Pharmaceutical and personal care products removal by advanced treatment technologies
- Autores: Mariem Chtourou Ben Hassen
- Directores de la Tesis: Hèctor Monclús Sales (dir. tes.), Victòria Salvadó Martín (codir. tes.), Khaled WALHA (codir. tes.)
- Lectura: En la Universitat de Girona ( España ) en 2018
- Idioma: español
- Tribunal Calificador de la Tesis: Jordi Bartrolí i Molins (presid.), Manel Poch Espallargas (secret.), Salai Cheettu Ammal (voc.)
- Programa de doctorado: Programa de Doctorado en Ciencia y Tecnología del Agua por la Universidad de Girona
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
Wastewater treatment plant (WWTPs) effluent is one of the most important sources of contaminants entering aquatic environment because they are designed only to eliminate organic matter, nitrogen and phosphorous.
The presence of anthropogenic chemical substances such as some non-steroidal anti-inflammatory drugs (naproxen, diclofenac and ibuprofen), neutral pharmaceuticals such as carbamazepine, endocrine disruptors such as triclosan, anthropogenic markers such as caffeine and antimicrobial agents such as methyl paraben are among some of the many other compounds detected at trace levels in WWTP effluent.
Advanced treatments such as membrane bioreactor (MBR) and adsorption process allow the elimination of pharmaceutical products to be improved, but their efficiency depends on the physicochemical properties of the pollutants, the characteristics of the water, the operating conditions and the types of treatment that have been applied. In this thesis, different wastewater treatments have been evaluated to assess the efficiency of pharmaceutical and cosmetic product removal. To remove contaminants, sorption is often the preferred separation process for aqueous systems. The most widely used sorbent is activated carbon but the high cost of this sorbent is its major drawback. A more economic, practical and efficient alternative adsorbent is cork.
Firstly, a state-of-art revision of advanced treatment technology for removing Triclosan (TCS) from waste water was carried out in an attempt to evaluate the most favourable technologies and discern any major limiting factors. The technological categories evaluated were: (i) adsorption, (ii) advanced oxidation processes, and (iii) membrane technology.
The results found in the second chapter are based on treating three PPCP compounds in a cyclic anoxic/aerobic membrane bioreactor. In fact, the target compounds selected for this study were specifically carbamazepine, caffeine and triclosan. The ultrafiltration membrane bioreactor process was an efficient and appropriate technology for chemical oxygen demand removal, as it achieved a removal average of 97%, removal rate for caffeine reaching up to 93.7 ± 9.7 and 89.7 ± 8.3 % for triclosan. In the case of carbamazepine, removal was lower (36.2 ± 6.8%) due to its recalcitrance. Low ammonia removal efficiencies were observed in both experimental systems suggesting that nitrification was inhibited by the presence of triclosan. The deterioration of sludge characteristics induced a fouling increment which forced several chemical cleanings to be carried out.
The last section is focused on cork and evaluates its potential as a sorbent material. The cork was firstly characterized to discern its structure. Then a fixed-bed column was chosen as the most suitable technology with which to evaluate the cork adsorption. Four pharmaceuticals (diclofenac, ketoprofen, naproxen and carbamazepine) and two cosmetic compounds (triclosan and methylparaben) were treated in wastewater effluent by using a fixed-bed column. Furthermore, a novel, simple, selective and low-cost method for the pre-concentration sample before chromatography was performed in real wastewater effluent. This methodology is based on a silicone rod micro extraction combined with HPLC-DAD to simultaneous determine the concentration levels of six compounds. The adsorption capacities of cork followed this order: TCS >CBZ and MPB> KET and NAP > DCF. This behaviour could be explained by the fact that the removal of PPCPs by cork is based on hydrophobicity and the charge of the PPCP molecules. Generally, the cork showed a much higher capacity for TCS sorption, minimizing the concentrations of triclosan and avoiding the inhibition effect into biological systems, as well as minimizing fouling in MBRs.
In the last part of this thesis, two different proposals were selected as the most suitable treatment technologies for treating wastewater with high concentrations of PPCPs. However, further analyses are required to evaluate the hybrid systems.
