Removal of microcontaminants by zero-valent iron solar processes at natural pH: Water matrix and oxidant agents effect.

This work deals with microcontaminants (MCs) removal by natural solar zero-valent iron (ZVI) process at natural pH in actual matrices. Commercial ZVI microspheres were selected as ZVI source and hydrogen peroxide and persulfate were used as oxidant agents. The experimental plan comprised the evaluation of sulphates and carbonates/bicarbonates effect on process performance, the possibility of adding an iron chelate (EDDS) to take advantage of leached iron and the treatment of MCs in actual MWWTP secondary effluent.

A Rational Analysis on Key Parameters Ruling Zerovalent Iron-Based Treatment Trains: Towards the Separation of Reductive from Oxidative Phases.

The development of treatment trains for pollutant degradation employing zerovalent iron has been attracting a lot of interest in the last few years. This approach consists of pre-treatment only with zerovalent iron, followed by a Fenton oxidation taking advantage of the iron ions released in the first step. In this work, the advantages/disadvantages of this strategy were studied employing commercial zerovalent iron microparticles (mZVI).

Evaluation of commercial zerovalent iron sources in combination with solar energy to remove microcontaminants from natural water at circumneutral pH.

Solar zerovalent iron (ZVI) was studied at circumneutral pH in combination with hydrogen peroxide and persulfate for removal of imidacloprid as a model contaminant in natural water. Three commercial ZVI sources, steel wool (ZVI-SW) and two iron micro-powders (ZVI-MS and ZVI-S) were independently evaluated. First, different ZVI corrosion conditions were tested in contact with air, exposed to natural solar radiation and with addition of oxidants, such as HO and SO, demonstrating the importance of released iron.

Aluminized surface to improve solar light absorption in open reactors: Application for micropollutants removal in effluents from municipal wastewater treatment plants.

This work proposes the evaluation of an aluminized surface on the bottom of open reactors to perform a photo-Fenton process, at circumneutral pH (using Fe III-Ethylenediamine-N,N'-disuccinic acid complex), for elimination of micropollutants (MPs) in real effluents from municipal wastewater treatment plants (EMWWTP). Firstly, the strategy was to initially investigate the real EMWWTP spiked with several MPs (acetaminophen, diclofenac, carbamazepine, caffeine, trimethoprim and sulfamethoxazole) with 20 and 100 μg L in a laboratory scale (evaluated by HPLC-UV) using a solar simulator. Finally, the removal of all MCs present in the real EMWWTP was monitored (evaluated by HPLC-MS) in a pilot-scale (90 L) in a raceway pond reactor (RPR).

Olive mill wastewater reuse to enable solar photo-Fenton-like processes for the elimination of priority substances in municipal wastewater treatment plant effluents.

Olive mill wastewater (OMW) appears as an interesting and innovative natural alternative to synthetic chelating agents of iron in solar photo-Fenton processes at circumneutral pH due to its high polyphenol content, valorizing wastewater typically found in sunny countries. The aim of this work was the reuse of OMW for the elimination of other recalcitrant microcontaminants: terbutryn, chlorfenvinphos, diclofenac, and pentachlorophenol. Highly diluted OMW (1:1500) was employed to keep the iron in solution at circumneutral pH.

Advanced treatment of urban wastewater by UV-C/free chlorine process: Micro-pollutants removal and effect of UV-C radiation on trihalomethanes formation.

The effect of the UV-C/free chlorine (FC) process on the removal of contaminants of emerging concern (CECs) from real urban wastewater as well as the effect of UV-C radiation on the formation of trihalomethanes (THMs) compared to FC process alone was investigated. Unlike of FC process, UV-C/FC was really effective in the degradation of the target CECs (carbamazepine (CBZ), diclofenac, sulfamethoxazole and imidacloprid) in real wastewater (87% degradation of total CECs within 60 min, Q = 1.33 kJ L), being CBZ the most refractory one (49.

Contaminants of emerging concern removal from real wastewater by UV/free chlorine process: A comparison with solar/free chlorine and UV/HO at pilot scale.

The removal of contaminants of emerging concern (CECs) from urban wastewater treatment plants (UWTPs) is really important to minimize the risk for human health and environment. In this study, the homogeneous advanced oxidation process (AOP) UV-C/free chlorine (UV-C/FC) was investigated at pilot scale in the degradation of a mixture of four CECs, in different water matrices and compared to a consolidated AOP, namely UV-C/HO. As matter of fact 90% degradation of CECs was observed after 15 min (Q = 0.