| Title | Investigation of electrochemical process for removal of emerging organic pollutants in wastewater treatment plant effluents by a boron-doped diamond electrode. |
| Abstract | Various studies over recent years have proved the increasing occurrence in effluent of wastewater treatment plants (WWTP)of several contaminants of emerging concern (CECs), which are not completely removed by the common technologies employed in conventional WWTP. CECs found at highest levels (ng L-1 to µg L-1) are pharmaceuticals, artificial sweeteners, pesticides, flame-retardants, plasticizers and perfluoroalkyl substances [1,2].
The main objective of this study was to investigate an electrochemical treatment based on a boron-doped diamond (BDD) electrode, as an advanced oxidation process (AOP) for the removal of several CECs from effluent of WWTP with enhanced performance in terms of efficiency and applicability [3].
Electrochemical treatments were performed with a CONDIAPUREÒ system using a DIACHEMÒ electrode stack in a flow through cell (CONDIAS GmbH, Germany), in both synthetic water and real secondary effluent. The electrode stack was composed by two BDD cathodes and one BDD anode and in situ oxidation was performed with four anode/cathode pairs applying a total current of 0.4 A. A total of 10 L of solution with the target organic pollutants was circulated through the reactor at a flow rate of 18.5 L/min.
The removal of a mixture of CECs (iopromide, carbamazepine, diclofenac, erythromycin, benzotriazol, sulfamethoxazole, caffeine, gabapentin, metoprolol, phenythoin, primidone, venlafaxine, TCEP) by the investigated electrochemical system was primarily assessed in synthetic model water spiked with the target contaminants at concentration in the range of 2-5 µg L-1. Removal below limit of quantification (LOQ) was achieved for all tested compounds after 200 min of treatment. Decay follows pseudo first order kinetics and kinetic constants (k) of 0.07 min-1 for sulfamethoxazole and diclofenac and in the range 0.03-0.01 min-1 for the other CECs were obtained, being TCEP the pollutant with slowest kinetics.
Afterwards, the secondary effluent of the municipal WWTP Garching (Germany) was employed as a real water matrix which revealed the occurrence of several CECs (including the mixture of selected compounds listed above) at concentration levels between 20 ng L-1 and 20 µg L-1. The electrochemical treatment of the effluent was performed under the same conditions employed with the spiked synthetic water. Results demonstrated removal below LOQ for all the target CECs after 300 min with lower degradation rates than in the spiked synthetic water solution (k <= 0.01 min-1).
The detection of transformation products of investigated CECs was performed by UPLC-QTOF/MS/MS, by employing a non-target analysis approach which was based on accurate MS and MS/MS data and open source databases and software. |
| Source | EAAOP5 - 5th European Conference on Environmental Applications of Advanced Oxidation Processes., Prague, Czech Republic, June 25-29, 2017 |
| Keywords | emerging organic pollutantswastewateradvanced oxidation processes |
| Year | 2017 |
| Type | Contributo in atti di convegno |
| Authors | S. Murgolo, Uwe Hübner, B. Helmreich, J. E. Drewes, G. Mascolo |
| Text | 379851 2017 emerging organic pollutants wastewater advanced oxidation processes Investigation of electrochemical process for removal of emerging organic pollutants in wastewater treatment plant effluents by a boron doped diamond electrode. S. Murgolo, Uwe Hubner, B. Helmreich, J. E. Drewes, G. Mascolo 1 CNR, Water Research Institute, Via F. De Blasio 5, Bari, Italy corresponding e mail giuseppe.mascolo@ba.irsa.cnr.it . 2 Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, Garching, Germany Various studies over recent years have proved the increasing occurrence in effluent of wastewater treatment plants WWTP of several contaminants of emerging concern CECs , which are not completely removed by the common technologies employed in conventional WWTP. CECs found at highest levels ng L 1 to µg L 1 are pharmaceuticals, artificial sweeteners, pesticides, flame retardants, plasticizers and perfluoroalkyl substances 1,2 . The main objective of this study was to investigate an electrochemical treatment based on a boron doped diamond BDD electrode, as an advanced oxidation process AOP for the removal of several CECs from effluent of WWTP with enhanced performance in terms of efficiency and applicability 3 . Electrochemical treatments were performed with a CONDIAPUREÒ system using a DIACHEMÒ electrode stack in a flow through cell CONDIAS GmbH, Germany , in both synthetic water and real secondary effluent. The electrode stack was composed by two BDD cathodes and one BDD anode and in situ oxidation was performed with four anode/cathode pairs applying a total current of 0.4 A. A total of 10 L of solution with the target organic pollutants was circulated through the reactor at a flow rate of 18.5 L/min. The removal of a mixture of CECs iopromide, carbamazepine, diclofenac, erythromycin, benzotriazol, sulfamethoxazole, caffeine, gabapentin, metoprolol, phenythoin, primidone, venlafaxine, TCEP by the investigated electrochemical system was primarily assessed in synthetic model water spiked with the target contaminants at concentration in the range of 2 5 µg L 1. Removal below limit of quantification LOQ was achieved for all tested compounds after 200 min of treatment. Decay follows pseudo first order kinetics and kinetic constants k of 0.07 min 1 for sulfamethoxazole and diclofenac and in the range 0.03 0.01 min 1 for the other CECs were obtained, being TCEP the pollutant with slowest kinetics. Afterwards, the secondary effluent of the municipal WWTP Garching Germany was employed as a real water matrix which revealed the occurrence of several CECs including the mixture of selected compounds listed above at concentration levels between 20 ng L 1 and 20 µg L 1. The electrochemical treatment of the effluent was performed under the same conditions employed with the spiked synthetic water. Results demonstrated removal below LOQ for all the target CECs after 300 min with lower degradation rates than in the spiked synthetic water solution k <= 0.01 min 1 . The detection of transformation products of investigated CECs was performed by UPLC QTOF/MS/MS, by employing a non target analysis approach which was based on accurate MS and MS/MS data and open source databases and software. Published version EAAOP5 5th European Conference on Environmental Applications of Advanced Oxidation Processes. Prague, Czech Republic June 25 29, 2017 Internazionale Contributo Contributo in atti di convegno sapia.murgolo MURGOLO SAPIA giuseppe.mascolo MASCOLO GIUSEPPE |
