scholarly journals Photocatalytic Degradation of Pesticides in Natural Water: Effect of Hydrogen Peroxide

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Natividad Miguel ◽  
María P. Ormad ◽  
Rosa Mosteo ◽  
José L. Ovelleiro
Keyword(s):  
Hydrogen Peroxide ◽  
Titanium Dioxide ◽  
Organic Carbon ◽  
Water Effect ◽  
Chemical Parameters ◽  
Physical Chemical ◽  
Doc Concentration ◽  
Chlorine Demand ◽  
Organic Pesticides ◽  
Photocatalytic Processes

The aim of this paper is to evaluate the effectiveness of photocatalytic treatment with titanium dioxide in the degradation of 44 organic pesticides analyzed systematically in the Ebro river basin (Spain). The effect of the addition of hydrogen peroxide in this treatment is studied, and a monitoring of effectiveness of photocatalytic processes is carried out by measurements of physical-chemical parameters of water. The application of photocatalytic treatment with 1 g L−1of TiO2during 30 minutes achieves an average degradation of the studied pesticides of 48%. Chlorine demand, toxicity, and dissolved organic carbon (DOC) concentration of water are reduced. If hydrogen peroxide is added with a concentration of 10 mM, the average degradation of pesticides increases up to 57%, although chlorine demand and toxicity of water increase while DOC concentration remains unchanged with this treatment. The application of either photocatalytic treatments does not produce variations in the physical-chemical parameters of water, such as pH, conductivity, colour, dissolved oxygen, and hardness. The pesticides which are best degraded by photocatalytic treatments are parathion methyl, chlorpyrifos, α-endosulphan, 3,4-dichloroaniline, 4-isopropylaniline, and dicofol while the worst degraded are HCHs, endosulphan-sulphate, heptachlors epoxide, and 4,4′-dichlorobenzophenone.

scholarly journals Hydrogen peroxide distribution, production, and decay in boreal lakes

2004 ◽  
Vol 61 (8) ◽  
pp. 1520-1527 ◽  
Author(s):  
Petri J Häkkinen ◽  
Alexandre M Anesio ◽  
Wilhelm Granéli
Keyword(s):  
Hydrogen Peroxide ◽  
Water Column ◽  
Decay Rates ◽  
Boreal Lakes ◽  
Chemical Characteristics ◽  
Mixing Depth ◽  
Physical Chemical ◽  
Doc Concentration ◽  
Iron And Manganese

The distribution, production, and decay of hydrogen peroxide (H2O2) were studied in 10 boreal lakes of differing physical–chemical characteristics. Diurnal and vertical fluctuations in H2O2 concentration were followed in the lakes by sampling at six depths three times per day. In addition, incubations of water filtered through 0.2-µ mesh were made under artificial irradiation to study the abiotic production and decay of H2O2. H2O2 concentrations after 8 h of artificial irradiation were significantly correlated with neither absorption coefficients at 320 nm nor with dissolved organic carbon (DOC) concentrations. However, H2O2 concentration increased rapidly with DOC concentration among lakes with DOC concentrations below 10 mg·L–1. The H2O2 concentration after exposure to ultraviolet radiation was positively related to the half-life of H2O2, which in turn was negatively correlated with iron and manganese concentrations (r2 = 0.68 and 0.70, respectively). In situ H2O2 concentrations at the surface of the water column ranged between 30 and 1041 nmol·L–1 and were largely determined by the decay rates of H2O2 and the mixing depth of the water column.

scholarly journals Physico-chemical determinant parameters in the color of vertisolization and tirsification processes

2019 ◽  
Vol 19 (2) ◽  
pp. 40-44
Author(s):  
J. M. Recio Espejo ◽  
C. Borja Barrera ◽  
F. Díaz del Olmo ◽  
F. Borja Barrera
Keyword(s):  
Statistical Analysis ◽  
Organic Carbon ◽  
Climatic Conditions ◽  
Parent Material ◽  
Chemical Processes ◽  
Chemical Parameters ◽  
Physical Chemical ◽  
Physico Chemical ◽  
Definitive Role

A statistical analysis is carried out on the influence that certain physico-chemical parameters exert on tirsification and vertisolization pedological processes that occur under certain geomorphological conditions in Andalusia region (Spain). Both processes occur on a parent material with high contents in smectitic clays, massive and uniform and contrasting climatic conditions where periods of humidity and those of drought  alternate. Chromic Vertisol (tirsificated) versus Calcium Vertisol (vertisolizated) (FAO, 2015) shows a greater interrelation between parameters given its greater weathering. Organic carbon controls a large part of its physical-chemical processes where the lateral washing of salts and carbonates together with manganese, always in a lower concentration than iron, play a definitive role in the blackening of its horizons. The chemical fertility is always low and  the geomorphological conditions seems to account for its agricultural capacity.

scholarly journals Influence of Gold Nanoparticles on the Photocatalytic Action of Titanium Dioxide in Physical-Chemical Parameters of Greywater

2022 ◽  
Vol 23 (1) ◽  
pp. 182-192
Author(s):  
Hipólito Carbajal-Morán ◽  
Javier Márquez-Camarena ◽  
Carlos Galván-Maldonado
Keyword(s):  
Gold Nanoparticles ◽  
Titanium Dioxide ◽  
Chemical Parameters ◽  
Physical Chemical

scholarly journals Mineralization of Azo Dye Using Combined Photo-Fenton and Photocatalytic Processes under Visible Light

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Selma K. Kuriechen ◽  
Sepperumal Murugesan ◽  
Samuel Paul Raj
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Carbon ◽  
Visible Light ◽  
Azo Dye ◽  
Coupled System ◽  
Nitrogen Doped ◽  
The Individual ◽  
Photocatalytic Processes ◽  
Total Organic Carbon Analysis ◽  
Carbon Analysis

Visible-light-assisted photodegradation of an azo dye, Reactive Red 180 (RR180), in the presence of nitrogen-doped TiO2 (N-TiO2) has been studied. The photodegradation of RR180 is evaluated through decolorization studies and total organic carbon analysis. The efficacy of hydrogen peroxide (H2O2), potassium peroxomonosulfate (oxone or PMS), and potassium peroxodisulfate (PDS) in improving the photodegradation of the dye in the N-TiO2-RR180 system is also examined. The effect of combining photo-Fenton-like reaction with N-TiO2-mediated photodegradation of RR180 under visible light has been investigated. The photoactivity of N-TiO2-RR180-Fe3+/Cu2+-oxidant systems is compared with the individual techniques of photocatalysis and photo-Fenton-like reactions. The coupled system possesses superior photomineralization ability towards the abatement of RR180.

Semiconductor Mediated Photocatalysed Reaction of Two Selected Organic Compounds in Aqueous Suspensions of Titanium Dioxide

2012 ◽  
Vol 15 (2) ◽  
Author(s):  
Niyaz A. Mir ◽  
M.M. Haque ◽  
A. Khan ◽  
K. Umar ◽  
M. Muneer ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Titanium Dioxide ◽  
Organic Carbon ◽  
Photocatalytic Degradation ◽  
Organic Compounds ◽  
Substrate Concentration ◽  
Degradation Kinetics ◽  
Irradiation Time ◽  
Aqueous Suspensions ◽  
Kinetics Of

AbstractSemiconductor mediated hydrogen peroxide-assisted photocatalytic degradation of two selected pesticide compounds, chloramben (1) and cyanazine (2) has been investigated in aqueous suspensions under a variety of conditions. The degradation was studied by monitoring the depletion in total organic carbon (TOC) content and decrease in substrate concentration as a function of irradiation time. The degradation kinetics of pesticide compounds 1 and 2 were investigated under different conditions such as type of TiO

Submikroninių aerozolio dalelių kilmės ir fizikinių-cheminių parametrų įtaka atmosferos šiluminei pusiausvyrai

2020 ◽  
Author(s):  
◽  
Julija Pauraitė-Dudek
Keyword(s):  
Chemical Parameters ◽  
Radiative Balance ◽  
Submicron Aerosol ◽  
Physical Chemical ◽  
The Impact ◽  
Aerosol Source

The impact of submicron aerosol source and physical-chemical parameters on atmospheric radiative balance

Dry and storm weather transport of coliforms and faecal streptococci in combined sewage

1995 ◽  
Vol 31 (7) ◽  
pp. 311-320 ◽  
Author(s):  
R. M. Ashley ◽  
W. Dabrowski
Keyword(s):  
Data Collection ◽  
Coliform Bacteria ◽  
Pathogenic Microorganisms ◽  
Chemical Parameters ◽  
Physical Chemical ◽  
Sediment Bacteria ◽  
Wet Weather ◽  
Faecal Streptococci

Combined sewage coliform bacteria are important as indicators of pathogenic microorganisms and of their possible discharge into the environment. Whilst specifying limits for viruses, most legislation recognises the difficulty of enumerating such organisms and also prescribes limits for coliforms. Despite the importance of these organisms, little is known about their numbers and behaviour in sewerage systems. A data collection programme is described which has monitored dry and wet weather sewage coliform bacteria and also sediment bacteria. These data are used to review recent UK recommendations for assessing bacteria numbers in storm discharges. It is concluded that relationships between bacteria numbers and other physical/chemical parameters may be developed during DWF, but are seasonally and catchment dependent. Extension of DWF measurements to predict storm bacteria may be possible with more data.

Management of Dairy Waste in the Sonoran Desert Using Constructed Wetland Technology

1999 ◽  
Vol 40 (3) ◽  
pp. 57-65 ◽  
Author(s):  
Martin M. Karpiscak ◽  
Robert J. Freitas ◽  
Charles P. Gerba ◽  
Luis R. Sanchez ◽  
Eylon Shamir
Keyword(s):  
Sonoran Desert ◽  
Suspended Solids ◽  
Waste Treatment ◽  
Oxygen Demand ◽  
Dairy Wastewater ◽  
Chemical Parameters ◽  
Treatment Facility ◽  
Physical Chemical ◽  
Scirpus Validus ◽  
Surface Wetland

An integrated wastewater treatment facility, consisting of upper (solids separators, anaerobic lagoons, and aerobic ponds) and lower (wetland cells) subsystems, has been built to replace the lagoon at a dairy in Arizona, USA. The collection sump of the new waste treatment facility collects all dairy wastewater outflow. Wastewater is then pumped to solids separators, and flows by gravity to anaerobic ponds and aerobic ponds. The upper subsystem is expected to treat the water sufficiently so that the wetland cells may achieve further pollutant reductions. The lower subsystem, comprised of 8 surface wetland cells with an approximate surface area of 5,000 m2, receives outflow from the ponds. The cells are planted with cattail (Typha domingensis), soft-stem bulrush (Scirpus validus), and reed (Phragmites australis). After treatment is completed via the lagoons and ponds followed by the wetland cells, the wastewater can be reused to flush barns or to irrigate crops. Performance of the overall system is evaluated by measuring physical, chemical and biological parameters in water samples taken from selected locations along the treatment system. Chemical parameters studied include biochemical oxygen demand, pH, total suspended solids, nitrogen species. Biological monitoring included coliforms (total and fecal) and Listeria monocytogenes.

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