Persistent organic pollutants (POPs) degradation in natural waters using a V-UV/UV/TiO2 reactor

2009 ◽  
Vol 9 (6) ◽  
pp. 653-660
Author(s):  
K. Azrague ◽  
S. W. Osterhus
Keyword(s):  
Water Quality ◽  
Hydroxyl Radicals ◽  
Natural Waters ◽  
Inorganic Carbon ◽  
Total Inorganic Carbon ◽  
Chlorobenzoic Acid ◽  
Efficient Process ◽  
Radical Concentration ◽  
Vacuum Uv ◽  
Good Probe

This paper presents the use of a V-UV/UV/TiO2 reactor (M300 water purifier®) for the removal of sulfamethoxazole and atrazine from natural water. The efficiency of the different processes (photolysis, Vacuum UV (V-UV) and photocatalysis) within the photoreactor was investigated using para-chlorobenzoic acid (pCBA) which is a good probe for hydroxyl radicals. The effect of pH, dissolved organic carbon (DOC) and total inorganic carbon (TIC) was also studied. V-UV was found to be the most efficient process for pCBA degradation within this unit. No photocatalytic degradation was observed. The water quality largely affected the efficiency of the system. Indeed, both DOC and TIC lowered the hydroxyl radical concentration in the system, but DOC did it to a larger extent. Atrazine and sulfamethoxazole, were successfully degraded, and as for pCBA, V-UV was the most efficient process. Sulfamethoxazole displayed a better removal by photocatalysis than atrazine and pCBA. In addition, there was a larger contribution of photolysis during the degradation of sulfamethoxazole than of atrazine. The UV254 nm absorbance of the water affected the photolysis of sulfamethoxazole which has a high molar extinction coefficient and quantum yield at 254 nm, while the DOC is mainly competing with the pollutants for the hydroxyl radicals.

scholarly journals Studying the Effect of Channel Geometry on Different Water Quality Variables for Effective Designs and Waste Allocation Plans for Waterways

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2176
Author(s):  
Sherine El Baradei
Keyword(s):  
Water Quality ◽  
Inorganic Carbon ◽  
Negative Impact ◽  
Channel Length ◽  
Mitigation Measures ◽  
Total Inorganic Carbon ◽  
Reference Case ◽  
Channel Geometry ◽  
Water Quality Variables ◽  
Allocation Plans

It is necessary to study the parameters that affect water quality in order to devise mitigation measures if water quality would be at risk or negatively affected by those parameters. Those parameters are physical, chemical, biological, and hydraulic characteristics. This research will study the effect of channel geometry on different water quality variables, which is important in designing new irrigation canals in order to see how its geometry will affect water quality and lessen any negative impact if possible; also this study could aid in designing more reliable waste allocation plans for waterways. The studied geometric characteristics are top width, bottom width, water depth, side-slopes and channel length. Sheikh Zayed canal in Egypt is taken as the reference case study canal. Studied water quality variables are algae, nutrients, total dissolved solids (TDS), total suspended solids (TSS), pH, alkalinity and total inorganic carbon. It was found that concentrations of all water quality variables in water changed as a result of changing channel geometry. Some water quality variables such as algae, nutrients, and TSS are greatly affected, whereas others such as pH, alkalinity and total inorganic carbon are slightly affected.

On methodological approaches to the improvement of surface water bodies and target indicators of the natural waters’ quality

2021 ◽  
Vol 27 (1) ◽  
pp. 6-14
Author(s):  
V. Zaslonovsky ◽  
◽  
N. Sharapov ◽  
M. Bosov ◽  
◽  
...  
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Natural Water ◽  
Aquatic Ecosystems ◽  
Natural Waters ◽  
Water Bodies ◽  
Surface Water Bodies ◽  
Methodological Approaches ◽  
Natural Water Bodies

The paper is devoted to the development of proposals concerning the improvement of surface water bodies and the appointment of target indicators of the natural waters’ quality. The paper considers a variety of problems of preserving, restoring and improving the quality of natural surface waters: from regional features of the formation of natural water composition, to differences in the requirements for the quality of water consumed. The object of the study is the qualitative indicators of the waters of natural water bodies, and the subject of the study is the methodological approaches to the normalization of these indicators. The purpose of the work is to identify the main shortcomings in the domestic system of rationing the quality of natural waters, and to form appropriate proposals. For this purpose, the following tasks were set and solved: to review the methodological approaches to assessing and rationing the quality of natural waters used in some foreign countries and in the Russian Federation, to identify the main causes and shortcomings; to make proposals for improving the current system of water quality rationing. The result of this work is the conclusions about the lack of impact of the strategy operating in Russia in the development of schemes of complex use and protection of water objects, standards of permissible impact on water bodies, the appointment of permissible discharge limits in terms of maintaining and improving the water quality of natural water bodies. The reasons that led to this are indicated. The necessity of taking into account, in addition to the physical and chemical composition, also hydrobiological parameters is shown. It is concluded that instead of fisheries management standards, environmental standards should serve as the basis for target indicators of water quality of natural water bodies, which determine the well-being of humans and the stable functioning of aquatic ecosystems, taking into account regional factors. Proposals were made to adjust the methodological approaches to the implementation of this strategy. According to the authors, these proposals will speed up the solution of the main objectives of the strategy – the ecological improvement of water bodies, the preservation of unique aquatic ecosystems and the environmentally safe development of territories that previously experienced relatively small anthropogenic impacts (Eastern Siberia and the Far East)

scholarly journals Carbonate system distribution, anthropogenic carbon and acidification in the western tropical South Pacific (OUTPACE 2015 transect)

2018 ◽  
Vol 15 (16) ◽  
pp. 5221-5236 ◽  
Author(s):  
Thibaut Wagener ◽  
Nicolas Metzl ◽  
Mathieu Caffin ◽  
Jonathan Fin ◽  
Sandra Helias Nunige ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
South Pacific ◽  
Total Alkalinity ◽  
Total Inorganic Carbon ◽  
Saturation State ◽  
Anthropogenic Carbon ◽  
Subsurface Waters ◽  
Derived Properties ◽  
Intermediate Waters ◽  
South Pacific Gyre

Abstract. The western tropical South Pacific was sampled along a longitudinal 4000 km transect (OUTPACE cruise, 18 February, 3 April 2015) for the measurement of carbonate parameters (total alkalinity and total inorganic carbon) between the Melanesian Archipelago (MA) and the western part of the South Pacific gyre (WGY). This paper reports this new dataset and derived properties: pH on the total scale (pHT) and the CaCO3 saturation state with respect to aragonite (Ωara). We also estimate anthropogenic carbon (CANT) distribution in the water column using the TrOCA method (Tracer combining Oxygen, inorganic Carbon and total Alkalinity). Along the OUTPACE transect a deeper penetration of CANT in the intermediate waters was observed in the MA, whereas highest CANT concentrations were detected in the subsurface waters of the WGY. By combining our OUTPACE dataset with data available in GLODAPv2 (1974–2009), temporal changes in oceanic inorganic carbon were evaluated. An increase of 1.3 to 1.6 µmol kg−1 a−1 for total inorganic carbon in the upper thermocline waters is estimated, whereas CANT increases by 1.1 to 1.2 µmol kg−1 a−1. In the MA intermediate waters (27 kg m−3 <σθ<27.2 kg m−3) an increase of 0.4 µmol kg−1 a−1 CANT is detected. Our results suggest a clear progression of ocean acidification in the western tropical South Pacific with a decrease in the oceanic pHT of up to −0.0027 a−1 and a shoaling of the saturation depth for aragonite of up to 200 m since the pre-industrial period.

scholarly journals Development and Substantiation of Regional Water Quality Standards in Respect of Heavy Metals Content for the Upper Kama Basin Water Bodies

2015 ◽  
pp. 50-64
Author(s):  
Keyword(s):  
Heavy Metals ◽  
Water Quality ◽  
Temporal Variability ◽  
Natural Waters ◽  
Quality Standards ◽  
Water Bodies ◽  
Water Quality Standards ◽  
Industrial Complexes ◽  
Basin Water ◽  
Regional Water

The paper presents a new methodology for establishing regional water quality standards for the Upper Kama water bodies. Water bodies of the Upper Kama Basin are receiving wastewater from one of the largest industrial complexes of the Kama basin – Solikamsk-Berezniki industrial hub. The approach takes into account factors that determine the content of heavy metals in natural waters and the spatial/temporal variability of their content in the water bodies of the Upper Kama basin. The developed approach is implemented in establishment of regional water quality standards for the Upper Kama basin.

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