Decay Of Hydrogen Peroxide Research Articles

Innovative method of utilising hydrogen peroxide for source water management of cyanobacteria.

The treatment and control of cyanobacterial blooms using copper-based algaecides in water reservoirs have historically been used; however, due to the adverse impact of copper on the environment, water authorities have been researching and studying new and innovative ways to control cyanobacterial blooms. Hydrogen peroxide has been investigated as an environmentally friendly alternative, and this research aims to determine the impact of water quality on its effectiveness based on the decay characteristics in different water samples. Natural water samples from South Australian reservoirs and riverwere used to evaluate hydrogen peroxide decomposition and provide a better strategy for water operators in using it as an algaecide. Our experiments show the dependency of hydrogen peroxide decomposition not only on water quality but also on the initial hydrogen peroxide dose. A higher initial hydrogen peroxide dose can trigger the increase of pH, leading to increased consumption of hydrogen peroxide. In addition, the hydrogen peroxide decomposition is significantly accelerated with the rise of copper concentration in water samples. Moreover, it is found that UV light can also affect the decomposition rate of hydrogen peroxide. The hydrogen peroxide decay is more significant under UV light for the samples with lower hydrogen peroxide concentrations. Our study also shows the impact of dissolved organic carbon (DOC) on hydrogen peroxide decomposition is not substantial. The study also presents a modelling method to optimise hydrogen peroxide application based on water quality characteristics. Our findings can provide knowledge for the water industry to produce a suitable model which can be used to optimise the application of hydrogen peroxide for the control of cyanobacteria.

Heterotrophic Bacteria Exhibit a Wide Range of Rates of Extracellular Production and Decay of Hydrogen Peroxide

Bacteria have been implicated as both a source and sink of hydrogen peroxide (H2O2), a reactive oxygen species which can both impact microbial growth and participate in the geochemical cycling of trace metals and carbon in natural waters. In this study, simultaneous H2O2 production and decay by twelve species of heterotrophic bacteria were evaluated in both batch and flow-through incubations. While wide species-to-species variability of cell-normalized H2O2 decay rate coefficients [2x10-8 to 5x10-6 hr-1 (cell mL-1)-1] was observed, these rate coefficients were relatively consistent for a given bacterial species. By contrast, observed production rates (below detection limit to 3x102 amol cell-1 hr-1) were more variable even for the same species. Variations based on incubation conditions in some bacterial strains suggest that external conditions may impact extracellular H2O2 levels either through increased extracellular production or leakage of intracellular H2O2. Comparison of H2O2 production rates to previously determined O2- production rates suggests that O2- and H2O2 production are not necessarily linked. Rates measured in this study indicate that bacteria could account for a majority of H2O2 decay observed in aqueous systems but likely only make a modest contribution to dark H2O2 production.

Hydrogen peroxide kinetics in water radiolysis

The kinetics of the formation and reaction of hydrogen peroxide in the long time γ- radiolysis of water is examined using a combination of experiment with model calculations. Escape yields of hydrogen peroxide on the microsecond time scale are easily measured with added radical scavengers even with substantial amounts of initial added hydrogen peroxide. The γ-radiolysis of aqueous hydrogen peroxide solutions without added radical scavengers reach a steady state limiting concentration of hydrogen peroxide with increasing dose, and that limit is directly proportional to the initial concentration of added hydrogen peroxide. The dose necessary to reach that limiting hydrogen peroxide concentration is also proportional to the initial concentration, but dose rate has a very small effect. The addition of molecular hydrogen to aqueous solutions of hydrogen peroxide leads to a decrease in the high dose limiting hydrogen peroxide concentration that is linear with the initial hydrogen concentration, but the amount of decrease is not stoichiometric. Proton irradiations of solutions with added hydrogen peroxide and hydrogen are more difficult to predict because of the decreased yields of radicals; however, with a substantial increase in dose rate there is a sufficient decrease in radical yields that hydrogen addition has little effect on hydrogen peroxide decay.

Metrological aspects of acoustic emission conditions under hydrogen peroxide decomposition monitoring

The work objective is to study the metrological aspects of the acoustic emission (AE) method as applied to the monitoring of the hydrogen peroxide decay rate. The AE changing parameter that determines the method metrological properties as a whole is selected. It is established that the process of the hydrogen peroxide decomposition causes stress waves in the local liquid volume. This leads to the formation of the acoustic signals that allow firmly control this process through the AE method. The metrological evaluation of the method implemented in two stages is analyzed. The significance of the first stage allowing for the quality relative AE-research is identified. The experiments performed have confirmed high sensitivity of the proposed method. Thus, it is possible to carry out effective relative studies of the compared processes according to the AE parameters. The acoustic emission data show that instrumental and methodological errors of the AE method in general can be significant in case of the counter conditions, and this fact can be a benchmark for future research.

LiOH - H2O2 - H2O trinary system study for the selection of optimal conditions of lithium peroxide synthesis

Using solubility method the decay kinetics of peroxide products contained in liquid phase of LiOH - H2O2 - H2O trinary system with 2 to 6% by wt hydrogen peroxide content in liquid phase in 21 to 33 °C temperature range has been studied. Conducted studies have allowed to determine temperature and concentration limits of solid phase existence of Li2O2·H2O content, distinctness of which has been confirmed using chemical and qualitative X- ray phase analysis. Stabilizing effect of solid phase of Li2O2·H2O content on hydrogen peroxide decay contained in liquid phase of LiOH - H2O2 - H2O trinary system under conditions of experiments conducted has been shown.

Spatial and temporal variability of widespread dark production and decay of hydrogen peroxide in freshwater

Hydrogen peroxide (H2O2) is an oxidant and reductant of redox active metals and a potential source of strong oxidants such as the hydroxyl radical (·OH). H2O2 production in freshwater has been largely attributed to photo-oxidation of chromophoric dissolved organic matter, while its decay has been linked to enzymatic processes as well as to chemical reactions with metals. More recently, however, microorganisms were postulated as a significant source as well as a sink of H2O2 in freshwater. In this study, we examined the spatial and temporal variability of dark H2O2 production rates ( $${\text{P}}_{{{\text{H}}_{ 2} {\text{O}}_{ 2} }}$$ ) and pseudo-first order dark decay rate coefficients ( $${\text{k}}_{{{\text{loss,H}}_{ 2} {\text{O}}_{ 2} }}$$ ) in incubations of water samples from sites with a range of trophic states in Colorado (CO) and Massachusetts (MA). Observed values of $${\text{P}}_{{{\text{H}}_{ 2} {\text{O}}_{ 2} }}$$ and $${\text{k}}_{{{\text{loss,H}}_{ 2} {\text{O}}_{ 2} }}$$ ranged from 3 to 259 nM h−1 and 0.02 to 8.87 h−1, respectively. Microbial cell numbers and chlorophyll content correlated strongly with $${\text{k}}_{{{\text{loss,H}}_{ 2} {\text{O}}_{ 2} }}$$ while filtering the freshwater samples removed the majority of $${\text{k}}_{{{\text{loss,H}}_{ 2} {\text{O}}_{ 2} }}$$ , indicating breakdown by biota as the major sink of H2O2. Dark production of H2O2 was also ubiquitous, but $${\text{P}}_{{{\text{H}}_{ 2} {\text{O}}_{ 2} }}$$ was not well correlated with indicators of microbial abundance. For instance, several oligotrophic sites (with low $${\text{k}}_{{{\text{loss,H}}_{ 2} {\text{O}}_{ 2} }}$$ ) exhibited moderately high $${\text{P}}_{{{\text{H}}_{ 2} {\text{O}}_{ 2} }}$$ , while a sample with unusually high chlorophyll content (and a correspondingly high $${\text{k}}_{{{\text{loss,H}}_{ 2} {\text{O}}_{ 2} }}$$ ) had a relatively low $${\text{P}}_{{{\text{H}}_{ 2} {\text{O}}_{ 2} }}$$ . One possible explanation for this phenomenon is that the ability to break down H2O2 is similar among different microorganisms, but the ability to produce H2O2 differs with microbial composition.

Measurement of the Rate of Hydrogen Peroxide Thermal Decomposition in a Shock Tube Using Quantum Cascade Laser Absorption Near 7.7 μm

ABSTRACTHydrogen peroxide (H2O2) is formed during hydrocarbon combustion and controls the system reactivity under intermediate temperature conditions. Here, we measured the rate of hydrogen peroxide decomposition behind reflected shock waves using midinfrared absorption of H2O2 near 7.7 µm. We performed the experiments in diluted H2O2/Ar mixtures between 930 and 1235 K and at three different pressures (1, 2, and 10 atm). Under these conditions, the decay of hydrogen peroxide is sensitive only to the decomposition reaction rate, H2O2 + M → 2OH + M (k1). The second‐order rate coefficient at low pressures (1 and 2 atm) did not exhibit any pressure dependence, suggesting that the reaction was in the low‐pressure limit. The rate data measured at 10 atm exhibited falloff behavior. The measured decomposition rates can be expressed in Arrhenius forms as follows: urn:x-wiley:05388066:kin20827:equation:kin20827-math-0001 urn:x-wiley:05388066:kin20827:equation:kin20827-math-0002

Low‐Dose Hydrogen Peroxide Application in Closed Recirculating Aquaculture Systems

AbstractThe aim of the present work was to simulate water treatment practices with hydrogen peroxide (HP) in recirculating aquaculture systems (RAS). Six identical 1,700‐L pilot‐scale RAS were divided into two experimental groups based on daily feed allocation and operated under constant conditions for a period of 3 months. The organic and nitrogenous loadings of the systems differed fourfold between the two groups and were achieved by predefined constant daily feed loads and constant additions of water. The fixed cumulative feed burden was 1.6 × 103 mg feed/L in the low‐intensity RAS and 6.3 × 103 mg/L in the high‐intensity RAS. The decay of HP in rearing tanks and disconnected biofilter units was investigated by means of HP spiking experiments. The decay in high‐intensity RAS rearing units and biofilters was orders of magnitude faster than that in low‐intensity units. The application of HP impaired biofilter nitrite oxidation in low‐intensity RAS but not in high‐intensity RAS. The impact of HP exposure time on biofilter nitrification capacity was then assessed in biofilter bench‐scale experiments with nitrite spiking. Exposure time was found to significantly affect nitrite oxidation. Compared with unexposed biofilter elements, nitrite oxidation was reduced more than 90% following 3 h of exposure to 15 mg HP/L, whereas 30 min of exposure had only minor negative effects on nitrite oxidation. The findings of this study demonstrate the potential for developing HP water treatment practices for RAS and contradict prevailing notions that HP cannot be used safely in RAS that employ biofiltration. The development of effective new HP treatment protocols for recirculating aquaculture could reduce the current dependence on formalin to improve water quality and control parasitic loads.

INFLUENCE OF SELECTED METAL IONS ON STABILITY OF HYDROGEN PEROXIDE IN PRESENCE OF EDTA

UDK 546.215:546.4/.8
 Stability of hydrogen peroxide in time was investigated in the presence of various metal ions and a complexing agent ethylenediaminetetraacetic acid (EDTA). Metal ions: Fe(III), Mn(II), Co(II), Cu(II), Ni(II), Zn(II) and Pb(II) were applied at different concentrations with a chelator in a concentration of 1 ·10-5 mol/dm3, and the solutions were kept at 4oC between the measurements. Obtained data indicate the existence of pronounced catalytic effect for Fe(III), Mn(II), Co(II) ions on stability of hydrogen peroxide. Cu(II) ions showed significant catalytic influence only when applied at high concentration. Ni(II), Pb(II) and Zn(II) did not show significant catalytic effect on the decay of hydrogen peroxide at applied concentrations.

Peracetic acid degradation and effects on nitrification in recirculating aquaculture systems

Peracetic acid (PAA) is a powerful disinfectant with a wide spectrum of antimicrobial activity. PAA and hydrogen peroxide (HP) degrade easily to oxygen and water and have potential to replace formalin in aquaculture applications to control fish pathogens, for example the ectoparasite, Ichthyophthirius multifiliis. We studied water phase PAA and HP decay in three aquaculture situations, i) batch experiments with two types of system waters, ii) PAA decay at different fish densities, and iii) degradation of PAA in submerged biofilters of recirculating aquaculture systems (RAS). Furthermore, effect of PAA on the nitrification activity and the composition of the nitrifying population were investigated. PAA and HP decay showed first order kinetics. High dosage PAA/HP in water with low COD inhibited HP removal, which was not observed in water having a higher COD content. PAA decay was significantly related to fish stocking density, with half life constants for PAA of 4.6 and 1.7 h at 12 and 63 kg m − 3 , respectively. PAA application to RAS biofilter showed rapid exponentially decay with half life constants of less than 1 h, three to five times faster than the water phase decay rates. Biofilter surface specific PAA removal rates ranged from 4.6 to 13.9 mg PAA m − 2 h − 1 and was positively correlated to the nominal dosage. Low PAA additions (1.0 mg L − 1 ) caused only minor impaired nitrification, in contrast to PAA application of 2.0 and 3.0 mg L − 1 , where nitrite levels were significantly increased over a prolonged period, albeit without fish mortality. The dominant ammonium oxidizer was Nitrosomonas oligotropha and the dominant nitrite oxidizer was Nitrospira. Based on the present findings and other recent results from field and in vitro studies, application perspectives of PAA are discussed.

Hydrogen peroxide distribution, production, and decay in boreal lakes

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 H2O2concentration 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. H2O2concentrations after 8 h of artificial irradiation were significantly correlated with neither absorption coefficients at 320 nm nor with dissolved organic carbon (DOC) concentrations. However, H2O2concentration increased rapidly with DOC concentration among lakes with DOC concentrations below 10 mg·L–1. The H2O2concentration 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 H2O2concentrations at the surface of the water column ranged between 30 and 1041 nmol·L–1and were largely determined by the decay rates of H2O2and the mixing depth of the water column.

Generation and decay of hydrogen peroxide in estuarine waters

Apart from its central role in photosynthesis, one of the most dramatic effects of light in marine and freshwater systems is its ability to generate reactive chemical intermediates. Of these, hydrogen peroxide is one of the more stable and easily detected. Aspects of the generation and decay of hydrogen peroxide in the Port Hacking River estuary, New South Wales, have been investigated in a number of field and laboratory studies. Peroxide concentrations in surface waters in the early morning are relatively uniform over the estuary and typically less than 35 nM, whereas concentrations in mid-afternoon in excess of 100 nM have been observed. Variation of peroxide concentration with depth in the deep basins of Port Hacking is dependent on the extent of structure within the water column, with little mixing of surface- generated peroxide into poorly-illuminated bottom waters under stratified conditions. Laboratory studies confirmed that light induces the production of hydrogen peroxide, the initial rate of production increasing with increasing molar absorptivity of the filtered water sample. Filtration of samples had little effect on the generation of hydrogen peroxide but dramatically reduced the rate of decay of photogenerated hydrogen peroxide.