Advanced treatment of urban wastewater by UV-C/free chlorine process: Micro-pollutants removal and effect of UV-C radiation on trihalomethanes formation.
Water Res
; 169: 115220, 2020 Feb 01.
Article
in En
| MEDLINE
| ID: mdl-31677437
ABSTRACT
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 60â¯min, QUVCâ¯=â¯1.33â¯kJâ¯L-1), being CBZ the most refractory one (49.5%, after 60â¯min). The UV-C radiation significantly affected the formation of THMs. THMs concentration (mainly chloroform) was lower in UV-C/FC process after 30â¯min treatment (<1⯵gL-1â¯=â¯limit of quantification (LOQ)) than in FC process in dark (2.3⯵gL-1). Noteworthy, while in FC treated wastewater chloroform concentration increased after treatment, UV-C/FC process resulted in a significant decrease (residual concentrations below the LOQ), even after 24â¯h and 48â¯h post-treatment incubation. The formation of radicals due to UV-C/FC process can reduce THMs compared to chlorination process, because part of FC reacts with UV-C radiation to form radicals and it is no longer available to form THMs. These results are encouraging in terms of possible use of UV-C/FC process as advanced treatment of urban wastewater even for possible effluent reuse.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Water Pollutants, Chemical
/
Water Purification
/
Environmental Pollutants
Language:
En
Journal:
Water Res
Year:
2020
Document type:
Article
Affiliation country:
Italy