Algal Organic Matter Degradation by Chemical and Photo-Chemical Processes: a Comparative Study

• Published in: Water, air, and soil pollution air, and soil pollution, 2022-11, Vol.233 (11), Article 457
• Main Authors: Leite, Luan de Souza, Silva, Kamila Jessie Sammarro, dos Santos, Danilo Vitorino, Sabogal-Paz, Lyda Patricia, Daniel, Luiz Antonio
• Format: Article
• Language: English
• Subjects: Algae; Atmospheric Protection/Air Quality Control/Air Pollution; Chemical reactions; Climate Change/Climate Change Impacts; Comparative analysis; Comparative studies; Degradation; Disinfection; Drinking water; Earth and Environmental Science; Environment; Environmental monitoring; Hydrogen peroxide; Hydrogeology; Iron; Optimization; Organic matter; Performance degradation; Performance evaluation; Peroxides; Phytoplankton; Process parameters; Purification; Reaction time; Removal; Soil Science & Conservation; Trihalomethanes; Ultraviolet radiation; Water; Water Quality/Water Pollution; Water reservoirs; Water treatment
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-022-05921-1

Algal organic matter (AOM) in water reservoirs is a worldwide concern for drinking water treatment, once it is one of the main precursors for disinfection by-product formation. Oxidative processes have been widely applied in drinking water treatment to improve microalgae removal; however, there is little information about their performance for AOM degradation. In this context, this study aimed to evaluate the performance of hydrogen peroxide (H 2 O 2 ), Fenton (H 2 O 2 /Fe(II)), and photo-Fenton (H 2 O 2 /Fe(II)/UV) processes for AOM removal. Low AOM removals (0.46 to 12.02%) were found using H 2 O 2 . The highest AOM removals for H 2 O 2 /Fe(II) (29.8%) and H 2 O 2 /Fe(II)/UV (67.0%) were obtained using 40 and 30 mg Fe∙L −1 at 150 min, respectively. In general, high pH values decreased AOM removals for H 2 O 2 /Fe(II) and H 2 O 2 /Fe(II)/UV processes and increased them for H 2 O 2 application. All oxidative processes had stabilized at 150 min, and further reaction time did not significantly increase the AOM removal. Trihalomethane formation potential (THMFP) was evaluated using the optimal conditions of each process. Reductions of THMFP were 42.0, 74.0, and 83.4% for H 2 O 2 , H 2 O 2 /Fe(II), and H 2 O 2 /Fe(II)/UV, respectively. This study showed the potential of oxidative processes to complement AOM removal by the traditional technologies applied in water treatment. Further studies are required to optimize the parameters involved in the process to improve the cost-effectiveness of the processes and applicability in water treatment. Graphical Abstract