Showing papers on "Magnesium peroxide published in 2020"

Effects of solid oxygen fertilizers and biochars on nitrous oxide production from agricultural soils in Florida.

Abstract: Elevated levels of nitrous oxide (N2O) emissions are a matter of concern in agricultural soils especially when flooding (hypoxic conditions) results from over irrigation or frequent rains. This study is the first to report the use of two solid oxygen fertilizers (SOFs, calcium peroxide and magnesium peroxide) to reduce N2O production in mineral and organic soils amended with N fertilizer in a short-term laboratory incubation besides two biochars. In general, organic soil had greater N2O production than mineral soil. Soils amended with nitrogen fertilizer exhibited increased N2O production, by 74 times in mineral soil and 2 times in organic soil. Both solid oxygen fertilizers in mineral soil (98-99%) and calcium peroxide in organic soil (25%) successfully reduced N2O production than corresponding N fertilized treatments. Additionally, a greater level of available nitrate-N (52-57 and 225 mg kg-1 in mineral and organic soil, respectively) was recorded with the solid oxygen fertilizers. Corn residue biochar with N fertilizer increased N2O production in mineral soil but decreased in organic soil, while pine bark biochar with N did not affect the N2O production in either soil. Depending on soil, appropriate SOFs applied were able to reduce N2O production and maintain greater nitrate-N levels in flooded soil. Thus, solid oxygen fertilizers can potentially be used as an effective way to reduce N2O emission from hypoxic soil in agricultural production systems.

Comparison of Chemical and Biological Strategies for the Cleanup of Diesel/Biodiesel Blend–Contaminated Groundwater

Abstract: The widespread use of diesel/biodiesel blends as a transportation fuel can increase the risk of groundwater contamination, which requires remediation actions Two pilot-field experiments were conducted to assess and compare their potential to treat groundwater contaminated with B20 (20% biodiesel and 80% diesel, v/v), using combined iron and sulfate biostimulation (CISB) and a modified Fenton system (MFS) A low-cost and sustainable product recovered from acid mine drainage was used to stimulate both iron- and sulfate-reducing conditions The modified Fenton system was composed of magnesium peroxide to promote the slow release of hydrogen peroxide by magnesium peroxide decomposition Fe2O3 recovered from acid mine drainage was used as catalyst for modified Fenton reaction Both technologies demonstrated to efficiently degrade B20-blend aromatic hydrocarbons However, the application of MFS maintained BTEX dissolved concentrations below the detection limit (1 μg L−1) over 22 months, while in CISB, the dissolved concentrations of BTEX compounds were > 50 μg L−1 after 84 months Additionally, total PAH dissolved concentrations in MFS experiment were lower than those observed for the CISB plot In MFS, microbial growth was inhibited as opposed to CISB in which microbial growth enhanced up to 3 orders of magnitude Therefore, though MFS was more efficient to meet remediation goals relative to CISB approach, if the site requires complete restoration, less aggressive technologies such as CISB should be considered This novel pilot study presents chemical and biological technologies that can potentially be applied to remediate diesel/biodiesel blends in groundwater

Radiation Stability of Magnesium Phosphate Ceramic Under γ-Irradiation: Formation of Hydrogen and Peroxides

Abstract: Radiation stability of MgHPO4‧3H2O magnesium-phosphate ceramic was studied. It was shown that the effect of γ-radiation from 60Co s accompanied by the formation of hydrogen. Oxygen is recorded in trace amounts (less than 1% relative to hydrogen). At a dose of 4–5 MGy, the yield of hydrogen is approximately 0.055 ± 0.005 molecule/100 eV. At larger doses, the accumulation of hydrogen reaches the stationary level. It was found that the “oxidizing component,” hydrogen peroxide, formed in the radiolysis of hydrate water reacts in all probability with magnesium to give magnesium peroxide, MgO2. The irradiation has no noticeable effect on the mechanical strength of the magnesium-phosphate compound.

Newly generated magnesium peroxide used for malodorous river water treatment

Abstract: In this study, malodorous river water was treated by microwave enhanced composite technology. On this basis, the catalyst of iron hydrated oxide was developed. Newly generated magnesium peroxide was catalyzed by iron hydrated oxide. With total organic carbon (TOC) as the index, the water quality was improved significantly. The optimal operating conditions were as follows: the amount of iron of 15 mmol/250 mL wastewater, the calcination temperature of 500°C, the amount of hydrogen peroxide of 8 mL, the amount of magnesium sulfate of 6 g, and the microwave irradiation power of medium-high (539 W). The removal rate of TOC was the highest at 72.38% under these conditions.

Composite material for removing alga-derived odorous substances in black and odorous water, and preparation method and application thereof

Abstract: The invention discloses a composite material for removing alga-derived odorous substances in black and odorous water, and a preparation method and an application thereof. The composite material is composed of an oxygen releasing agent and an embedding agent. The preparation method comprises the following steps: (1) uniformly mixing the oxygen releasing agent, bentonite, sodium alginate and polyvinyl alcohol according to a certain ratio, adding deionized water, and performing stirring, wherein the oxygen releasing agent is one of calcium peroxide, magnesium peroxide and sodium peroxide; (2) tabletting the obtained mixture in a tabletting machine, and drying the mixture to prepare an oxygen slow-release material for later use; (3) adding a proper amount of potassium ferrate into the black and odorous water, adjusting the pH value, stirring for a reaction, and standing for precipitation; and (4) adding a proper amount of the oxygen slow-release material into the black and odorous water. The composite material has the advantages of reasonable formula, low cost, environmental friendliness, easiness in method implementation, simplicity in operation, effectiveness in absorption and flocculation of various inorganic and organic pollutants in the black and odorous water, inhibition of harmful algae, elimination of peculiar smell, and solving of the problem of insufficient dissolved oxygen in the black and odorous water.

Biomass boiler decoking agent and using method thereof

Abstract: The invention relates to a biomass boiler decoking agent. The decoking agent is peroxide of alkaline earth metal elements. Specifically, the decoking agent is composed of calcium peroxide and/or magnesium peroxide. A biomass fuel and the decoking agent are uniformly mixed in proportion and then added into a biomass boiler for combustion. The fine peroxides are dispersed around the coke and in gapsof the coke; under the condition that the biomass fuel is combusted and heated, peroxide is decomposed into oxygen and oxide, on one hand, oxygen can explode large coke into small broken particles, on the other hand, combustion of biomass fuel can be facilitated, the combustion temperature can be increased, the coke can be molten again, the oxide and the molten coke are dispersed and mixed, largecoke is prevented from being further generated, and therefore the effect of removing the large coke is achieved.