Adsorption study of environmentally relevant concentrations of chlortetracycline on pinewood biochar

• Published in: The Science of the total environment Vol. 571; pp. 772 - 777
• Main Authors: Taheran, M., Naghdi, M., Brar, S.K., Knystautas, E.J., Verma, M., Ramirez, A.A., Surampalli, R.Y., Valero, J.R.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.11.2016
• Subjects: Abies - chemistry; Activation; Adsorption; Anti-Bacterial Agents - chemistry; Biochar; Charcoal - chemistry; Chlortetracycline; Chlortetracycline - chemistry; Isotherm; Picea - chemistry; Pinewood; Pinus - chemistry; Water Pollutants, Chemical - chemistry; Wood - chemistry; Isotherm; Chlortetracycline; Activation; Adsorption; Biochar; Pinewood
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2016.07.050

The presence of pharmaceutically active compounds (PhACs) in water and wastewater has raised concerns because of potential environmental impacts and thus their removal is of high importance. The adsorption behavior of chlortetracycline (CTC) from aqueous solution on raw and activated pinewood biochar was studied at 298 K. The effect of initial pH of the solution was studied by performing the experiment at three different pHs (1, 5 and 9). At each pH, CTC showed varied electrostatic charge (+1, 0 and −1, respectively) which affected its adsorption. The results indicated that CTC followed Langmuir isotherm and the related parameters were calculated. Also, it was observed that the maximum adsorption occurred at pH1. The adsorption capacity of CTC for raw and activated biochar was at least 2.1 and 208.3mg/g adsorbent, respectively. The characteristics of biochars were studied using zeta potential analyzer, laser size analyzer and scanning electron microscopy (SEM). The results showed that raw and activated biochars are promising candidates for removal of CTC from water due to the acidic character of pinewood that can result in better interaction with ionizable compounds at lower pHs. [Display omitted] •Activated pinewood has considerable potential for adsorption of CTC from water.•CTC follows the Langmuir model for adsorption on raw and activated biochar.•In lower pH, adsorption on biochar is enhanced due to lower electrostatic repulsion.