Environmental remediation in circular economy: End of life tyre magnetic pyrochars for adsorptive removal of pharmaceuticals from aqueous solution

• Published in: The Science of the total environment 2020-10, Vol.739, p.139855-139855, Article 139855
• Main Authors: Feizi, Farzaneh, Reguyal, Febelyn, Antoniou, Nikos, Zabaniotou, Anastasia, Sarmah, Ajit K.
• Format: Article
• Language: English
• Subjects: Economic assessment; End of Life Tyres; Magnetic pyrochar; Pyrolysis; Sorption
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2020.139855

We demonstrate a challenge-based innovation of End of Life Tyres (ELTs) pyrolysis for magnetic pyrochar production and synthesis with evidence of its use as low cost, novel adsorbent for pharmaceuticals removal from aqueous solutions. Magnetic tyre pyrochar (MTC) derived from ELTs at Technology Readiness Level 3-7 (TRL3-7), was tested for the removal of ciprofloxacin (CIP), propranolol (PRO) and clomipramine (CLO), from water, at varied pH and ionic strengths. The morphological and chemical properties of the adsorbents were assessed using Brunauer Emmett Teller (BET) surface area, Vibrating Sample Magnetometer (VSM), Fourier Transform Infrared (FTIR), Scanning Electron Microscope coupled with Energy Dispersive X-ray (SEM-EDS), elemental analysis and zeta potential measurements. MTC showed excellent adsorption efficiency of 85%, 90% and 92% for CIP, PRO and CLO respectively, higher than that of the non-magnetic tyre pyrochar (TC), due to the larger surface area, and porosity and lower polarity. Adsorption of the compounds onto MTC was highly pH dependent, and favourable at low ionic strength. The experimental data were well described by pseudo-second order kinetic and Freundlich isotherm models. Based on FTIR and zeta potential analysis, the interaction mechanisms were explained by cation-π, π-π EDA, cation exchange, electrostatic repulsion and hydrophobic effect. In the context of the circular economy, this ELTs based low cost magnetic adsorbent (estimated at $299/t) can be potentially used at full-scale industrial wastewater treatment for elimination of drugs from aqueous solutions, offering sustainable environmental remediation. [Display omitted] •Development of magnetic tyre pyrochar (MTC) by end of life tyres (ELT) pyrolysis.•MTC exhibited higher surface area and micropore volume than tyre pyrochar.•Adsorption of antibiotics onto MTC was highly pH and ionic strength dependent.•Production cost of ELTs pyrochar was $299/t, lower than existing biochar price.