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 Simultaneous Removal of Arsenate and Chromate from Ground- and Surface- Waters by Iron-Based Redox Assisted Coagulation

2020 ◽  
Vol 12 (13) ◽  
pp. 5394
Author(s):  
Asterios Laskaridis ◽  
Ioannis Sarakatsianos ◽  
Nikolaos Tzollas ◽  
Ioannis A. Katsoyiannis
Keyword(s):  
Drinking Water ◽  
Surface Waters ◽  
Natural Waters ◽  
Iron Concentration ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Matrix Composition ◽  
Ph Values ◽  
Water Matrix ◽  
Iron Based

Arsenic (As) and chromate (Cr(VI)) contamination of ground and surface waters is a major problem worldwide. Given that a new drinking water limit is anticipated for Cr(VI) and that the limit of arsenic in drinking water is quite low (10 μg/L), there is an urgent need for evaluating technologies that could be efficient for removal of both contaminants simultaneously. In this work, the use of Fe(II) redox assisted coagulation was investigated to simultaneously remove the contaminants of interest. The basic principle of this technology is that Fe(II) could react with Cr(VI) and form Fe(III)-hydroxides and insoluble Cr(III) species, while the freshly formed Fe(III) hydroxides are very efficient adsorbents for As(V). The effect of pH, the water matrix composition, Fe(II) dose, initial contaminant concentrations, NOM presence and phosphate concentration were the examined parameters. The results revealed that with a dose of 2 mg/L Fe(II), residual As(V) and Cr(VI) concentrations were both below 10 μg/L, from initial concentrations of 50 μg/L. Though, this is effective only at circumneutral pH values. This is however not a big obstacle, since most natural waters, especially groundwaters, have near neutral pH values. At these pH values, residual iron concentration was far below 200 μg/L. The presence of phosphate anions inhibited As(V) removal but had no effect on Cr(VI) removal. Increasing Fe(II) concentrations eliminated the effect of phosphate and provided simultaneous phosphate removal. Therefore, Fe(II) coagulation can be applied, with secured results, for simultaneous As(V), Cr(VI) and phosphate removal from waters.

scholarly journals Efficiency and Energy Demand in Polishing Treatment of Wastewater Treatment Plants Effluents: Photoelectrocatalysis vs. Photocatalysis and Photolysis

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 821
Author(s):  
Maria Cristina Collivignarelli ◽  
Marco Carnevale Miino ◽  
Hamed Arab ◽  
Massimiliano Bestetti ◽  
Silvia Franz
Keyword(s):  
Energy Demand ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Electrical Energy ◽  
Operating Costs ◽  
Surface Areas ◽  
Electrolytic Oxidation ◽  
Electrical Energy Per Order ◽  
Plasma Electrolytic ◽  
Operation Results

Photoelectrocatalysis (PEC), photolysis (PL), and photocatalysis (PC) were applied to increase the biodegradability of wastewaters effluents sampled from a plant collecting both municipal wastewaters and aqueous waste. In PEC, the catalyst was a porous TiO2 photoanode obtained by plasma electrolytic oxidation and electrically polarized during operation. In PC a dispersion of TiO2 powders was used. The same irradiation shielding, and similar catalyst surface areas were set for PC and PEC, allowing a straightforward evaluation of the catalytic effect of the electrical polarization of TiO2 during operation. Results showed that the chemical oxygen demand (COD) and color removal rates follow the order: PEC > PL and PEC > PC. The specific biodegradability rate (SBR) increased following the same order, the PEC process allowing SBR values more than twice higher than PL and PC. The operating costs were calculated based on the electrical energy per order of COD, color, and SBR values, demonstrating that at the laboratory scale the energy demand of PEC is significantly lower than the other two tested processes.

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 Conversion of organic micropollutants with limited bromate formation during the Peroxone process in drinking water treatment

2015 ◽  
Vol 8 (2) ◽  
pp. 25-34 ◽  
Author(s):  
A. H. Knol ◽  
K. Lekkerkerker-Teunissen ◽  
C. J. Houtman ◽  
J. Scheideler ◽  
A. Ried ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Drinking Water ◽  
Water Temperature ◽  
River Water ◽  
Drinking Water Treatment ◽  
Minor Effect ◽  
Organic Micropollutants ◽  
Model Compounds ◽  
Water Matrix ◽  
Ozone Dose

Abstract. Advanced oxidation with O3 / H2O2 (peroxone) was conducted on pilot plant scale on pre-treated Meuse river water to investigate the conversion of organic micropollutants (OMPs) and the formation of bromate. Fourteen selected model compounds were dosed to the pre-treated river water on a regular basis to assess the efficiency of the peroxone process and to establish the influence of the water matrix. The ozone dose was the main factor in the conversion of the model compounds, however, the ozone dose was limited because of bromate formation. The hydrogen peroxide dosage had only a minor effect on the conversion, but it limited the bromate formation effectively. In terms of limited chemical consumption, maximal conversion and to comply the strict Dutch drinking water act for bromate of 1 μg L−1, a practical peroxone setting was 6 mg L−1 hydrogen peroxide and 1.5 mg L−1 ozone. During the investigation period, the average conversion of the model compounds was 78.9 %. The conversion of OMPs was higher at higher water temperatures and lower concentrations of DOC and bicarbonate. The bromate formation also was higher at higher water temperature and lower bicarbonate concentration and proportional with the bromide concentration, above a threshold of about 32 μg L−1 bromide. The peroxone process can be controlled on basis of the (derived) parameters water temperature, bicarbonate and DOC.

scholarly journals Conversion of organic micropollutants with limited bromate formation during the Peroxone process in drinking water treatment

2015 ◽  
Vol 8 (1) ◽  
pp. 21-51
Author(s):  
A. H. Knol ◽  
K. Lekkerkerker-Teunissen ◽  
C. J. Houtman ◽  
J. Scheideler ◽  
A. Ried ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Drinking Water ◽  
Water Temperature ◽  
River Water ◽  
Drinking Water Treatment ◽  
Minor Effect ◽  
Organic Micropollutants ◽  
Model Compounds ◽  
Water Matrix ◽  
Ozone Dose

Abstract. Advanced oxidation with O3/H2O2 (peroxone) is conducted on pilot plant scale on pre-treated Meuse river water to investigate the conversion of organic micropollutants (OMPs) and the formation of bromate. Fourteen selected model compounds are dosed to the pre-treated river water on a regular basis to assess the efficiency of the peroxone process and to establish the influence of the water matrix. The height of the ozone dose is the main factor in the conversion of the model compounds. The conversion of OMPs can be increased by further increasing the ozone dose, however, the ozone dose is limited concerning the bromate formation. The hydrogen peroxide dosage has only a~minor effect on the conversion, but it limits the bromate formation effectively. In terms of limited chemical consumption, maximal conversion and adherence to the strict Dutch guideline for bromate in drinking water, a practical full-scale setting is 6 mg L−1 hydrogen peroxide and 1.5 mg L−1 ozone. During the investigation period, the average conversion of the model compounds was 78.9%. The conversion of OMPs is higher at higher water temperatures and lower concentrations of DOC and bicarbonate. The bromate formation also is higher at higher water temperature and lower bicarbonate concentration and proportional with the bromide concentration, above a threshold of about 32 μg L−1 bromide, below which no bromate is formed. The peroxone process can be controlled on basis of the (derived) parameters water temperature, bicarbonate and DOC.

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.

Changes in lipid peroxidation during pregnancy and after delivery in rats: effect of pinealectomy

Reproduction ◽  
2000 ◽  
pp. 143-149 ◽  
Author(s):  
RM Sainz ◽  
RJ Reiter ◽  
JC Mayo ◽  
J Cabrera ◽  
DX Tan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Oxidative Damage ◽  
Energy Demand ◽  
Physiological State ◽  
High Energy ◽  
Free Radical Scavengers ◽  
Radical Scavengers ◽  
Oxygen Requirement ◽  
Pregnant Rats

Pregnancy is a physiological state accompanied by a high energy demand of many bodily functions and an increased oxygen requirement. Because of the increased intake and utilization of oxygen, increased levels of oxidative stress would be expected. In the present study, the degree of lipid peroxidation was examined in different tissues from non-pregnant and pregnant rats after the delivery of their young. Melatonin and other indole metabolites are known to be direct free radical scavengers and indirect antioxidants. Thus the effect of pinealectomy at 1 month before pregnancy on the accumulation of lipid damage was investigated in non-pregnant and pregnant rats after the delivery of their young. Malonaldehyde and 4-hydroxyalkenal concentrations were measured in the lung, uterus, liver, brain, kidney, thymus and spleen from intact and pinealectomized pregnant rats soon after birth of their young and at 14 and 21 days after delivery. The same parameters were also evaluated in intact and pinealectomized non-pregnant rats. Shortly after delivery, lipid oxidative damage was increased in lung, uterus, brain, kidney and thymus of the mothers. No differences were detected in liver and spleen. Pinealectomy enhanced this effect in the uterus and lung. It is concluded that during pregnancy high levels of oxidative stress induce an increase in oxidative damage to lipids, which in some cases is inhibited by the antioxidative actions of pineal indoles.

Resorcinarene Cavitand Polymers for the Remediation of Halomethanes and 1,4-Dioxane

2019 ◽  
Author(s):  
Luke Skala ◽  
Anna Yang ◽  
Max Justin Klemes ◽  
Leilei Xiao ◽  
William Dichtel
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
High Capacity ◽  
The United States ◽  
Water Sources ◽  
Disinfection Byproducts ◽  
Porous Polymer ◽  
Organic Micropollutants ◽  
Executive Summary ◽  
Regulatory Limits

<p>Executive summary: Porous resorcinarene-containing polymers are used to remove halomethane disinfection byproducts and 1,4-dioxane from water.<br></p><p><br></p><p>Disinfection byproducts such as trihalomethanes are some of the most common micropollutants found in drinking water. Trihalomethanes are formed upon chlorination of natural organic matter (NOM) found in many drinking water sources. Municipalities that produce drinking water from surface water sources struggle to remain below regulatory limits for CHCl<sub>3</sub> and other trihalomethanes (80 mg L<sup>–1</sup> in the United States). Inspired by molecular CHCl<sub>3</sub>⊂cavitand host-guest complexes, we designed a porous polymer comprised of resorcinarene receptors. These materials show higher affinity for halomethanes than a specialty activated carbon used for trihalomethane removal. The cavitand polymers show similar removal kinetics as activated carbon and have high capacity (49 mg g<sup>–1</sup> of CHCl<sub>3</sub>). Furthermore, these materials maintain their performance in real drinking water and can be thermally regenerated under mild conditions. Cavitand polymers also outperform activated carbon in their adsorption of 1,4-dioxane, which is difficult to remove and contaminates many public water sources. These materials show promise for removing toxic organic micropollutants and further demonstrate the value of using supramolecular chemistry to design novel absorbents for water purification.<br></p>

scholarly journals A Sizing Method for PV–Battery–Generator Systems for Off-Grid Applications Based on the LCOE

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1988
Author(s):  
Ioannis E. Kosmadakis ◽  
Costas Elmasides
Keyword(s):  
Renewable Energy ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
Temporal Distribution ◽  
Electrical Energy ◽  
Optimal Number ◽  
Diesel Generator ◽  
Levelized Cost Of Electricity ◽  
Sufficient Power ◽  
Battery Energy

Electricity supply in nonelectrified areas can be covered by distributed renewable energy systems. The main disadvantage of these systems is the intermittent and often unpredictable nature of renewable energy sources. Moreover, the temporal distribution of renewable energy may not match that of energy demand. Systems that combine photovoltaic modules with electrical energy storage (EES) can eliminate the above disadvantages. However, the adoption of such solutions is often financially prohibitive. Therefore, all parameters that lead to a functionally reliable and self-sufficient power generation system should be carefully considered during the design phase of such systems. This study proposes a sizing method for off-grid electrification systems consisting of photovoltaics (PV), batteries, and a diesel generator set. The method is based on the optimal number of PV panels and battery energy capacity whilst minimizing the levelized cost of electricity (LCOE) for a period of 25 years. Validations against a synthesized load profile produced grid-independent systems backed by different accumulator technologies, with LCOEs ranging from 0.34 EUR/kWh to 0.46 EUR/kWh. The applied algorithm emphasizes a parameter of useful energy as a key output parameter for which the solar harvest is maximized in parallel with the minimization of the LCOE.

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