scholarly journals Degradation of Neonicotinoids and Caffeine from Surface Water by Photolysis

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7277
Author(s):  
Alexandra Raschitor ◽  
Alberto Romero ◽  
Sandra Sanches ◽  
Vanessa J. Pereira ◽  
Joao G. Crespo ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Surface Water ◽  
Electrical Energy ◽  
Radiation Absorption ◽  
Short Exposure ◽  
Preliminary Evaluation ◽  
Water Matrix ◽  
Indirect Photolysis ◽  
Electrical Energy Per Order ◽  
By Products

Along with rapid social development, the use of insecticides and caffeine-containing products increases, a trend that is also reflected in the composition of surface waters. This study is focused on the phototreatment of a surface water containing three neonicotinoids (imidacloprid, thiamethoxam, and clothianidin) and caffeine. Firstly, the radiation absorption of the target pollutants and the effect of the water matrix components were evaluated. It was observed that the maximum absorption peaks appear at wavelengths ranging from 246 to 274 nm, and that the water matrix did not affect the efficiency of the removal of the target pollutants. It was found that the insecticides were efficiently removed after a very short exposure to UV irradiation, while the addition of hydrogen peroxide was needed for an efficient caffeine depletion. The electrical energy per order was estimated, being the lowest energy required (9.5 kWh m−3 order−1) for the depletion of thiamethoxan by indirect photolysis, and a concentration of hydrogen peroxide of 5 mg dm−3. Finally, a preliminary evaluation on the formation of by-products reveals that these compounds play a key role in the evolution of the ecotoxicity of the samples, and that the application of direct photolysis reduces the concentration of these intermediates.

A pilot-scale investigation of ozonation and advanced oxidation processes at Choa Chu Kang Waterworks

2015 ◽  
Vol 10 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Jenny Wang ◽  
Achim Ried ◽  
Harald Stapel ◽  
Yaning Zhang ◽  
Minghui Chen ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Contaminants ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Electrical Energy ◽  
Pilot Scale ◽  
Oxidation Processes ◽  
Water Matrix ◽  
Electrical Energy Per Order ◽  
Efficient Option

A two-year comprehensive advanced oxidation processes (AOPs) pilot test was completed for a Singapore waterworks in 2011–2013. This study focused on oxidative removal of spiked organic contaminants with ozone and ozone-based AOPs (ozone application together with hydrogen peroxide, which is necessary for AOPs). The ‘optimized H2O2 dosage’ test philosophy was verified during the test period – keeping the residual ozone at 0.3 mg/L in the water for disinfection purpose by minimizing the H2O2 dosage. This study also monitored the bromate concentration in both ozone- and AOP-treated water, and all the samples reported below the laboratory detection limit (<5 µg/L), which is also lower than the WHO Guidelines for Drinking Water Quality (<10 µg/L). For comparison, a low pressure UV-based AOP test was conducted in the final stage of the study. The electrical energy per order (EEO) value is compared with ozone- and UV-based AOPs as well. The results indicated that ozone-based AOP with an optimized hydrogen peroxide dosage could be the most energy efficient option for this specific water matrix in terms of most selected compounds.

scholarly journals Optimization of UV/H2O2 processes for the removal of organic micropollutants from drinking water: effect of reactor geometry and water pretreatment on EEO values

2016 ◽  
Vol 17 (2) ◽  
pp. 508-518 ◽  
Author(s):  
C. H. M. Hofman-Caris ◽  
D. J. H. Harmsen ◽  
A. M. Van Remmen ◽  
A. H. Knol ◽  
W. L. C. van Pol ◽  
...  
Keyword(s):  
Drinking Water ◽  
Energy Demand ◽  
Electrical Energy ◽  
High Energy ◽  
Additional Treatment ◽  
Matrix Composition ◽  
Organic Micropollutants ◽  
Water Matrix ◽  
Reactor Geometry ◽  
Electrical Energy Per Order

Increasing concentrations of organic micropollutants, like pharmaceuticals, in surface water may require additional treatment for drinking water production. The UV/H2O2 process is very effective for this purpose, but is known for its relatively high energy demand. This energy demand may be decreased by improving the water matrix composition and/or by optimizing UV reactor geometry. Thus, operational costs of the process may be decreased. This can be visualized by calculating the Electrical Energy per Order (EEO). By optimizing the water matrix, e.g. by pretreating the water by filtration over activated carbon or with O3/H2O2, the energy demand decreased up to 70%. This is affected by the concentration and type of the natural organic matter present. By optimizing reactor geometry an additional decrease in energy demand, up to 40%, could be obtained. How efficient the process may become strongly depends on the characteristics of the micropollutants involved.

scholarly journals Effect of Background Water Matrices on Pharmaceutical and Personal Care Product Removal by UV-LED/TiO2

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 576
Author(s):  
Azar Fattahi ◽  
Ivana Jaciw-Zurakowsky ◽  
Nivetha Srikanthan ◽  
Leslie Bragg ◽  
Robert Liang ◽  
...  
Keyword(s):  
Surface Water ◽  
Rate Constants ◽  
Municipal Wastewater ◽  
Electrical Energy ◽  
Wastewater Effluent ◽  
Ultrapure Water ◽  
Personal Care Product ◽  
Uv Led ◽  
Water And Wastewater ◽  
Electrical Energy Per Order

In this study, we evaluated the effectiveness of UV-LED-irradiated TiO2 in removing 24 commonly detected PPCPs in two water matrices (municipal wastewater effluent and Suwannee River NOM–synthetic water) and compared their performance with that of ultrapure water. Relatively fast removal kinetics were observed for 29% and 12% of the PPCPs in ultrapure water and synthetic surface water, respectively (kapp of 1–2 min−1). However, they all remained recalcitrant to photocatalysis when using wastewater effluent as the background matrix (kapp < 0.1 min−1). We also observed that the pH-corrected octanol/water partition coefficient (log Dow) correlated well with PPCP degradation rate constants in ultrapure water, whereas molecular weight was strongly associated with the rate constants in both synthetic surface water and wastewater. The electrical energy per order (EEO) values calculated at the end of the experiments suggest that UV-LED/P25 can be an energy-efficient method for water treatment applications (2.96, 4.77, and 16.36 kW h m−3 in ultrapure water, synthetic surface water, and wastewater effluents, respectively). Although TiO2 photocatalysis is a promising approach in removing PPCPs, our results indicate that additional challenges need to be overcome for PPCPs in more complex water matrices, including an assessment of photocatalytic removal under different background water matrices.

scholarly journals Transformation of Contaminants of Emerging Concern (CECs) during UV-Catalyzed Processes Assisted by Chlorine

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1432
Author(s):  
Edyta Kudlek
Keyword(s):  
Hydrogen Peroxide ◽  
Water Samples ◽  
Water Environment ◽  
Toxicity Assessment ◽  
Contaminants Of Emerging Concern ◽  
Post Processing ◽  
Processing Water ◽  
Living Organisms ◽  
Trace Concentrations ◽  
By Products

Every compound that potentially can be harmful to the environment is called a Contaminant of Emerging Concern (CEC). Compounds classified as CECs may undergo different transformations, especially in the water environment. The intermediates formed in this way are considered to be toxic against living organisms even in trace concentrations. We attempted to identify the intermediates formed during single chlorination and UV-catalyzed processes supported by the action of chlorine and hydrogen peroxide or ozone of selected contaminants of emerging concern. The analysis of post-processing water samples containing benzocaine indicated the formation of seven compound intermediates, while ibuprofen, acridine and β-estradiol samples contained 5, 5, and 3 compound decomposition by-products, respectively. The number and also the concentration of the intermediates decreased with the time of UV irradiation. The toxicity assessment indicated that the UV-catalyzed processes lead to decreased toxicity nature of post-processed water solutions.

scholarly journals L-TARTARIC ACID: PRODUCTION TECHNOLOGY, ECONOMIC GROWTH AND QUALITY CONTROL

2018 ◽  
Vol 15 (30) ◽  
pp. 12-18
Author(s):  
G. D. LEIROSE ◽  
M-F GRENIER-LOUS TALOT ◽  
A. H. OLIVEIRA
Keyword(s):  
Economic Growth ◽  
Hydrogen Peroxide ◽  
Quality Control ◽  
Quality Assurance ◽  
Tartaric Acid ◽  
Molecular Formula ◽  
Natural Substances ◽  
By Products ◽  
Final Consumer

Natural substances are the basis of many types of industries and represent a growing market. The study of these products and the development of analytical methods should accompany this growth to ensure quality and provenance to consumers. An example to be discussed is the L(+)-Tartaric acid, an organic compound of molecular formula C4H6O6. This organic acid is widely applied in wine, food and pharmaceutical industry. It is obtained naturally through the fermentation of fruits, especially grape and tamarind. Synthetically, there are two ways of obtaining L(+)-tartaric acid on industrial scale. It can be synthesized by the reaction of maleic anhydride with hydrogen peroxide, which is derived from petroleum by-products. And by biotechnological synthesis, in which cis-epoxy succinic acid, also derived from petroleum, is converted into L(+)-tartaric acid by hydrolase enzyme. The market for tartaric acid is growing and is considered promising. Currently, there is a lack of legislation and specific rules that allow classification of tartaric acid according to its origin. This legal vacuum precludes quality assurance for the consumer. This lack of safety is a matter of great concern as applications of tartaric acid come directly to final consumer.

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