F-400 activated carbon. The bi-component adsorption systems were reasonably well-fitted by the extended Freundlich model equation. Meanwhile, the reduction of macroscopic parameters (Total Organic Concentration, TOC, Total Nitrogen, TN, carbonates (CO32−) and aromaticity) in the real hospital wastewater was achieved in high percentages (from 64 to 98.8%). Moreover, the carbon adsorbents were proven as efficient materials in the removal of the pharmaceutical compounds from the hospital effluent matrix; after the treatment, only trace-level concentrations of atenolol and trazodone were detected.

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