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 Degradation pathways of pentachlorophenol and benzo(a)pyrene during heterogeneous photocatalysis

2018 ◽  
Vol 77 (10) ◽  
pp. 2407-2414 ◽  
Author(s):  
E. Kudlek ◽  
M. Dudziak
Keyword(s):  
Analytical Techniques ◽  
Toxicity Assessment ◽  
Heterogeneous Photocatalysis ◽  
Biologically Active ◽  
Photochemical Oxidation ◽  
Gas Chromatography Mass Spectrometry ◽  
Degradation Pathways ◽  
Wide Range ◽  
Trace Concentrations ◽  
By Products

Abstract Organic micropollutants, in particular those of anthropogenic origin, may have a toxic influence on water organisms. Photochemical oxidation processes are one of the most effective methods of decomposition of a wide range of those compounds. During the oxidation process a large number of different by-products are generated, which can still be biologically active. The development of analytical techniques, including the reduction of the detection limit to several fg/L, allows the identification of even trace concentrations of compounds. The paper presents the determination of pentachlorophenol and benzo(a)pyrene degradation pathways during the process of heterogeneous photocatalysis carried out in the presence of titanium dioxide. The gas chromatography–mass spectrometry (GC-MS) analysis of post-processing samples indicated the formation of different by-products of the parent micropollutants. Moreover, the toxicity assessment demonstrates for both tested micropollutants an increase in the toxicity within the whole time of the UV irradiation process run.

Environmental significance of atrazine in aqueous systems and its removal by biological processes: an overview

2013 ◽  
Vol 8 (2) ◽  
pp. 159-178 ◽  
Keyword(s):  
Drinking Water ◽  
Ground Water ◽  
Water Environment ◽  
Biological Processes ◽  
Biological Degradation ◽  
Environmental Significance ◽  
Carbon And Nitrogen ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Living Organisms

Atrazine, a chlorinated s-triazine group of herbicide is one of the most widely used pesticides in the World. Due to its extensive use, long half-life and various toxic properties, it has very high environmental significance. Up to 22 mg l-1 of atrazine was found in ground water whereas permissible limit of atrazine is in ppb level in drinking water. As per Indian standard there should not be any pesticide present in drinking water. Among many other treatment processes available, Incineration, adsorption, chemical treatment, phytoremediation and biodegradation are the most commonly used ones. Biological degradation of atrazine depends upon various factors like the operating environment, external carbon and nitrogen sources, carbon/ nitrogen ratio (C/N), water content and the bacterial strain. Although, general atrazine degradation pathways are available, the specific pathways in specific conditions are not yet clearly defined. In this paper extensive review has been made on the occurrence of atrazine in surface and ground water bodies, probable sources and causes of its occurrence in water environment, the toxicity of atrazine on various living organisms and its removal by biological processes.

Temporal variability of disinfection by-products concentration in urban public water system

2013 ◽  
Vol 14 (4) ◽  
pp. 393-398
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Temporal Variability ◽  
Water System ◽  
The Other ◽  
Major Constituent ◽  
System P ◽  
Public Water System ◽  
Drinking Water Samples ◽  
By Products

The occurrence of trihalomethanes (THMs) was studied in the drinking water samples from urban water supply network of Karachi city that served more than 18 million people. Drinking water samples were collected from 58 locations in summer (May-August) and winter (November-February) seasons. The major constituent of THMs detected was chloroform in winter (92.34%) and summer (93.07%), while the other THMs determined at lower concentrations. Summer and winter concentrations of total THMs at places exceed the levels regulated by UEPA (80 μg l-1) and WHO (100 μg l-1). GIS linked temporal variability in two seasons showed significantly higher median concentration (2.5%-23.06%) of THMs compared to winter.

scholarly journals Upconversion-based nanosystems for fluorescence sensing of pH and H2O2

2021 ◽  
Author(s):  
Chunning Sun ◽  
Michael Gradzielski
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Excitation Energy ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Fluorescence Sensing ◽  
Living Organisms

Hydrogen peroxide (H2O2), a key reactive oxygen species, plays an important role in living organisms, industrial and environmental fields. Here, a non-contact upconversion nanosystem based on the excitation energy attenuation...

scholarly journals Synthesis of 2-Substitued Indoles via Pd-Catalysed Cyclization in an Aqueous Micellar Medium

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3917
Author(s):  
Sofia Siciliano ◽  
Elena Cini ◽  
Maurizio Taddei ◽  
Giorgia Vinciarelli
Keyword(s):  
Water Environment ◽  
Delivery Mode ◽  
Micellar Medium ◽  
Dielectric Heating ◽  
Microwave Dielectric ◽  
Microwave Dielectric Heating ◽  
Heating Mode ◽  
Aqueous Micellar Medium ◽  
By Products ◽  
Better Than

The synthesis of 2-substituted indoles starting from the corresponding unprotected 2-alkynylanilines was made possible in 3% TPGS-750-M water using Pd(OAc)2 alone as the catalyst. The reaction was sensitive to the heating mode respect to the nature of the starting material as, in many cases, convectional heating was better than microwave dielectric heating. The MW (microwave) delivery mode had also an influence in the formation of by-products and, consequently, product yields. A tandem Sonogashira-cyclisation reaction was also accomplished using Pd(OAc)2/Xphos in the nanomicellar water environment.

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.

Sign in / Sign up

Export Citation Format

Share Document